Im building a 350 for my s10, and I am trying to do it on a budget. I am going to run a 150 shot of nitrous. Will I be ok to run the 2 bolt main stock crank and rods with forged pistons, or do you guys think that I will need to get a cast scat crank and forged rods.I am going to use all ARP studs and fasteners. I would like to keep the red line around 6000-6500.

 

You'll probably be fine.

 

I really dont want there to be any question, if there is a chance then I will replace.

 

Ever read "The Deacon's Masterpiece" by Oliver Wendell Holmes?

 

You're like Confucius Chris, answering a question with a question.

91dime, there's no such thing as 100% certainty. There's always a chance. You can get closer and closer to 100% perfection, but the cost goes up exponentially.
How deep are your pockets, and how sure do you want to be?
Or... You'll probably be fine

and of course you meant to say "in my camaro" rather than S10 right?

 

Socrates, not Confucius.

 

i've done it, with cast pistons too. i also broke three rods one time, compleatly destroying everything under the intake. (i believe it could have been a rod bolt that started the whole chain reaction) i know it can be done, but i don't know how many times you can do it. i can spend around $300 bucks getting a junk yard 350 and freshing it up and it will last over 30 hard passes. about a year for me 6 times to the track, and maybe 5 passes a time. i pound out the rod bearings pretty good, and i usually go through a bit of water at the track. i know how i could fix it, but for $300, why?

 

Yea I left that way to open. Im building a 350 for my street/weekend s10, so it doesnt need alot of power. Id like to make about 350-400hp + nitrous. Im going to use a TPI setup, cast iron heads, hyd flat tappet cam, nothing crazy. The budget isnt set yet, but for what im doing I dont think it needs to be high. This truck will see the strip maybe once to see what I can do. Do you guys think I can use the cast crank and rods for what I would like to do. Thanks, and sorry for the confusion.

 

Yep, one of his teaching methods.

Jake

 

Your GM cast crank is better quality than the Scat or other aftermarket cast crank. If you need forged, go aftermarket; otherwise your odds are better with the stock crank. What year 350 are you rebuilding? Later years had the PM rods, which are more than adequate for 500 fwhp.

 

Its a early engine, I think a 70 or 71. I thought the PM rods were in LT1s, but Im sure I can go to the junk yard and get a set of rods from a late model engine for pretty cheap. Also I was reading "How to build max performance chevy small blocks on a budget" and they were saying its safe to run hyper pistons in engines running nitrous. Because you can run tighter tolerances than a forged piston. Is that true? Thanks for the help!

 

Yes, I've been running hyper pistons in my LT1 for years spraying 150 and 175 shots. As long as the tune is good - plenty of fuel, conservative spark - you'll be fine.
If you get PM rods from a junkyard engine, they probably need resizing to give them a good bearing fit with the crank. With that expense, you're just as well off buying a decent set of new rods.

I race with a guy that uses nothing but junkyard LT1 engines. Does nothing to the shortblock other than new rod bearings and new stock oil pump, then installs his favorite cam and heads. He sprays these motors to the tune of 500-600 fwhp and gets hundreds of runs out of them

 

Please elaborate on this statement about the stock crank.

 

Tony Bischoff (BES Racing Engines) here in Southeast Indiana relayed his experience to me with aftermarket cast cranks. He's this year's Hot Rod Magazine Master Engine Builders Champion (and last year's runner-up)and builds and maintains bracket racing engines for customers across the country. For mild applications around 500 hp in a SBC, he has in the past worked within customer budget concerns and used aftermarket cast rotating assemblies. He's told me that many of those cranks are cracked upon teardown inspection after a season or two of bracket racing, but he cannot recall ever finding a GM cast crank cracked. So naturally, he discourages anyone from spending money on aftermarket cast cranks.

 

Interesting. I will be tearing mine down shortly, and will make it a point to look for cracks.

 

What type crank are you running? Look in the fillets next to the rod and main journals.......well duh! where else would you look?
If you don't spend a lot of time in the 6000-7000 rpm range, I wouldn't expect to find anything. The type of torsional damper you run is also a factor at those revs.
Let us know what type of use / how long / the engine has seen. Your findings may be a good data point for street applications.

 

It is a Scat cast crank. It is 3.48 stroke with 6.0 rods. I drove it this year from June until November, 3 to 5 days a week, depending on weather. It saw 7000 rpm at least once everyday I drove it. This is my damper
http://www.naparts.com/ProductModelD...ctModelId=7479

I am doing the teardown just because I have until next spring with nothing else to wrench on.

 

Well I think I made a decision on what I am going to do. Summit has a bottom end kit for a good price. For the cash I would have in having everything checked machined and reconditioned I can buy a kit and know its all new. Im between http://store.summitracing.com/partdetail.asp?CP=1∂=SES-3483006550&N=700%200&Ntt=SES~3483006550%20or%20SES~3483004550%20or%20SES~3483006650%20or%20SES~3483003550&Ntk=&rsview=sku&Ns=

or

http://store.summitracing.com/partdetail.asp?CP=1∂=SES-3483004550&N=700%200&Ntt=SES~3483006550%20or%20SES~3483004550%20or%20SES~3483006650%20or%20SES~3483003550&Ntk=&rsview=sku&Ns=

 

Don't forget to allow for those kits to be balanced.

 

Yeah I forgot about that, whats that usually cost? I was thinking around $250? I know alot of you guys run hyper pistons but will I be better off in the long run with forged if I run nitrous?

 

You'd have to check with local machine shops for prices. Hypereutectic pistons are plenty strong, as long as you never have detonation. If you do, they'll shatter. Forged pistons are more forgiving and will take more abuse before you melt holes in them.

 

91dime, Whatever rotating assembly you go with, make sure to get it and do a test fit to check the deck clearance in the block before final machining/decking the block. The budget rotating assemblies are notorious for using "short" pistons that will give you a huge quench clearance with standard deck heights, and result in disappointing performance.