Thread: Stroker ideas
11-15-2009, 02:11 PM #1
Anyone know if the webs from a domestic engine could be used to construct a longer stroke fuji crank? Would it take some machining to narrow the webs? What about snowmobile cranks? I have been thinking about a Stroker project using a SLT if I can find one.
11-15-2009, 05:26 PM #2
11-15-2009, 05:35 PM #3
11-15-2009, 05:49 PM #4
The distance between the center of the crank pin and the centerline of the crank is equal to 1/2 the total stroke. The rod length just changes the distance the piston is from the crankpin on its journey up and down. By using a longer stroke with shorter rods, the piston does not extend higher than it would before, but it does drop further into the cylinder.
Does anyone know how close to the top of the cylinder the piston gets in a stock 780? I know the rods are 120mm from piston pin centerline to crank pin centerline, but I am not sure of some of the other measurements. I guess I may have to pull out the caliper and do some precise measurements. If I have room to toss the piston up an extra 1.5mm I may build a crank with 780 rods on a 785 core to get 68mm of stroke. Then I just got to calculate port height in relation to crank degrees to see how far the porting is changed. I may be able to compensate a little with a 1mm cylinder base gasket which would result in the piston only extending up and extra 0.5mm beyond the stock deck height. In fact...now that I am thinking about this, I may just try it with my 650 jugs and extra case I have sitting here just to see if I can get it to work before I commit to getting 780 jugs, pistons, and modded heads to build the Stroker! I love experimenting!!!
11-15-2009, 06:48 PM #5
11-15-2009, 06:57 PM #6
11-15-2009, 07:07 PM #7
[quote=beerdart;1267628]Piston travel will always be the same weather the rod is 3" or 6" the travel/Stroke will be the same.[/quote
thanks for the info, I'm still learning
11-15-2009, 07:33 PM #8
I believe thats why a 327 chevy back in the day was quick revving up the r's. Shorter stroke on the crank thus quicker rpm's.
11-15-2009, 10:42 PM #9
And also why guys took the crank out of a Chevy 400 and put it into the 350 to make a 383 Stroker! Less moving mass than the 400 and more displacement (and torque) than the 350. Plus the big valved heads matched up perfectly to the 383 displacement.
11-15-2009, 11:54 PM #10
- Join Date
- Oct 2006
- Cleveland OH
I'm sure you've seen this already, but these would be the guys that can guide you in the right direction.
Maybe they even have a stroked crank webs laying around the shop already?
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