stock crankshaft- 420a

how much horsepower/ rpms can a stock crank handle with low comp. pistons and a turbo?

I know next to nothing about the 420a motors but if you are already doing new pistons and rods (as im sure you know the stock ones dont go well with boost) why not do the crank while your at it?

You'd be better off asking this question at 2gnt.com. I know they are pretty strong and can handle a good amount of HP but I can't give you an exact number, not too many guys on here have turbo'd the 420a.

Why though, what mods are you planning for?

The stock crank is fine. To this day I have never heard of anyone breaking a crank because of to much hp.

Crank should be good, its only 4 pistons. Maybe stronger bearings?

So i don't have to worry about hp, but how many rpm's? I should be worrying about the rods first right?

Unless your building a motor that is going to rev over 8k you should be fine. Pistons and rods are the weakest link in these motors.

You may just want to make sure the crankshaft is balanced when doing a rebuild, but the stocker is fine for about 8k rpm and ~400hp or so IIRC. Even then, it could still probably hold up to even more. Cranks are strong... they have to be. As Silver said, the rods/pistons are weak. They're moving all over the place and held into position by basically one part. The crank on the otherhand is held on by basically the whole engine. And unless you have a 7-bolt, isn't going anywhere.

God bless the 8 bolt ...lol :P