JE, Weisco, or Ross Piston??? And A pic of my bike..

[Silver400EXinBR]

Well, I have a completkly stock 2001 400ex. I figured its time to do sumthing to the motor. I have a Hot Cam, Stage 2. I am port and Polishing it, I am about to order the Curtis Sparks x-6 Full Exaust, SO, Now I might as well get the Piston Kit to get in it and If I am going to buy a piston, I might as well bore it to a 416. So now is the predicument....Should I go with the Je 416 Piston Kit, The Weisco one, or the Ross???? Please tell me which would be the best for my set up, ANd why its better than the others. I would greatly appreciate all the information I can get on it. That's the only 3 I am going to stay in the range of, So please just let me know as much as ya'll know thanks alot.
Here's a pic of my ride.....

http://www.altimas.net/registry/users/Black3.5Lv6/images/lg_mine.JPG

[jonc623]

hey randy i hear the je has real good pistons that is who im going with next time my 440 has wb kit in it now and it works great real good with your old pipe do you want me to send you a copy of mt parts and manual cd?

[BigThumper33]

The JE and Ross are nearly the same with their 416 pistons. The Ross is a few grams lighter.


I'm disappointed with Wiseco's, their compression ratios they advertise are not even close to being accurate. My 10.8:1 comp Ross piston had a higher comp ratio than my "advertised" 11:1 wiseco. When comparing the two side by side it was obvious the wiseco was way off. I believe it was actually a 9.8:1.

[QuadJunkies]

I have heard nothing but good about Ross..This is what I chose.....;)

[Natertot426ex]

Ross or JE!!!!

[Silver400EXinBR]

Yea, I know I am going to go witha higher compresion like 11.1. SO I would like to get tht if tht is what is advertised. HOw much more horsepower do yall think i should pick up with the full CS exaust, JE 11.1 416 piston, port and polishing, and the stage 2 hot cam??? and with all that... SO yall have any clue where I should start with jetting????

[Quadzilla]

First off, go w the Ross over the JE. The Ross piston is literally a new and improved JE. The motorcycle piston tech that designed the JE pistons moved to Ross a few years back and just improved his original design.

Now onto the horsepower numbers. Assuming it is built correctly, you are looking at anywhere from roughly 35-42 hp. Things like exhaust, porting and jetting/carb factor in. Porting and especially the carb will make a significant difference. Try to go with an FCR as a first choice and an Edelbrock as a close second. Oh, don't forget to use XR gaskets vs EX to get the proper compression. Just about all of these pistons have the compression rated using XR gaskets because the pistons were designed for an XR which uses thinner gaskets from the factory. The piston part #'s are typically the same for the XR and EX which means that is you use EX gaskets you will get a lower than advertised compression ratio on all of these. Mickey Dunlap and many other builders don't even use a base gaskets, just the Honda liquid gasket stuff and sometimes pull the layers apart on the head gasket and use only a layer or two for even higher compression and a better squish, etc. Good luck!

As you can see from my sig, I have the Weisco 11:1 piston. I too believe that it is not 11:1. That is not necessarily a bad thing though. My bike is extremely dependable, starts easily, and I can run regular if I want. The added displacement and increased intake from the cam have turned my bike into a sreaming fast hill climbing machine. I am not a racer, I just want a dependable fast ride to run through the desert and dunes with my friends.

BTW Youre bike is rocking, where do you guys get those great plastics?

[Hondaluva]

As you can see from my sig, I have the Weisco 11:1 piston. I too believe that it is not 11:1.


golfman400ex


What gasket thicknesses did you use to set it up? I ended up using no base gasket and a .027" Cometic head gasket to get me 10.6:1. I'm very happy with the results. Had I set it up with stock 400EX gaskets I would have about 9.4:1 (not good)!!

Apparently I am the only person on the planet to use the stock gaskets. My bike revs nicely although I have only tested it against my friend's piped and jetted 500cc preditor. He used to walk away from me, but now I keep him close reguardless of the distance of the race. I can't wait to compare with other bikes at Pismo Beach this week.
I would like to know my exact compression though, any suggestions?

[QuadJunkies]

Originally posted by golfman400ex
Apparently I am the only person on the planet to use the stock gaskets. My bike revs nicely although I have only tested it against my friend's piped and jetted 500cc preditor. He used to walk away from me, but now I keep him close reguardless of the distance of the race. I can't wait to compare with other bikes at Pismo Beach this week.
I would like to know my exact compression though, any suggestions? nope..make that 2:)

[Silver400EXinBR]

well, I I ordered my piston kit yesterday and the xr gasket kit. I gotta pick them up today. So, she will be going in the shop Monday for bout a week or so. I will keep yall updated on how she runs...

[Hondaluva]

I would like to know my exact compression though, any suggestions?

Well in order to do it right you would have to get back into the top end and measure the deck height which is the distance from the top of the flat part of the piston to the top of the cylinder. Then you have to know the bore, stroke, CC's of the combustion chamber, CC's of piston dome (if any) CC's of valve pockets on the piston and your gasket thickness. Then you load it all into a CR calculator. If you are really interested I could help you further...but if you are happy with your current set up, it's probably best to leave it alone. But if you are ever back in the top end, it's not difficult to check it out and worth it to know. AND it would be very easy to change the gasket thickness and pick up some compression. Trust me .020" - .030" can make a huge difference.

[WhiteBros400ex]

I would say Ross or JE i am dispointed in the performance of my wiseco but i mean it was still tons better then stock;)