Hi Guys, I'm in limbo at the minute, with everything out getting machined etc.
Hopefully the crank will be ready within the fortnight, drive side journal has been hard chromed and machined, and he's now onto crank journals and balancing.
My query is on the barrel and head. My barrels have been done, bored to 40 thou. The machinist had to skim 2 thou off the top of the barrel. My head just went in and he has said that it had blown out in the centre and pitted and will need to be skimmed as well. He can't give me any details at the minute, until he gets on to it, but he's hoping to keep it to a minimum, hopefully 5-6 thou..
Now I have dropped the piston Comp down already, from, if I can remember, 8.6-1 to 8.0-1.
I understand that to compensate for any such milling, a thicker head gasket can be used to compensate but this also drops compression, which I'm trying to get away without doing. As far as skimming the head down, if it wasn't damaged, as it is and just bent, I wouldn't have this done, but I don't have an option, as he has said, it won't seal properly.
What would be the minimum amount of total skimming one could get away with, before a thicker head gasket would need to be used ??? I may be looking at around 8 thou total, between the barrel face and the head, hoping that's all,, I had heard or read up here and on various formats, 5-6 thou total shouldn't make a difference from standard.
This may sound silly, I'm still learning LOL, Can the 2 thou off the barrel face, be made up with a thicker base gasket ? or have I lost the plot LOL....
I guess hearing from those that have had to use the thicker head gasket, what amount was skimmed, or the amount that would definitely need a thicker head gasket....
Interested in people thoughts/experience here..
It's a 76 t140V...
Thanks in advance
Col
Hopefully the crank will be ready within the fortnight, drive side journal has been hard chromed and machined, and he's now onto crank journals and balancing.
My query is on the barrel and head. My barrels have been done, bored to 40 thou. The machinist had to skim 2 thou off the top of the barrel. My head just went in and he has said that it had blown out in the centre and pitted and will need to be skimmed as well. He can't give me any details at the minute, until he gets on to it, but he's hoping to keep it to a minimum, hopefully 5-6 thou..
Now I have dropped the piston Comp down already, from, if I can remember, 8.6-1 to 8.0-1.
I understand that to compensate for any such milling, a thicker head gasket can be used to compensate but this also drops compression, which I'm trying to get away without doing. As far as skimming the head down, if it wasn't damaged, as it is and just bent, I wouldn't have this done, but I don't have an option, as he has said, it won't seal properly.
What would be the minimum amount of total skimming one could get away with, before a thicker head gasket would need to be used ??? I may be looking at around 8 thou total, between the barrel face and the head, hoping that's all,, I had heard or read up here and on various formats, 5-6 thou total shouldn't make a difference from standard.
This may sound silly, I'm still learning LOL, Can the 2 thou off the barrel face, be made up with a thicker base gasket ? or have I lost the plot LOL....
I guess hearing from those that have had to use the thicker head gasket, what amount was skimmed, or the amount that would definitely need a thicker head gasket....
Interested in people thoughts/experience here..
It's a 76 t140V...
Thanks in advance
Col