[DeTomaso] McLain Automotive
Daniel C Jones
daniel.c.jones2 at gmail.com
Wed Aug 20 14:28:27 EDT 2014
> Dan Jones might be willing to make some comments.
I haven't had a chance to finish the full write up and add links to the
video, dyno graphs and pictures but here's what I have so far:
Mark's previous engine was supposed to be a stroker but, when torn down,
turned out to be a 0.030" over 351C with flat top pistons, Eagle rods and a
stock 3.5" nodular iron crankshaft. Camshaft was a Competition Cams 308
Magnum roller which was being run with 1.6:1 ratio rockers and 0.020"
intake and exhaust lash. Heads were closed chamber 4V that were filled on
the intake side, along with port plates on the exhaust side. The intake
was a Holley Strip Dominator with the floors raised to match the stuffed
heads. Inspection revealed both heads were cracked and Mark needed headers
so we had some we had some flexibility when it came to replacement cylinder
heads. We ended up going with a set of Ford Motorsport A3 heads and a
matching A331 intake that I had on hand. Plans were to test the raised
floor Strip Dominator on the A3 heas but that didn't work out so Dave
decided to do some work on the A331. Externally, the Edelbrock A331 looks
like a Torker:
http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/A331_vs_Torker_01.jpg
but has smaller A3 ports and no cross-over:
http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/A331_vs_Torker_02.jpg
You can see how much smaller the A3 port is here:
http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/4V_intake_gasket_on_A3_head.jpg
That's a 4V gasket on top of an A3 port. What's not obvious is the A3 roof
is higher (obscured behind the gasket). You can clearly see the evolution
of the high port heads here:
http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/351C_head_comparison_b_exh_cropped.jpg
On the left is an iron 4V modified with an aluminum high port exhaust port
plate like they ran in Pro Stock. You can see the lower edge of the
original exhaust port (painted blue). In the middle is an A3 port which is
slightly higher with a more uniform round shape, instead of the weird area
changes of the iron 4V port. At the right is a ported C302B. Note the
C302B ports start out much smaller:
http://s1127.photobucket.com/user/danielcjones2/media/351%20Cleveland%20Stuff/351C_head_comparison_b_int_cropped.jpg
Based upon the iron Pro Stock 351C heads, the A3 ports were designed by
Jack Roush, Bud Moore and Leonard Wood. As cast, they have the largest
intake port volume (241 cc's) and exhaust port volume (134 cc's) of the
high port family of Ford Motorsport heads:
http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/highport_comparison_cropped.jpg
There's a slight bend on intake port walls to accommodate the pushrods and
the raised floor increases port radius, straightening the turn for incoming
mixture and minimizing fuel separation. A3s can have a couple of different
exhaust bolt patterns. Mark's heads have the later exhaust port bolt
pattern and had some previous port work done. Before rebuilding them with
new valves, Dave dropped in a pair of valves from Mark's old heads and put
the A3s on the flow bench. He also flowed the 4V heads I could run the
original engine through Dynomation for comparison purposes. Results were:
Lift Int Exh Int Exh
Inches CFM CFM CFM CFM
A3 A3 Stuffed 4V
0.025 13.9 11.6 13.4 14.3
0.050 34.5 28.6 34.1 25.2
0.100 67.1 57.4 69.9 52.9
0.150 96.1 88.8 94.1 80.1
0.200 135.4 110.0 121.0 99.4
0.300 198.8 145.3 183.1 133.4
0.400 245.5 169.1 225.5 158.4
0.500 288.7 188.6 266.1 174.7
0.600 320.6 206.2 300.8 182.6
0.700 343.0 223.2 325.0 188.6
0.800 353.4 234.1 310.3 193.3
Ford Motorsport A3 High Port aluminum heads and port floor filled iron 4V
heads tested on Dave McLain's SuperFlow flow bench at 10" and converted to
28". Clayed intake radius but no exhaust pipe. Tested on 4.030" diameter
bore tube with a valve chamfer like a stock block. Valves used for testing
were from one of Mark's old heads. As with most of the Cleveland heads
we've tested, they generate little to no swirl motion. I didn't measure
the port area on these A3 heads but they should be very close to the set I
previously measured:
2.74 square inches minimum intake port area
1.88 square inches minimum exhaust port area
intake port 2.125" high by 1.725" wide (3.665 square inches)
exhaust port 1.65" high by 1.725"? wide (2.27 square inches)
In previous dyno testing, the Edelbrock Scorpion performed quite a bit
better than the Torker. The Scorpion looks much like the Torker but is a
couple of inches taller with a level carb pad. Since the Pantera mounts
the engine level, Dave milled a 1" tall open spacer to level out the carb
pad and welded it to the A331. The spacer also permits the porting to be
extended higher up the plenum which allows larger, more gradual, radii into
the tops of the runners. Dave had previously welded extensions onto the
runner entries when we tested the A331 intake on my 403C. Based upon that
testing, Dave decided to shorten the extensions. Several spacers were
tested on dyno with the HVH 1" merge spacer being best. A simple 4 hole 1"
spacer was also pretty good.
Mark races his Pantera in open road races like Silver State and the Pony
Express but rarely runs it on the street. With his stock ZF gearing and
tire diameter, he's RPM limited. A 3.75" stroke was chosen as it would
have acceptable piston speed at maximum RPM while supporting his 550+ HP
goal. Also, Mark wants to run on 92-93 octane pump gas and with the 3.75"
stroke, flat top pistons and the A3 combustion chamber volume, the
compression ratio worked out to be 11:1 which should work with pump gas,
given the cam's overlap. Previously, I wrote a program to calculate the
speed in gear at a given shift point RPM, along with the RPM drop going
into the next gear. Mark's Pantera has the Dash 2 ZF gearing:
1st gear = 2.23
2nd gear = 1.47
3rd gear = 1.04
4th gear = 0.846
5th gear = 0.705
final drive ratio = 4.22:1
He's running 315/35/17 tires with a calculated diameter of 25.68".
