twisted wedge,xe282,dss piston?
- Thread starter nitrousED
- Start date
86Cobra
Founding Member
Michael Yount
Mustang Master
Be careful of advice where people are telling you peak lift and piston to valve clearance are related. They are not. If someone thinks they are, they don't really understand what's happening inside the cylinder. At peak lift the pistons are way down the cylinder - p to v clearance at peak lift can be measured in inches. Once you understand what the issues are, you'll realize the only way you can achieve certainty on the clearance is to measure your clearance/your engine. Even two engines with identical components may have different clearance issues due to tolerance stacking.
You needn't remove the heads to make clearance checks if your pistons have their reliefs configured for your heads. The drop valve measurement method is done with the heads on; attached is a link for another clerance checking method with the heads on. You're looking for minimums of .080" intake and .100" exhaust. Click on the link - it also explains what the real clearance limiting issue is. In your case, if there's an issue (and you won't know til you measure) it's related to the cam's duration, not it's lift. Oh, and if you don't have enough clearance, installing a thicker gasket is usually not a very good solution. It will kill the quench in the cylinder and probably lead to a very detonation-prone motor. The solution will be later opening intake timing and/or earlier closing exhaust timing or deeper reliefs. Good luck.
http://www.geocities.com/jjonibones/PVC.html
You needn't remove the heads to make clearance checks if your pistons have their reliefs configured for your heads. The drop valve measurement method is done with the heads on; attached is a link for another clerance checking method with the heads on. You're looking for minimums of .080" intake and .100" exhaust. Click on the link - it also explains what the real clearance limiting issue is. In your case, if there's an issue (and you won't know til you measure) it's related to the cam's duration, not it's lift. Oh, and if you don't have enough clearance, installing a thicker gasket is usually not a very good solution. It will kill the quench in the cylinder and probably lead to a very detonation-prone motor. The solution will be later opening intake timing and/or earlier closing exhaust timing or deeper reliefs. Good luck.
http://www.geocities.com/jjonibones/PVC.html
bmo37
Founding Member
if you want to sleep at night , don't listen to everyone else, just break out the clay and valve spring compressor with your feeler guage.
86Cobra
Founding Member
TWs require relocated valve reliefs. As long as you have the DSS pistons with TW valve reliefs, you'll be fine. But, as others said, check it anyway. Every motor is different so you never know for sure until you check.
