Purpose of Steam Holes?

DJCarbine · Apr 21, 2007

In my recent travels on google it appears that 289 blocks have steam holes that allow, well.... pockets of steam to escape the block and prevent overheating. The GT40 heads I put on do not have these holes. Are these holes necessary, or simply a precautionary. I'd hate to rip the heads off and drill the holes unless it was critical.

65fast · Apr 22, 2007

Had the same problem when installing 65 289 heads on a new roller block, I did not drill the holes. The general consensus I got was it did not matter if you drilled the holes.

coolblue65 · Apr 22, 2007

When I bought my Trickflow heads the instructions said you had to drill steam holes in your block if they didn't already have them. So, I called Trickflow to see if it was absolutely necessary to drill the holes in my block because I didn't have them already, they ended up saying I had to drill the holes.

HistoricMustang · Apr 22, 2007

coolblue65 said:
When I bought my Trickflow heads the instructions said you had to drill steam holes in your block if they didn't already have them. So, I called Trickflow to see if it was absolutely necessary to drill the holes in my block because I didn't have them already, they ended up saying I had to drill the holes.

I did the same on my 289 block when installing the newer model Edelbrock heads. Simply follow the instructions provided.

HistoricMustang

Jimmys66 · Apr 23, 2007

I had the opposite. I had holes in the block and not in the heads. Pooped up 2 head gaskets before I drilled the holes in the heads.

I would have never thought it would make a difference either.

65fastbackresto · Jan 18, 2008

I didnt drill the holes in the block

with my Edelbrock heads, and my car over heats real easy, I think I`m gonna have to tear the heads off and do it before summer.

VTStang66 · Jan 18, 2008

Does anybody have pics of these steam holes? I've never heard of them. I have Edelbrock heads and ran them for a couple years with no heating problems, but the engine was mild. I have water passage holes, but I don't see any others.

65fastbackresto · Jan 18, 2008

To my knowledge its only needed

on blocks older then 1981. Me and my engine builder went round and round over this issue and I let him talk me out of it.......big mistake on my part.

Chances are if you needed to drill yours you`d already know. Mine heats up in like 10 seconds or less when I flog it, and every part is new, including radiator.

Here is part of an email I received from Edelbrock tech on the issue.

The cylinder head has a large, roughly kidney shaped, water passage cast into it that feeds the steam hole, it is not a separate distinct hole. Our heads are reversible, there is a hole in the appropriate area on both sides. Please note that the driver’s side and passenger’s side holes are in different positions. The steam hole would be drilled in the block, it would not have to match the shape of the hole on the cylinder head. Although I am uncertain of the precise consequences of not drilling that hole, I would have to assume that it would cause a significant cooling issue.

rbohm · Jan 18, 2008

the steam holes are there to prevent hot spots, and to prevent those hot spots from becoming heating issues when the cooling system ages.

PUNISHER RACING · Jan 18, 2008

You absolutely have to drill them to match the block if not the steam will push the gasket up and start to empty coolant into your crankcase. Had this happen to me with a 68 289 and aftermarket heads.

65fastbackresto · Jan 18, 2008

Is this something I can do with it in the car?

Will the metal shavings go down into the block and hurt it?

The guy that wants the pics of where the holes go, try the Edelbrock website, I bet there is info on there, look for the old style heads 1981 or older, and there should be a spec sheet with the part. Mine were part number 60229.

Harndog · Jan 18, 2008

As far as metal shaving's in the block. Best case would be to have the block cleaned afterwards but I have seen guys put a globe of vasoline on their drill bit and it will catch most if not all of the shavings. Good luck

mrmustangman357 · Jan 19, 2008

does this apply to the 351W?

Jimmys66 · Jan 19, 2008

PUNISHER RACING said:
You absolutely have to drill them to match the block if not the steam will push the gasket up and start to empty coolant into your crankcase. Had this happen to me with a 68 289 and aftermarket heads.

This is what happened to me. Both of my head gaskets failed at the steam hole.

65fastbackresto · Jan 19, 2008

I think it applys to small block fords in general

that are running aftermarket heads that require the steamhole provision.

PUNISHER RACING · Jan 19, 2008

You don't drill the block you drill the bottom of the head to correspond with the block. I believe this is only necessary on blocks earlier than 70 or 72

mrmustangman357 · Jan 19, 2008

my 351w's block didnt have steam holes. it is a mid 70s casting

Jimmys66 · Jan 19, 2008

PUNISHER RACING said:
You don't drill the block you drill the bottom of the head to correspond with the block. I believe this is only necessary on blocks earlier than 70 or 72

I feel like I'm your follow up show.....

At the time I was using a 72 302 block and a 69 351w head. The 351w head did not have the steam holes.

Finding the location to drill the head was easy. My new set of 302 head gaskets had a hole in them. Mark it with a sharpie and drill.

danny clemens · Jan 19, 2008

Do AFR 185s on an early 351W need the holes drilled?

C0V3R · Jan 19, 2008

Anyone got a photo of a steam hole?

Purpose of Steam Holes?

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