10.6:1 with timing advance?

[Martin Blair]

with a je 10.6 :1 416 kit can i run a xr head gasket and a sparks timing advance key?

I will rpoablly need to mix race gas and premium. The premium pump gas here is only 91 octane, so what should i mix it with?

[Martin Blair]

my question is on xc racing mickey dunlap said they dont change the cames unless they get about 11:1 would my motor even at 10.6:1 a xr gasket and andvanced timing still benifit from a cam?

thanks.

[cals400ex]

oh yeah, you would benefit from a cam. are you sure it is a 10.6 and not a 10.8 piston? however, a 10.6 piston for example might have a compression of 10.8 to 10.9 with the thinner gaskets. i would say a cam would benefit greatly.

[Martin Blair]

yeah is 10.6 im getting it from c&d, my question is does whoe does this sound for a build?

JE 10.6:1 416 pisotn kit

XR 400 cam and headgasket, my ? about this is should i go XR 400 for woods racing or hotcams stage 2? and if i get XR cam what all do you order from service honda the cam assembly im guessing?

Spark timing advance key

how does this sound? what fuel mix will i have to run?

[Silverfox@C&DRacing]

one correction for you if you are getting the JE 416 piston kit it is a 10.8:1. I am running the timing key in my bike with the 416 kit runs good.

[Bad Habit]

Look at my mods below. I have the advance key in as well. It makes it run a tad hotter, but the motor revs alot smoother, IMO. It really purrs nicely in the mid to upper rpm range.

If you use the thin, metal gasket, it will bring the JE piston close to 11:1. This is what I use.

I run straight Sonoco 110 fuel. I may be a bit over doing it with the octane, but I'd rather run the straight race gas to get the benefit of cool burning. And it's not like I'm burning hundreds of gallons of fuel through my bike, so the extra money is not that big of a deal.

Let me know if you need any help, we're not far from eachother.

[Bad Habit]

Oh ya, I would stay away from HotCams. I do not have any personal experience with them, but I have heard alot of negatives about them. Go ahead and spend another $20-$30 and get a Web.

[Martin Blair]

but web you ahve to harden the riockers, this winter most of my money is goign into suspension and im not doing porting, new valves extra just a drop in cam and a 416 piston, save the rest for next year.

so if i get a 10.8:1 piston kit and cometo gasket set should it stay at 10.8:1? also with the advanced timing i will probably run racgas, would 2 gallons of 110 mixed to 3 gallons of premium do ok? you enxdc up with a final ratio of 104 octane? I alos plan on runiing just a XR cam for now.

Also Yellow416 where do you buy your race fuel from?

If i take the timing advance out would i be able to run regular pump gas?

thanks

[Silverfox@C&DRacing]

Originally posted by Yellow416ex
Oh ya, I would stay away from HotCams. I do not have any personal experience with them, but I have heard alot of negatives about them. Go ahead and spend another $20-$30 and get a Web.

all of the problems are fixed if you buy from the right people the ones that inspect every cam that leaves the door.. If I thought they were junk I would not be running them in my bike.

[Martin Blair]

well then maybe i will get a hotcam.

so what aobut running pump gas, here its only 91 octane so will that work without the timing key in?

Or could i run Air Plane fuel i know iots higher octane just not sure how much higher.

does Je or Ross sell anything less the 10.8:1 for 416 or, 426 kits, i would relaly like to run pump gas instead of race gas because this bike willb e raced in hairscrambles but more riding is done on trails.

[Bad Habit]

I buy my fuel from Day Automotive in Independence, MO.

The advance key doesn't really have an effect on what octane you need to run. Compression ratio is the determining factor, and 91 is technically good enough for 11:1. So any increase is going to be good because the higher octanes burn cooler.
IMO, you are going to see a bigger benefit with compression not bore size. A stock bore 11:1 is going to run better than a 9:1 416 bore (if you could find one).

I stand corrected on the HotCams. Again, I have no personal experience and was going off of what a couple guys told me coupled with the comments on these boards. I'd trust C & D cause they DO have experience with them. BTW, you don't need hardfaced rockers with all Web cams, or other manuf cams for that matter. It depends on the lift and duration of a particular grind.

Cometic recommeded to me the metal (thinner) gasket which increases compression slightly. They don't recommend because of the compression, but because it's a better gasket.

[Martin Blair]

so i could rum pump gas with timing advanbce and 10.8:1?

Silverfox does c&d sell 10.8:1 stock bore je pistons, would i sell that much of a change between stock bore 10.8:1 and 416 10.8:1? i need a good cam for wodds racing so im goign with a TC racing XC cam, there drop end and add lowend but dont sacrifice mid and topend.

but it would run coller with racegas, so when i go racing and run the mtor hard for 2 straight hours i might want to run racegas during races?

[TRX_Thumper]

i got a 10.8:1 je 416 piston with an xr400 headgasket...i had a 155 main in it and it wouldnt run on 93 so i got some 110 an mixed it 50/50 and it ran great...but the jettin wasnt right then...im runnin a 170 main now and mine runs on 93 pump gas just fine...but for harescrambles and long rides in the summer heat ill mix 3 gallons of 93 to 1 gallon of 110

[Martin Blair]

so for racing and really working the motor i would mix it but if i just go out for a sunday ride where we spend only 2 -3 hours riding and stop at the truck half a dozen times it should be good?

what benifits would i see from just the tc cam, or would i get more from a carb bore? im putting more into suspension i will work the motor next year with a bore but this year im on a budget because money is goign into suspension so a TC XC cam or carb bore would be more noticable?