4-bolt main caps, air-gap Q

[Andreas]

My buddy are installing 4-bolt main caps on his 4.3 Ty motor.
He gets a air-gap 0.015" while the Pro-gram recommends 0.0015" to 0.002"

Is that the way it is for every one, that you have to shave of 0.0013" to 0.0135" from the caps?

 

[NecroWolf]

Re: 4-bolt main caps, air-gap Q

i think you use a blunt chisel on the block to tighten the gap

 

[4C FED]

Re: 4-bolt main caps, air-gap Q

I don't think it's quite so simple to just put the 4 bolt caps on, drill the extra holes & go.
It probably needs to be align-bored to get everything straight & the bearing crush correct.

This is what Clevite recommends for bearing clearance. http://mahleclevite.com/techbulletins/CL77-1-205R.pdf

 

[Syclone #1721]

Re: 4-bolt main caps, air-gap Q

Yes....all blocks are machined a little different so the caps are made a little heavy to be trimmed with a cap cutter to get the correct air gap. ANd yes, once installed the block has to be line bored and honed.

 

[Andreas]

Re: 4-bolt main caps, air-gap Q

i think you use a blunt chisel on the block to tighten the gap

Funny

 

[Andreas]

Re: 4-bolt main caps, air-gap Q

I don't think it's quite so simple to just put the 4 bolt caps on, drill the extra holes & go.
It probably needs to be align-bored to get everything straight & the bearing crush correct.

This is what Clevite recommends for bearing clearance. http://mahleclevite.com/techbulletins/CL77-1-205R.pdf

No he doesnt think so either. He's got a small machine shop. Block is up in the milling machine for the drilling of the extra maincap holes. We were just surprised that the start gap was 10 times off...
Every other machine work lika bore the cylinders, align-bore, valvework on the vortecs is being done by race-motor builder.