[DeTomaso] Comments about engine build welcome

[David in Durango]

Dan, how we doing for $$$$$$$$$$$$$$$$$$$$$$?

If you folks don't know, Dan is the greatest - even when he only knew me as 
a pest (as if I've gone beyond that now) and beyond - always helpful. 
Support him.

The Pope
TPR's own Icky Old Man



----- Original Message ----- 
From: "Charles Engles" <cengles at cox.net>
To: <unlisted-recipients:>; <no To-header on input>
Cc: <detomaso at realbig.com>
Sent: Saturday, January 10, 2009 7:52 PM
Subject: Re: [DeTomaso] Comments about engine build welcome


> Dear Dan,
>
>
>                 Gee,  another dazzling techno-mechanical tour-de-force.
> It is amazing how dyno testing tends to clear up the common cloud of
> "best-guess" and opinion  that hovers over 351C engines.
>
>                  If you think this information is useful and valuble, then
> consider emailing Dan Jones and inquire about a monetary donation to his
> 351C Dyno Project.  It will obviously be a major resource and benefit for
> all Pantera owners.  Contact Dan.   There are *more* engine parts and 
> combos
> to test!!
>
>
>                            Warmest regards,  Chuck Engles
>
>
>
> ----- Original Message ----- 
> From: "Daniel C Jones" <daniel.c.jones2 at gmail.com>
> To: "Christopher Kimball" <chrisvkimball at msn.com>
> Cc: "Pantera List Serve" <detomaso at realbig.com>
> Sent: Saturday, January 10, 2009 5:45 PM
> Subject: Re: [DeTomaso] Comments about engine build welcome
>
>
>>> The cam is meant for 351 cu-in.  How should the cam specs be changed to
>>> better work with the 408 cu-in displacement?
>>
>> If a cam is optimized for 351 CID, then you would want to narrow the lobe
>> separation angle approximately 1 degree for every 16 degrees of
>> displacement
>> increase.  In your case, that would be 3 or 4 degrees.  However, your cam
>> is
>> probably not optimized for 351 CID and canted valve heads, For the 351C
>> I'm
>> currently dyno testing, the optimum (theoretical) LSA is 107 degrees.  An
>> optimal angle for a 408C would be maybe 104 degrees.  You won't seen many
>> off-the-shelf cams with a lobe center that narrow, though some circle
>> track
>> cams are ground with tight LSA's (104 to 106 degrees).  A very tight lobe
>> separation angle needs a very efficient exhaust to keep the reversion to
>> an
>> acceptable degree.
>>
>>> Suggested RPM Limit: 6000
>>
>> At what RPM do you want the HP to peak?  In a 408C, the overlap of the 
>> cam
>> you've specified would peak at 5000 RPM, perhaps less, and the engine
>> would
>> stop making power well before your 6000 RPM limit.  In my testing of a
>> 408C with another 10 degrees of duration:
>>
>> 232/236 degrees @ 0.050" lift (294/298 @ 0.004"), 0.609"/0.621" lift, 108
>> LSA
>> Crane Cams grind number (custom): HR-232/352-2S-8
>>
>> the engine peaked in the 5500 to 5600 RPM range, no matter what the
>> intake,
>> carb or headers we tried.  In a 10:1 compression 408C with ported iron 4V
>> heads (322 CFM at 0.6" lift) and a Holley Strip Dominator intake, it made
>> over 480 HP through the mufflers on a dyno that is known to read 5% low
>> compared to the calibrated Engine Masters dynos.  Taking that into
>> account,
>> the engine made over 500 HP corrected.  A second 408C with more cam
>> (peaked
>> made 525 HP (550+ HP taking into account the dyno calibration), even
>> though
>> its heads were not as good as our earlier 408C.  Best shift point is
>> typically
>> around 400 to 500 RPM beyond power peak which would be right at your 6000
>> RPM
>> limit.  Personally, I wouldn't use anything less than that can in a 408C.
