306.5in stroker

[heartlandoffroad]

Thank You

Yea I think there is more in it but time is not allowing me to try different throttle body's, headers and retune when I get more time to play with it and learn more about the software I'm sure it will make more power. We're happy with it for now though.

[gremlinsteve]

whats the cam specs again?

steve

[heartlandoffroad]

------------------------------------intake--------exhaust
Duration at .050-------------------236------------242
lobe lift---------------------------.3400-----------.3400
separation----110---------------op---cl------------op-----cl
timing events at .050----------12---44-----------55-----7
duration at-------.006-------------282---------------292
gross valve lift--------------------.544--------------.544
degree intake lobe to----------------------106

[5-90]

1) I'd love to see how you fit that crank. I've an idea to do a "four-by-four" stroker on a RENIX block, 4.000" bore and 4.000" stroke (netting just short of 302cid.) I have been given to understand that clearancing is a bit of a problem, after discussions with Flatlader racing and thinking about using their offset crank to do the job (at something like 4.165" or so, for the 258ci block.) Perhaps the smaller rods and journals helped you?

2) I'd also like to see how you encounter and handle harmonics. Even with the lightweight crank, 6k rpm can be rocky territory - from reading up on Barney Navarro (racing a turbocharged/destroked AMC six at Indy, yonks ago...) his team found there was a serious harmonic issue around 6000-7000rpm or so, and I think they ended up snapping a couple of cranks before they figured out there wasn't anything they could do about it - primarily due to the /length/ of the crankshaft, and not support (all of the AMC sixes have seven mains. They're built around the same block, internally. That's why cams and cranks all swap.) That's also got a lot to do with why ChryCo set the rev limiter somewhere short of 6k rpm - so you don't stumble into the harmonic issue. Navarro's team ended up with a six that would spin somewhere around 9k or so, but you had to hurry through the 6-7k on the way up there.

I'm not trying to belittle the idea, I love it! Just handing out a warning and a request for information, that's all...

[heartlandoffroad]

1) I'd love to see how you fit that crank. I've an idea to do a "four-by-four" stroker on a RENIX block, 4.000" bore and 4.000" stroke (netting just short of 302cid.) I have been given to understand that clearancing is a bit of a problem, after discussions with Flatlader racing and thinking about using their offset crank to do the job (at something like 4.165" or so, for the 258ci block.) Perhaps the smaller rods and journals helped you?

2) I'd also like to see how you encounter and handle harmonics. Even with the lightweight crank, 6k rpm can be rocky territory - from reading up on Barney Navarro (racing a turbocharged/destroked AMC six at Indy, yonks ago...) his team found there was a serious harmonic issue around 6000-7000rpm or so, and I think they ended up snapping a couple of cranks before they figured out there wasn't anything they could do about it - primarily due to the /length/ of the crankshaft, and not support (all of the AMC sixes have seven mains. They're built around the same block, internally. That's why cams and cranks all swap.) That's also got a lot to do with why ChryCo set the rev limiter somewhere short of 6k rpm - so you don't stumble into the harmonic issue. Navarro's team ended up with a six that would spin somewhere around 9k or so, but you had to hurry through the 6-7k on the way up there.

I'm not trying to belittle the idea, I love it! Just handing out a warning and a request for information, that's all...

There is very little clearancing that needs to be done with this setup. The rod doesn't set out any farther than a standard stroker and with the smaller journal size you actually have more room. You can see the clearancing that need to be done in some of the previous pics.

Like I had said previously I have set the limiter at 6000rpm and for it to run strong to 5600rpm. therefore it wouldn't be into the 6000rpm range. That has changed a little just from dyno results. When I degreed in the cam straight up the power came in a little to late for what I wanted so I then advanced it 2 deg. which dropped peek hp rpm by 350rpm but it brought in the torque where I wanted it. So now there is no reason to twist this motor any harder than 5200rpm and I reset the limiter to 5500 now. So no worries

[Flash]

Jon!!! (5-90) Glad to see you over here..........Aspecaly commenting on some of the deeper subjects here.
LIKE THIS ONE!


Flash

[SilverXJ]

Just wondering how this engine performed and if its still doing well.

[beiwulf]

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