Valve to piston clearance

[madsupra88]

Hey guys,

I’m getting ready to check my valve to piston clearance and just wondering if any of you guys ran into a problem of not having enough clearance? My block had 0.010 milled of which put my pistons 0.010 above deck, and my head had around 0.040 milled off to get a clean surface to run a MLS gasket , also my new cam is a 9.2 mm . I was planning on running a 1.4 mm gasket to get 8.8 CR that I was shooting for. My pistons are wisco with valve relief also what is the recommended clearance ? :1zhelp: . thanks

 

[madsupra88]

ttt

 

[Doward]

There's not so much a 'recommended' clearance, as a minimum clearance. Clay it and see what you get

 

[madsupra88]

There's not so much a 'recommended' clearance, as a minimum clearance. Clay it and see what you get

im not going to have time to do it until next week, do you think ill run into a problem with the lift on the cam and milling ? ohh i run stock valves

 

[Dan_Gyoba]

Okay, so you've got 0.050 milled off (1.27mm) and are compensating for that with a 0.2mm increase in gasket thickness... That still takes more than 1mm from your clearance. Add in increased cam lift and I can about guarantee that you are now running an interference engine. Take good care of that timing belt, 'cause if it goes, you've got an engine rebuild on your hands.

 

[madsupra88]

Okay, so you've got 0.050 milled off (1.27mm) and are compensating for that with a 0.2mm increase in gasket thickness... That still takes more than 1mm from your clearance. Add in increased cam lift and I can about guarantee that you are now running an interference engine. Take good care of that timing belt, 'cause if it goes, you've got an engine rebuild on your hands.

i know thats a total of 2.7 mm in clearence loss, i'm getting mixed answers :aigo:

 

[Dan_Gyoba]

You won't know for sure until you clay it, but I would expect contact.

 

[Poodles]

larger cams CAN make them hit, but you'd have to clay it to be sure...

Factory spec is quite big IIRC...

 

[madsupra88]

how much room do normaly have before hitting ? thanks

 

[madsupra88]

ttt

 

[madsupra88]

you think ill have a problem with the crower 264 cam ? i think the lift is 8.6

 

[bfr1992t]

Too many variables for our ESP (Extra Supra Perception) abilities to tell, clay it. Don't forgot to put a HG between the block and head when you do.