I've noticed a lot of used Carillo rod sets for auction on various sites. These are usually "used 1 race, Nascar rods".
Also in most cases they're 2" big end dia.
I've been considering using a factory lg journal forged crank and having the rod journals turned down .10" to fit a set of these rods. Assuming I can find a set that is the right width at the bottom.
question 1 - Would these rods be a good choice for a street/ strip machine?
question 2 - Would turning down a factory forged crank -.10" be a good or bad idea in terms of strength?

Thank you, to those with greater experience than my own.

 

Can't tell ya about the rods, but I'd estimate that the crank journals are about a 1/4inch thick (based on some exploded Mopar cranks I've seen)...i/e .25, so taking off .10 would be a really bad idea for strength integrity, IMO.

 

Crank journals 1/4' thick??
I didn't mean opening up the big end of the rod, I meant turning down the crank rod journals .10".
Explain please...

 

I meant the journals on the crank...they are hollow, like a pipe, not solid,,,and based on the broken cranks I've seen (albeit never a GM one) the journals only appear to be about .25 thick.

 

They are aluminum. They are carefully designed to last about 575 miles, that being about the distance that an engine has to go in a 500 mile race under the one-engine rule; some qualifying practice, qualify, race practice, race.

I wouldn't buy them, or any other aluminum moving part, for something I depended on to get me somewhere. Strip only, yes; any street duty at all, no.

Yes, it would be a bad idea to turn a crank down that far, since the case-hardening usually goes no farther than .060" or so deep. You'd need to get the crank re-hardened (nitrided, or whatever.... somewhat similar in principle to gun bluing).

Ever tried to balance a crank meant for steel rods, with aluminum rods on it?

All around, a risky set of parts; probably 80% or more of their useful life used up, and not the right part to begine with, and way too much work as to be done around them to make them fit in.

 

It's kind of off the subject, but I'm having a hard time picturing a hollow crankshaft. Do they have a huge lightening hole drilled in them, or do you mean they're hollow like a chocolate easter bunny?

 

http://www.racecar2000.com/classifie...w-ad-9875.html RB, check the above link and let me know if these are the aluminum rods you're talking about.
These are the only ones I have a link to, but there are some on other sites that look just like these that sell for half as much. They're H beam.
I'll take your word for it on the crankshaft. But let's say I got my hands on a compatible crank. Are these rods something I should be interested in?

 

No, those are steel. The ones I was referring to are usually aluminum, and you see them on ebay alot.

These would be a better risk than aluminum, but I still don't know if I'd want to use a set of rods that has been subjected to a full design lifetime (1 race) of stress.

NASCAR engine builders try to get all their parts as light as possible, but still finish a race. If they don't have a part fail every once in a while (preferably on a dyno), then they're still too heavy. Then they throw all the internals away and replace them for the next use of the block.

The typical hot setup these days is to use journals of "Honda diameter", that being a convenient step down in diameter from the stock small block size. They make cranks with those dimensions. They're made from scratch to be that size, not turned down from stock. I don't know off the top of my head what the actual measurement is.

 

Thanks, RB. They sure look pretty.