10:1 or 11:1

[alex10]

I'm going to be rebuilding my 400ex here in a couple weeks and I'm wondering whether to get a 10:1 or 11:1 wiseco 416 piston. What are the performance differences between the two and what minimum octane could I run with them. thanks

I say 10:1 just because its low enough to even run advanced timing as far as 6 degrees without the need for a higher octane fuel. Its a step above stock and noticable.

[400ex28]

11:1

[rideracelivemx7]

11:1. you can still run pump or 93, which i run 93. you can use the sparks key if you want. there was a rider on here that said he ran a 426 kit with the 11:1 and the CS key and he had no problems nor heat. and your not in danger of blwing a head gasket. i think youll be plenty happy with the 11:1. its a nice boost in performance. and the 10:1 i dont think youll notice to much. i mean sure itll be a didfference but not to much. considering the stock comptression is 9:1

[alex10]

Can I use 87 octane if I have to with 11:1? I have no problem getting 93 which is what I'll run. 11:1 it is.

I know of someone that ran a 10.8:1 piston, thinner head gasket, and advanced ignition timing by 6 degrees and it pinged a lot on 93.

[alex10]

Advancing the ignition will give you more chance of detonation.

[NacsMXer]

Originally posted by rideracelivemx7
11:1. you can still run pump or 93, which i run 93. you can use the sparks key if you want. there was a rider on here that said he ran a 426 kit with the 11:1 and the CS key and he had no problems nor heat. and your not in danger of blwing a head gasket. i think youll be plenty happy with the 11:1. its a nice boost in performance. and the 10:1 i dont think youll notice to much. i mean sure itll be a didfference but not to much. considering the stock comptression is 9:1

X2

If you're gonna go through the trouble go 11:1. You can run on 93, stock rod is still ok, etc. My last motor was a 440 with a 10:1 Wiseco with a Webcam and it wasn't a huge difference over piped/jetted, just better gains all around.

[NacsMXer]

Originally posted by alex10
Can I use 87 octane if I have to with 11:1? I have no problem getting 93 which is what I'll run. 11:1 it is.

I would run 93 at the bare minimum with 11:1 compression ;) I wouldn't even want to run 87 stock, these motors run pretty hot.

[Honda#4]

I would run 93 at the bare minimum with 11:1 compression I wouldn't even want to run 87 stock, these motors run pretty hot.

Yea it will run hot with 89 ,my cases were hot enough I couldnt even hold my hand on them so then I switched to 93 and its much better

[leasureryan]

EVERYONE needs to run atleast 93 octane in thier equipment....reguardless if it is stock or not.....89 etc is junk watered down these days....not that 93 is any better. I always wondered why people are so "penny pinching" with thier expensive toys.


Can anyone tell me why you shouldn't run good gas???

[Honda#4]

IDK but I paid $20 for 4 gallons of gas so price may have play in it.

Why dont gas stations just have 93 and thats it? J/W

[drew416ex]

You also have to take a cam into consideration. With a stock cam and 11:1 your cylinder pressure will be pretty high so you may actually have to run a higher octane than 93. Lets say you have 12:1 compression with a stage 2 cam, you will actually have less cylinder pressure than the 11:1 due to valve overlap. Plus, you will only get half of the benefit of the piston with a stock cam.

[leasureryan]

my quad has air box mods, piped and jetted....thats it.....and I run 3 gallons of 93 octane at $4.35 a gallon mixed with 1 gallon of Turbo Blue 110 octane at $7.15 or so a gallon......If my quad was set up high compression...I would run straight 110....but for now..until it blows up or needs rebuilt....I will run the mix. Motor runs strong and cool with mix gas and 20w-50 GN4 in it.



I ran VP 114 octane in my Blaster....but high octane is a must in any 2 stroke built to the moon like that one was...lol. Detonation is a *****!

[shallow518]

ethanol plays a big part in gas. 93 is the only one that doesnt have up to 10% of ethanol in it. ethanol is horrible for high performance motors

[boosted3g]

Ethanol is an excellent fuel for performance engines, i dont know where you got that info. Far better than gas and quite possibly all but the most exotic race gas. Also 93 contains the most ethanol of all the "pump" gasolines. Some still have no ethanol added at all.

[shallow518]

my bad. i must have read something backwards or wrong when i looked it up. i saw that you had to change over some fuel injected motors to be compatible with ethanol. sorry for the wrong info. and thank you for the correction. ill make sure to pay closer attention to things when i look them up.

[gojk]

Deff go with 11:1, although you might want to go with a JE or CP piston at 10.8:1. I went with Wiseco, but to get it to a true 11:1 you have to deck the cylinder .040 if I remember correctly. If I had to do it again, I would go with a JE or CP and get the as advertised CR.

[01440ex]

ok so through all this...i have a 440 kit in my 400 but not sure about the cam...it does smoke a lot until warm...im looking to rebuild it but dont know what setup to go with or what kind fuel to run either...ive been running 89 in it and it gets really hot...so i mite switch now also....ive seen the 440 kits on ebay with new jugs but am kinda afraid of buying a kit off there...what do you guys think...and then getting either a stage 2 or 3 cam for it...any imputs would be greatly appreciated....