sparks 416 piston

[honda729]

does anyone know if the sparks 416 piston with 12.5:1 compression is a good piston or is it something thats gonna blow up every time i ride.

[zrpilot]

The 12.5:1 applied correctly is a good power making option. Done INCORRECTLY it can be a nightmare. I think here are some things to consider.
1) Heavy duty head studs are a good idea (almost a must)
2) You will have to run 100+ gas

Just my $.02

[Chino886]

Originally posted by zrpilot
The 12.5:1 applied correctly is a good power making option. Done INCORRECTLY it can be a nightmare. I think here are some things to consider.
1) Heavy duty head studs are a good idea (almost a must)
2) You will have to run 100+ gas

Just my $.02

I will agree with what ZRpilot has already stated!

I will add that on these 4 strokes, compression is POWER! :devil:

[honda729]

I've been told that I need to replace the valves and the rockers. Do I really need to do this.

BTW Who makes a good set of head studs

[zrpilot]

Originally posted by honda729
I've been told that I need to replace the valves and the rockers. Do I really need to do this.

BTW Who makes a good set of head studs


The valves and rockers may be a good idea, but I don't see how they are related to a higher compression piston..

Talk to Colby at C&D about the hd studs.

[JOEX]

Originally posted by honda729
I've been told that I need to replace the valves and the rockers. Do I really need to do this.

BTW Who makes a good set of head studs
When going that far in building a motor most people will be upgrading the cam to match the high comp piston.

Alot of the higher end cams require hardened rockers and better springs. It think shortened valve guides come into play also.

[gojk]

Don't forget that the stock rod is a known weak point on the 400ex engine and it gets glaring obvious when going above 11:1 compression. So if you go 12.5:1 you might want to think about a carillo rod.

[dragex400]

I have a 12:1 in my 416 and havn't had any problems yet. I also have extreme port work done, and a stage three hot cam. I also run a msd ignition and turn my rpms up to 11500 and advance my timing curve. I run vp c-12 race fuel. The setup does run very good. I drag race and have beat 250r's built for dragging and I can half track a 450 with minor mods, pipe, jet, filter, cam. Its always a race with a 450 that is really built, depends on how good the rider is. Although there is a cannondale that races at the drag track and he KILLS me and everyone else in the class. He has like 10 grand into is engine. Its unbelieveable. Anyway it is a good set up. I think I'm gonna sell mine this fall and get a ktm 525 and build it into a drag machine, since thats all I do. Oh, I also have stock rockers, valves, springs but I did install the gt thunder hd studs.

[honda729]

I do plan on getting a hot cams stage 2 cam. Is it really worth replacing everything for the extra compression. is there going to be a big enough power gain to feel over a weisco 11:1 piston

[gcart2]

the 11:1 would do you fine. hot cam is suggested. i love my setup. i can go to the trackand race any 450 out ther.... it just depends on the rider. but read my sig... my setup is great.