lifter bore adj hole

[outsider347]

What dia hole suggested in the lifter bore for the adj lifters?

Tks

[Ol' Ron]

I don't think it makes much difference, I use 3/16 but 1/2" might be alittle big'
G

[Bored&Stroked]

I usually use a long 3/16 drill bit that I get from McMaster Carr. You can't easily get any sort of drill in the valley, so you need an extra long bit.

[pistonbroke]

I did 3/16's but don't make the same mistake
I did. Drill the holes as low down on the lifter bore wall as possible, about half of mine were just to high so the holding tool wouldn't quite pass into the lifter, Tim

[Tim Ayers]

Depending on the type of cam you are using, I may suggest scalloping the top portion that faces in towards the valley. With a high lift reground cam, the adjusting screw on an adjustable lifter can sometimes sit below the top of the lifter boss which makes it hard to turn the adjusting screw.

[Bored&Stroked]

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Originally Posted by Tim Ayers

Depending on the type of cam you are using, I may suggest scalloping the top portion that faces in towards the valley. With a high lift reground cam, the adjusting screw on an adjustable lifter an sometimes sit below the top of the lifter boss which makes it hard to turn the adjusting screw.

Good idea! I usually do this as it allows you to adjust the lash with the lifter all the way down on the heel of the cam (which is where you're supposed to do it!).

[Bored&Stroked]

When you're running longer valves, this also helps one get to the adjuster screws - which is a real pain if you don't relieve the tops of the lifter bores.

[outsider347]

Thank you Gents.

[Ol' Ron]

Remember................ The lifters were made for stock valves and cam. They work well on cams with up to.350 lift. More lift requires the adjusting screw to cume out of the lifter creating a loose condition and noisy lifters. The easy solution is to use the SBC 1.5 valve which is .060" longer. They also make a larger 1.6 valve winch will allow you to repair a bade seat with out using a seat insert .
Gramps

[outsider347]

Tks Ron
Great info

[Karl Wolf]

I have been wondering if these hole could be drilled from the bottom side of the block.
This may involve figuring out where the lifter locates,
while on the back side of the cam lobe,
to make a jig - a drill guide.
Karl

[flatjack9]

Originally Posted by Ol' Ron

Remember................ The lifters were made for stock valves and cam. They work well on cams with up to.350 lift. More lift requires the adjusting screw to cume out of the lifter creating a loose condition and noisy lifters. The easy solution is to use the SBC 1.5 valve which is .060" longer. They also make a larger 1.6 valve winch will allow you to repair a bade seat with out using a seat insert .
Gramps

Some of the original Johnsons came with a thicker adjuster bolt.

[TomT/Williamsburg]

The lifter hole info is great - comparing a stock lift cam to your new cam should give you an idea of where to drill your hole as you look at the groove in your lifter. What I have been taught is to get one intake and one exhaust valve set up with your adjustable lifter and set the rest to that measurement to make your adjustments that much easier/ closer to what you need for the other 7 cylinders. I might be stating the obvious to most who have done builds but I figure I would throw it out there …

[outsider347]

Originally Posted by TomT/Williamsburg

The lifter hole info is great - comparing a stock lift cam to your new cam should give you an idea of where to drill your hole as you look at the groove in your lifter. What I have been taught is to get one intake and one exhaust valve set up with your adjustable lifter and set the rest to that measurement to make your adjustments that much easier/ closer to what you need for the other 7 cylinders. I might be stating the obvious to most who have done builds but I figure I would throw it out there …

Good idea
tis

[Newc]

I would like an illustration on drilling and dishing bore, so chip cleaning could be done early before assembly. Newc

[Ol' Ron]

Another bit of information that might help here. Because I had to do allot of blocks, drilling these holes became a time issue. If one hole was off you had to drill another, and if you had the engine assembled, where would the chips go. been there dine that. SSSOOOOO I took an old distributor shaft drilled a hole in the end and pressed in a short philips driver sharpened to a point. Now the size of the shaft was just right and the hole loation was easy to dril with the long drill. Now this operation only took a few minuts from start to finish. Don't forget to clean the holes.
Gramps/
If I could post pictures I'd post one??????

[Tim Ayers]

Originally Posted by Newc

I would like an illustration on drilling and dishing bore, so chip cleaning could be done early before assembly. Newc

Correct. My engine is all buttoned up. I'll try to find one of the rebuilding books that shows these operations in great detail.