440 tapping under load

[offshore78]

I have a 440 big bore on a 400ex(2004) model. it is a 12:5:1 CR. after about 30 mins of riding it starts tapping under load. Some of my friends said to retard the timing a little, others said to run a higher octane(race fuel) 107/110 octane in it. Just wondering if this has happened to any one! Any info would be awesome!

[400ex28]

Run the race fuel.

[AZ440ex]

Originally posted by 400ex28
Run the race fuel.

X2

Sounds like it is getting hot and starting to detinate:eek2:

[86 Quad R]

that'd be my guess ;)

[Ruby Soho]

head gasket?

[drew416ex]

Originally posted by Ruby Soho
head gasket?

X2, do you have hd studs. And you should also run race gas.

[xtullyx16]

tapping or ticking? maybe its just normal noise from ur cam? im right to think u have a hotcams stage 1 or 2?

Originally posted by AZ440ex

Sounds like it is getting hot and starting to detinate:eek2:

definatly dont want tht
thts just waiting 4 ur head gasket 2 go

[offshore78]

thxs for the info, sounds like the race gas is the way to go!!

[AZ440ex]

Originally posted by Honda or DI3
definatly dont want tht
thts just waiting 4 ur head gasket 2 go

+1 Detination will pop a head gasket in no time. IMO that is why so many people think a 440 is bad and you must have oversized studs. I have run both desert am MX racing on a 440 with 11:1 on race fuel for 5 years on stock head studs with Zero problems. People run junk gas and it kills the motor. I inspect fuel stations and you would not belive the junk in the average gas station fuel system. Everything from water to sludge!! Race fuel is pure and clean, even if you only ran 100 octane its still a cleaner fuel.

[400exrider707]

At 12.5:1 compression on a 440 build, you definitely need to be running race gas. I would suspect some damage is already done. It doesn't take much for detonation to do damage. I would also recommend the heavy duty head studs on that motor as well, especially now that you've detonated the motor a few times, because that means the motor was HOT, and that heat breaks down the aluminum in the cylinder and allows the head studs to pull. Keep an eye on that headgasket.

[offshore78]

thxs for all the info, one more Question... What octane in the race fuel should i run in it?

[drew416ex]

110 would be good.

[GrAnSpOrT]

Sorry to steal thread. But what type of fuel is best in a 460 stroker motor?

[drew416ex]

Originally posted by GrAnSpOrT
Sorry to steal thread. But what type of fuel is best in a 460 stroker motor?

It doesnt really matter what size the engine is, just how much compression it has. Most companies recomend 100 octane min. on 12:1, but it wont hurt to run 110. Its safe to run 93 on 11:1, but I like the added reassurance of the race gas, plus its just a cleaner burning fuel.

[hypersnyper6947]

I have 11:1 440 and i run 93 with octane booster, is this good, my mods are in my signature. BTW im getting rid of the lectron for a 450 carb i dont know if that matters or not.

[drew416ex]

Originally posted by hypersnyper6947
I have 11:1 440 and i run 93 with octane booster, is this good, my mods are in my signature. BTW im getting rid of the lectron for a 450 carb i dont know if that matters or not.

I dont know if octane boosters actually work. Ive read that they do and that they dont. I havnt ever tried them. You should be fine with 93 on that compression with the stage 2 cam. I prefer race gas because it is cleaner than fuel from a gas station and mine runs a little cooler on it too.

[hypersnyper6947]

How much would it cost to get some race fuel with lower octane like 100, i have ticking in my engine head too but im pretty positive its just my valves, they get louder with the stage 2 cam. Also if i get my carb jetted to 93 and then run 100 race will that mean i have to re jet or should it be good.

[drew416ex]

Im not sure how much 100 octane runs, but that would be fine for that compression. I want to say its around $5 a gallon here and 110 is $7. You should check the jetting. You may only have to go up one or two sizes on the main if any.

[AZ440ex]

I run 110 or 112. Both are about 6.50-7.00 bucks. They have 100 at the pump here but you gotta wonder how fresh it is. Once race fuel is open the shelf life isn't long. I am lucky a bulk fuel plant here will sell in small quantities so I do not worry about freshness. As for octane boosters, they are crap!! You can't help junk gas by adding octane.

Also with VP 112 I usually run a bit of Lucas upper cylinder lubercant. VP has a tendancy to be "dry". It's leaded so it should be alright on the valves but I just add a little protection.

Just don't get into the 114-118 octane. You will lose power unless you have a motor built for it.

[AZ440ex]

Originally posted by hypersnyper6947
How much would it cost to get some race fuel with lower octane like 100, i have ticking in my engine head too but im pretty positive its just my valves, they get louder with the stage 2 cam. Also if i get my carb jetted to 93 and then run 100 race will that mean i have to re jet or should it be good.

The stage two cam is pretty noisy.

[AZ440ex]

Originally posted by GrAnSpOrT
Sorry to steal thread. But what type of fuel is best in a 460 stroker motor?

Run race fuel. You spent the money on the motor, it's not worth getting junk fuel and ruining it.

If for some reason you must use 93 always pump the 1st gallon in your truck/ car. This will get any possisle mid or low grade out of the hose/ pump etc..

[odog]

i dont want to steal the thread but i was wondering since most people in this thread that posted is running a 440 or a 440 stroked how do u guys compare to the 450rs

[hypersnyper6947]

I have not got to ride mine much but the guy i bought it from had it at 12.5:1 CR and he said he used to beat 450s.

[drew416ex]

I have no problems with most 450's. There are the ones that are strokers that I cant hang with but most of them arent a problem.

[hypersnyper6947]

^
Yea i bet you do, your mods sound pretty awesome, i would love to see the look on the 450 guys face when you smoke them. hopefully when i finish mine i can beat a few also.

[drew416ex]

Originally posted by hypersnyper6947
^
Yea i bet you do, your mods sound pretty awesome, i would love to see the look on the 450 guys face when you smoke them.

I love it. They just kinda sit there with a dumb look on their faces and then say they wernt trying or they are having problems with it that day. Excuses excuses!