Head Gasket Queation

[improper]

I am about to rebuild my motor with a JE 85mm piston. It came with a gasket kit, but the kit appears to be a stock bore gasket kit. Will this head gasket work?

 

[DeadLastRacing]

Good post.....I'm do the the same thing

 

[improper]

Yeah, I've been following your rebuild since your quad got wrecked. Looks good by the way!
I think I'm just going to contact JE on monday and see what they say.

 

[91warrior]

i do believe that a stock gasket kit will work. i never heard of getting specific gaskets for a specific bore unless there was an aftermarket sleeve installed. im running the same size piston as both of you are getting, but my gaskets came with the piston. but i looked on the website that i got it from, and the gasket kit they sell doesnt ask for what size bore you have, unlike when ordering a piston you have to specify which size piston you want. i never thought of it before, but im positive that just a stock head gasket will work. i hope this helps

 

[improper]

On the JE website it lists OEM gasket for the stock bore piston and the it just says to call for the 85 mm piston. I sent them an email, we'll see what they say.

 

[jasonp]

i do believe that a stock gasket kit will work. i never heard of getting specific gaskets for a specific bore unless there was an aftermarket sleeve installed. im running the same size piston as both of you are getting, but my gaskets came with the piston. but i looked on the website that i got it from, and the gasket kit they sell doesnt ask for what size bore you have, unlike when ordering a piston you have to specify which size piston you want. i never thought of it before, but im positive that just a stock head gasket will work. i hope this helps

Stock gasket is made for up to a 84mm bore.
The sealing compression ring has to be 1mm outside of cylinder wall to properly seal. So a custom gasket is needed. I talked to Cometic about this.

 

[91warrior]

ok thanks jason im glad you cleared that up.

 

[improper]

Yeah, thanks jason. Got an email back from JE today saying you do need a gasket set up for an 85mm bore.

 

[kyler]

where can you get the bigger gasket because i am getting ready to put a 12:1 JE 85mm in my 01

 

[DeadLastRacing]

Vesrah or cometic. I just got the top end EST cometic set.

 

[kyler]

ok thanks is it a special one or can i just order a regular one?

 

[jasonp]

Vesrah or cometic. I just got the top end EST cometic set.

Yeah dude that is the best stuff, you shouldn't have a problem. Good deal. You can also tell them you want the thinnest gasket they make in EST for 85mm bore piston. I believe he told me around .022" for the headgasket and .010" for base is the lowest he could go which was more then clearance to piston to head from what I measured.. "deck height". So all you have to tell them is this.

 

[DeadLastRacing]

Well ****....I just orderd and got the EST 85mm bore top end kit. Will me deck be ok then? I figured as much since they know about that stuff. The head gasket does look thinner then the stock gasket for sure. Also how you make sure the base gasket stay in the right spot.....there is some float room and I don't want it to move outta place when I put it all back together.

 

[jasonp]

Well ****....I just orderd and got the EST 85mm bore top end kit. Will me deck be ok then? I figured as much since they know about that stuff. The head gasket does look thinner then the stock gasket for sure. Also how you make sure the base gasket stay in the right spot.....there is some float room and I don't want it to move outta place when I put it all back together.

you can put a spot of yamabond or sealant on the gasket to keep it from moving on you.
Yes your deck height should be ok. If you are using both gaskets it will most likely not be a problem.

 

[improper]

Do you need to use the base gasket or can i just use some sealer?

 

[jasonp]

Do you need to use the base gasket or can i just use some sealer?

no you don't have to as long as you have enough deck height clearance it would be ok. (top of the piston to the bottom of the head should be no less then .035" min) Use some hi-temp good quality sealer.