What compression with a 11.1 wiseco

[Fatal]

when i installed my 406cc new wiseco piston high compression i mesure the compression and it give me 225 lbs of compression is it too high or its normal i didn t split my head gasket to get more compression !

[zrpilot]

I wonder if the advanced timing key has something to do with this.

Did you time the cam with this key installed? Could that have then advanced the timing of the cam?

I don't know, but 225 PSI seems high..

Just my $.02

[Fatal]

i didnt know how to time the cam with the advanced key ?? i didnt time the stock cam when i put the key on my quad !

[zrpilot]

Right, because the relationship between the piston and the cam was set at the factory. When you installed the advance key with the stock cam all that did was to move the flywheel six degrees, giving six degrees of "spark" advance only and not effecting the cam timing.

when the new cam was put in the "advanced" timing mark caused the piston to be in a different position then with the stock key and that MAY explain what you are seeing.

I may be wrong, but I think this may be an issue.

I'm sure GPracer2500 would have good thoughts on this one!!!

[GPracer2500]

225 does seem high. I'd find another guage and check it again. I've got three different compression testers and only one of them reads correctly.

ETA: A timing key will rotate the flywheel slightly (I think the Sparks is 6 degrees). So, your TDC mark would now be 6 degrees off. But that's not much. I believe one tooth this way or that on the cam sprocket is about 10 degrees. If an ign adv key is installed and the timing marks on the cam gear look a little off and moving the crank a smidge past the TDC mark (6 degrees in this case) aligns everything again, then the cam timing is correct.

FWIW, I had a JE 10.8:1 416cc, a HC stg 2 (old version), and I can't remember what gaskets. It pumped about 180psi cold at 1300ft.

[400exstud]

Originally posted by GPracer2500

FWIW, I had a JE 10.8:1 416cc, a HC stg 2 (old version), and I can't remember what gaskets. It pumped about 180psi cold at 1300ft.

You HAD a 416? I thought that you still did. 450R or something top secret?

[GPracer2500]

Sold the EX a few months ago. She was good to me, but our time together had come to an end.

[2muchquad]

225lbs of comp is good for just about ANY motor.:)

[underpowered]

225 is about right, you should have about 180 stock, so you went up in compression so i would say 225 is about right. i have right at 200 in my 426 that has been together for 3 years.