To Notch the lifters / Hoover mod. or not?

[Bug53]

[oprn]

If the center post is thin on the top from clearancing why not just open up the bottom and leave the top alone?

Also, why just a single slot on the lifters? The Hoover mods call for 3 slots as I recall.
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[modok]

1/8 NPT is what most would use.
that's larger than it actually needs to be but the case is thick enough around there it should work fine.

There is 1/16 NPT but the taps seems not to live long and they seem to get stuck easy, bet I'm not the only one. That might be too small or it might not I don't recall.

[Bug53]

What is the recommended method of closing up the hole where the case plug was after drilling?
I was thinking a small NPT pipe plug but if you guys have a tried-and-true method I'm in.

[txoval]

Makes no sense to me…without the port open more oil would flow into case sump area as it dead heads there instead of going to the lifters/pushrods

Plenty of engines built without it, but I see it as a benefit.

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[RickS]

I find it interesting that Todd Francis, who produces the TF-1 case, does the horizontal drilling, but does not drill through the cam saddle. He leaves that up to each individual to decide if they want to do it. He told me some builders aren’t sold on the idea. Food for thought.

[txoval]

This why I said above to not mess with the oil slots/paths in the bearing saddle. The clearancing done on the aluminum cases pretty much removes that option.

Drilling and connecting the ports is super easy on the aluminum cases…as you see it’s almost done.

VW did make these mods on the Type 4, but never did on the Type 1 because they were cheap low power/low rpm engines

[modok]

Connecting the oil passage seems like a good idea. I have not done it to any of my own engines yet, but can't see a real downside unless you drill too far.
Did it to one engine I built for a guy, that was a BUS engine so maybe it will helpful.

ALSO don't forget to put the oil pump in and see that the case passages line up correctly with the oil pump. Any air leak on the INLET side of the pump is bad news. That can bite you if overlooked.

[Bug53]

It seems to me that the pathway is already there thru all the lifter bores right up to the last one. It almost makes no sense that the factory wouldn’t have gone all the way to the end. Where the cases were milled and drilled it would have been a free modification that cost VW nothing. An extra 10 seconds and a drilling down thru the bearing post wouldn’t have taken them more than a minute per case .

So with that said why didn’t VW do it??
With the level competence and extreme engineering the Germans were capable of this couldn’t have been an oversight.
With feedback coming to VW from across the globe why were these two drillings not done. My new aluminum case has the bearing post drilled about 80% in already with a large supply galley.

My lifters aren’t Udo’s but simply CB lightweights. At 69 I’m not planning on ever seeing them again or hope I never have to Lol!!
As you can see the center bearing post is reduced from stroker clearancing.

[Bug53]

It seems to me that the pathway is already there thru all the lifter bores right up to the last one. It almost makes no sense that the factory wouldn’t have gone all the way to the end. Where the cases were milled and drilled it would have been a free modification that cost VW nothing. An extra 10 seconds and a drilling down thru the bearing post wouldn’t have taken them more than a minute per case .

So with that said why didn’t VW do it??
With the level competence and extreme engineering the Germans were capable of this couldn’t have been an oversight.
With feedback coming to VW from across the globe why were these two drillings not done. My new aluminum case has the bearing post drilled about 80% in already with a large supply galley.

My lifters aren’t Udo’s but simply CB lightweights. At 69 I’m not planning on ever seeing them again or hope I never have to Lol!!
As you can see the center bearing post is reduced from stroker clearancing.

[modok]

grinding a little groove in the lifters is of such low importance that I don't care if you do or not. I doubt it will matter.

Unless they are really nice lifters, in which case I'd be more hesitant to do it because the next guy might feel different about it.
If they are cheap lifters that will get thrown away later then go for it.

It's a part of the VW history now, being notable as the one thing Hoover and Berg actually agreed about, so that's cool. But it doesn't mean it's important in how the engine performs, FAR down on the list.

[Bug53]

[Bug53]

I do see the saddle is reduced on the clearanced case.
Maybe I’ll just radius the top ends of the supply holes.

[txoval]

By completing the drill mod you’re creating a second path of oil to the lifters > pushrods > head.

More available volume so that when you slot the lifters you get the additional oil to the heads.

Porting the oil slots in the cam bearing saddles is the one I don’t do. With the second path it’s unnecessary and if you do it, both sides of the case need to align…meaning port both equally. Good luck with that. On a clearanced case there’s not much meat left on the saddle to do so.

[Howard 111]

Is this what you are talking about?

http://www.geneberg.com/popup_image.php?pID=415
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http://www.thesamba.com/vw/forum/viewtopic.php?t=531270

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