So I started to assemble my 110" TC with Hillside stage 4 heads and the T-man 660-PS2 cams.. I had Scott install 2.02" intakes and 1.65" exhausted. He also took approximately .080" off the surface of the heads to get me to 85 cc's.
First thing I did was take a set S&S lifters and take all the oil out of them so I could completely collapse them into a solid to be able to take an accurate valve to piston clearance..
I used the old .030" head gaskets and reassembled everything with playdough in the valve reliefs.. I set the pushrods to zero lash and turned the motor over several times just to make sure there was no interference.. The motor rolled over without issue..
I disassemble everything and removed the cylinders heads to measure the playdough/clay and on the front cylinder the actual clearance on the intake valve relief was about .030" and the rear was at .040".. The radius seemed pretty good but I'm not the most comfortable with the clearance..
I'm going to open the valve reliefs a little.. I think if I add .030" to both front and rear I should be good..
These measurements are from a solid lifter so even if the lifter pumps up completely I think I should still have the clearance I need..
I have at least .060" on the exhaust both front and rear so I should be good there.. The exhaust valves just barely contacted the playdough..
Looking for a little confirmation, thanks...
The Red playdough is the rear cylinder and the multi color is the front.. Wish I had some plain old grey clay...

 

I find it's better to leave the clay in place and cut it in half with a razor blade. That way I can see exactly the profile the valve made. Also pulling off clay that is really thin, it's possible to stretch the clay and give a bad reading. Also I would take a reading on your ACR. Since the heads are machined 0.080", you want to make sure you have room for the ACR to open. Sometimes you have to shim them up.

I would think that 0.060" as a minimum clearance on the valve flat, I prefer to see more. The radius is ok at 0.030".

 

Maybe I'll set it up again but by looking at you your second pic it looks like where the valve touched the clay to be almost identical to mine.... The only place the valve touched was out at the radius of the valve relief.. I think I might be ok.. The only other thing I could think of is that the only time it'll ever get that close to the piston is if the lifter pumps up completely and I doubt that's ever going to happen unless that is the valve floats... My spring pressure on the seat is 180 and at .660 is 384.. I think I'll be okay..

 

Here are a couple more, gives a better detail.

 

The ACR's, memory says they open about 0.020", but I'm not 100% certain on the number. You want the ACR recessed a little, maybe 0.020" minimum.

These are set at 0.020", and with the 0.030" head gasket will give plenty of room.

 

Thanks.. I think I'll give it another shot.. Also I forgot to mention that I will not be using the ACR'S.. I had manuals installed so I could do away with the Auto's..

 

Also I wipe a little light weight oil (household oil) on the valves and head surfaces that I don't want sticking to the clay. I wipe it on by my finger, just a slight amount.

 

If what you are using is playdough, I wouldn't.. I use the stuff shown. Get it at any good arts and crafts store.. BTW, the old green one is about 48 years old.. You can resurrect the stuff by adding vegetable oil and kneading it but it was getting kind of small.

 

I bought some new clay during Covid, so I had to order online. I think it's a five pound brick. It should last me awhile.

 

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