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View Full Version : good high reving race engine? *nitrous injected*



307chevelle
03-07-2008, 07:32 PM
aluminum motown block (350mains/4.155 bore)(head studs installed)
scat forged crank (3.480 stroke)
scat forged 4340 rods (5.7")
JE nitrous series pistons (12.2:1)
JE hardened nitrous series rings
milidon 7qt pro comp oil pan
erson cam (234/244 .466/.510 112* lsa)(.528/.578 with 1.7 rockers)
dart pro 1 heads (200cc intake/64cc chambers 2.05/1.60)(1.437 double springs)(cnc'd exhaust)
Lunati 1.7 ratio rocker arms
crane stud girdle
crane pushrods
lunati double roller timing chain set
custom sheet metal intake (port matched and direct port nitrous installed 2 in the runners and one in the plenum)
wilson manifolds 1" tapered carb spacer
willys custom road race carb (850cfm road race floats 1.590" venturi's)
NOS pro shot fogger (3 stages at 75/150/300)


is there anything i need to change or do you have any suggestions?

Texas Hotrod
03-07-2008, 08:08 PM
Have heat barrier coatings applied to the piston domes, the chambers and the valve faces. Then have dry film applied to the skirts.
There's coatings that can be applied to insulate the intake as well.

With all that $$$ tied up, it would have been nice to build at least a 406 instead of a 355 (if my figures are correct (I'm brain dead from a busy week). The shorter stroke will be good for winding it up (what RPMs do you plan on running), a well built 406/427 is capable of 6500+ RPM anyway. Longer rods would have been extra insurance also.

1.7 rockers? Are the Crane push rods up to the task. High RPMs need stout springs. 1.7 rockers + stiff springs X high RPM = push rod issues. I'm a firm believer in Comp Cams products myself, though Lunati does make nice stuff. Never cared for Erson and Crane.
Is that a flat tappet cam or a roller? Is it nitrous specific (no loss if it isn't) ?

Make sure the bowl areas are clean and opened up properly, that's no place for restrictions (no ledge at the seat/casting area) and back-cut all the valves.

What car, tranny, gear ratio???

Sounds like a nice build. Congrats on the cool stuff.

slowcamaro
03-07-2008, 08:10 PM
Just how high to you expect to rev?

307chevelle
03-07-2008, 09:20 PM
Have heat barrier coatings applied to the piston domes, the chambers and the valve faces. Then have dry film applied to the skirts.
There's coatings that can be applied to insulate the intake as well.

With all that $$$ tied up, it would have been nice to build at least a 406 instead of a 355 (if my figures are correct (I'm brain dead from a busy week). The shorter stroke will be good for winding it up (what RPMs do you plan on running), a well built 406/427 is capable of 6500+ RPM anyway. Longer rods would have been extra insurance also.

1.7 rockers? Are the Crane push rods up to the task. High RPMs need stout springs. 1.7 rockers + stiff springs X high RPM = push rod issues. I'm a firm believer in Comp Cams products myself, though Lunati does make nice stuff. Never cared for Erson and Crane.
Is that a flat tappet cam or a roller? Is it nitrous specific (no loss if it isn't) ?

Make sure the bowl areas are clean and opened up properly, that's no place for restrictions (no ledge at the seat/casting area) and back-cut all the valves.

What car, tranny, gear ratio???

Sounds like a nice build. Congrats on the cool stuff.

first off idk if i want to run pro touring or a drag class yet so maybe this could be for both

i like the coatings idea i'll have to look into that

its a 377ci sbc and would use 6" rods with a 377 piston but those are 406 pistons so i need a smaller rod


rpm range from 4000-8000

the rods are chromolly and from what i hear should do the trick

the cam is nirtous specific (custom grind)

valves will be back cut and i think ive decidded to cnc the whole head

dont have a car yet but im thinking something like a buick roadmaster wagon (yah i know its kinda outside the box) but it would be chopped and body dropped so it rides low and havent picked a tranny yet but prolly a built turbo 400

and gears idk yet any recomendations?

chicane67
03-07-2008, 10:04 PM
Cam is a little small.

And why would you run 1.7 rockers... when you could just put a real camshaft in it ?? Coil bind issues, requirements of a really stiff push rod (which Crane doesnt have; look up Manton pushrods) and stud deflection at that ratio are just going to be the beginning of problems.

I would build the cam with the lift already in it... or step up to some good shaft rockers.

307chevelle
03-08-2008, 06:04 AM
Cam is a little small.

And why would you run 1.7 rockers... when you could just put a real camshaft in it ?? Coil bind issues, requirements of a really stiff push rod (which Crane doesnt have; look up Manton pushrods) and stud deflection at that ratio are just going to be the beginning of problems.

I would build the cam with the lift already in it... or step up to some good shaft rockers.

i was tossing around the idea of this cam but didnt know

comp roller (276/284 .630/.630) but they dont give me the LSA

ProdigyCustoms
03-08-2008, 08:56 AM
That is a bit big. I would be looking in the 264 / 272 range, around .630 lift with 1.6 wil net in the .680 range. Keep the LCs tight if you want it to rev and want horsepower up top, but you wont get the ultimate nitrous advantage off it as you would with wider LCs. But I like to build my stff to run on motor and then spray them.

chicane67
03-08-2008, 01:46 PM
Yeah... I think that is a little too big. I like to run NA as hard as it can and then add to it... just as Frank stated.

Texas Hotrod
03-08-2008, 03:49 PM
I read a dyno test (Hot Rod/Car Craft) on a nitrous specific cam -vs- non nitrous w/similar specs. There was very little difference in the 2.
Are nitrous cams more expensive???

Build a long rod 327 w/titanium valves, a small cam and put a turbo on it. It'll wind up to 8Krpm w/o any issues.
You'll be picking pieces up off the ground if you treat a big cammed 377 that way. You're just looking for problems.
Build the big motor, put the spray to it and put a 6K pill in the MSD box. There won't be any reason to rev it any higher.

307chevelle
03-09-2008, 11:15 AM
That is a bit big. I would be looking in the 264 / 272 range, around .630 lift with 1.6 wil net in the .680 range. Keep the LCs tight if you want it to rev and want horsepower up top, but you wont get the ultimate nitrous advantage off it as you would with wider LCs. But I like to build my stff to run on motor and then spray them.

this one seems a bit scetchy

crane roller
260/268 .670/.625

but im looking at this one

comp cams
264/270 .630/.630

what do you think about that last one?