Starting assembly of my motor. The porter suggested that with the over size valves that I should open up the releif on the piston .060" or so on the intake side. So I got out my dremmel and went to work
First, tape up the sides good to prevent anything from getting between the rings and mark it

Second pic shows the relief cut 1/2 done

Last pic is the finished relief cut.

Fairly easy to do. Vaccum clean and wipe down before removing tape. It's probably closer to .080" but thats cool. Don

 

Ouch !

 

why cut the pistons .060 for valves that are only .006 bigger??stock are 1.84. how much compression you loose with that cut???

 

Re-do your math 1.840 + .006 = 1.846
1.840 + .060 = 1.90

 

05 ups are 1.850. you do intake and exh cuts??? looks like a little compression loss with 4 .080 cuts. about 2 ccs each??

 

Why didnt you do the big bore the first time around? It would only cost about $300 more. $150 pistons and $150 bore cylinders. Saves money buying head gaskets twice. I know $300 is $300, but when spending the money, why not just save up and do it all at once?

 

When I started this I was working full time. After I got into it I:
a) took a 10% salary reduction..
b) went from 40hrs to 20 hrs per week. I would have loved to have done the 95" now but my budget became extremely limited in a hurry. The heads are actually set for a 95" build so when I do it again this winter I won't have any head work to do. I thought this was the best way to go with the $ I had.Maybe not but it's done now. I hope that makes sense?

 

Don, did you wax the pistons to check clearance before you hit em with a Dremel?

 

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Don, tape over the oil returns as well.


What is the lift on the cams??

With the stock pistons,
You may want to carefully check piston to valve clearance at full lift.






1.840 + .060 = 1.90

divide that .060 by 2.

.030 on each side of the valve...........

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I hear that! I too have felt the cash flow crunch! Sucks working in the trades in a bad economy!