Topic: briggs 31 ohv head

[Murray_wide_body]

So if I take some off the head and get the flywheel for the motor it will throw off the timing that much that it will break the crank? That doesn't make much sense to me but yet I'm new to this so Idk but just knowing basic engine knowledge would tell me all that Will happen is more compression

[redline]

In a 15 race stretch, I broke 6 cranks.
I was good at it.
Then, I quit breaking them.
But, what do I know.

[BIG AL 202]

In a 15 race stretch, I broke 6 cranks.
I was good at it.
Then, I quit breaking them.
But, what do I know.

SO WHY DID YOU STOP BREAKING THEM?

[redline]

SO WHY DID YOU STOP BREAKING THEM?

Pulled some timing, quit turning over 6K, stopped cutting the heads, and then switched to Tecumseh.
The switch to Tecumseh was the biggest gain in reliability and power.

[EUBANK RACING]

shaved head or no shaved head, 4000 rpm at 30* timing you are going to break crank, .125 off head, arc rod and crank will turn 6500 rpm all day long at 30*, don't know how much they took off block to true it but I have .125 off the head and runs dang good

[BIG AL 202]

switched to Tecumseh.

Why did i know you were going to say that!! lol

[redline]

shaved head or no shaved head, 4000 rpm at 30* timing you are going to break crank, .125 off head, arc rod and crank will turn 6500 rpm all day long at 30*, don't know how much they took off block to true it but I have .125 off the head and runs dang good

Huh? So you need to keep it over 4000 rpm, then the crank wont break?
Or, are you saying "If you turn it over 4000 rpm, you will break the crank regardless of what mods are done".?
Our Briggs ran pretty good too..

[Darkviper]

If you run a ARC billet crank you will have no problems.

[nic_hayes]

If you run a ARC billet crank you will have no problems.

I broke an ARC crank so don't say you will have no problems. It's all about how much timing and how fast you are going to turn one. The head has nothing to do with the cranks breaking.

[PJG56]

shaved head or no shaved head, 4000 rpm at 30* timing you are going to break crank, .125 off head, arc rod and crank will turn 6500 rpm all day long at 30*, don't know how much they took off block to true it but I have .125 off the head and runs dang good

explain please.

[Darkviper]

If you run a flathead hub it has way to much timing for ohv IV done it most people do. Run avs hub cause that's what timing should be on a ohv.

[PJG56]

That's not the answer to my question.
Yourgoing to break crank @ 4000 with 30deg timing but not 6500 with 30deg timing?

[George Herrin]

Hub depends on which ohv non avs or avs, yes they are different.

[Darkviper]

No what I'm saying is if you run a non avs motor run if you run flathead billet flywheel make sure you order avs hub for it because when you run flathead hub they timing is way higher on ohv motor and avs hub is the timing you should use.

[George Herrin]

if a 28 non AVS I disagree. Best way to know your timing regardless of block used is use a degree wheel. 30* piston should be approximately .200 in the hole.