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redhondi400
06-07-2005, 08:55 PM
ok my 400 started smoking so it is time to do some work. I am going to put a high compression piston. What else should I do. I was think of a cam. Someone had mentioned to me a bigger oil cooler. Any sugggestions?
ranger400ex1994
06-07-2005, 09:31 PM
i would get a wiseco 11:1 compression piston with either a stage 1 hot cam if you want bottom end or a stage 3 or old 2 hot cam for more top. also a good port job will do alot. i have a 11:1 compression wiseco piston stock bore and a old stage 2 hot cam with full MX porting and it made a huge difference in power.
jokerman_28
06-07-2005, 09:58 PM
go 13:1 either JE or Ross. bore it over too. for a cam the hotcam stage 3 (old 2).
a high compression piston is the cheapest horsepower gain really. it'll cost you like $100 more for gas a year... for the power difference, its worth it.
400exrider707
06-07-2005, 10:23 PM
Originally posted by jokerman_28
go 13:1 either JE or Ross. bore it over too. for a cam the hotcam stage 3 (old 2).
a high compression piston is the cheapest horsepower gain really. it'll cost you like $100 more for gas a year... for the power difference, its worth it.

Then heavy duty head studs will be necessary with that much compression. Also boring doesn't really give you much power, so its not necessary to kill your cylinder life unless it needs to be bored.
jokerman_28
06-07-2005, 10:44 PM
just a 13:1 416 w/ cam and a pipe... it WILL give you power...
ranger400ex1994
06-08-2005, 03:15 PM
ya i was going to go with either a 416 or a 426 but my cylinder still looked good so i just had it cleaned up and put a stock bore piston in it. ya the bore really dosent add much power it all in compression the more you got the more power you make. but my next bore will be a 426.
PHIL_B54
06-08-2005, 06:18 PM
from the looks of your sig, you are wanting a reliable upgrade...not a race engine.

Stick with the 406-416 11:1 Wiseco or JE. If you want to bump the comp up a hair after that, use XR gaskets or no base at all. You will need a cam to get the benifit from the high compression. You should be able to do this (piston, cam, gaskets, machining) for around $350 depending on your machining cost.