Assuming a 7000 RPM shift point:
Shifting from 1st to 2nd, Fall Back Engine RPM = 4614 at 57 MPH
Shifting from 2nd to 3rd, Fall Back Engine RPM = 4952 at 86 MPH
Shifting from 3rd to 4th, Fall Back Engine RPM = 5964 at 122 MPH
Shifting from 4th to 5th, Fall Back Engine RPM = 5833 at 150.0 MPH
In 5th gear, 7000 RPM equates to 180 MPH. With the rev limiter set at 7200
RPM, that works out to 185 MPH. I also have some wind tunnel data on the
Pantera (Ford tested a Pantera in a wind tunnel and the results were
published in Issue 29 of the Italian design magazine "Style Auto"), along
with a couple of other sources for a Pantera's frontal area and drag
coefficient. I ran the numbers through a program I wrote to calculate
power required to overcome aerodynamic drag and it was apparent that Mark's
new engine would provide a bunch more power than required to peg the rev
limiter in 5th gear. I also ran some brake specific fuel consumption
figures and it looks like he could run out of fuel at the longer (90+
miles) open road races, if he was WOT the entire way, but I figure he can
coast a long way from 185 MPH :-)
For this sort of application, Dave likes the Reed ULX line of solid roller
lobes. The Reed ULX lobes are older designs that are relatively easy on
the valve train, so work well in endurance racing and marine applications.
Reed is no longer in business but Steve Demos has the lobes. I ran a cam
optimization to optimize power between 4000 to 7000 RPM and crossed the
result against the ULX lobe catalog, then ran several combinations of
intake and exhaust lobes and lobe separation angles and sent the results to
Dave. The cam picked was the smallest one which Dynomation predicted would
be the best below 6000 RPM and close to the others on peak power. The
simulation prediction was for just under 600 HP. Competition Cams solid
roller lifters were chosen and, for Mark's useage, Dave recommends just
changing them out every couple of years. Dave soaks the lifters in mineral
spirits and blows them out 3 or 4 times to get all the assembly grease out,
then soaks them in 10W-30 motor oil before putting in the engine.
Given the sustained high RPM intended usage, several oiling system
modifications were made. The right side only lifter bores were bushed and
an 0.040" restrictor was placed in the back of the left side galley. The
previous builder had fitted a plug under the front main bearing. Dave
doesn't think that helps anything but it doesn't hurt either so he left it
alone. Oil pump is a stock volume and pressure Melling M84A with a Melling
oil pump drive shaft and a "10 quart" Aviad gated and baffles Pantera road
race oil pan. Clearances were set at 0.0025" for the mains and 0.0022" for
the rods using Federal Mogul main bearings and Clevite rod bearings.
On the cooling system, Dave made a plug with a 0.100" hole for the bypass
passage in the block. A -4 AN line was run from the back of each head.
They tee together and run to the suction side of the water pump where Dave
put a 0.060" restrictor so that the engine always pulls coolant and any
bubbles out of the back of the heads. Dave thinks that can be important in
the Pantera because the engine sits level.
The MSD Pro Billet distributor from the original engine was re-used. It
had the two light springs and the plain colored advance limiter bushing but
wasn't very consistent so Dave locked out the timing which made the idle a
lot better. On the dyno, without any flywheel mass, idle was 1200 RPM.
Once it's in the car with a flywheel attached, idle can be set a bit
lower. Timing was best at 30 degrees. With this much cam and only 11:1
static compression, it shouldn't be too hard to start. If Mark decided to
put a curve back in the distributor, it needs to be really short. An
aluminum-bronze gear was installed on the distributor and the gear on the
cam de-burred to try to help make the gear last longer. Moderate heat
range "Street" Autolite 3923's spark plugs were used on the dyno. In an
aluminum headed application, they are hot enough to stay clean with normal
driving and cold start/short trip use. For race use, Dave provided a set
of AR 3910's which are about 2 heat ranges colder than the 3923's. Dave
noted that engines can be quite sensitive to heat range. Several years ago
he had a problem with this in a circle track engine. The customer had run
the same plugs in the engine for over a season with no fouling or trouble
of any kind. In the off season he changed to another car with a better
chassis and I also worked on the engine package to find some more power.
He could run about four laps and burn up the plugs if the track was pretty
heavy (dirt track). But if the track was slightly slicker and had less
grip the plugs would look perfect and never cause a problem. A data logger
was installed on the car and the difference between the heavy and normal
track as far as the engine went was almost non existent. The time the
driver was off the throttle was only about 1/10 of a second less on the
heavy track but it was enough to cause a problem where the plug would go
from looking fine to absolutely burned up! Switching to something colder
cured the problem and they still stay clean enough that he can run a set of
plugs for most of a season.
The Ford Motorsport M-9439-A341 intake manifold gaskets for the A3 heads
are no longer available. Fel Pro makes two intake gasket sets for the
Motorsport high port heads. Though 1229 is listed for A3 heads, the port
opening measures the close to C302B heads (1.35" x 2.20"). 1265 is listed
for B351 and C302B heads but the port size is listed as 1.35" x 2.22".
Both are "trim to fit" for the A3 heads. P/N 1229 has round holes on both
ends in case coolant is run through the intake (Windsor block
application). Both 1229 and 1265 of those are 0.060" thick. Fel Pro makes
similar intake gaskets in thinner (p/n 12531 is 0.030", 12532 and 1253S2
are 0.045") and thicker (12535 is 0.120") sizes for Yates heads that could
probably be adapted if you need to compensate for head or intake milling.
On the exhaust side, Fel Pro makes two different header gaskets for high
port heads. P/N 1417 is for the early exhaust bolt pattern and has a 1.94"
diameter round port size. P/N 1431 is for the later pattern and has a
1.81" diameter round port size.
