Build update!

[05DodgeDakota]

Parts are ordered! Here is what's happening:
JE 12:1 87mm Piston (416cc)
Hotcams Stage 2
Full Port and Polish

[CJM]

You do realize 12:1 means 100+ octane or race gas right?

11:1 is the highest you can go with running on pump gas.

[05DodgeDakota]

Originally posted by CJM
You do realize 12:1 means 100+ octane or race gas right?

11:1 is the highest you can go with running on pump gas.

My engine builder seems to think that It will be fine. and I trust his opinion, he's been building and racing quads for 30 years.

hell, aren;t the 450s 12:1 stock?

[CJM]

Originally posted by 05DodgeDakota
My engine builder seems to think that It will be fine. and I trust his opinion, he's been building and racing quads for 30 years.

hell, aren;t the 450s 12:1 stock?

Not to badmouth your engine builder, but Im pretty sure I know more about 400ex's than he does. That being said 2 different engines-450r is water cooled, 400ex is air cooled. Only way to keep it cool is to keep it moving, larger oil tank, larger oil cooler and a fan on the oil cooler.

Reason you need to run 100+ octane in a 12:1 setup on an EX is detonation, you run less the sucker will ping like crazy.

Good luck!

[01boneless]

mark my words You run less than 100 octane in that setup and itle be done in a hour. also please tell me you are doing hd head studs?

[dxcody]

i also reccomend you listen to CJM

and just like boneless said, HD head studs are a must too or else you will probably be taking it all back apart in 6 weeks.

As CJM pointed out, "air cooled" so if your just going like 2nd gear not getting much air that headgasket and stock studs wont last long. Just ask the previous owner of my quad. :ermm:

[cheater13]

I have a 12.5:1 compression piston and i run 93 octane with no problem but mine isn't bored.

[powerbomb400]

We do alot of woods riding and so when I bored mine I went with a 88 mm and a 10.1 to 1 compression thought about the 11.1 to 1 but I believe with the 10.1 it will be easier on the head and valves and serve my purpose. I run race gas 99.5% of the time but I felt that the higher compression would put alot of stress on the valve componets.

[01boneless]

Originally posted by cheater13
I have a 12.5:1 compression piston and i run 93 octane with no problem but mine isn't bored.

im suprised your is not fried and boreing dose not make much off a diffrence the higher compression makes for heat and compression is where you get your power i say you run some race gas and it will probley suprise you how much better it will pull imho :D

[05DodgeDakota]

no offense to anyone here because I appreciate yalls input everytime I ask a question but Rick Todd has been building and racing quads for 30 years, and since I don't personally know anyone on here or your qualifications, I have to put my trust in him. Just wish me luck on this build. I'm gonna buy a larger oil tank, but I'm not gonna be running race gas. I might try 100LL Av gas. I also am not running the HD studs. I asked about it and the timing chain and my builder does not think it's necessary. He will resurfacing the gasket surfaces, which he says leads to so many blown headgaskets.

[CJM]

okey dokey, good luck with it.

[01boneless]

good luck ! :D we will be here for your pulled studs and over heated motor :D lol jk