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Discussion Starter · #1 · (Edited)
Yesterday evening we finished up some testing on a customer's 557 Ford build for some sort of a mud racing truck and it turned out well making over 730 horsepower at 6000rpm and 730lbs/ft at 4800rpm for torque. It was built on as tight of a budget as possible and I reused as many of his parts as I could including a nice billet roller timing set, Lunati rockers, pushrods and a Comp roller cam core. The customer was very impressed with the torque and horsepower but I think mostly the SOUND of the engine made the greatest impression.

The engine is nothing fancy: a set of C8VE heads that I fitted with stainless 2.190 intake and 1.75 exhaust valves and mildly ported hitting the high spots as outlined by Scott Johnston many times here on the forum. They had been rebuilt before and the guides were good as were the screw in studs and guide plates which were already fitted. I also machined them for a double spring and positive seal that would work with the cam.

Cam was a reground solid roller about 270 at .050 duration using Reed ULX lobes which are very easy on parts, .721 lift.

Short block was a D1VE block, 4.440 bore, Scat I beam rods, 6.700 length and a steel 4.500 stroke crank from Performance Crankshaft. Pistons are flat tops with one(intake) valve relief.

Block was filled to the bottom of the water pump holes, bored and torque plate honed. Oil crossover was restricted to .040 and Competition Cams roller lifters were used.

Stock Melling M84D pump and Moroso 4X4 oil pan. , Stock Ford electronic distributor(locked out timing and MSD bronze gear added). Valvoline regular 20W-50 oil, 2 qt Hastings LF426 filter.

The headers used were Mad Dog over the frame headers for a 4X4, 2 inch tubes into a 3.5 inch collector 20 inches long.

He's not allowed to run a Dominator in his class so the carburetor was something that the customer got from Bigs, a 1000cfm down leg booster combo which worked pretty well. It's on a ported Victor 4150 style intake and it seemed to like a 1 inch HVH on top of a 1 inch open spacer about the best overall.

We ran the engine on 110 leaded racing gasoline, VP I think it was. Timing requirement was 29 degrees total.

I'm not sure exactly what it would cost to build this whole combo but I'm sure it could be done for close to $6000 with some careful shopping.
 

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Dave,

Your port work on those heads was a bit more than mild IMO. You did a damned good job on those heads to get the intake flow rates where they were.

Kudos on a job very well done

Passenger car iron heads making 738 HP at 6000 rpm...
You gotta love that.


:D :D :D
 

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Discussion Starter · #15 ·
Block was not zero decked and the piston is in the hole about .010. I didn't feel it justified the extra expense of cutting the decks since they looked nice. With a flat piston the compression ratio is about 13.25:1 or so give or take a little.


The horsepower peak was centered right at 6000rpm with the engine making 736 at 5800 and 734 at 6200rpm, 738 at 6000. I pulled the engine to about 6250 where it was making 729 horsepower.

Torque peak was at about 47-4800rpm with 735lbs/ft.
 

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Dave, Please do not tell me you did not take advantage of the "magic" zero deck thing.....LOL!!
 

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Real Impressive Dave:eek: Thanks for sharing:)
 

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What was the CC on the heads? I'm guessing with a 13+ cr and flat top they are cut down a bit.

Did you expect the HP to peak so low? Seems with that cam would have been a bit higher?

Steve
 

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Discussion Starter · #19 ·
CC on the head was 74cc nominal. Heads were milled but only to resurface the deck. Also, very little grinding was done in the chamber itself. I had 4 cc's in a single valve relief on the piston. A 557 inch engine makes getting high compression very easy even leaving the piston down from the deck a little.

I did expect/want the engine to peak at about 6000rpm. With this cylinder head and displacement the ports get very high velocities at even moderate rpm so horsepower and torque tend to peak early. I was glad to see the torque peak under 5000rpm too. What's deceptive is that the engine doesn't really "brick wall" at 6000rpm and it doesn't really fall off much at all to 6500rpm which is about as fast as the customer is going to rev the engine.

Large engines can really swallow a lot of cam timing yet still remain quite tame. I had it idling at about 1200rpm on the dyno and it sounded surprisingly mild.
 

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557"

That is a really nice build on a budget Dave.

Engines like this are exactly what the mudracer crowd go for; good horsepower, lots of torque for a good price. Your customer should be very happy with this engine.

Mark
 
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