Balance shaft block

Lynn D. Brown

New member
Balance shaft block

Jesse,

In past posts, some people think it may not be as strong a block. The extra holes will weaken it and the shaft will add reciprocating weight.
 

myclone

Donating Member
Im 99.9% sure that the balance shaft block timing chain cover is diff than the old school 4.3 (read: no after market covers). Its been a while since I put my eyeballs on a balance shaft block so I cant recall for sure.

What I know 100%... If you get rid of the balance shaft then you have to plug the oil passages to it or you'll have a massive oil leak/no oil pressure.

Things Ive heard... The blocks arent as beefy as the older non balance shaft blocks. Dunno myself and about the only way to find out is have one sonic checked until ppl start trying to build em to see what level they start giving out (kinda expensive to do it that way if ya ask me).
 

vortecfiero

New member
Not to mention the reason for the counter rotating balence shaft in the first place...

I've had both engines and believe me the counterbalenced Vortecs are a hell of a lot smoother and easier on mountsand accessory brackets.
It pulls to 5500 rpm and a red line of around 6000 RPM is also nice.

My block has about 30,000 miles of beating on it and it runs smooth and quiet.


Without the shaft most evenfire or semi even fire 6s want to buck like a bronco and rock like a boat and the same time (Harmonic Rotating Couples?)

BYTW I've heard that the balence shaft was designed by Porche Reasearch under contract to Mitsubishi who still holds the Patient

If ya have any questions about, or want pics of, the lifter valley fire away
 

jwaller

Evil Genius/SyTy Guru
briggs and stratton made the shaft and BC it turns at half crank speed it doesnt take away that much power.

I can also attest to it's smoothness. makes my sy idle like a caddy.

the timing chain cover IS different and they made them in steel and plastic. depending on the year.
 
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