416 piston?? is it worth doing??

[BigLuke]

I plan on rebuilding my engine this fall and was thinking about boring it and using the 416, 11.1 piston. Question is it worth it and what other mods will improve apon this?
I already have a stage 2 Hot Cam Yoshi slip, K&N and jet kit but was looking for some more reliable power gains. Any suggestions??

[Honda#4]

It's totally worth it and a ported head wouldnt be a bad thing to do either

[Colby@C&DRacing]

The 416 is a good choice it will compliment your cam and exhaust well.

[04TRX400EX]

Originally posted by Colby@C&DRacing
The 416 is a good choice it will compliment your cam and exhaust well.

Hot Cams designs the Stage 2 to work best with higher compression big bore engines, so yes, a 416 11:1 piston should show marked improvement.

[BigLuke]

thanks guys. I think Im gonna look into porting it as well.

[BigLuke]

I called to order the piston and they said that Wiesco has the 11.1 and JE only made a 10.8 piston next up in JE was 12.1 CP ratio. Which one should I go with or are they both good quality pistons?

[smelly$cat]

When I had my 426 done, they recommended CP as the best quality/most reliable/best reputation as of late.

[tobin440]

have you thought about going with wiseco

[04TRX400EX]

If you approach or exceed 12:1 compression you get into race fuel territory. For reliability reasons, I'd stick to the JE 10.8 or the Wiseco 11. The compression difference is not going to be noticed between the two. Personally, I'd go with the JE.

[smelly$cat]

My CP piston is 13:1. As such, I have to run race fuel. I run straight 114 "trick" fuel. A local station has it on-site in tanks. 6.50ish per gal.... For as often as I ride, it's not a big deal for the cost. If I rode more often, I'd run lower compression and pump fuel.

[IMSROLL450R]

I would run the 12:1 CP, they are great pistons and are absolutely not less reliable than the 10.8 or 11:1. Still run on pump gas too. Might as well go as high as you can without running race fuel. There will be a power difference between a 10:1 and a 12:1 as well, and it will be noticible. In the long run it will cost you no more to run the 12:1 CP and to me they are the most reliable. I have ran a 14:1 Venom/CP in my 450 for 4 rebuilds and who knows how many hours, just rering and go.

[BigLuke]

Ok I couldnt wait on ordering the stuff so heres whats on order...

JE 12.1 CP 87mm piston
Cometic gasket set
Barnett Kevlar Dirt Digger clutch set
Kibblewhite Black Diamond intake and exhaust valves

I was gonna wait but why not go fast now.

[Sweaney]

I just got done with pretty much the same setup. I just got the motor broke in and I have not really opened up but I can definitely tell there is a huge power difference. You should think about having the head ported and polished.

[Chino886]

Originally posted by Sweaney
I just got done with pretty much the same setup. I just got the motor broke in and I have not really opened up but I can definitely tell there is a huge power difference. You should think about having the head ported and polished.

I can't wait to hear your final ride report!:devil:

[IMSROLL450R]

Originally posted by Chino886
I can't wait to hear your final ride report!:devil:

I can't wait to see him behind me at Taylorville.........

I'll be on the red and black bike, running half throttle.....

But for real it should be a runner, plannin on doing it to the 07 EX I have.

[BigLuke]

thanks guys you all have been helpful! Ive got a friend with a lightly modded Z400 who likes to bash on ex's I think he'll be in for a surprize when its done. I hope mine will be faster.....

[BigLuke]

Parts are in!! Gonna drop the engine off tommorrow. I cant wait to get it back, also order the CRF450R timing chain.

[brian76708]

im thinking about doing the same how much did all of that cost you?

[BigLuke]

JE 12.1 87mm piston -132.00
Kibblewhite valves -28.00 ea
CRF timing chain -32.00
Cometic gasket set -48.00
Barnett kevlar clutch -108.00

Labor for install and boring was 150.00, who says Honda repair shops are high??? Helps to know people too!

[xtullyx16]

whats the proper break-in? i just built my 426ex

[BigLuke]

not sure yet, Id say take it easy for the first few hours then change the oil and your good?

[BigLuke]

Just picked it up on Lunch!! Im going to try and get it running tonight!

[BigLuke]

Ok its been a while since I posted here. I got the 400 back together runs f'n awesome!! This thing is a beast!! Ive gained power from bottom end on up. I switched to 110 race gas and had to play with my jetting a bit but finally got it dialed in. The Barnett clutch holds well even in a second gear full throttle clutch drop, lol!
Only thing I have left to do is find a FCR carb and get that tuned and I'll be set!:D

[honda400ex2003]

I think you will like the 416 i do mine!!!! steve

[brian76708]

Originally posted by brian76708
im thinking about doing the same how much did all of that cost you?

not thinking any more im doing haha.

[BigLuke]

Deffinatley worth it man, next time around Im gonna go 426, 13.1, port and polish some and do some dirrrt drags!

[Homerx]

Not trying to hijack, but when you guys are going 416 are you haveing your cylinder bored with studs in or out? Thx

[BigLuke]

Not sure prolly out, I wasnt there watchin.

[Homerx]

Its just that I wanna get mine done soon and have read that they should be done in, or hot spots can develope afterwards when they are reinserted. Basically from the studs putting a couple of thousands of flex on the cylinder wall. ?:confused:

[Honda#4]

You leave them in

[Homerx]

Originally posted by Honda#4
You leave them in
Thats what I was thinking, thanks.

[Exrider434]

Would a 89mm 11.5:1 still run on pump gas?

[Homerx]

Yep but I would be looking for the highest octane you could to help cooling. 94 and up