XR400 headgasket in a 400ex?

[leechi]

Hello!

the XR400 headgasket is the same for 400ex?

i listen that it gives more compresion?

or is better put the original 400ex headgasket?

thanks!!!

[hornetgod13]

I put a XR400 head gasket on my 416EX when I rebuilt it. It's thinner than a stock 400EX gasket and is a perfect fit. Since it's thinner it allows for a little more compression.

[leechi]

but this headgasket is safety that the stock ?

[hornetgod13]

Yes, it is as safe as a stock gasket.

[leechi]

OK

but, muy hotcams stage 1 got more lift that stock cam.......

whit stage1 hc and xr400 headgasket.....works great???

[Hondamaster5505]

Originally posted by leechi
OK

but, muy hotcams stage 1 got more lift that stock cam.......

whit stage1 hc and xr400 headgasket.....works great???

better than the stock gasket.

The cam's have a longer duration, so they loose a little compression. Thats why people do piston's and cams at the same time. The hc piston to make up for the lost and then some.

So with the thinner gasket, that's a lot better. It'll help raise the compression a little to go along with the cam

[leechi]

ok

but a xr headgasket, hc stage 1

and a dynatek rev box???

works great?

or the dynatek are bad for this¿?

[blankenship]

i have heard that the xr 400 head gasket is the only way to get true 11/1 or 12/1 or any other high comp pistons you MUST HAVE THE XR 400 HEAD GASKET to make it the TRUE compression of the Piston because the head gasket on the 400ex is thicker

[enduro400rider]

^^^^^ I believe thats how it used to be, all the oversized pistons used in the 400ex were just xr400 pistons. since they were designed for the xr they were to be used with the thinner xr gaskets. i thought the companies fixed that problem and made a differant piston for the 400ex to compensate for the gasket thickness. either way id say use the XR gasket, it cant hurt..

yeap the xr400 gaskets adds about .2 to the compression ratio. So stock is 9.1:1 with just the xr400 gasket you should be around 9.3:1. And it is the only way to correctly measure compression and match what your piston actually says

[hornetgod13]

I've got 4 months on my 416cc (87mm), 11:1 Wiseco, XR head gasket, and Stage 1 Hotcam set up. No problems or issues. It runs like a champ. My only complaint is a sore neck from the snappy throttle. It's wicked fast off idle.

[leechi]

oh! the XR headgasket are perfect for the 400ex!!!

i put one one my 400!!!!

but.....whit a dynatek rev box, the xr headgasket works good?

[hornetgod13]

I run a ProCom rev box with my XR400 Gasket and it works fine. :macho

[leechi]

ok! thanks!!!

[AZ440ex]

Originally posted by enduro400rider
^^^^^ I believe thats how it used to be, all the oversized pistons used in the 400ex were just xr400 pistons. since they were designed for the xr they were to be used with the thinner xr gaskets. i thought the companies fixed that problem and made a differant piston for the 400ex to compensate for the gasket thickness. either way id say use the XR gasket, it cant hurt..

Four Stroke tech made a piston 0.040 taller to fix that or you can have the head shaved or a XR gasket. Not only will you get more compression it actually creates the idea "quench" area on the top of the piston keeping it cooler.

[Claas900]

yup you want a quench of about .037 is safe. You can use different base and head gaskets to get that or shave the head.

[leechi]

i think that isn´t good idea runs whit a lot of compression

isn´t safety engine

[AZ440ex]

Originally posted by leechi
i think that isn´t good idea runs whit a lot of compression

isn´t safety engine

Ok, but here is straight from Micky Dunlap. And his motors rock!!


"On most after-market pistons, the pin to deck height is the same as stock. You should have a minimum of .040 clearance between the piston and head with everything torqued down. Right now the piston is about .043 too low and you are not getting a true compression ratio as advertised by most piston companies. For instance, a 440 11:1 flat top piston advertised is really only about 9.75:1 if you measured the volume correctly. In order to get the deck heights better, I use Honda HT silicone seal on the cylinder base and an XR400 gasket if you are running an 80 over piston or smaller. This will get you close to what your deck height should be. Keeping the squish clearance down to .040 gives a better quench area around the outside of the piston keeping it cool and less chance for detonation. You will be able to run an 11:1 motor on pump gas in most cases and have a more efficient flame travel and quicker burn rate across the top of the piston."


http://www.atvriders.com/articles/askmickey1.html

[leechi]

ok thanks! good info!

i add a XR400 headgasket to my proyect :cool: