Some questions

[Hognose]

I tried searching but did not find any exact ansears that I need help with. Couple things.
A n/a 109 block. Is is suitable for a 10 sec motor build? Can I use the na crank as well?
Would a girdle help make evrything stronger especially by using a n/a crank?

Is 20 under cut too much for a 10 sec motor on a turbo crank?


Thanks

 

[boostingbuick]

All 109 blocks are the same. But the n/a crank is a very weak part. I would not run this. And if you are shooting for the tens then I would look into steal caps or a girdle. I use a 10/10 crank, but if it can be possible I would not use a 20/20 crank. I have heard of some guys running a crank cut that much with some luck, just seems risky to me.

 

[Steve V]

If I was building a 10 sec motor,I would not use a NA crank. Get a nice turbo crank or open the wallet for a billet one and a girdle.

 

[turbofabricator]

A turbo crank can safely be machined .040" The weakest portion of a crank is the rod fillets. The turbo cank has compressed (rolled) fillets and even if you machine the journal just to the depth of the rolled "troughs", it will still be as strong as new. You could gain some durability by having the crank nitrided, but not really needed. If you detonate a good crank in a low ten second car, the rods and crank are prone to failure in short order.

 

[Junior Samples]

I have std/std crank for sale. 229 rolled fillets...cheap... rods, slugs take it all..low miles

 

[Grumpy]

Is 20 under cut too much for a 10 sec motor on a turbo crank?


Thanks

nope... have a 20/20 crank in Melissa's car ..high 9 low 10 car that is beat to death everyday wellll not in the snow

 

[Hognose]

Ok, great advice thanks! I appreciate the help.