>> Depending upon the heads and intake you settle on, I could spec a
>> variation
>> on the above specs using some lobes that seem to hold on better past 
>> power
>> peak (it'll hold the power peak for a wider RPM before falling off).
>>
>> Be aware that Comp's hydraulic rollers are ground on a reduced base 
>> circle
>> austempered ductile iron core.  The Crane and Reed hydraulic rollers 
>> we've
>> used on the dyno engines used standard base circle steel cam cores.  It
>> varies from block-to-block but there can be lifter issues with hydraulic
>> roller cams in 351C blocks.  A friend ran into interference issues with a
>> Comp hydraulic roller using OEM Ford lifters (dog bone and spider
>> retention).
>> He had to use the more expensive Crane link bar lifters.  On our current
>> 351C dyno engine, the lifter bores have a chamfer that exposes the oil
>> feed
>> hole on OEM Ford hydraulic lifters.  We also tried the new Comp cams link
>> bar lifters which look very nice and use their solid roller lifter body
>> but they had the oil feed hole in the same place as the Ford lifters.
>> The fix was a set of the Crane link bar lifters which have the oil hole
>> placed lower.  Our previous dyno 351C did not have either of these
>> probblems
>> and accepted a standard base circle cam with either the Ford or the Crane
>> link bar lifters (and presumably the Comps though we didn't test them).
>> Since this varies from block-to-block, you may want to check clearance
>> before assembling the short block.  The first problem can sometimes be
>> fied by grinding on the block (a local machine shop has a little fixture
>> they use to clearance 351C blocks being fitted with hydraulic roller
>> cams).
>> and the second can be fixed by bushing the lifter bores.  Either is easy
>> on
>> a disassembled engine but on an assembled engine the Crane link bars 
>> might
>> be the best way to go.  The Crane link bar lifters have worked in all the
>> 351C blocks we've tried, with reduced or standard base circle cams but 
>> are
>> several hundred dollars more expensive than the OEM Ford lifters.  The
>> Comps
>> are more expensive still.
>>
>> Whatever cam core you decide on, make sure your distributor gear is
>> compatible. I made a lengthy post on the gear options a while back.
>>
>>> Timing Set:  Pro Gear true roller.
>>
>> Beware if that has the Rolon chain from India.  When Barry Rabotnick was
>> at
>> Speed-Pro, they had a bunch of off-shore companies tryingto become
>> suppliers,
>> so they piggy-backed some timing chain and sprocket testing onan OE
>> bearing
>> durability test.  The Rolon chain from India cost them the test motor 
>> test
>> a couple times when they failed before the test was completed.  A summary
>> of
>> the test results for the chains is listed below.  Speed Pro ended up 
>> using
>> Dynagear sprockets and Morse chain but had some quality control issues
>> then
>> Dynagear went out of business.  After that they sourced the high end
>> Cloyes
>> sets (which used French Renold and German Iwis chain) and the quality
>> control
>> complaints went away.  The Ford Motorsport 351C timing sets I've examined
>> all
>> used the French Renod chain.  While there are many companies who sell
>> timing
>> sets, most do not make their own product.  They source the gear and chain
>> from
>> other companies and can change suppliers without warning.  The sprockets
>> come
>> from Rollmaster (Australia), SA Gear (US but not the best quality) and
>> Cloyes
>> (US, not pretty but good quality).  Avon also makes some sprockets but
>> sources
>> others.  Dynagear (US) used to make sprockets but went out of business. 
>> A
>> bunch of the performance aftermarket companies are selling poor quality
>> chain
>> from India (Rolon), along with sprockets from pretty gears from Australia
>> (Rollmaster, J.P Performance) or SA gears.
>>
>> Chain durability testing summary:
>>
>> Iwis (German) - looks very nice but was not tested, but has excellent
>>                reputation as OE supplier, used in high end Rollmaster
>>                and some high end Cloyes sets
>> Cloyes (US) - tested OK
>> Renold (France) - tested excellent, used in most high end Cloyes sets
>>                   but not always
>> Morse (US and Mexico) - tested excellent
>> Daido (Japan) - tested excellent
>> Tsubaki (Japan) - tested excellent
>> KCM (Japan) - looks very nice but was not tested
>> Rolon (India) - failed test
>>
>> Note: Some of the test data was from Speed Pro, other from TRW.