Dave initially ran the engine on his dyno carb, a Bobby Oliver built Holley
950 HP to baseline against the annular booster Holley 830 from Mark's
original engine. The Holley 830 is far from Dave's favorite carb. As
supplied, it had 82 jets and no power valves. After considerable dyno
tuning, it ended up with 92 and 96 jets with power valves front and rear.
Generally speaking, taking the power valve out of the circuit makes you
need to add about 10 or 12 jet sizes to make up the difference. Having to
go so far on jetting usually indicates the carb (size/boosters) selected is
wrong for the application. Given a choice, Dave would have opted Holley
4779 prepared by Competition Carburetion (Bobby Oliver) with a circle
track/road racing package. This is about the same as their normal 4779
except for the float configuration and for adding a rear power valve. This
reduces the jetting requirement in the rear which can help prevent loading
up during a hard de-acceleration into a corner.
The overall parts list ended up looking like:
4.04" bore Probe forged flat top pistons (1/16", 1/16" with 3mm oil rings)
SCAT 4340 forged steel rods (6.125" long with 7/16" ARP bolts)
3.75" stroke Scat 4340 forged crankshaft, SVO (Windsor snout design with
Cleveland main diameter) crankshaft, internally balanced (p/n:
4-351C-3750-6125)
4.04" bore x 3.75" stroke = 384.6 cubic inches
11:1 compression
Ford Motorsport A331 (modified by Dave McLain)
Ford Motorsport A3 high port aluminum Cleveland heads
SI stainless valves (2.19" intake, 1.71" exhaust)
Manley guide plates
1.73:1 ratio Competition Cams "gold" aluminum roller rockers
Jomar stud girdle
Solid roller cam using Reed ULX lobes:
254/258 @ 0.050" (R290ULX/R292ULX), 0.692"/0.701 less lash (0.024" and
0.026"), 110 LSA, 109 ICL
Competition Cams solid roller lifters
PBM/Erson 3850 chrome silicon double valve springs with dampers
Installed at 1.950", 223 lbs seat and 582 lbs open for the intake, 601
lbs for the exhaust
Comp Cams titanium retainers
Rollmaster timing set that's made for the Cleveland block/SVO style crank
combination
Oiling mods are bushed lifter bores on the right side only with an 0.040"
restrictor in the back of the left side galley
Stock volume and pressure Melling M84A oil pump, Melling oil pump drive
shaft
Aviad Pantera gated and baffled road race oil pan
Clearances are 0.0025" mains 0.0022" rods using Federal Mogul mains and
Clevite rod bearings
Main bearing size is 1/2 under and rods are -1 to get these clearances
with the Scat forged steel crank
Romac 351C SFI spec harmonic damper, zero balance
Flow Kooler water pump
Cooling system modifications
0.100" diameter block bypass passage plug, petcocks in the back of the
heads to let air out of the rear of the engine with a -4
AN line from each head that tees together and runs to the suction side of
the water pump with a 0.060" restrictor so that the
engine always pulls coolant and any bubbles out of the back of the heads
Cometic MLS head gaskets and Fel-Pro gaskets elsewhere
MSD Pro Billet mechanical advance distributor (small cap for Pantera
firewall and rear window clearance) with aluminum-bronze distributor gear
Autolite 3923 spark plugs for street (moderate heat range), AR 3910 for
race (about 2 heat ranges colder than the 3923s)
Precision Proformance high port 4-into-1 Pantera headers
830 annular discharge Holley (from Mark's previous engine)
Ford Racing polished cast aluminum valve covers
double roller timing chain
neutral balance aluminum flywheel
custom length 0.080"? wall push rods
Fuel pump block off plate (dyno providing the fuel flow)
Head bolts from Mark's original engine plus Grade 8's (and hardened
washers) for the 4 extra long ones on the exhaust side
With Mark's carb, the best pull was 623 HP at 6800 to 6900 RPM and 521
ft-lbs at 5100 RPM through my Pantera 4-into-1 shorty high port headers and
2 1/2" diameter mufflers. The primaries on these range from 16 to 20
inches or so. Previous testing suggests the engine would make better power
with 3" inlet/outlet Magnaflow mufflers and a cross-over. Mark's original
plan was to cut off the 2 1/2" collectors from the Pantera headers and weld
on 3" diameter collectors but the dyno results with smaller collectors was
good enough for Mark. He'll keep the stock collectors and run 3"
inlet/outlet mufflers but may add a cross-over at a later date.
Dan Jones
On Wed, Aug 20, 2014 at 9:01 AM, mark skwarek via DeTomaso <
detomaso at poca.com> wrote:
> Chuck,
> Here it is.
>
> Dan Jones might be willing to make some comments.
> I'll do a full write up a little later this week when I can find the
> time but some basics are:
> A 4.04" bore Probe forged flat top pistons (1/16", 1/16" with 3mm oil
> rings)
> A 6.125" Scat forged connecting rods
> A 3.75" stroke Scat forged crankshaft, internally balanced (Part
> Number: 4-351C-3750-6125)
> A 4.04" bore x 3.75" stroke = 384.6 cubic inches
> A 11:1 compression
> A Solid roller cam using Reed ULX lobes:
> A 254/258 @ 0.050" (R290ULX/R292ULX), 0.692"/0.701 less lash (0.024"
> and 0.026"), 110 LSA
> A Competition Cams solid roller lifters
> A PBM/Erson 3850 chrome silicon double valve springs with dampers
> A Installed at 1.950", 223 lbs seat and 582 lbs open for the intake,
> 601 lbs for the exhaust
> A Titanium retainers
> A Rollmaster timing set that's made for the Cleveland block/SVO style
> crank combination
> A Oiling mods are bushed lifter bores on the right side only with an
> 0.040" restrictor in the back of the left side galley
> A Stock volume and pressure Melling M84A oil pump, Melling oil pump
> drive shaft and Aviad Pantera pan
> A Clearances are .0025 mains .0022 rods using Federal Mogul mains and
> Clevite rod bearings
> A Main bearing size is 1/2 under and rods are -1 to get these
> clearances with the Scat forged steel crank.
