Engine talk. Rebuild, and cam.

[duneracerweston]

Do you know the dome height of yours. The JE is .100". Which from what I've read is the most you want to go other wise you will effect combustion chamber dynamics. The wiseco might be shorter and larger around raised pad? I be worried your piston pad would hit the quench area of the head because it is not shaped like the combustion chamber.

What head gasket you running?

Yeah when I first rebuilt mine I just wanted to get it together and run it.

no i had though about doing the volume of the head to check compression ratio for mine after i was done with it. but i didnt and i dont know how tall or the volume of the wiseco either

cometic

 

[jasonp]

no i had though about doing the volume of the head to check compression ratio for mine after i was done with it. but i didnt and i dont know how tall or the volume of the wiseco either

cometic

On the piston build sheet it should be on there. Where it shows the weight and ****.

I thought you said you had a stock head gasket in the other thread?
What type of gasket you running and did you get a custom one?

 

[duneracerweston]

i am running a oem replacement cometic head gasket.

i didnt get a custom one because ive never seen the need to and with all the 350's i have around the house all the time i keep 2-3 topend gasket kits around just in case

 

[jasonp]

i am running a oem replacement cometic head gasket.

i didnt get a custom one because ive never seen the need to and with all the 350's i have around the house all the time i keep 2-3 topend gasket kits around just in case

What kind of cranking compression do you get with you engine?

 

[duneracerweston]

im still waiting on my gauge to come in im gonna guess around 185-200psi

 

[jasonp]

im still waiting on my gauge to come in im gonna guess around 185-200psi

I'm sure with your wheeler you will be running around 300 psi or some ****!!:haha: just kidding. I'm suprised you guys run a shop with out a compression gauge and leak down tester! There great tools.

I'm guessing with that cam around 175 psi or so.

I wonder what guys run with 12:1 pistons.

 

['00 WO-YA!]

I'm sure with your wheeler you will be running around 300 psi or some ****!!:haha: just kidding. I'm suprised you guys run a shop with out a compression gauge and leak down tester! There great tools.

I'm guessing with that cam around 175 psi or so.

I wonder what guys run with 12:1 pistons.

I'm hoping I'll be able to answer that before too awful long, Jason.
Weston, if you have a couple of Cometic head gasket kits around would you mind putting a caliber inside of one & telling me what the I.d of the fire ring is? If it's gonna fit the 85mm bore would you post up the part #?

 

[jasonp]

I'm hoping I'll be able to answer that before too awful long, Jason.
Weston, if you have a couple of Cometic head gasket kits around would you mind putting a caliber inside of one & telling me what the I.d of the fire ring is? If it's gonna fit the 85mm bore would you post up the part #?

You will have to be careful depending on the type, after you compresses it will change diameter. Have to be really careful as this will effect piston ring sealing and can cause hot spots if the gasket is to small and blow it out.

 

[duneracerweston]

Sure I'll get it to you tomorrow!

Jason I have one but the hose cracked about a month ago so it's toast after I get the gauge in ill check it for ya

 

['00 WO-YA!]

Thanks bud, you can just txt me if ya want....well, I guess posting it here would be good too, someone else may benefit from that info.

 

[DeadLastRacing]

piston-jug height .002
piston to deck .041
piston to valves was way more then the .070 i used to test for

Perhaps this is info we should put in a separate post (tutorials?), but how exactly are you guys getting this information? I know what too your using, but how do you go about measuring this stuff and what exactly are you measuring? This seems like great info to know if we could all know how to properly go about the process.

I have my head coming back to me soon and need to set my deck and clearance, I want to do it right so that I have optimal numbers, just need to know how to go abou that thou.

Thanks.

 

[jasonp]

Perhaps this is info we should put in a separate post (tutorials?), but how exactly are you guys getting this information? I know what too your using, but how do you go about measuring this stuff and what exactly are you measuring? This seems like great info to know if we could all know how to properly go about the process.

I have my head coming back to me soon and need to set my deck and clearance, I want to do it right so that I have optimal numbers, just need to know how to go abou that thou.

Thanks.

Best way I found when looking for correct deck height and sizing gasket thickness.

Install the piston with no rings on to the rod.

Install the jug, no base gasket.

Measure from top of the cylinder sleeve to side of the piston (wrist pin area) at TDC. This will give you a better measurement. Or in some cases measure from the top of the piston to the top of the sleeve.

This will tell you what thickness gaskets you are going to need.

I wouldn't recomend running the piston out of the cylinder but some engine builders do it.

Googled images for better idea.
http://www.google.com/imgres?q=meas...43&tbnw=228&start=62&ndsp=23&ved=0COwCEK0DMEU

http://www.google.com/imgres?q=meas...tart=39&ndsp=23&ved=0CL0CEK0DMDo&tx=131&ty=81

http://www.google.com/imgres?q=meas...art=15&ndsp=24&ved=0CNwBEK0DMCM&tx=106&ty=104

 

[duneracerweston]

On the piston build sheet it should be on there. Where it shows the weight and ****.

I thought you said you had a stock head gasket in the other thread?
What type of gasket you running and did you get a custom one?

wiseco dose not send a piston build sheet with weight and such.

and i measured the head gasket on one i just pulled apart and even after its been torqued its still at 87.57mm id

 

[miami1]

how are you getting 87+mm out of a stock gasket?

 

[beastlywarrior228]

wait can you use a gasket thats too big

 

[miami1]

i would think it would cause a lot of carbon build up and lower compression

 

[beastlywarrior228]

because im pretty sure mines for the 87mm

 

['00 WO-YA!]

I think you have to think about how close the tolerances are, there's hardly any room for carbon to build up there. The majority of engines built have a fire ring that's larger than the bore, you're sweating the small stuff if you're worried about that.

 

[duneracerweston]

how are you getting 87+mm out of a stock gasket?

wait can you use a gasket thats too big

i would think it would cause a lot of carbon build up and lower compression

because im pretty sure mines for the 87mm

I think you have to think about how close the tolerances are, there's hardly any room for carbon to build up there. The majority of engines built have a fire ring that's larger than the bore, you're sweating the small stuff if you're worried about that.

if you have carbon building up on a 2mm ledge between the head and jug and its causing issues you have bigger problems like were is all that carbon coming from?

if that tiny bit is lowering compression your motor never had it to start with because that is a oem replacement gasket so its ment for a 83mm bore but is big enough to go to .040 which is what it was used for and it did great till the rod bearing and cam bearings died on me. so no running "to big" a gasket wont hurt these tanks.

and if your hunting compression that bad, measure head volume and mill that sucker down to get you your compression your looking for.

just my past experience and .02

 

[jasonp]

wiseco dose not send a piston build sheet with weight and such.

and i measured the head gasket on one i just pulled apart and even after its been torqued its still at 87.57mm id

Interesting.. I just measured my EST custom gasket for 85mm bore and I'm getting around 85.25mm (it's are to get real acurate as there is 3 gaskets sandwhiched.. I would have thought wiseco would have sent a build sheet of the spec's. Most manufactures do that.