>>
>>
>> The Edelbrock heads probably aren't the best choice for 408 cubic inches
>> and the Performer 2654? intake isn't going to make the most of the heads.
>> You have to think of heads and intake combination.  It does little good
>> to have a set of heads that flows 300+ CFM, if your intake only flows
>> 250 CFM.  That was the case with the unported 4V dual planes we tested.
>> Porting the 4V dual planes helped quite a lot but the single plane Holley
>> Strip Dominator still bested them on the stroker engine, gave up no 
>> torque
>> and had a smoother torque curve.
>>
>> No one has offered up a set of Edelbrock (or AFD or CHI) 2V heads to test
>> but I do have ported Aussie which should be pretty close to the
>> Edelbrocks.
>> If you wish to stay with 2V heads, TFS has recently introduced a 2V port
>> aluminum 351C head.  If the published figures from TFS are to be 
>> believed,
>> it outflows the Edelbrock and similar 2V head offerings from CHI and AFD.
>> The TFS heads use larger 2.08" diameter intake valves and have a slightly
>> raised exhaust port.  Also, TFS plans to introduce a matching EFI lower
>> intake for use with their Windsor uppers.  Also, the exchange rate has
>> recently improved for importing from Australia, so the CHI or AFD heads
>> may be a better value.
>>
>>> 1)  Should I stay with the Edelbrock 2665 intake or would the 7564 RPM
>>> Air
>>> Gap be a better choice.  The builder thinks the Air Gap may be too tall
>>> and
>>> might not fit under the engine cover (although I have a cut-out already
>>> for
>>> a taller air cleaner) and that it may be more appropriate for racing 
>>> than
>>> street use.
>>
>> The 7564 Air Gap will not fit under a stock screen but shouldn't be a
>> problem
>> if you have a screen with a cutout.  Air gap intakes or intakes (or 
>> heads)
>> with
>> the heat risers blocked will take longer to warm up in cold weather. 
>> Even
>> in
>> milder weather, an electric choke will likely open too soon.  A manual
>> choke
>> will work better and a strong multi-strike capacitive discharge ignition
>> will
>> also help. If you want a lower profile intake that will fit under the
>> screen
>> with a drop base air cleaner and 2 1/4" tall element, the Weiand
>> X-Celerator
>> 351V-2V (7516) would be a much better choce the Performer.  In a tall
>> intake,
>> I'd probably go with one of Terry Parkers single planes though I think 
>> the
>> RPM Air Gap should work okay.  I'll be testing all of these intakes and
>> more
>> on the dyno.  The 2V intake manifold line-up looks like:
>>
>> Edelbrock Performer 2V dual plane
>> Edelbrock Performer RPM Air Gap 2V
>> Holley Street Dominator 351C-2V (p/n 300-12) single plane
>> Offenhauser Dual Port 351C-2V
>> Offenhauser Port-O-Sonic 351C-2V (p/n 6122) single plane
>> Parker Funnelweb 2V high rise single plane
>> Weiand X-Celerator 351V-2V (7516), both versions
>>
>> The exhaust is very important, particularly with a narrow lobe separation
>> angle.  In dyno testing, we lost 50 HP with Euro GTS mufflers on a 408C
>> and
>> 50 HP wih standard Pantera mufflers on 351C.  We gained it all back with 
>> a
>> pair of 3" inlet/outlet Magnaflow mufflers.
>>
>>> Stroker Kit: Scat 9000 series 408 cu-in with cast crank,forged I-beam
>>> rods
>>> & forged dished pistons.
