426 cleveland stroker

[racingrick]

I see a lot of 4.0" stroke with 6.0" rods in 408 Clevelands (1.5 ratio).

A 426C with a 4.1" stroke and 6.0" rods is 1.46 ratio.

Does piston speed also play a role in the destruction of Cleveland cylinder walls?

[Jac Mac]

Originally Posted by racingrick

I see a lot of 4.0" stroke with 6.0" rods in 408 Clevelands (1.5 ratio).

A 426C with a 4.1" stroke and 6.0" rods is 1.46 ratio.

Does piston speed also play a role in the destruction of Cleveland cylinder walls?

Its kinda hard to isolate piston speed, it comes with the territory in longer strokes & if the owner insists on pushing the RPM it does become a major factor. Depends on what the application is really, Put it in a class where the high RPM is not continous & the stroker will probably last, try it in a boat or circuit car ( Road course or Nascar long track types ) where high revs are for longer periods and the short rod combo will self distruct.

The best example that we probably have here is the SBF combos of: 4.125 bore X 3.25" stroke versus the 4.00" bore by 3.40" stroke. Both are the same capacity @ around 346/347 ci, but the short stroke/big bore motor can rev higher, yet really gives nothing away down low either.

Clevos are pretty popular down under with the Aussie Falcon crowd & an easy swap to a 6" rod ( The 302c had a 6" rod/3.00" stroke ) plus an Aussie 1.425" pin height piston makes a nicer motor out of the 351c & virtually eliminates the bore cracking problem.

One other problem the std 351c has, the std rod/piston combo pulls the piston skirt well below the cyl bore @ BDC, the 6" rod cures that, but it returns again if you lengthen the stroke, on the Jet Boats we worked with that ran continous @ around 5500 plus the piston skirt would get a very defined 'mark' on the skirt where the piston 'rocked' @ BDC largely due to the lack of bore support.

[Mark O'Neal]

Rod ratio is irrelevant.