232 head on a 308

jjnan58yahoocom
jjnan58yahoocom Expert Adviser
wasn't there a thread on this subject about machining a groove on the 232 head to eliminate detonation? If the 232 was at 81 to 82 cc this would be about 8.1 on my engine. I currently have a 262 head with 92 cc which is 7.57 . It does not detonate with 23 degrees total advance with 87 octane. I have been told that the 232 will be awful. my name is Gerald

Comments

  • Ol racer
    Ol racer Senior Contributor
    edited October 2018
    FYI
    There is more modification required on a 232 head combustion chamber as Rudy Bennett could better explain to prevent detonation. A 7x 232 Head had a very different chamber than the stock 232 heads.

    Grooves run from the valve over to top of piston are more for enhancing combustion.
  • jjnan58yahoocom
    jjnan58yahoocom Expert Adviser
    Is there anybody out there running a 232 head on a 308 non 7x ? It is my opinion that the old racing engines with larger valves and very deep block relief needed the 232 head to make up for lost compression! Gerald
  • wasn't there a thread on this subject about machining a groove on the 232 head to eliminate detonation? If the 232 was at 81 to 82 cc this would be about 8.1 on my engine. I currently have a 262 head with 92 cc which is 7.57 . It does not detonate with 23 degrees total advance with 87 octane. I have been told that the 232 will be awful. my name is Gerald

    I see that the previous discussions are linked below... My experience with the Singh Power Groove is as follows: I have a stroker Hornet engine in my 41 Hudson race car. It has a lot of modifications, including 7x valves, a huge block relief, and a Clifford head that has been modified a little bit as well. I'm running the Isky .446 cam, two Holley 2bbl carbs, and 11.25:1 compression.
    I had to run 103 octane leaded race gas to prevent pinging, and the car ran pretty warm... to the extent that I had to park it and let it cool down between passes, and I would push it through the staging lanes until my turn to race. I took the Clifford head off, and set it up on the mill, and cut the grooves in the head with a (I think) 3/16 ball end mill. then I put it back together. I even used the same head gasket, so this is the only change I made. (I am using a solid copper head gasket) The car now runs on 91 octane pump gas, and it is street driven without any heating issues.
    I'm not sure cutting the groove will help much on a stock engine. I tried it on the 56 engine in my '40, making a much smaller groove (about .090' deep and .090" wide) than in my race car, and after six months, or so, it developed a crack in the groove in cylinder #5.