>>
>> Thart's the kit we used on both 408C's we've tested.  You might check
>> with Alex Denysenko of MoneyMaker Racing on pricing.  Alex has very
>> good prices (typically beats the big catalog places like Summits) and
>> knows Fords very well.  Also, MME (Mark McKeown) has recently post his
>> 2009 prices at $1199 for a 408 Cast steel kit with the SCAT 9000 series
>> crank, 4340 I beam rods with 7/16 cap screws and non custom forged
>> pistons.
>> Those are the flat top piston prices.  The dished pistons are $20 more.
>>
>> In case you've not seen it, I've attached a couple of posts on testing
>> our first 408C.
>>
>> Dan Jones
>>
>> Here's a follow-up to the 408C that Dave Mclain built and dyno tested
>> for local Pantera owner Glen Hartog (original post is at the bottom).
>> We got a chance to finish the dyno testing this past weekend at Dave
>> Mclain's shop in Cuba, Missouri. This is a 10:1 compression street
>> motor that had previously made 468 HP at 5500 RPM and 486lbs/ft at 4500
>> through the mufflers on 93 octane premium from the local Mobil station.
>> The best pulls came with only 28 degrees total timing and a ported Ford
>> low rise dual plane aluminum intake manifold. The engine makes 440 or
>> more lbs/ft from 3100 to about 5600rpm but drops off after that. We
>> knew the heads outflow the intake by a wide margin so we suspected the
>> intake may be holding back the combo. However, the Blue Thunder high
>> rise dual plane we tried was not as good as the ported Ford intake.
>> Given the heavy Cleveland valves and 1.73:1 rocker ratio, we also
>> suspected the OEM hydraulic lifters might not be up to the task so
>> we returned to finish the dyno session with a set of Crane link bar
>> hydraulic lifters (actually the Ford Motorsport part number lifters
>> made by Crane) and a Holley Strip Dominator single plane intake
>> manifold.
>>
>> We first tried the Holley Strip Dominator intake. Equipped with a
>> one inch spacer, it moved the HP peak up slightly and made around 15 HP
>> more at the top than the OEM Ford intake. I forget what it made without
>> the spacer but it was between the ported Ford intake with spacer and
>> the Strip Dominator with spacer. Dave's got the numbers on his PC.
>> Dave opined that with more RPM, the difference would likely grow and
>> noted the Strip Dominator would benefit from some plenum entry work.
>> The torque curve with the Strip Dominator was smoother, likely due to
>> the Boss dual plane going into and out of tune. I also brought along
>> an Edelbrock Torker and an Edelbrock A331 (raised port version of the
>> Torker that matches A3 Ford Motorsport high port heads). It looked
>> like the A331 wouldn't seal at the bottom of the port without milling
>> it to drop it down, so we passed on testing it. Though it doesn't have
>> much of a reputation on stock displacement 351C's, the Torker did pretty
>> well. I forget the exact numbers but it was within a few HP of the
>> Strip Dominator. Apparently it likes the extra cubes.
>>
>> In the old (October 1993) Super Ford Article "Planes of Power",
>> the Strip Donminator made 498 HP at 6250 RPM. The Torker was down
>> 18 HP at 480 HP at 6750 RPM. That engine was a 13.7:1 compression
>> ratio, 377 cube offset ground 351C crank, stroker with a Madden solid
>> roller cam of 264/270 degrees duration @ 0.050" lift and 0.723 inch
>> lift. Not sure what the lobe centers were but springs were 210 lbs
>> on the seat and 510 lbs open. Given the much larger cam and higher
>> compression ratio, that engine should have performed much better.
>> Glen's 10:1 compression ratio hydraulic roller cam motor made
>> substantially more torque (50+ ft-lbs) and a bit less HP at a lower
>> RPM. Not a bad trade off for a pump gas motor expected to live a
>> long trouble free life on the street.
>>
>> We didn't re-baseline the engine with the dual plane at the start,
>> so we slapped the ported Ford intake back on. As mentioned above,
>> it was down around 15 HP to the Strip Dominator but the overall
>> numbers were also down relative to the first day of testing, even
>> though we had corrected for atmospheric conditions.
