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How much to stroke....

Waterthunder

Waterthunder

Well-known member
I would stroke it to a 3.75 or a 3.875 stroke it will make a very reliable airboat motor! I wouldn't stroke it anymore then that. It cracks me up people build these huge strokers and all the power they gain in stroke they throw out in a small cam shaft or a special small base circle cam. There is a reason ALL the Nextell cup motors and NHRA Pro Stock motors run huge journal camshafts even the new production stuff has gone that way. I personally try to run all the stroke I can without having to throw away any power buy using a smaller base circle cam! On most small block Chevy's the line is 3.875 with a good Eagle stroker rod! With a stock style rod you can run a 3.75 but you will have to grind them a little on the top of the big end to clear the cam!
 
I will ask him today I have a customer that I was building a complete 383 stroker for. He upgraded to a LS1 after I started. All the bottom end work has already been done I have already clearanced the block for the crank and the rod's were clearanced for the cam. The crank and rod's are all good Eagle stuff. I ordered the pistons for a 64cc heads. The block was magnafluxed and is guaranteed free of crack's, the 4 bolt block was bored with a torque plate, while the mains were torqued and the rotating assembly was balanced after I clearanced everything. The mains were also line honed and everything is new with Plasma moly rings and Clev 77 bearings, motor also has a new balancer and flywheel and new cam bearings installed. Everything is clearanced and cleaned and bagged waiting to be assembled. He just wants what he paid for the machine work and parts!
 
AKA Tortional loss and even worse..the harmonics thrown into the valvetrain.. Although in most airboat engines with (relatively-speaking) low spring pressures, low/reasonable RPM and mediocre ramp rates, it's not too big of an issue. Don't get me wrong....I avoid it like the plague as I've preached it here as well as to many people "In the know", but in this case I think the most important thing to consider is cylinder block integrity. The water jacketing on a 350 Chevy is very close to the crankcase near the pan rails, and usually anything over 3.75 even with steel rods runs a risk of finding water once you clearance it. On a 400 block the 3.875 or larger is less of an issue since the water jacketing is smaller and there is more material (Anyone interested would be happy to know that the 350 Bowtie/"NASCAR" block of old is nothing more than 400 casting cores). I have several 4" stroke engines out there, that to the best of my knowledge are still alive and well, but I hated buildin em, and they keep my up at night when I think about em...Take it as you will. and once again JMO

Felber
 
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