Okay, I'll get the "stroker" crank, but what rods do I get?

[pro_am]

Since i'm getting a crank with a longer stroke, do I have to get longer rods? If so, how does that work? How long of rods to I need to get? Thanks for the help fella's/ladies.
jake

[SaabJohan]

Longer stroke -> shorter rods and/or pistons with lower compression height.

[pro_am]

So, as long as the rods are just long enough to clear the crank weights, then I should be okay? Thanks for the help, I feel really stupid about this.
Jake

[MagicRat]

Originally Posted by pro_am

So, as long as the rods are just long enough to clear the crank weights, then I should be okay? Thanks for the help, I feel really stupid about this.
Jake

Thats simplifying things too much. The rods and/or pistons must also place the top of the pistons at the correct point at top dead center.
Any one who makes a stroker crank will also have recommendations for the correct rods and pistons. Use what they suggest.

[pro_am]

I talked to my guy at the machine shop, and he said that a stoker engine doesn't last more than a few years at best. So I decided to go with either a 350 or a 327, no sure which yet. Thanks for the help though. The stroker kit just seems like too much hassle.
Jake

[MagicRat]

Telling us that it was a small bolck Chevy would help a lot.
You must mean a 383, which is a 350 with a 400 crankshaft in it.
This is an excellent combination and very common. I am at a loss as to why the machinest feels they would not last as long.
It depends on the application. For a truck or heavier car, a 383 is better. For a lighter car, the 350 is better since you can build it to rev more freely and make better top end power.
Also the 350 is cheaper.

[Evil Result]

Rod angle might be the concern.... while increasing the stroke at the crank you will need to get shorter rods and pistons.... with the smeller rods the piston is pushed up against the cylinder wall harder causing excessive wear, basicly you want to keep your rod to stroke ratio at 1.7 or more (rod length/stroke).

http://www.chevytalk.com/tech/engine/rod_angle.html

This ratio also effects the acceleration of the pistion through the length of the stroke.

http://www.grapeaperacing.com/GrapeA...ectingrods.pdf

[timberdoodle]

ya pro am the 383 doesnt last very long at all. The larger stroke puts increased wear on the piston sidewall which gives it a short life span. Not only that but 350 is a much more common and easier to build block.

[quaddriver]

yes and no. usually a stroker crank requires rods AND piston changes. and while longer rods are sexier, they cause the location of the wrist pin to put constraints on the piston top (compression height, ring intersection)

stroker engines tend not to last because they are built for one purpose: more power for racing. A proper rebuild, stroked or not should last just fine. (keeping or mind that removing metal from cyl walls and crank journals weakens the object - no way to get around that)

[timberdoodle]

nough said, stick with the 350, i have one built 30 over with vortec aluminum heads and am getting 370hp as ballpark.