>>
>> We next tried the Crane lifters. They are dimensionally identical
>> to the Ford lifters so can be swapped without a pushrod change. Dave
>> noted the custom length intake and exhaust pushrods on this engine are
>> slightly different in length. During reassembly it was noticed that some
>> of the intake keepers showed signs of contact at lifter collapse so the
>> intake rocker arms were clearanced. Once everything was buttoned back up,
>> the Crane lifters were tested and showed essentially no difference. At
>> this point, we suspect the cam has too little duration to make peak power
>> at the desired 6000 RPM, though Dave mentioned increasing the intake 
>> valve
>> spring pressure would be worth a (future) test. The cam specs are:
>>
>> Crane Cams grind number (custom): HR-232/352-2S-8
>> Intake 232 deg duration @ 0.050" tappet lift
>> 294 deg duration @ 0.004" tappet lift.
>> 0.609" lift with 1.73:1 rocker ratio
>> Exhaust 236 deg duration @ 0.050" tappet lift
>> 298 deg duration @ 0.004" tappet lift.
>> 0.621" lift with 1.73:1 rocker ratio
>> 108 degrees lobe separation, intake centerline 103 ATDC
>> degreed in at 102.25 intake centerline with new chain
>> (should lose about .5 to 1 degree once timing chain loosens up)
>>
>> BTW, the cam is a stock base circle core though the exhaust base circle
>> is a bit smaller than the intake due to the lobe profile.
>>
>> Up next was a test of the Pantera headers and exhaust. We had baselined
>> the engine using a borrowed set of Hooker Competition headers (probably
>> part number HOK-6920HKR) with 1 3/4" diameter by 27" long primaries, 3"
>> diameter by 8" long collector with 12 inch long collector extensions and
>> 3" inlet/outler Magnaflow stainless steel mufflers. Glen had a set of
>> Euro GTS mufflers and had purchased the matching GTS headers from the
>> Pantera Performance Center. These are nicely made with a thick flange
>> and ceramic coating. The GTS headers are often refered to as tri-y's
>> but are, in fact, 4-into-1 headers with short tri-y collectors. Like
>> most under-car Pantera headers, the primaries are very short. The
>> collector is also quite short and relatively small in diameter, though
>> the primaries are large (2" diameter) and matched the port better than
>> the Mustang headers. They also don't bend down at the head port exit
>> like the Mustang headers. The GTS headers did pretty well. Compared
>> to the Mustang long tubes, the GTS headers with a collector extension
>> was a near match. Without the extension, they gave up some torque but
>> were close on HP. Unfortunatey, the GTS mufflers were terrible and lost
>> some 50 HP compared to the 3" inlet/outlet MagnaFlows. Though the body
>> of the GTS mufflers is short the tips are very long so the overall length
>> was a bit more than the much less restrictive MagnaFlows. It looks like
>> the MagnaFlow muffler will fit under a Pantera and they make a version
>> with 3" inlet and dual 2.5" outlets which would retain the quad tip
>> Pantera look. Given that the diameter of GTS collector outlet (looked
>> like 2 1/4" or 2 1/2" ID, I forget to measure it) is much less than the
>> 3" pipes we used, it's possible a set of 2 1/2" pipes might not lose
>> any power compared to the 3" pipes. Something to test on a future dyno
>> session, perhaps. Glen likes the look of the GTS mufflers and plans on
>> gutting them to try gain back some of the lost power.
>>
>> Finally, we tested an out-of-the-box Holley 750 double pumper. Unlike
>> the vacuum secondary 750, the 750 DP uses down leg boosters (the vacuum
>> secondary version uses straight leg boosters). We tried jetting it both
>> leaner and richer but the original jetting (71 primary jets, 80 secondary
>> jet with power valve on primary side only. BTW, the carb has the HP type
>> reinforced metering blocks) made the most power. It was down 10 or 11 HP
>> at the peak compared to the 950HP dyno carb, which is acceptable. The
>> carbs were tested without the aid of a bellmouth, K&N stub stack or air
>> cleaner. I had brought along a freebie 850 with annular boosters that
>> was in unknown condition. We tossed it on for a quick test but it really
>> needs a rebuild kit.
