416 questions.

[DEAL]

I'm building a 416 and have a few questions.
I've heard of 400ex's having weak cam chains. Since I'm on a bit of a budget I don't have a ton of money to spend. So I'm wondering if I'm ok running my stock cam chain.
I'm only running 11:1 compression so will I have any head gasket problems?
And also what jetting should I run, I'm at sea level, with an opened air box, slip on pipe and the head will be ported.
Thanks.

[cals400ex]

i am running the stock timing chain with my 406. i also have the 11:1 compression. i have not had any head gasket problems either. i am running a modded airbox lid, uni filter, complete pipe, 11:1 compression piston, and stage 2 hotcam. my jetting is:

160 main
45 pilot
2.75 turns out on the fuel skrew
4th position on the needle

i am close to sea level and the temp right now is 50's in the night and around 70 in the day.

[Silverfox@C&DRacing]

I am still running on my stock cam chain since 99 and have had a 416 since 00 and the chain is still holding up.

[josh]

you should be fine with the stock cam chain, i rode a 440 with a stock cam chain and a aftermarket EVERYTHING besides the chain and valve springs, it hauled and it ran fine, most reliable 440 i've seen, it did have a J.E. piston in it, but if you port the head it will actually lower your compression slightly wich theoretically takes stress off some components such as cam chains and valve/valve springs/and some other internal top end peices, it should work ok tho, and you'll have to take your clutch out if you want to change that chain so it's kinda a pain, good luck tho

[emiliano22]

My experience with my 416 11:1 is this.

Main jet 165
Pilot jet 45
No head gasket problems. :)
No cam chain problems. :)
and
No bigger changes in power. :mad:
Somebody say I need the cam for big power change, but I'm not sure.
The only thing important is change the oil and filter more often.

[airheadedduner]

Originally posted by josh
but if you port the head it will actually lower your compression slightly wich theoretically takes stress off some components such as cam chains and valve/valve springs/and some other internal top end peices, it should work ok tho, and you'll have to take your clutch out if you want to change that chain so it's kinda a pain, good luck tho

How is that so?? I know that is true on a 2-stroke, but thumpers have valves, no matter how big the port is the valve seals it. I can see a diffenent cam could hold the exhaust valve open longer but I don't think any are made that way cause you would loose intake charge out the port.


I have a stock cam chain in my 440, it is fine, it is an 01'.

[DEAL]

Thanks alot guys.

[josh]

Originally posted by airheadedduner
How is that so?? I know that is true on a 2-stroke, but thumpers have valves, no matter how big the port is the valve seals it. I can see a diffenent cam could hold the exhaust valve open longer but I don't think any are made that way cause you would loose intake charge out the port.


I have a stock cam chain in my 440, it is fine, it is an 01'.

well my theory was if you look at a compression calculator it asks for the dome size, if you largen the dome size on the head, it actually does SLIGHTLY lower the compression and makes more air flow and faster airflow, so technically if you do a decent size port job, i mean by taking metal away from the dome than it will VERY SLIGHTLY lower your compression ratio, nothing really noticable but in theory it does, it shows up more on something like a v8 because you buy different heads with different dome sizes which makes a big difference, or if you port it it does the same effect, just leaves the valves at the stock distance from the piston, i was talking VERY SLIGHTLY though

[F-16Guy]

If you're on a budget and are questioning your stock chain, the CRF450R chain will work perfect, is stronger, and sells for about $28 from Service Honda. I used one in the last rebuild I did with no problems so far.:cool:

[airheadedduner]

Originally posted by josh
well my theory was if you look at a compression calculator it asks for the dome size, if you largen the dome size on the head, it actually does SLIGHTLY lower the compression and makes more air flow and faster airflow, so technically if you do a decent size port job, i mean by taking metal away from the dome than it will VERY SLIGHTLY lower your compression ratio, nothing really noticable but in theory it does, it shows up more on something like a v8 because you buy different heads with different dome sizes which makes a big difference, or if you port it it does the same effect, just leaves the valves at the stock distance from the piston, i was talking VERY SLIGHTLY though
But the ports are past the valves. Porting is not taking material away from the combustion chamber. I know what compression ratio is. If the valve is sealing at the same time as normal, compression should be the same.