Cylinder head CC question
 

Does anyone know if the Mark IV cylinder heads for the 365 mag and 330 "peanut port" heads have the same CC volume?
Gary

Re: Cylinder head CC question
 

I believe they are both 119 cc or thereabouts. You can check the casting numbers on www.mortec.com.

Re: Cylinder head CC question
 

.. ..also casting will vary from what the OEM specs are. One pair listed as a 119cc may be 122cc and another set may be 124cc. If you are boderline on a safe compression ratio your best bet is to have the heads CC'd.

Re: Cylinder head CC question
 

Thanks,
Just wanted to know if swapping heads would change the CR.
Gary

Re: Cylinder head CC question
 

Magnum heads should be Rectangular ports. The best bet would be to get the casting numbers and check mortec. I replaced my peanut port 118cc heads with a set of Large Oval (820s)110cc heads and picked up compression. You can CC the heads yourself with a piece of plexiglass some grease and a surenge. This will give you a pretty close estimate. You could have your heads milled down and pick up compression you may drop 3-4 cc's and pickup .3 compression points.