how big can i go on cam now???

[hippy440]

i have a weisco 11:1 440 kit in my quad i did it a while back when every body was saying that they didnt actualy have that much compression!!! so i had the cylinder decked .30 and used the thin head gasket! i put in a xr cam but it is way too weak for me!!!! so how big could i go before i have interfearence problems????????

[Big - D Racing]

Why did you do that with your cylinder, why didn't you just put in a je piston at 12:1 compression? Now your worrying about putting in a bigger cam? Why? Do you think a bigger cam is going to cause your valves to hit your piston or something? Xr cams are crap period go to a full race cam and put in a new piston!

Big-d I know what you trying to say but think of this.

If he goes to a new 12:1 piston there is a verygood possiblility that it will now have correct pin to piston top dimensions and then with the decking the piston may be above the deck at TDC. This combined with the higher lift may run into some clearance problems.

Of course you can adjust slightly by using the thicker (.040) stk headgasket but with measureing the clearance and measuring the cyl volume you will not know what you need.

Another problem is getting info from the piston mfg's. J&E has ZERO (0) info on the 440 pistons and sells them as proprietory to the engine builders and sale co's etc. And dont bother trying to get info from sparks or FST on their J&E made stuff since they just want you to send in your motor since thats how they make a living. No that having them do it is a bad idea (It may be better even) but it is rather expensive.

I will tell you this much that the newer hi comp 440 pistons from the builders are claimed to address the height problems and no longer require the decking.

I have looked into this and a thought thats going round in my head is if this would work out.

Current deck is .030 (actually avg) and running .025 cometic head and .012 base gaskets, now if you were to go with the 12:1 piston with the corrected pin to deck dimensions and switched back to the .040 head gasket (not sure on the base gasket yet but may need to swap that also) that you should end up with a slightly higher comp and smaller cyl vol. But if you went with a thk stk base you could expect the piston to be at the head gasket and have about the 12:1 advertized.

I have not had the time to work this out and have not been able to get any good info on the specs needed so if anyone has any numbers etc post em up.

To answer your question, sorry got distracted b4.

As far as clearence problems go you will need to measure your current clearence and work the dimensions out with the cam mfg, or just dont go too big.

[hippy440]

ttt