Porting horizontal oil channel in head

46yblock · #1 (**permalink**) 12-22-2008, 09:40 PM

This isnt huge, but today I hogged out the horizontal oil channel in one of theheads, using a $20 Dremel want-to-be from China. Tool worked great! One of the small olive leaf stones made quick work of the channel, taking only 5 minutes. Smoothed out all the bumpy casting plus eliminated two mini mountains of cast inside the channel, so oil flow to rocker shaft will be better with less probability of blockage. Plan to do the other head tomorrow. It is so easy every head should have it done, especially if they have been milled significantly.
Mike

bigwin56f100 · #2 (**permalink**) 12-22-2008, 11:05 PM

Mike,
An old guy I know showed me how he used to open up the gasket in the same area to increase flow. I open it up from hole to hole, Inlet to outlet, or should I say block hole to head hole.

Kevin Bigwin

46yblock · #3 (**permalink**) 12-23-2008, 01:31 AM

Kevin, yeah that is kind of what I did. Didnt mess with the gasket or widen the channel, but deepened it about .010 and smoothed. Will post a pic tomorrow of the new channel in the gallery if anyone is interested. If a person stretched the 5 minutes into 15 and did some polishing, it would make even more difference. The ECR A heads I was talking about in another post have a noticeably shallower channel than the later 113s. Maybe that is the same with other earlier heads, and could have produced problems.

How did you modify the gasket without ruining it? Seems kind of tricky. So say the gasket was widened .020, that would give an additional flow channel of .010 by .043 deep on each side, assuming the port in the head was not widened. Right?

The little tool was impressive. It wouldnt work on intake or exhaust ports, but was perfect for this.

bigwin56f100 · #4 (**permalink**) 12-23-2008, 08:36 AM

I use my dremmel (sp) tool with a small cut off wheel. It doesnt look the prettiest, but I have not had any problems.

I never thought about your way before, Especially since heads have been shaved, the channel you are talking about can get real small. Good tip of the day!
Kevin

46yblock · #5 (**permalink**) 12-25-2008, 02:46 PM

This may be a pic of the first head I did:

The second one came out better. Started with the Olive leaf stone and then tried to finish with a tiny wire wheel which didnt do anything but disintegrate. Then looked at the round ball stones. They fit the groove very well. So used one of them and was very pleased. The ball stone would work best from the very beginning because it gave a better finish, and allowed the dremel type tool to be worked at a right angle to the channel which made it less likely to jump out and mar up the deck surface.

The channel on the second head ended up approx. .020 deeper than the unfinished version, which will help offset the head's heavy surfacing. On a head surfaced minimally, I dont think deepening would be a good idea, as it might produce decreased oil velocity at that point and a greater deposit of sludge. But smoothing the rough cast surface should still be a benefit.