> A Romac harmonic damper
> A Ford Motorsport A3 high port aluminum Cleveland heads
> A Ford Motorsport A331 (modified by Dave)
> A 1.73:1 ratio Competition Cams "gold" aluminum roller rockers
> A Jomar stud girdle
> A Manley guide plates
> A SI stainless valves (2.19" intake, 1.71" exhaust)
> A Cooling system modifications
> A 0.100" diameter block bypass passage plug, petcocks in the back of
> the heads to let air out of the rear of the engine with a -4 AN line
> from each head that tees together and runs to the suction side of the
> water pump with a 0.060" restrictor so that the engine always pulls
> coolant and any bubbles out of the back of the heads
> A Cometic MLS head gaskets with Fel-Pro gaskets elsewhere
> A MSD Pro Billet distributor with bronze gear
> A Autolite 3923 spark plugs for street (moderate heat range), AR 3910
> for race (about 2 heat ranges colder than the 3923s)
> A 30 degrees total timing
> A Precision Proformance high port Pantera headers
> A 830 annular discharge Holley (from Mark's previous engine)
> Mark runs his Pantera in open road races and rarely drives it on the
> street.A His ZF has the original gearing so we wanted something that
> would pull well from 3500 to 7000+ RPM.A I designed the cam to
> maximize the power between 4000 and 7000 RPM, with a torque peak at
> around 5000 RPM.A I designed several cams using the Reed ULX lobes and
> the one chosen was the smallest (lowest overlap) and had the best power
> below 6000 RPM, along with the flattest torque curve.A The Reed ULX
> lobes are older designs that are relatively easy on the valve train so
> work well in endurance racing and marine applications.A Dave spent
> some time modifying the A331 intake.A A 1" thick open spacer was
> milled to level the carb and welded to the intake.A On top of that,
> several 1" spacers with an HVH 1 inch merge spacer working best.
> Dynomation was predicting a little under 600 HP and usually
> under-predicts the so I thought we'd hit 600 HP.A Final results were
> 623.1 HP at 6900 RPM and and 521.6 ft-lbs at 5100 RPM running through
> the 4-into-1 Pantera headers with 2 1/2" pipes and mufflers.A The
> torque curve is really flat in the operating RPM range.
> More details to follow...
> Dan Jones
> i
>
>
>
> [1]Posts: 236 | city, state or province, country: east haddam,
>
> On Wednesday, August 20, 2014 9:42 AM, "cengles at cox.net"
> <cengles at cox.net> wrote:
> Dear Mark,
> Ah, the McLain Shop. I am curious about your experience.
> I anticipate that I will have them do some small work for me. I was
> favorably impressed after a phone conversation with Dave. Dan Jones'
> affliation is obviously a good sign.
> What did you have them do on your engine? Did you have a
> good experience?
> Warmest regards, Chuck Engles
> On Wed, Aug 20, 2014 at 7:17 AM, mark skwarek via DeTomaso wrote:
> > I just had my engine shipped from Cuba, MO to CT for $300.00 by R&L
> > Carriers. I picked it up at their terminal. 5 days.
> >
> >
> > Mark
> >
> > On Wednesday, August 20, 2014 6:18 AM, Mikael
> > <[2]mikael_hass at mail.tele.dk> wrote:
> >
> >
> > Hi
> >
> > I may need to send a shortblock from St Louis Missouri to Atlanta
> > Georgia in a month or two. Size 31x25x21" weighs 157kg
> >
> > What freight companies would be worth contacting to get this done,
> > cheap and safe?
> >
> >
> > Thanks
> >
> > Mvh/Regards
> >
> > Mikael
> >
> > _______________________________________________
> >
> > Detomaso Forum Managed by POCA
> >
> > DeTomaso mailing list
> > [3]DeTomaso at poca.com
> > [4]http://poca.com/mailman/listinfo/detomaso_poca.com
> >
> > ------------------------------
> >
> > _______________________________________________
> >
> > Detomaso Forum Managed by POCA
> >
> > DeTomaso mailing list
> > [5]DeTomaso at poca.com
> > [6]http://poca.com/mailman/listinfo/detomaso_poca.com
>
> References
>
> 1.
> http://pantera.infopop.cc/eve/forums?a=userposts&sortType=1&u=2940019434
> 2. mailto:mikael_hass at mail.tele.dk
> 3. mailto:DeTomaso at poca.com
> 4. http://poca.com/mailman/listinfo/detomaso_poca.com
> 5. mailto:DeTomaso at poca.com
> 6. http://poca.com/mailman/listinfo/detomaso_poca.com
>
> _______________________________________________
>
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>
-------------- next part --------------
> Dan Jones might be willing to make some comments.