>>
>> We forgot to check the Crane steel distributor gear for wear but Dave
>> can do that before Glen picks up the engine.
>>
>> Dan Jones
>>
>>
>> **********************************************************************
>> Original post:
>>
>> I recently spent some time on the dyno at Dave McClain's shop in Cuba,
>> Missouri with a friend's 408 cube Cleveland stroker. Spec's on the
>> engine are:
>>
>> 4.030" bore
>> SCAT 4" cast crank
>> 6" SCAT rods with SBC pin dimensions
>> dished forged pistons
>> approximately 10:1 compression
>> 4V closed chamber heads milled/drilled for screw in studs and guideplates
>> Mid-Lift 1.73:1 roller rockers
>> springs with 140 lbs seat pressure 320 open (approx)
>> Ford over-the-counter aluminum dual plane (Boss 351C with Holley carb
>> pattern)
>> Boss 351 cast aluminum valve covers with screw-in Ford rubber grommets
>> and push-in K&N breather
>> Hooker Competition headers, 1 3/4" diameter by 27" long primaries,
>> 3" diameter by 8" long collector (probably part number HOK-6920HKR)
>> 12 inch long collector extensions and 3" inlet/outler Magnaflow mufflers
>> Mallory Unilite distributor with mechanical advance only
>> Boss 351C valve covers
>> Dave's dyno carb (Competition Carburetion 950HP carburetor, 4 corner
>> idle, no PCV port, did not use the dyno bellmouth)
>> Crane Cams grind number (custom): HR-232/352-2S-8
>> Intake 232 deg duration @ 0.050" tappet lift
>> 294 deg duration @ 0.004" tappet lift.
>> 0.609" lift with 1.73:1 rocker ratio
>> Exhaust 236 deg duration @ 0.050" tappet lift
>> 298 deg duration @ 0.004" tappet lift.
>> 0.621" lift with 1.73:1 rocker ratio
>> 108 degrees lobe separation, intake centerline 103 ATDC
>> degreed in at 102.25 intake centerline with new chain
>> (should lose about .5 to 1 degree once timing chain loosens up)
>> Crane steel distributor gear (0.531 inch ID to match Mallory distributor)
>> OEM Ford 5.0L hydraulic roller lifters and spider arrangement
>>
>> The engine is destined for Glen's Pantera and he wanted to stick with
>> the Ford dual plane intake so he could retain the stock engine screen.
>> Knowing the Ford intake would be a limiting factor, Dave worked on the
>> poorer flowing runners to bring them closer to the better ones.
>> Surprisingly, the worst runners were not the lower plane runners but
>> the upper runners which "look" better. The divider was cut down and
>> the plenum entry blended back to help the worst runners. Two 4 hole
>> spacers and one open spacer was tried. Spacer height was limited to
>> 1" since that's all that will fit under the stock Pantera engine
>> screen with Ford intake. The open spacer worked best but all peaked
>> right around 5500 RPM.
>>
>> The heads are closed chamber 4V heads with some short side radius work,
>> a good valve job and stainless valves with 30 degree back cuts on intake
>> side only. Here's what they pulled on the flow bench:
>>
>> 351C-4V
>> lift int exh int int
>> #1 #1 #2 #3
>> .050 33.6 27.1 32.7 31.1
>> .100 64.7 55.9 64.6 64.1
>> .200 123.0 100.1 129.8 134.5
>> .300 188.5 138.9 195.1 200.2
>> .400 246.4 166.4 251.7 253.3
>> .500 294.5 182.7 296.5 294.6
>> .600 322.1 186.5 322.5 322.0
>> .700 333.3 185.2 338.9 330.2
>>
>> Flowed at 10" and converted to 28", some porting (shortside radius work),
>> 2.19"/1.71" diameter valves, no intake manifold or exhaust pipe. Intake
>> port area is 3.25 sq. in. Exhaust is 3.14 sq. in. Dave's got the data
>> for the rest of the ports but this all I could pull off the screen dumps.
