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I have some questions.

What angle is the hole drilled in the cylinder head?

What works best single cross drilled or double cross drilled for the head?

I would like to preform this modification to my 85 glh-t omni's motor while I have it out.
 

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Missed it, I think this answers my question.


***NOTE***

the holes in the head go the opposite way compared to the block

block is down and forward

head is up and forward

so looking at an imaginary cut away of the cross drilled passage from the bellhouseing end of the motor it would be like -->-- (dashes being the gasket)
 

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Discussion Starter #83
"What angle is the hole drilled in the cylinder head?"

You can check out this post on page 5, the angle is 40-45* (degrees) but it is not critical. What is critical is that you get it exactly between the cylinders. If you are off a little either side the hole will pass too closely to the cylinder wall and after the engine has been run, if you disassemble the engine you will actually be able to see a line that is where the hole went. On a over boared engine this could result in a huge problem where the hole actually opens intot eh cylinder.

At the beginning, Shelby was double cross drilling the blocks but discontinued this because of the difficulty in getting it right basically 8 times on every block, it is also very easy to snap the bit when it breaks through to the water jacket and hits the other side of the jacket. If you snap a bit off in the hole it's not coming out unless you are very lucky. A snapped off bit has to be accessed through an adjacent freeze plug hole

If you cross drill your block, and head, you then must use the appropriate head gasket for a cross drilled engine. We believe that the reason that the factory eliminates some of the steam vents on a cross-drilled head/block combination is to prevent having too many passages for coolant to flow actually reducing flow and pressure through the engine. So its best to have a factory cross drilled head, an owner cross drilled block and the MP 006 style head gasket. I THINK the 006 is the one for a cross drilled application, but you should check that, I am going from memory here.

http://www.turbododge.com/forums/f4/f19/612961-how-cross-drill-2-2-block-5.html#post3075386
 

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For the record Shelby never double crossdrilled any blocks in Engines sold to the public.

Chrysler found the issue with the situation you described.

Ed Peters talks about this in the Phoenix 97 Convention tapes originally sold by T.U.

Excellent tapes for anyone interested in 2.2/2.5 Chrysler Engines from a Chrysler Engineers point of view.

A great book for anyone interested in the Shelby Dodge history is Joel Jacksons Fast Days:

FAST DAYS

Thanks
Randy
 

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Run out of the end of the head, #4 plate, to the heater not from the stat. Then run the heater to the suction of the pump, like a Daytona not a L body. This drastically increases bypass flow through the head and will deal with dead spots. Porting the water pump housing is also on that list for cooling. If you have both types run a slotted gasket like the 005 they made or make your own holes in the 006. Lot of ways to go around the issue.
 

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yes, the 006 is for cross drilled engines.
 

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I have an 86 2.2 turbo block (possibly TII) that has what appears to be factory double cross drilling...
The holes are pointed straight down.
 

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That's not factory with the holes straight down.

Have you ever run it and do you know if it had a 006 head gasket??

I bought an unfinished project 1988 Engine that had this done and am deciding what gasket to use if I ever assemble it.

Thanks
Randy
 

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I have not ran it yet and not sure of head gasket choice yet. I love MLS head gaskets like Cometic, but I've never had an issue with FelPro.

So wth these holes just going straight down joining the rest of the coolant passage just under the deck's surface, they're not cross drilled holes at all lol! Awe heck, the things people do.
 

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Curious if your head is drilled to match??

Cross drilling holes goes between the siamesed cylinders at an angle.

I don't know if anyone has drilled the holes straight and what the result would be.

Your post reminded me of my block!!

Thanks
Randy
 

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I don't have the head that was on it, but I do have a brand new '88 turbo 782 head that only has the rear 3 cross drilled holes, wondering if I should drill the other 3 to match?..
 

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I'm looking for actual information on the angle of the hole required, their depth, where they lead/go and how long and big a hole we are talking about.
 

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I'm looking for actual information on the angle of the hole required, their depth, where they lead/go and how long and big a hole we are talking about.
Did you bother to actually read this thread? It's all spelled out. Some of your info requested I listed in post #68 on page 4 of this thread.
 
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