Cadillac 472/500 engine build, oil choice ??'s

[DoubleWasp]

If you're going to be racing this underoiled engine with nitrous, you need VR1 or GT-1.

Anyone who suspects their valvetrain components of failing on a hot street engine is surely not using Jesel or T&D. Heck, they're probably not even using comp.

Stay away from the shat Chinese Ebay stuff, and you won't have a problem.

 

[userfriendly]

I assume everyone knows their engine math when it comes to calculating horse power from torque and RPM, and back again.

If you build a 10:1 compression 500 CID engine with a street compatible camshaft, expect the peak torque to be about 550 ft lbs from 3,000 rpm to 4000 rpm, then dropping of sharply.

Now add 250HP NOS at 3,500 rpm, add that to your torque figure of 550 lbs and what do you have for a total?

I know for a fact that most of you that looked at my cam specs thought: "Oh, that guy is out to lunch, that cam will cut the torque drastically".

OK, now lower the NA peak torque to 400lbs, add your 250 HP nitrous, what is your peak torque now?

 

[userfriendly]

A 150 HP shot of N0S will add 263 lbs of torque at 3,000 rpm.
A 250 HP shot of N0S will add 328 lbs of torque at 4,000 rpm.

 

[skyactiv]

I use to read Car Craft and Hot Rod eons ago and remember a Cady 500 C.I. engine build or 2. Something was mentioned about the engine needing a thick viscosity due to the wide bearings.

 

[RoadRaceJosh]

Originally Posted By: used_0il
I assume everyone knows their engine math when it comes to calculating horse power from torque and RPM, and back again.

If you build a 10:1 compression 500 CID engine with a street compatible camshaft, expect the peak torque to be about 550 ft lbs from 3,000 rpm to 4000 rpm, then dropping of sharply.

Now add 250HP NOS at 3,500 rpm, add that to your torque figure of 550 lbs and what do you have for a total?

I know for a fact that most of you that looked at my cam specs thought: "Oh, that guy is out to lunch, that cam will cut the torque drastically".

OK, now lower the NA peak torque to 400lbs, add your 250 HP nitrous, what is your peak torque now?


250hp at 3500 RPM is 375 ft/lbs.

 

[userfriendly]

Correct, 250X5252/3500=375

Now add 375 to the naturally aspirated torque figure of 550=925 lbs or 616 hp at 3,500 rpm.

Here is a typical mud bog story;

The truck leaves the line at 6,500 rpm, wheels spinning and 300HP N0S all in.

Truck gets bogged down, tires drag the rpm down to the torque converter stall, engine blows up.

Next 10 trucks, same thing.

But, the 11th truck has 304 degrees at .050 on 116 LSA, oh, that's big!!(36/88 88/36)
Truck gets bogged down, but finishes the race.

You have to finish the race to win.

 

[RoadRaceJosh]

A proportional nitrous controller can give you a nearly fixed torque increase so that the BMEP stays reasonable and the engine stays together.

If you want "boost" for more than a few seconds at a time I'd rather turbocharge. It's cheaper in the long run and certainly more convenient. For an occasional short race nitrous works. My racing last weekend was 9 hours on Saturday and 5.5 hours on Sunday spread across 3.5 drivers.

 

[punisher]

What sort of oil for a 500ci Caddy used with nitrous and run on the strip? Any oil that will keep cast rods from breaking, the valve train from coming apart when it revs, and can keep the pistons from melting.

Love those engines but you have to realize the limitations, and the costs to overcome those limitations. You will need to keep the RPMs down. High lift-short duration cam. Make sure your valve train geometry is perfect (that's the weakness). The engine is a torque monster, not a horsepower monster. Make your torque where the engine can run comfortably and enjoy it for what it is. Any power adders, and forged rods are about mandatory, and forged pistons should be in the conversation to.

EDIT: Main studs.....mandatory. For those suggesting roller cams....I don't know if I would stress the lifter valley with a roller cam. That's a lot of potential side loading on a block not really designed for it. Even if you did have a nice roller cam, and lifters, you still have to shell out the big bucks for an expensive rocker and stud setup for the head.

 

[userfriendly]

Enjoy it for what it is? OK, it's a good choice for a boat anchor.

 

[53' Stude]

Well guys, the drivetrain is coming from MTS (maximum torque specialists). Brother is like me and dad: trying to find to take the old engine apart and go from there