>> Dave said the shortside radius was everything on the 4V heads. He also
>> opined the 2V short side was worse and would likely respond to similar
>> modifications.
>>
>> Flow data for head with dual plane Ford intake and 780 Holley carb body:
>>
>> 351C-4V
>> lift int int int int int
>> port port port port port
>> #1 #2 #3 #4 #5
>> .200 124.0 127.4 133.0 128.9 126.4
>> .400 217.9 228.8 228.6 231.7 228.2
>> .600 258.9 270.5 271.7 282.4 271.9
>> .800 274.4 ----- 285.3 279.7 271.8
>>
>> Running through the mufflers, on Mobil 93 octane premium, the best pulls
>> came with 28 degrees timing, the reworked Ford aluminum intake with a 1
>> inch open spacer. Corrected numbers are 468 horsepower at 5500rpm and
>> 486lbs/ft at 4500. It was a cool day and the air density ratio was very
>> good, 98.17% for a 1.0238 correction factor. Air temp was 56 Degrees F,
>> humidity 36% and abs baro 29.26 in Hg. Very good conditions for the
>> 1100ft altitude. Dave was an EMC contestant and said his dyno is known
>> to be about 4% conservative when compared to other setups. Our dyno pulls
>> were from 3000 to 6000 RPM and the engine makes 440 or more lbs/ft from
>> 3100 to about 5600rpm. After that, the engine drops off. The intake
>> and the OEM Ford hydraulic roller lifters are the possible limiting
>> factors
>> in this build so we plan to try the FRPP/Crane link bar lifters and a
>> Holley
>> Strip Dominator intake manifold to see if wee can pull another 500 RPM or
>> so. Hoping to make 500 HP through the mufflers. Once we've satisfied our
>> curiosity, we'll try a 750DP and GTS Pantera headers and mufflers. Kirk
>> Evans did some header testing a while back and found the GTS headers were
>> pretty decent (compared to the other Pantera headers tested) but the
>> mufflers were pretty bad. We'll run the tests with and without mufflers.
>> Also, Dave thinks we'll only lose about 10 HP with the 750DP versus the
>> dyno carb. Interestingly, he didn't bother to jet the dyno carb on the
>> dyno, claiming his previous experience with that carb was that jetting
>> only
>> made a slight difference in power.
>>
>> We also tested a Blue Thunder high rise intake but it actually made less
>> power than the modified Ford intake. The Blue Thunder made 437 horsepower
>> and 463 ft-lbs torque, at 5500 and 3900rpm respectively. Adding a 1" open
>> spacer to the Blue Thunder helped the torque about 6 HP but horsepower
>> stayed the same. It would be interesting to see what Dave could do with
>> the Blue Thunder but we're going to try a Holley Strip Dominator single
>> plane, instead. The heads alone flow 322 CFM at 0.600" lift but when you
>> add the ported dual plane intake, spacer, and carb body the flow drops
>> into 270 to 280 CFM range. Dave used a neat trick for the manifold
>> testing.
>> He used hardware store weather stripping instead of RTV or cork gaskets.
>> Cheap, easy and lasts long enough for the dyno pulls.
>>
>> Earlier I had taken some A/B measurements on several intakes:
>>
>> A B
>> Holley Strip Dominator 4 5/16 5 3/8
>> Blue Thunder 4 7/16 5 3/8
>> Ford aluminum dual plane 3 1/4 4 3/8
>> Weiand Xcelerator 2V 4 3/16 5 1/8
>>
>> I know for a fact the Weiand Xcelerator 2V will clear the stock Pantera
>> screen with a 2 1/4" tall 14" diameter K&N element but there isn't a lot
>> of room beyond that. A slightly smaller diameter air cleaner (13") should
>> clear the decklid and allow a bit more space. At worst, Glen will have to
>> either mill the spacer or the intake 1/4" or try a different style air
>> cleaner. If he's so inclined, a taller engine screen (or spacers under
>> the stock screen) can be installed.
