Thread: piston to valve clearance, JWT c3 cams

well you can measure the vertical distance from the lowest point of the valve to the flat face of the block. I did it with dental plaster and a piece of glass, if you do it that way you need to put some plasticene in the spark plug hole.

Then you know that the valve is at 15 degrees ( close enough, the design number for the head is 29 degrees between the valve stem angles), so take the sine of the 15 and divide the vertical distance by sin(15), that gives you the actual lift before collision, with an allowance of the head gasket for valve wobble etc.

If you look carefully at an sr16 piston you will see that the fly cut goes down quite a bit below the deck height, and people have found limits on cam gear usage with C2/3 cams.

Mike

Wonderful isn't it? Ask for factual answers, more than once in the same thread, and get opinions galore! I got into it with one of the more respected guru's here over the same issue. I feel for you.

Best way to know your answer is to spend the time and use the clay on the piston top method. Pull the head, put some clay on the piston where the valve might contact, reassemble the head with the appropriate cams, hand crank it over, disassemble and measure the thickness of clay under the valve squished area. Expensive and time consuming but you will know without a doubt.

i was running c3's on my flat top 11:1 pistons (dont start with the whole wiesco is wrong thing...been threw it on the other forum haha! ) with no problems.

Do NOT run those rocker arm stoppers. Period.


Chris.

good to know, that means I should be safe running a 10:1 UK motor with C2's.

Yes, I had noticed that. (:

And thankyou. It seems this is going to be the way I'll have to go.

In the mean time, I have ordered c2 cams, and won't be running cam gears intially. I am also in the process of obtaining a set of SR16ve pistons.

Please do elaborate or perhaps link to a thread where you experiences have been shared?

Under which conditions did you have problems with these?

^When did you get a UK motor? What happen to the boost project? I'm going to run BC2's on my 10:1 motor, then order a set of S4's down the road and do a dyno comparison.

about 2 weeks ago, I still have 1 DET left and I just sold 2 of them. I have to many projects going on, don't try to keep up!!! lol.

sending you a PM about BC2's

this comparssion will be very interesting