Few Motor Questions

[RUFIO]

i just need some advice...the cam, piston, gaskets, and jets are going in at one time......

Is the xr400 cam made buy hotcam? b.c in Denis Kerk mag. in the hotcams section i see "xr400r" cams and people have been saying they're proving less problems than a h.c stage II...?

If you were to buy the xr400/hc stage 2, where would you get it for the cheapest/most reliable?

I hear ross is lighter but JE is a bigger company and stronger...what piston and what size piston to go with these engine mods:
-Sparks x4
-UNI Filter
-160 MJ (What size when the cam/piston are in?)
-Many holes drilled in the stock airbox lid.
-The xr400 cam or the hotcam

Thanks, any advice will help. :confused:

[RUFIO]

bump

[wilkin250r]

The 400EX motor is based on the Honda XR400 dirtbike engine. The XR400 cam is a genuine honda cam. Theoretically, you should not see any more problems with the XR400 cam than you would see with your stock can, and I think it is a drop-in replacement with a more aggressive grind.


I'm not 100% sure on this, someone feel free to correct me...

[Teufel]

Go with the Wiseco piston, they are a quality product and they support the sport.
Do some research(not just opinion) on the cam. Talk to hot cam and Web cam for example. The Xr cam is good stuff but honda will rape you for the price

wiseco doesnt make a "true" piston i wouldnt go with them unless u knew what u were getting into

[Mxbubs]

AS FAR AS I KNOW, and I dont know much, but I believe all the cams are made by honda, these companys get them and put their "house" grind on them. I believe that is what the core is for.

Can anyone comment?

[Teufel]

Originally posted by XxHonda_RacerxX
wiseco doesnt make a "true" piston i wouldnt go with them unless u knew what u were getting into



What do you mean :confused: :confused:

[muff]

Originally posted by Teufel
What do you mean :confused: :confused:

he means that although the wisco says you're gettin 11:1 compression your prolly only getting around 10:1

[Steven]

good questions...

yes hotcams did have a flange fitment problem with a batch of thier cams but they are still a very good company and sell a quality product. i got my cam after the bad batch and mine is doing great. figure $130

je and ross both make great pistons. go with whatever you like. you cant go wrong with either. i liked the ross because i was able to call ross pistons, get a person, and order the piston right from them for a good price. the bore you want depends on the coin you want to blow. the oem tube will take up to a 426 i think. anything after that and you'll need a new big bore sleeve.
the power difference between a 440 and 426 is small. aim for 11:1 compression with the piston. figure $130 for the piston from ross.

gaskets? whatever, i have had good luck with cometic.

you will need to rejet after these mods.

have fun

steve

[JD400exrider]

Rufio,

The XR cam is the cam used in the xr 400 motorcycle. It is a slightly better cam than the stock trx 400 cam.

If your looking for more aggressive cam than the OEM xr 400 cam I would suggest the Honda HRC cam. This cam is made by Honda and is the hop up cam for the xr 400 motor cycle or trx 400. It is close to the same grind as the hot cams stage 2. I am running one and did not see much drop off on the low end, although pulls very well on the mid to top end. It is Honda Quality and does come with the flange and decompression installed on it.
HRC cam around 275.00 Part # 14000-NKK-000
I think the xr cam is 130.00 +/- from service honda


It seems that the hot cam problems have been addressed with the flange being casted onto the cam. Hot cam does not use the decompression.

The Ross or JE piston are both good pistons.
I am running a 416 JE 10.8-1 piston, the HRC cam, OEM gaskets. Working well ;)

Call C&D racing (One of the site sponsors) They will hook you up with piston and gaskets and a Hot cam if you choose. Colby checks every cam that leaves the place.
Good People and Good Service Good Price

Good Luck

[RUFIO]

Originally posted by Steven
the bore you want depends on the coin you want to blow. the oem tube will take up to a 426 i think. anything after that and you'll need a new big bore sleeve.

[RUFIO]

Originally posted by Steven
the bore you want depends on the coin you want to blow. the oem tube will take up to a 426 i think. anything after that and you'll need a new big bore sleeve.

Does the "11:1" or the compression judge the displacment?

If i order bigger than a 426, will ross be able to give me the correct sleeve according to the size piston want?

What size jets with a 426, 426 or 440?


Thanks this is very helpfull.

[F-16Guy]

Originally posted by muff
he means that although the wisco says you're gettin 11:1 compression your prolly only getting around 10:1
That only holds true with the Wiseco flat-top, 11:1, 89mm piston. I did the math when I assembled my 416, and it was almost dead on 11:1 CR. All of their other 11:1 pistons are domed, yealding the correct CR.
As far as the XR cam is concerned; it's less aggressive than the HotCams Stage 2, but an improvement over stock. You can get one from servicehonda.com for $127 + shipping, which includes the cam, decompression mechanism, and flange all assembled and ready for install. That's cheap compared to any aftermarket cam. You'll loose the compression release if you use anything but the XR or HRC cam.

[RUFIO]

Originally posted by RUFIO
Does the "11:1" or the compression judge the displacment?

If i order bigger than a 426, will ross be able to give me the correct sleeve according to the size piston want?

What size jets with a 426, 426 or 440?


Thanks this is very helpfull.

no u can get 11:1 in any displacement you would like, i am not sure but most likely, you would prolly move up a couple

also which cam is more aggressive HRC or hotcam stage 2