Stroker Questions

[01CandyBlue]

Okay, I have been reading alot about stroker motors and am looking at pursuing that setup and have some very specific questions, first with the dome sizing/clearance/compression issues there are the ideas of cutting the domes, spacing the jugs or the head, I think spacing the head may be out because of my aftermarket head (trinity) and I read a post from Jim at passion where he mentioned that if you space the jugs the transfers are put to better use, I understand this concept but maybe not the whole concept of the stroker, if you have a longer stroke and then space the jugs up that wouldnt that raise your ports and seems to me it would defeat the purpose of the stroker? But does increasing your rod length give you more ability to open the heights and bottoms of the ports to develop more power? Where does the torque gains of the stroker setup come from? The fact that your stroke is increased or the fact that your ports can be modified so much more sizing it develops more power, also what would be more beneficial, a 4mm stroke or a seven, does it require case mods to fit a seven and is it even worth it? One mor what carbs would i go to? thanks in advance for any replies, sorry for the rambling just so many questions...

[Leadfoot350]

Check out bansheeracing.com for dynos of the cheata cub cylinders. People say the 4mm is not worth the money unless your stock crank broke. They say it is only 5-7 more hp and if your going to stoke it then go +7. Remember with all the horsepower you will have to buy a lot of other things for it to work such as radiator, maybe straight cut gears, lock-up clutch, basket........ The price goes sky high. Im not sure why strockers give more tourque but they do.

[jeffro189]

Im not sure why strockers give more tourque but they do.

323918[/snapback]

 

if you +7 mm over a stock crank that is like a 7mm longer lever so you will produce more torque. or think of it like this if you had a 12" ratchet and exerted 10 pounds of force on it you would have 10 foot pound coming out. if you had a 18" ratchet and exerted the same 10 pounds of force on it then you would have 15 foot pounds come out. it is the smae concept.

[23champ]

if you +7 mm over a stock crank that is like a 7mm longer lever so you will produce more torque. or think of it like this if you had a 12" ratchet and exerted 10 pounds of force on it you would have 10 foot pound coming out. if you had a 18" ratchet and exerted the same 10 pounds of force on it then you would have 15 foot pounds come out. it is the smae concept.

324639[/snapback]

Nice analogy

 

[racer]

a 7mm stroker does not have a 7mm longer lever. it has a seven millimeter longer stroke, the actual lever length is increased by 3.5mm. you have to accomodate for the piston going up and down. if your crank did have the pins centered 7mm further out then it would make for a 14mm stroker. you follow?

[superchicken]

torque is also inclreased by a heavier rotating mass,and a longer powerstroke

[Wallrat]

I just put a +4 longrod in mine. That's the biggest you can get without trenching the cases. I personally had my stock head cut to accept the added stroke. With this setup you need to get porting specifically for the added stroke. Other options are to run a spacer plate or a thicker base gasket. I went with the cut head since I didn't have any porting and spacers tend to f'k with the case volume. I haven't gotten my porting done yet since I ran out of money but even without the porting I noticed a significant increase in power bottom to top, but mostly on bottom. With porting it should pull my arms off nicely. There's also a shortrod version that will wind up a little faster but at the cost of reliability. With the longrod setup you'll also need to get some 795 pistons. As far as carbs go, I like the keihin 35 pwk air strykers with dual clamp on k&n's. Also on the to-buy list should be some aftermarket reeds if you don't already have them.