I haven't had a chance to finish the full write up and add links to the
video, dyno graphs and pictures but here's what I have so far:
Mark's previous engine was supposed to be a stroker but, when torn
down, turned out to be a 0.030" over 351C with flat top pistons, Eagle
rods and a stock 3.5" nodular iron crankshaft.A Camshaft was a
Competition Cams 308 Magnum roller which was being run with 1.6:1 ratio
rockers and 0.020" intake and exhaust lash.A Heads were closed chamber
4V that were filled on the intake side, along with port plates on the
exhaust side.A The intake was a Holley Strip Dominator with the floors
raised to match the stuffed heads.A Inspection revealed both heads
were cracked and Mark needed headers so we had some we had some
flexibility when it came to replacement cylinder heads.A We ended up
going with a set of Ford Motorsport A3 heads and a matching A331 intake
that I had on hand.A Plans were to test the raised floor Strip
Dominator on the A3 heas but that didn't work out so Dave decided to do
some work on the A331.A Externally, the Edelbrock A331 looks like a
Torker:
A [1]http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleve
land%20Stuff/A331_vs_Torker_01.jpg
but has smaller A3 ports and no cross-over:
A [2]http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleve
land%20Stuff/A331_vs_Torker_02.jpg
You can see how much smaller the A3 port is here:
A [3]http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleve
land%20Stuff/4V_intake_gasket_on_A3_head.jpg
That's a 4V gasket on top of an A3 port.A What's not obvious is the A3
roof is higher (obscured behind the gasket).A You can clearly see the
evolution of the high port heads here:
A [4]http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleve
land%20Stuff/351C_head_comparison_b_exh_cropped.jpg
On the left is an iron 4V modified with an aluminum high port exhaust
port plate like they ran in Pro Stock. You can see the lower edge of
the original exhaust port (painted blue).A In the middle is an A3 port
which is slightly higher with a more uniform round shape, instead of
the weird area changes of the iron 4V port.A At the right is a ported
C302B.A Note the C302B ports start out much smaller:
A [5]http://s1127.photobucket.com/user/danielcjones2/media/351%20Clevel
and%20Stuff/351C_head_comparison_b_int_cropped.jpg
Based upon the iron Pro Stock 351C heads, the A3 ports were designed by
Jack Roush, Bud Moore and Leonard Wood.A As cast, they have the
largest intake port volume (241 cc's) and exhaust port volume (134
cc's) of the high port family of Ford Motorsport heads:
A [6]http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleve
land%20Stuff/highport_comparison_cropped.jpg
There's a slight bend on intake port walls to accommodate the pushrods
and the raised floor increases port radius, straightening the turn for
incoming mixture and minimizing fuel separation.A A3s can have a
couple of different exhaust bolt patterns.A Mark's heads have the
later exhaust port bolt pattern and had some previous port work done.A
Before rebuilding them with new valves, Dave dropped in a pair of
valves from Mark's old heads and put the A3s on the flow bench.A He
also flowed the 4V heads I could run the original engine through
Dynomation for comparison purposes.A Results were:
A LiftA A IntA A ExhA A A IntA A Exh
A Inches CFMA A CFMA A A CFMA A CFM
A A A A A A A A3A A A A3A A A A Stuffed 4V
A 0.025A 13.9A 11.6A A 13.4A 14.3
A 0.050A 34.5A 28.6A A 34.1A 25.2
A 0.100A 67.1A 57.4A A 69.9A 52.9
A 0.150A 96.1A 88.8A A 94.1A 80.1
A 0.200 135.4 110.0A 121.0A 99.4
A 0.300 198.8 145.3A 183.1 133.4
A 0.400 245.5 169.1A 225.5 158.4
A 0.500 288.7 188.6A 266.1 174.7
A 0.600 320.6 206.2A 300.8 182.6
A 0.700 343.0 223.2A 325.0 188.6
A 0.800 353.4 234.1A 310.3 193.3
Ford Motorsport A3 High Port aluminum heads and port floor filled iron
4V heads tested on Dave McLain's SuperFlow flow bench at 10" and
converted to 28".A Clayed intake radius but no exhaust pipe.A Tested
on 4.030" diameter bore tube with a valve chamfer like a stock block.A
Valves used for testing were from one of Mark's old heads.A As with
most of the Cleveland heads we've tested, they generate little to no
swirl motion.A I didn't measure the port area on these A3 heads but
they should be very close to the set I previously measured:
A 2.74 square inches minimum intake port area
A 1.88 square inches minimum exhaust port area
A intake port 2.125" high by 1.725" wide (3.665 square inches)
A exhaust port 1.65" high by 1.725"? wide (2.27 square inches)
In previous dyno testing, the Edelbrock Scorpion performed quite a bit
better than the Torker.A The Scorpion looks much like the Torker but
is a couple of inches taller with a level carb pad.A Since the Pantera
mounts the engine level, Dave milled a 1" tall open spacer to level out
the carb pad and welded it to the A331.A The spacer also permits the
porting to be extended higher up the plenum which allows larger, more
gradual, radii into the tops of the runners.A Dave had previously
welded extensions onto the runner entries when we tested the A331
intake on my 403C.A Based upon that testing, Dave decided to shorten
the extensions.A Several spacers were tested on dyno with the HVH 1"
merge spacer being best.A A simple 4 hole 1" spacer was also pretty
good.
Mark races his Pantera in open road races like Silver State and the
Pony Express but rarely runs it on the street.A With his stock ZF
gearing and tire diameter, he's RPM limited.A A 3.75" stroke was
chosen as it would have acceptable piston speed at maximum RPM while
supporting his 550+ HP goal.A Also, Mark wants to run on 92-93 octane
pump gas and with the 3.75" stroke, flat top pistons and the A3
combustion chamber volume, the compression ratio worked out to be 11:1
which should work with pump gas, given the cam's overlap.A Previously,
I wrote a program to calculate the speed in gear at a given shift point
RPM, along with the RPM drop going into the next gear.A Mark's Pantera
has the Dash 2 ZF gearing:
A 1st gear = 2.23
A 2nd gear = 1.47
A 3rd gear = 1.04
A 4th gear = 0.846
A 5th gear = 0.705
A final drive ratio = 4.22:1
He's running 315/35/17 tires with a calculated diameter of 25.68".A
Assuming a 7000 RPM shift point:
A Shifting from 1st to 2nd, Fall Back Engine RPM = 4614 atA 57 MPH
A Shifting from 2nd to 3rd, Fall Back Engine RPM = 4952 atA 86 MPH
A Shifting from 3rd to 4th, Fall Back Engine RPM = 5964 at 122 MPH
A Shifting from 4th to 5th, Fall Back Engine RPM = 5833 at 150.0 MPH
In 5th gear, 7000 RPM equates to 180 MPH.A With the rev limiter set at
7200 RPM, that works out to 185 MPH.A I also have some wind tunnel
data on the Pantera (Ford tested a Pantera in a wind tunnel and the
results were published in Issue 29 of the Italian design magazine
"Style Auto"), along with a couple of other sources for a Pantera's
frontal area and drag coefficient.A I ran the numbers through a
program I wrote to calculate power required to overcome aerodynamic
drag and it was apparent that Mark's new engine would provide a bunch
more power than required to peg the rev limiter in 5th gear.A I also
ran some brake specific fuel consumption figures and it looks like he
could run out of fuel at the longer (90+ miles) open road races, if he
was WOT the entire way, but I figure he can coast a long way from 185
MPH :-)
For this sort of application, Dave likes the Reed ULX line of solid
roller lobes.A The Reed ULX lobes are older designs that are
relatively easy on the valve train, so work well in endurance racing
and marine applications.A Reed is no longer in business but Steve
Demos has the lobes.A I ran a cam optimization to optimize power
between 4000 to 7000 RPM and crossed the result against the ULX lobe
catalog, then ran several combinations of intake and exhaust lobes and
lobe separation angles and sent the results to Dave.A The cam picked
was the smallest one which Dynomation predicted would be the best below
6000 RPM and close to the others on peak power.A The simulation
prediction was for just under 600 HP.A Competition Cams solid roller
lifters were chosen and, for Mark's useage, Dave recommends just
changing them out every couple of years.A Dave soaks the lifters in
mineral spirits and blows them out 3 or 4 times to get all the assembly
grease out, then soaks them in 10W-30 motor oil before putting in the
engine.
