[77 TRASHCAN]

Originally Posted by b-man

You have a lot invested in your heads.

Pay a machinist to drill the hole and install the brass sleeve, you’ll be glad you did.

Yes!!! A machine shop has better ways and tools to do this job once and correctly!!!

[HWYSTR455]

Originally Posted by steve25

He found the issue gang!

Enlighten us please.


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[steve25]

Please explain to me why a machine shop is better equipped to do this repair if you would?

More then anything it takes patience during the insertion and epoxy phase of the repair and time cost money when you have someone else do it.

[HWYSTR455]

Nevermind, went back and figured it out.


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[steve25]

Sorry, I did not mean to ingnor your question.

[Tim Corcoran]

Originally Posted by steve25

A drill press would be the best way to do it, but you would need to cut a lenght of wood to a 14 degree angle to sit the head on.

I have always done it with a big hand held electric drill that I have which has a side bar handle .
Maybe you could brorow one or get you hands on one from a tool rental shop.

Steve

I believe the valves are 14 degrees from the cylinder head to block mating surface, but it looks like the push rod holes are 90 degrees to the head mating surface. So why would I need a 14 degree shim under the head to drill the push rod holes on my drill press? Is there something I am not understanding.?

[VCho455]

Good to hear. My buddy’s shop is finishing up a 426 Chrysler rebuild that started off like this. Big dollar factory Hemi car just purchased at auction. Several months later the owner couldn't figure out why it ran poorly. Long story short the heads had been hogged out and there was a quarter sized hole between two of the intake ports. There were traces of epoxy where someone tried to fix their mistake. Needless to say both heads ended up being junk. Good to hear yours are salvageable.

[DogMeister]

Can someone describe to me exactly where the vacuum leak was? I'm facing an identical issue on #4 cylinder. 461 stroker, brand new RA III cam and lifters, 1970 HO intake manifold. I'm not clear on whether it was in the intake or head and where.

Thanks in advance.

[steve25]

Tim if your doing it not by drill press means the 1/2” bit will just follow the hole there now and you will be fine & dandy.

[steve25]

Dog mister, Tim had ground thru the push rod buldge in a intake port and the epoxy repair that he did failed on him.

[Tim Corcoran]

If the pushrod hole is 90 degrees to the head surface I would feel more comfortable drilling it in a drill press

[HWYSTR455]

Originally Posted by DogMeister

Can someone describe to me exactly where the vacuum leak was? I'm facing an identical issue on #4 cylinder. 461 stroker, brand new RA III cam and lifters, 1970 HO intake manifold. I'm not clear on whether it was in the intake or head and where.

Thanks in advance.

I missed it too, zoom on pic on post #24


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[DogMeister]

Originally Posted by steve25

Dog mister, Tim had ground thru the push rod buldge in a intake port and the epoxy repair that he did failed on him.

Thanks. So it was in the cylinder head then. There's been no work done to mine so I guess I'll keep looking for my #4 misfire. Going to listen for vacuum leaks and do some plug/wire swaps today. Maybe swap intake gaskets too.

[Tim Corcoran]

Dog, if you follow through this complete chain and check all the things I did I think you will find your miss fire.

[mgarblik]

I would have a sleeve installed in a seat and guide machine or a mill so you can get it in there straight. I coat with epoxy like Steve said. I have many sizes of thin wall stainless steel tubing. It installs easier than copper and is thinner. PM me and I will send you a piece for postage. Glad you found the problem. Once the head is off, no big deal to fix.

[Tim Corcoran]

PM sent

[PAUL K]

I'm not understanding why the head needs to be removed and machined to .500 ..... Why not just tap a sleeve in the existing pushrod hole?

[Tim Corcoran]

Originally Posted by PAUL K

I'm not understanding why the head needs to be removed and machined to .500 ..... Why not just tap a sleeve in the existing pushrod hole?

Paul
I'm treading in new territory here and I have no idea if that is even possible or not.

[77 TRASHCAN]

Originally Posted by PAUL K

I'm not understanding why the head needs to be removed and machined to .500 ..... Why not just tap a sleeve in the existing pushrod hole?

I'm guessing the push rod hole may not be of a uniform size from top to bottom?
Needs to be machined to next minimum size to fit a specific known sleeve size, maybe?

[PAUL K]

Originally Posted by 77 TRASHCAN

I'm guessing the push rod hole may not be of a uniform size from top to bottom?
Needs to be machined to next minimum size to fit a specific known sleeve size, maybe?

No that shouldn't be the reason. Pontiac machines the pushrod holes and brass tubing is commonly available in a corresponding size. Most hardware stores carry it. We've sleeved pushrod holes many times in the past.

Unless I'm missing something, drilling the hole larger may really complicate things.... But I like keeping chit simple. I leave the complicated projects for the Pro's.