Bernhard

I have both cranks factory 455 steel and N Cast Crank. The Question I have in a limited build 525 hp and 500 Tq max. Is it better to use the lighter N carnk. What is the safe max limit of a N crank. 5700 max rpm 3500lb car.

507OLDS

There really is no exact HP limit for the N-cranks.There are other factors that help or hurt the crank,like the weight of the rotating assembly,main caps.
In the application you stated above,an N-crank will work just fine,even with the heavier parts.
I run an N-crank in the 507,spinning it to 5800rpm.I have lightweight pistons,H-beam rods,and factory caps with straps.This was built over 12yrs ago,and if it was built today,there are better parts that can be used.

Bernhard

Thanks for the reply. I was thinking about using aftermarket eagle rods and probe pistons. I was looking into after market caps but after a few calls I was looking at $1000.00 ouch. Would you use straps again or run a hallo?
Thanks
Bernhard

507OLDS

A set of 4 caps should be about $500.00. I have a few sets for future builds.
You will get all sorts of opinion about the halo girdle.I'd rather go all or nothing.Either run good caps,or the best girdle.

chadman

For what you are looking to achieve HP wise I would use the N crank, straps, Eagle rods and Icon pistons. That is exactly what I run and have had zero issues. I did previously run reconditioned stock rods and they wouldn't stay round on the big end so I went to the Eagles.

cutlassefi

What he said.

Bernhard

The cost of the machinie work was a $1000 + $500 for the caps. I would like to get away with studs and sraps or studs and halo. The align hone was $319. for studs/strap/halo. I don't want it to turn into a $7000 plus engine. If the straps work for my power level then straps it is.
Thanks for the replys

Bernhard

Icon pistons V probe pistons pros and cons?

Run to Rund

If you don't use nitrous, stock caps with studs or even bolts will work fine. I would not prefer straps. By the time you pay to machine the stock caps and buy straps, you could put in good caps. Some have argued that cutting the caps and using straps is weaker than stock caps. I don't know. Sam Murray's D stocker ran 10.80s on stock caps with studs.

Bernhard

Thanks again for all the feed back.

507OLDS

Yes,people normally mill the caps the thickness of the straps,but I left the caps stock height,and added the caps on top of them.I needed longer main studs to do so.I believe my main studs are Pontiac,as they were longer.
I've run plenty of 455's into the low 12's-11's with stock caps without straps.With more companies making aftermarket caps now,I just get those.

cutlassefi

I've done almost the same thing except I have the caps cut about .200 and use ford 460 studs.
Probe, SRP, Icon and Wiseco pistons differ in material and dish cc. Figure out what compression ratio you want and go from there.

Bernhard

I was going to go with program caps but after looking into the cost of caps plus fitting plus align bore and then hone $1500 Ouch. Why do not more people just run a longer stud.Not cutting the caps or small cut seams to make more sense. Is there any problem with the studs hitting the oil pan.I think I will just go with stock caps and studs works out to be under $400. The car will not have a engine plate just stock rubber mounts and a limiter, as this is a street car and want it to look as stock as possible. Any other recommendations to lower block stress and help it stay together?

cutlassefi

Just what you said, studs along with good rods and machine work and you should be fine.

jensenracing77

not to steal the thread but if you get the Eagle rods and Icon pistons, do the pistons still mount to the rods the same as stock or a full floating or?

Bernhard

You can get the rods full floating or press fit. I will be going full floating

jensenracing77

What are the pros and cons of either style? Are the pistons made to go either way with a snapring groove?

cutlassefi

Yes. Some say more hp with a full floating pin.

James Windsor

stock mains are fine unless your going to boost it! Oldsmobile blocks are high nickel ! Oldsmobile seen no need for 4 bolt mains!! They are low end torque monsters ! Not high reving!!

James Windsor

cutlassefi

Olds blocks are not “high nickel”. That’s an old wives tale, never been proven that I’ve seen.