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How big can you stroke a gen III hemi?

Posted By: migsBIG

How big can you stroke a gen III hemi? - 07/30/22 02:58 AM

Since Mopar guys always can’t leave engines stock, has anybody built a stroker late model hemi and if so, how big did they make it? I’m kinda curious as there seems to be a lot more tech for these engines and might be worth a change from a big block engine.
Posted By: gremlinsteve

Re: How big can you stroke a gen III hemi? - 07/30/22 12:55 PM

I’ve seen a 4.250 stroke crank
I don’t know if there has been bigger
Posted By: fbs63

Re: How big can you stroke a gen III hemi? - 07/30/22 02:01 PM

I'm sure others will disagree but there is a limit to how much stroke you can package effectively in a 9.24 or 9.28 deck height. The pistons for the 4.080 stroke crank are barely over 1" compression height with a 6.125 rod. Thats 1.50 rod ratio. More stroke means a shorter rod and then you start to pull the piston out of the bore at the bottom of the stroke too much. Technically the limiting factor is the main oil passage casting above the crank. I know BB Chevy 632 and such combos have 1.47 RR and run great but they have large bores and GREAT heads. It will take Thitek's best heads, LARGE solid roller cam and adjustable rockers at minimum to feed a 4.250 stroke on one. Just my opinion.
Posted By: csk

Re: How big can you stroke a gen III hemi? - 07/30/22 03:31 PM

https://board.moparts.org/ubbthread...i-will-be-possible-soon.html#Post2993049






Attached picture 265464238_2042809972547545_9094496563090535978_n.jpg
Posted By: toddinNH

Re: How big can you stroke a gen III hemi? - 07/31/22 05:42 PM

I'm sure there are unsmart people that will opt for the $10k plus stroker option from MMX, but for standard deck heights there are saner limits to what can be achieved. A 4.125" stroke should be accessible to most builders. Tom Molnar shows the 4.250" stroke, but that will require lots of compromises.
Posted By: moparjim79

Re: How big can you stroke a gen III hemi? - 07/31/22 10:39 PM

HHP sells a 440. N/a. Looks nice
Posted By: migsBIG

Re: How big can you stroke a gen III hemi? - 07/31/22 11:51 PM

108 inch increase and it makes 1000hp. The torque numbers would probably fun factor awesome, but not sure if that would be well worth it or not. Do they supply it assembled or just the parts?
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