PDA

View Full Version : XR400 head gasket........



trx400EXtreme
01-31-2008, 06:27 PM
good mod? i here that because it is thinner it adds more compression. how much more are we talking here? do you have to trim it at all?

the Z Man
01-31-2008, 06:47 PM
You have to be careful, I had a high dome piston that hit the valves from the difference, Z.

trx400EXtreme
01-31-2008, 06:51 PM
do you think there would still be clearence issues with the stock piston?

hornetgod13
01-31-2008, 07:05 PM
I have one installed on my 416EX and it has a 11:1 High Compression Piston and there is no clearance issues with the piston to valves. It's also large enough to accommodate an 87mm or smaller cylinder set up.
I have read the same that you have about the added compression but, I'm not sure how much. It's a 1/16th to 1/8th inch thinner than the stock head gasket I pulled off.

trx400EXtreme
01-31-2008, 07:09 PM
thanks. so just a guess. if stock is 10:1 comp., what might this bring it up to? 10.2-10.3:1?

Hondamaster5505
01-31-2008, 07:31 PM
Originally posted by trx400EXtreme
thanks. so just a guess. if stock is 10:1 comp., what might this bring it up to? 10.2-10.3:1?

Stock is like 9:1 or 9:5

so it might make it 10.5:1 ??

trx400EXtreme
01-31-2008, 08:29 PM
my bad, i did a little research and yea stock is more like 9.4:1 or something.

Pipeless416
01-31-2008, 08:49 PM
wiseco 11.1:1 pistons are actually about 10.8:1, however with an xr400 gasket, i've heard they become true 11.1:1 compression. im guessing they add about .3 to your compression ratio.

drew416ex
01-31-2008, 09:05 PM
you wont have a problem with valves hitting. I have a stroker crank, 11:1 piston and cam and I have no base gasket and mine dont come close to hitting.

drew416ex
01-31-2008, 09:12 PM
Originally posted by hornetgod13
I have one installed on my 416EX and it has a 11:1 High Compression Piston and there is no clearance issues with the piston to valves. It's also large enough to accommodate an 87mm or smaller cylinder set up.
I have read the same that you have about the added compression but, I'm not sure how much. It's a 1/16th to 1/8th inch thinner than the stock head gasket I pulled off.

Not trying to start anything but its not 1/16 - 1/8th inch thinner. The gasket itself might be 1/32 total if its that thick. The xr gasket is around .010"-.020" thinner.

hornetgod13
01-31-2008, 10:20 PM
Originally posted by drew416ex
Not trying to start anything but its not 1/16 - 1/8th inch thinner. The gasket itself might be 1/32 total if its that thick. The xr gasket is around .010"-.020" thinner.

1/32 to 1/16 as compared to the stock replacement gasket, I can see that. I didn't measure it. I wish I had now.

Maxx Racer
01-31-2008, 10:42 PM
.010 raises .3-.4 a compression point in a car. Give me gasket thickness stroke etc I'll probaly be able to find out what it will make it.