C.O.M.E Racing Holden 383ci Terminator update
With the recent release of our new 2004 series aluminium head for the Holden based V8 engine we were keen to prepare a set for our Torana race car's Terminator 383ci Holden V8 engine.
In actual fact the Terminator has a factory cast iron production block but in reality the rest is an amalgum of our own made and other aftermarket parts.
The original nodular cast iron crank (fitted originally in 1996 for the G/Gas Drag Racing class wars) went back in with only a polish and rebalance. A new set of our own manufactured 4340 steel 5.7" "H" beam rods and the original Ross Racing forged flat top pistons and new Speed Pro rings, King rod and main bearings.
The original C.O.M.E solid roller grind camshaft CSBR-272-112 LC was reinstalled.
Mainly to provide valid comparison information on the effectiveness of the new cylinder heads. No other components were altered at all. The same 13.5:1 compression ratio was retained, oil pan and oiling system with Moroso external oil pump, out of the box Holley 950 Pro Series gasoline carb, MSD 7 series ignition and Pro Power coil, MSD crank trigger, fully ported (by Wilson Manifolds U.S.A) Harrop single plane intake with Wilson 2" spacer. As before a stock Holden EFI distributor was used as our crank trigger dizzy.
The head comparison proved to be very impressive. The original cast heads flowed over 590 bhp through 188cc intake runners but exhaust flow was always a limiting factor on the factory item. The original cast heads had a set of Manley titanium valves, Manley 1.625" roller springs, titanium retainers and 10 degree jumbo locks. The valves and springs had done an awesome job but we replaced them with new items identical to the originals. Intake valve sizes are 2.05" and 1.60" exhaust. We use a custom made Jesel rocker arm system with 1.6:1 ratio on intake and 1.65:1 on exhaust. This setup went back on with the same chrome moly 5/16" Manton pushrods.
Our new heads were ported to flow over 630 bhp through an intake runner of about 195cc's. The exhaust ports flowed nearly 10% better than the cast heads with relatively little work. We will go much further with these heads incidentally when we build the first of our Torana's 400ci all alloy Terminator engines.
The results were pretty impressive from our point of view. The last runs on the dyno for this cast iron headed Terminator made 620 bhp @ 6750 rpm and 535ft.lbs torque with the 112 degree lobe centre cam.
Our newly freshened Terminator with the new 2004 series heads made 663 bhp @6750 rpm and 549 ft.lbs torque at the same 5250 rpm
Even more telling as to the effectiveness of these heads were the comparisons of power using Nitrous oxide. Our system is a simple plate system using the smallest NOS solenoids and non adjustable spray bar setup. This is rated at a maximum of 125hp system on a typical street strip Small Block engine.
The cast iron headed engine managed 809 bhp and the best E.T for the car with this setup was 8.54 @ 157 mph.
The 2004 alloy headed engine made 883 bhp at the same 1000 psi nitrous bottle pressure. A testament to the improved combustion chambers design, port design and other subtle improvements we have incorporated. We will run the car as soon as is possible to evalute any performance gains at the track but not before we add about 100-150lbs of lead shot to the front of the car to keep the nose down on launch. It was already a big problem.
The dyno sheets are available to anyone. Email us for copies to come@comeracing.com
More importantly, if you are building a race Holden V8 or everyday driver the 2004 series COME Alloy heads have no pears in the power stakes. Remember they flow over 570 bhp out of the box with a 2.02" intake valve and 120 cfm @ 10" through the exhaust port with only minor bowl blending to the bottom cut of the seats. there is no need to port these heads at all for 90% of street/strip aplication on 5 litre, 355 or 383 engine combinations both normally aspirated of forced induction setups.
O.K we are giving you the kicker to convince you to go with the best value for money heads for the Holden V8 anywhere.For February 2005 they are at special prices as follows:
2004 COME heads bare $2750.00 a pair delivered anywhere in Australia free.
2004 COME heads complete an assembled with 2.02" intake and 1.60" exhaust stainless valves, 3 angle valve job, bowl blending, 1.450" springs, chrome moly retainers, positive seals and H.D valve locks, machined to whatever chamber size you need $3750.00 a pair delivered anywhere in Australia free.
This offer valid only till 1st March 2005. To order call us on (03)9571-4204 and quote the WEB SPECIAL to receive these prices.
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