lowering 61x port timing

[D-Roc]

good info guys, i have another question, on a 61x cylinder with 35cc ada domes what is the squish that they usually come with? i checked mine along time ago and thought it was rather large but still gave me 180ish psi. (.07+/-) would there be any benifit to making the squish tighter and what is the best way? milling the top of the cylinder is what i was thinking. i have a ported cylinder that lowered the psi a bit. i was thinking of bringing it back up and setting it with the best squish. would there be any point or not enough to notice?

 

[teton]

good info guys, i have another question, on a 61x cylinder with 35cc ada domes what is the squish that they usually come with? i checked mine along time ago and thought it was rather large but still gave me 180ish psi. (.07+/-) would there be any benifit to making the squish tighter and what is the best way? milling the top of the cylinder is what i was thinking. i have a ported cylinder that lowered the psi a bit. i was thinking of bringing it back up and setting it with the best squish. would there be any point or not enough to notice?

I am running 37 cc ada domes on a 61x that i decked .008" and it runs at about 190 psi, the decking made my squish perfect ".045" so if you want to get the squish right you might need to run bigger domes if your worried about your compression increasing, but the 8 thousands or so of decking should only increase your compression 12psi or so

 

[DCRocks]

The 62T cylinder is a 701 not a 760

So if you have a cyl marked 62t, with pistons marked 64x, it has been bored out? Or had new sleeves installed? The sleeves in mine are larger in DIA than the 701 sleeves.

I should have probably left the 62T part out of the 760 cylinder, it can be called a 64X cylinder too.

Is the difference only in transfer port angle, or is there some other difference, as in an actual 64x mark on the 760 cyl?

The outside diameter of 62T 701 sleeves measures 87.35mm and 760 sleeves are 88.80mm at the very bottom where the sleeves get thinner. The big bore sleeves range from 90.08mm to 91.09mm and are the same diameter all the way down to the very bottom.

So to find out if it got big bore sleeves, or 760 sleeves, I need to check the thickness at bottom of the sleeves?

If it is 88.80mm, it is a stock 760 sleeve and if it is 90.08mm - 91.09mm they are BB? Did I get that correct?

 

[#ZERO]

All the 62T cylinders either 701 or 760 have 62T cast on the exhaust side, there are no marking that say 64X. Also the pistons on the 760 say 65U.

Yep... all the stock sleeves are thinner at the bottom and the big bore sleeves are the same size all the way down.