Given the sustained high RPM intended usage, several oiling system
modifications were made.A The right side only lifter bores were bushed
and an 0.040" restrictor was placed in the back of the left side
galley.A The previous builder had fitted a plug under the front main
bearing.A Dave doesn't think that helps anything but it doesn't hurt
either so he left it alone.A Oil pump is a stock volume and pressure
Melling M84A with a Melling oil pump drive shaft and a "10 quart" Aviad
gated and baffles Pantera road race oil pan.A Clearances were set at
0.0025" for the mains and 0.0022" for the rods using Federal Mogul main
bearings and Clevite rod bearings.
On the cooling system, Dave made a plug with a 0.100" hole for the
bypass passage in the block.A A -4 AN line was run from the back of
each head.A They tee together and run to the suction side of the water
pump where Dave put a 0.060" restrictor so that the engine always pulls
coolant and any bubbles out of the back of the heads.A Dave thinks
that can be important in the Pantera because the engine sits level.
The MSD Pro Billet distributor from the original engine was re-used.A
It had the two light springs and the plain colored advance limiter
bushing but wasn't very consistent so Dave locked out the timing which
made the idle a lot better.A On the dyno, without any flywheel mass,
idle was 1200 RPM.A Once it's in the car with a flywheel attached,
idle can be set a bit lower.A Timing was best at 30 degrees.A With
this much cam and only 11:1 static compression, it shouldn't be too
hard to start.A If Mark decided to put a curve back in the
distributor, it needs to be really short.A An aluminum-bronze gear was
installed on the distributor and the gear on the cam de-burred to try
to help make the gear last longer.A Moderate heat range "Street"
Autolite 3923's spark plugs were used on the dyno.A In an aluminum
headed application, they are hot enough to stay clean with normal
driving and cold start/short trip use.A For race use, Dave provided a
set of AR 3910's which are about 2 heat ranges colder than the
3923's.A Dave noted that engines can be quite sensitive to heat
range.A Several years ago he had a problem with this in a circle track
engine.A The customer had run the same plugs in the engine for over a
season with no fouling or trouble of any kind.A In the off season he
changed to another car with a better chassis and I also worked on the
engine package to find some more power.A He could run about four laps
and burn up the plugs if the track was pretty heavy (dirt track).A But
if the track was slightly slicker and had less grip the plugs would
look perfect and never cause a problem.A A data logger was installed
on the car and the difference between the heavy and normal track as far
as the engine went was almost non existent.A The time the driver was
off the throttle was only about 1/10 of a second less on the heavy
track but it was enough to cause a problem where the plug would go from
looking fine to absolutely burned up!A Switching to something colder
cured the problem and they still stay clean enough that he can run a
set of plugs for most of a season.
The Ford Motorsport M-9439-A341 intake manifold gaskets for the A3
heads are no longer available.A Fel Pro makes two intake gasket sets
for the Motorsport high port heads.A Though 1229 is listed for A3
heads, the port opening measures the close to C302B heads (1.35" x
2.20").A 1265 is listed for B351 and C302B heads but the port size is
listed as 1.35" x 2.22".A Both are "trim to fit" for the A3 heads.A
P/N 1229 has round holes on both ends in case coolant is run through
the intake (Windsor block application).A Both 1229 and 1265 of those
are 0.060" thick.A Fel Pro makes similar intake gaskets in thinner
(p/n 12531 is 0.030", 12532 and 1253S2 are 0.045") and thicker (12535
is 0.120") sizes for Yates heads that could probably be adapted if you
need to compensate for head or intake milling.A A On the exhaust side,
Fel Pro makes two different header gaskets for high port heads.A P/N
1417 is for the early exhaust bolt pattern and has a 1.94" diameter
round port size.A P/N 1431 is for the later pattern and has a 1.81"
diameter round port size.
Dave initially ran the engine on his dyno carb, a Bobby Oliver built
Holley 950 HP to baseline against the annular booster Holley 830 from
Mark's original engine.A The Holley 830 is far from Dave's favorite
carb.A As supplied,A it had 82 jets and no power valves.A After
considerable dyno tuning, it ended up with 92 and 96 jets with power
valves front and rear.A Generally speaking, taking the power valve out
of the circuit makes you need to add about 10 or 12 jet sizes to make
up the difference.A Having to go so far on jetting usually indicates
the carb (size/boosters) selected is wrong for the application.A A
Given a choice, Dave would have opted Holley 4779 prepared by
Competition Carburetion (Bobby Oliver) with a circle track/road racing
package.A This is about the same as their normal 4779 except for the
float configuration and for adding a rear power valve.A This reduces
the jetting requirement in the rear which can help prevent loading up
during a hard de-acceleration into a corner.