>>
>> Dave mentioned the SCAT cast crank had a Cleveland snout and did not
>> require the Ford Motorsport snout spacer. If you call SCAT and ask,
>> they'll tell you the snout spacer is needed. Note that the SCAT forged
>> cranks may still need the snout spacer. My 4340 forged steel SCAT crank
>> did need it but that crank was made a year or so ago. I don't know if
>> they have separate FMS and Cleveland crank part numbers now or not for
>> the forged cranks. 6" Scat I beam rod with SBC pin dimensions were used
>> and the rods and pistons were light enough quite a bit of material had
>> to be removed from the counterweights on the SCAT 4 inch stroke cranks
>> to use the 28.2oz balance factor. It would take some heavy metal to
>> make it internally balanced. Everything ends up pretty light:
>>
>> Piston 390 grams(with ring support)
>> Locks 4 grams
>> Rings 41 grams
>> Pin 117 grams
>> Rod Big End 437
>> Rod Small End 173
>> Bearing 37
>> Oil 3
>> Total: 1676 gram bob weight for a 50% balance factor.
>>
>> On the initial fire up, we heard some noise. I suspected a roller
>> rocker was hitting the Boss valve cover baffle since I've had that
>> happen before. However, Dave said he had checked that and the baffle
>> had been clearanced. When we removed the valve cover, there were no
>> marks on the rockers so that wasn't the source. Also, the sound appeared
>> to be coming from multiple locations. After wondering if it was just
>> start up slap from the cold forged pistons, Dave bumped the engine over
>> with the starter while I watched for valve train interference and
>> noticed that some of pushrods were just brushing the guide plates.
>> Dave made the guide plate slots deeper and that took care of the
>> noise. Glen thought catching was worth the dyno cost. It's one of
>> those things easy to catch on the dyno (and hard to verify during mock
>> since the lifters aren't pumped up) but would be a pain to catch and
>> fix in the car. Required intake and exhaust pushrods are different
>> lengths, BTW. That's likely due to the different intake and exhaust
>> lobes.
>>
>> I was surprised the Hooker Competition headers were only 1 3/4" 
>> primaries.
>> 4V headers tend to be 1 7/8" since that covers the exhaust port better.
>> The Hooker Super Comps are 2" but that's too large for this engine.
>> Some 351C headers make a sharp down turn right at the flange to clear
>> the narrow Mustang shock towers but the Hookers came out a few inches
>> before turning down. Pantera headers come straight out but the primaries
>> are very short and the collectors very short and small in diameter (2 
>> 1/4"
>> outlet). Glen is buying a set of GTS Pantera headers which have 2"
>> primaries feeding into a tri-y type collector of 2 1/4" diamter outlet.
>> It will be interesting to see how big a hit we take on those relative to
>> the Hooker headers.
>>
>> A friend has run both the OEM Ford lifters and the Ford Motorsport
>> M-6500-S58 retro-fit hydraulic roller lifters (made by Crane and
>> sold by them under part number 36532-16 but the FMS part number is
>> $30 cheaper through Summit Racing) and verified the lifters are
>> dimensionally identical. The pushrod cup is in the same location and
>> the plunger travel is the same so we can use the same pushrods. Marc
>> mentioned they set the pre-load a full turn, rather than the 1/2 turn
>> we were using. The full turn includes the setting of the locks (from
>> zero lash to locked in place). Marc also mentioned that is what Crane
>> recommends.
>>
>> Since Glen is going to use the left-over stock parts to build a back-up
>> engine, he's going to buy a set of the Ford/Crane link bar lifters and
>> we can swap the OEM lifters to the back-up engine. With the Strip
>> Dominator and the Crane lifters, we should see if the stock lifters
>> are a limiting factor.
>>
>> I've got all the flow data for the heads and intake so I'll run this
>> through Dynomation when I can spare the time and see how well it predicts
>> the trends.
>>
>> Dan Jones
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