[DeTomaso] 5481 New Heart Beat

[Daniel C Jones]

> 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:

 4.04" bore Probe forged flat top pistons (1/16", 1/16" with 3mm oil rings)
 6.125" Scat forged connecting rods
 3.75" stroke Scat forged crankshaft, internally balanced (Part Number:
4-351C-3750-6125)
 4.04" bore x 3.75" stroke = 384.6 cubic inches
 11:1 compression
 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
 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
 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 and Aviad Pantera pan
 Clearances are .0025 mains .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 harmonic damper
 Ford Motorsport A3 high port aluminum Cleveland heads
 Ford Motorsport A331 (modified by Dave)
 1.73:1 ratio Competition Cams "gold" aluminum roller rockers
 Jomar stud girdle
 Manley guide plates
 SI stainless valves (2.19" intake, 1.71" exhaust)
 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 with Fel-Pro gaskets elsewhere
 MSD Pro Billet distributor with bronze gear
 Autolite 3923 spark plugs for street (moderate heat range), AR 3910 for
race (about 2 heat ranges colder than the 3923s)
 30 degrees total timing
 Precision Proformance high port Pantera headers
 830 annular discharge Holley (from Mark's previous engine)

Mark runs his Pantera in open road races and rarely drives it on the
street.  His ZF has the original gearing so we wanted something that would
pull well from 3500 to 7000+ RPM.  I designed the cam to maximize the power
between 4000 and 7000 RPM, with a torque peak at around 5000 RPM.  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.  The Reed ULX lobes are older designs that are
relatively easy on the valve train so work well in endurance racing and
marine applications.  Dave spent some time modifying the A331 intake.  A 1"
thick open spacer was milled to level the carb and welded to the intake.
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.  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.  The torque curve is really flat in
the operating RPM range.

More details to follow...

Dan Jones
-------------- next part --------------
   > 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