The overall parts list ended up looking like:
A 4.04" bore Probe forged flat top pistons (1/16", 1/16" with 3mm oil
rings)
A SCAT 4340 forged steel rods (6.125" long with 7/16" ARP bolts)
A 3.75" stroke Scat 4340 forged crankshaft, SVO (Windsor snout design
with Cleveland main diameter) crankshaft, internally balanced (p/n:
4-351C-3750-6125)
A 4.04" bore x 3.75" stroke = 384.6 cubic inches
A 11:1 compression
A Ford Motorsport A331 (modified by Dave McLain)
A Ford Motorsport A3 high port aluminum Cleveland heads
A SI stainless valves (2.19" intake, 1.71" exhaust)
A Manley guide plates
A 1.73:1 ratio Competition Cams "gold" aluminum roller rockers
A Jomar stud girdle
A Solid roller cam using Reed ULX lobes:
A 254/258 @ 0.050" (R290ULX/R292ULX), 0.692"/0.701 less lash (0.024"
and 0.026"), 110 LSA, 109 ICL
A Competition Cams solid roller lifters
A PBM/Erson 3850 chrome silicon double valve springs with dampers
A Installed at 1.950", 223 lbs seat and 582 lbs open for the intake,
601 lbs for the exhaust
A Comp Cams titanium retainers
A Rollmaster timing set that's made for the Cleveland block/SVO style
crank combination
A Oiling mods are bushed lifter bores on the right side only with an
0.040" restrictor in the back of the left side galley
A Stock volume and pressure Melling M84A oil pump, Melling oil pump
drive shaft
A Aviad Pantera gated and baffled road race oil pan
A Clearances are 0.0025" mains 0.0022" rods using Federal Mogul mains
and Clevite rod bearings
A Main bearing size is 1/2 under and rods are -1 to get these
clearances with the Scat forged steel crank
A Romac 351C SFI spec harmonic damper, zero balance
A Flow Kooler water pump
A Cooling system modifications
A 0.100" diameter block bypass passage plug, petcocks in the back of
the heads to let air out of the rear of the engine with a -4
A AN line from each head that tees together and runs to the suction
side of the water pump with a 0.060" restrictor so that the
A engine always pulls coolant and any bubbles out of the back of the
heads
A Cometic MLS head gaskets and Fel-Pro gaskets elsewhere
A MSD Pro Billet mechanical advance distributor (small cap for Pantera
firewall and rear window clearance) with aluminum-bronze distributor
gear
A Autolite 3923 spark plugs for street (moderate heat range), AR 3910
for race (about 2 heat ranges colder than the 3923s)
A Precision Proformance high port 4-into-1 Pantera headers
A 830 annular discharge Holley (from Mark's previous engine)
A Ford Racing polished cast aluminum valve covers
A double roller timing chain
A neutral balance aluminum flywheel
A custom length 0.080"? wall push rods
A Fuel pump block off plate (dyno providing the fuel flow)
A Head bolts from Mark's original engine plus Grade 8's (and hardened
washers) for the 4 extra long ones on the exhaust side
With Mark's carb, the best pull was 623 HP at 6800 to 6900 RPM and 521
ft-lbs at 5100 RPM through my Pantera 4-into-1 shorty high port headers
and 2 1/2" diameter mufflers.A The primaries on these range from 16 to
20 inches or so.A Previous testing suggests the engine would make
better power with 3" inlet/outlet Magnaflow mufflers and a
cross-over.A Mark's original plan was to cut off the 2 1/2" collectors
from the Pantera headers and weld on 3" diameter collectors but the
dyno results with smaller collectors was good enough for Mark.A He'll
keep the stock collectors and run 3" inlet/outlet mufflers but may add
a cross-over at a later date.
Dan Jones
On Wed, Aug 20, 2014 at 9:01 AM, mark skwarek via DeTomaso
<[7]detomaso at poca.com> wrote:
A A Chuck,
A A Here it is.
A A Dan Jones might be willing to make some comments.
A A I'll do a full write up a little later this week when I can
find the
A A time but some basics are:
A A A 4.04" bore Probe forged flat top pistons (1/16", 1/16" with
3mm oil
A A rings)
A A A 6.125" Scat forged connecting rods
A A A 3.75" stroke Scat forged crankshaft, internally balanced
(Part
A A Number: 4-351C-3750-6125)
A A A 4.04" bore x 3.75" stroke = 384.6 cubic inches
A A A 11:1 compression
A A A Solid roller cam using Reed ULX lobes:
A A A 254/258 @ 0.050" (R290ULX/R292ULX), 0.692"/0.701 less lash
(0.024"
A A and 0.026"), 110 LSA
A A A Competition Cams solid roller lifters
A A A PBM/Erson 3850 chrome silicon double valve springs with
dampers
A A A Installed at 1.950", 223 lbs seat and 582 lbs open for the
intake,
A A 601 lbs for the exhaust
A A A Titanium retainers
A A A Rollmaster timing set that's made for the Cleveland block/SVO
style
A A crank combination
A A A Oiling mods are bushed lifter bores on the right side only
with an
A A 0.040" restrictor in the back of the left side galley
A A A Stock volume and pressure Melling M84A oil pump, Melling oil
pump
A A drive shaft and Aviad Pantera pan
A A A Clearances are .0025 mains .0022 rods using Federal Mogul
mains and
A A Clevite rod bearings
A A A Main bearing size is 1/2 under and rods are -1 to get these
A A clearances with the Scat forged steel crank.
