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holes in between cylinders through main web
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Author:  torkhp [ Sun Nov 11, 2012 6:04 pm ]
Post subject:  holes in between cylinders through main web

I've read where some guys have put holes between cylinders, I believe through the main webs, to help even out the pressures in the crankcase, in the belief that there is power to be made with this mod. I'm thinking that a vacuum pump would be required to make this effective. Any ideas or info will be greatly appreciated. Thanks guys.....still learnin

Author:  Adger Smith [ Sun Nov 11, 2012 7:04 pm ]
Post subject:  Re: holes in between cylinders through main web

It works, with or without a vac pump. Actually a vac pump makes the balance passages less effective, not as important. It is all about the balance of air movement in the sump.
I've had a couple of R&D guys tell me that the holes can help more when they are directional.

Author:  Ken0069 [ Sun Nov 11, 2012 8:18 pm ]
Post subject:  Re: holes in between cylinders through main web

Never heard anything about this before?? Would someone care elaborate on this and maybe include a link to a picture of what you're talking about? :-k

Author:  Adger Smith [ Sun Nov 11, 2012 8:51 pm ]
Post subject:  Re: holes in between cylinders through main web

Mark,
Look at the bottom end picture. See the closed cam, too!

http://www.popularhotrodding.com/engine ... ewall.html

Author:  Ken0069 [ Sun Nov 11, 2012 11:11 pm ]
Post subject:  Re: holes in between cylinders through main web

Thanks Adger, I understand now but I'd be somewhat reluctant to do that to a high HP SBC due to it possibly weakening the main web. Ever seen a 400 SBC blow the crank out the bottom pulling the main web with it? It wasn't pretty. #-o

Author:  rick360 [ Mon Nov 12, 2012 12:36 am ]
Post subject:  Re: holes in between cylinders through main web

Image
Adger Smith wrote:
Mark,
Look at the bottom end picture. See the closed cam, too!

http://www.popularhotrodding.com/engine ... ewall.html

I've seen them before, but I don't know how they make them other than a couple days with a die-grinder. ](*,) Does somebody make a tool for this? I guess I don't see the closed cam??? It looks like it is open and has a newspaper rolled up in the cam journals. :-k

Adger Smith wrote:
It works, with or without a vac pump. Actually a vac pump makes the balance passages less effective, not as important. It is all about the balance of air movement in the sump.
I've had a couple of R&D guys tell me that the holes can help more when they are directional.

When you say directional, which direction? all the same? You are talking about a radius on one side and sharp edge on the other? Interesting that compartmented oil pans are the hot ticket now but then you want to cut holes between the cylinders. I guess the holes keeps the air that's pumping under the pistons from going thru the oil to get to another cylinder where the piston is moving the opposite direction and takes a shortcut.

Rick

Author:  Ken0069 [ Mon Nov 12, 2012 4:29 am ]
Post subject:  Re: holes in between cylinders through main web

Dunno but it's my understanding that windage is what lubes some cam followers or at least that's what Comp Cams told me years ago after I wiped a roller tappet. Of course that was before those pressurized oiler lifters hit the market. Back then they said that their roller tappets weren't designed to operate under 1500 RPM because there wasn't enough windage to lube the old style lifters.

As far as the machining goes, there's some CNC stuff out there that will do that. In fact, I believe Kevin Blanks (Blanks Racing Engines) down in Clarksville, Va has a new machine that will do it as he just did the machining on TMC's Olds block that I mounted those aluminum caps on last year on it using an end mill then a conventional align hone.

Wonder if the "Cup" guys are doing this? :-k But then again, they run dry sump systems that act like a vacuum pump so maybe not? :-k

Author:  shrinker [ Mon Nov 12, 2012 5:21 am ]
Post subject:  Re: holes in between cylinders through main web

The engine we have in the race boat has sealed cam tunnel with the whole entire top of the engine as an oil bath, the scavenge sucks the oil from the absolute top of the rocker cover. there are squirters to flow oil onto each valve spring even though they are under oil. The valley is sealed and full of oil with a plug to save having to fill it with 10 liters too much ha ha. No oil sealing problems, no leaks, no under lubrication or overheating of anything. No smoke, no oil in cylinders or leaking down valves.

Author:  Adger Smith [ Mon Nov 12, 2012 10:59 pm ]
Post subject:  Re: holes in between cylinders through main web

It was a joke about the Cam tunnel being closed in the picture. I would bet he had a 55 mm cam in it and wanted to cover it up. Sharp eyes caught it!! :~)
Think about the cycle of up and down in an engine. I think what my buddies were saying is the placement of the hole to maximize the directional flow , letting high pressure fill low pressure similar to intake manifold plenum flow pulses. I have a picture one buddie sent me that has the holes in a totally different location than Wades. I've also had a couple of Cup blocks come through my shop with interesting lower end modifications. Both Ford. One had the cam tunnel sealed and the mains webs sealed way down into the pan area, no holes from chamber to chamber. The other was sealed off similarly and had cross feed holes down in ,below, the windage tray level. These two engines were bought from 2 different Cup shops. Not on e-bay. When I started pressing one of my buddies he buttoned up on me!!! Wish I knew more about these.....

BTW did anyone notice what kind of block that was?? and the sleeves in the bores?
Look closely at all the pictures . There is one that is a dead give away!! tony and his crew are sharp....

Author:  rick360 [ Mon Nov 12, 2012 11:53 pm ]
Post subject:  Re: holes in between cylinders through main web

Adger Smith wrote:
It was a joke about the Cam tunnel being closed in the picture. I would bet he had a 55 mm cam in it and wanted to cover it up. Sharp eyes caught it!! :~)
....
BTW did anyone notice what kind of block that was?? and the sleeves in the bores?
Look closely at all the pictures . There is one that is a dead give away!! tony and his crew are sharp....

You don't miss much do you Adger? Must be why they have you on the tech committee for EMC.

Sorry, I didn't catch the joke, [-( ... I thought I missed something. You can run 55mm cam journals in Stock Elim? They need that to loft the valves as high as they want?

I see the block is a 182 casting bowtie. My GM book lists that block but doesn't say what bore it is but it must be bigger/thicker walls since he is sleeving it down to whatever legal bore he needs for a 283. For cylinder wall strength I assume.

Rick

Author:  racear2865 [ Tue Nov 13, 2012 10:28 pm ]
Post subject:  Re: holes in between cylinders through main web

If you look closely, the main bearings are cross hatched for anudder set of mains on top of deem
reed

Author:  Ken0069 [ Tue Nov 13, 2012 11:03 pm ]
Post subject:  Re: holes in between cylinders through main web

Talked to Don Kowalsky of Kowalsky Racing Engines today about the holes in the main webs and he says that he tried that on several of his NASCAR LMS lease engines back about 3 years ago but didn't see any power from it so he stopped doing it. :-k

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