A A A Romac harmonic damper
A A A Ford Motorsport A3 high port aluminum Cleveland heads
A A A Ford Motorsport A331 (modified by Dave)
A A A 1.73:1 ratio Competition Cams "gold" aluminum roller rockers
A A A Jomar stud girdle
A A A Manley guide plates
A A A SI stainless valves (2.19" intake, 1.71" exhaust)
A A A Cooling system modifications
A A A 0.100" diameter block bypass passage plug, petcocks in the
back of
A A the heads to let air out of the rear of the engine with a -4 AN
line
A A from each head that tees together and runs to the suction side
of the
A A water pump with a 0.060" restrictor so that the engine always
pulls
A A coolant and any bubbles out of the back of the heads
A A A Cometic MLS head gaskets with Fel-Pro gaskets elsewhere
A A A MSD Pro Billet distributor with bronze gear
A A A Autolite 3923 spark plugs for street (moderate heat range),
AR 3910
A A for race (about 2 heat ranges colder than the 3923s)
A A A 30 degrees total timing
A A A Precision Proformance high port Pantera headers
A A A 830 annular discharge Holley (from Mark's previous engine)
A A Mark runs his Pantera in open road races and rarely drives it
on the
A A street.A His ZF has the original gearing so we wanted something
that
A A would pull well from 3500 to 7000+ RPM.A I designed the cam to
A A maximize the power between 4000 and 7000 RPM, with a torque
peak at
A A around 5000 RPM.A I designed several cams using the Reed ULX
lobes and
A A the one chosen was the smallest (lowest overlap) and had the
best power
A A below 6000 RPM, along with the flattest torque curve.A The Reed
ULX
A A lobes are older designs that are relatively easy on the valve
train so
A A work well in endurance racing and marine applications.A Dave
spent
A A some time modifying the A331 intake.A A 1" thick open spacer
was
A A milled to level the carb and welded to the intake.A On top of
that,
A A several 1" spacers with an HVH 1 inch merge spacer working
best.
A A Dynomation was predicting a little under 600 HP and usually
A A under-predicts the so I thought we'd hit 600 HP.A Final results
were
A A 623.1 HP at 6900 RPM and and 521.6 ft-lbs at 5100 RPM running
through
A A the 4-into-1 Pantera headers with 2 1/2" pipes and mufflers.A
The
A A torque curve is really flat in the operating RPM range.
A A More details to follow...
A A Dan Jones
A A i
A A A A [1]Posts: 236 | city, state or province, country: east
haddam,
A A On Wednesday, August 20, 2014 9:42 AM, "[8]cengles at cox.net"
A A <[9]cengles at cox.net> wrote:
A A Dear Mark,
A A A A A A A A A Ah, the McLain Shop.A I am curious about
your experience.
A A I anticipate that I will have them do some small work for me.A
I was
A A favorably impressed after a phone conversation with Dave.A Dan
Jones'
A A affliation is obviously a good sign.
A A A A A A A A A What did you have them do on your
engine?A Did you have a
A A good experience?
A A A A A A A A A A A A A A Warmest regards,A Chuck
Engles
A A On Wed, Aug 20, 2014 at 7:17 AM, mark skwarek via DeTomaso
wrote:
A A > I just had my engine shipped from Cuba, MO to CT for $300.00
by R&L
A A > Carriers. I picked it up at their terminal. 5 days.
A A >
A A >
A A > Mark
A A >
A A > On Wednesday, August 20, 2014 6:18 AM, Mikael
A A > <[2][10]mikael_hass at mail.tele.dk> wrote:
A A >
A A >
A A >A A Hi
A A >
A A >A A I may need to send a shortblock from St Louis Missouri
to Atlanta
A A >A A Georgia in a month or two. Size 31x25x21" weighs 157kg
A A >
A A >A A What freight companies would be worth contacting to get
this done,
A A >A A cheap and safe?
A A >
A A >
A A >A A Thanks
A A >
A A >A A Mvh/Regards
A A >
A A >A A Mikael
A A >
A A > _______________________________________________
A A >
A A > Detomaso Forum Managed by POCA
A A >
A A > DeTomaso mailing list
A A > [3][11]DeTomaso at poca.com
A A > [4][12]http://poca.com/mailman/listinfo/detomaso_poca.com
A A >
A A >A A A ------------------------------
A A >
A A > _______________________________________________
A A >
A A > Detomaso Forum Managed by POCA
A A >
A A > DeTomaso mailing list
A A > [5][13]DeTomaso at poca.com
A A > [6][14]http://poca.com/mailman/listinfo/detomaso_poca.com
References
A A 1.
[15]http://pantera.infopop.cc/eve/forums?a=userposts&sortType=1&u=29
40019434
A A 2. mailto:[16]mikael_hass at mail.tele.dk
A A 3. mailto:[17]DeTomaso at poca.com
A A 4. [18]http://poca.com/mailman/listinfo/detomaso_poca.com
A A 5. mailto:[19]DeTomaso at poca.com
A A 6. [20]http://poca.com/mailman/listinfo/detomaso_poca.com
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References
1. http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/A331_vs_Torker_01.jpg
2. http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/A331_vs_Torker_02.jpg
3. http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/4V_intake_gasket_on_A3_head.jpg
4. http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/351C_head_comparison_b_exh_cropped.jpg
5. http://s1127.photobucket.com/user/danielcjones2/media/351%20Cleveland%20Stuff/351C_head_comparison_b_int_cropped.jpg
6. http://i1127.photobucket.com/albums/l621/danielcjones2/351%20Cleveland%20Stuff/highport_comparison_cropped.jpg
7. mailto:detomaso at poca.com
8. mailto:cengles at cox.net
9. mailto:cengles at cox.net
10. mailto:mikael_hass at mail.tele.dk
11. mailto:DeTomaso at poca.com
12. http://poca.com/mailman/listinfo/detomaso_poca.com
13. mailto:DeTomaso at poca.com
14. http://poca.com/mailman/listinfo/detomaso_poca.com
15. http://pantera.infopop.cc/eve/forums?a=userposts&sortType=1&u=2940019434
16. mailto:mikael_hass at mail.tele.dk
17. mailto:DeTomaso at poca.com
18. http://poca.com/mailman/listinfo/detomaso_poca.com
19. mailto:DeTomaso at poca.com
20. http://poca.com/mailman/listinfo/detomaso_poca.com
21. mailto:DeTomaso at poca.com
22. http://poca.com/mailman/listinfo/detomaso_poca.com
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