The Ford Barn

tubman · 07-30-2016, 05:15 PM

Now that I've got the chamber volumes and squish where I want them on these heads, it's time to install them. I was getting all set to do this when I noticed that the head bolt holes seemed to be quite large. A little measuring and I found that while he head bolts are .425 inches in diameter, the holes in the heads all run about .500". That's a difference of .075, which to me is quite a bit. I put a head on temporarily with 4 bolts, and was able to move it around a surprising amount. It seems to me that this movement could be conducive to head gasket problems. What to do? In a perfect world I'd send the whole engine out and have locating pins installed, but this is already assembled and almost ready to go. Since I am using aluminum heads, I had already purchased a set of special head bolt washers from Gary ("GOSFAST"), so I pm'd him to see what he had to say. He pins the heads on all of his builds, but as I said, that is impractical for me at this juncture. I was thinking that special "step-washers" might be the answer, so I ordered a set from Jegs's. Gary didn't seem to think much of this, and mentioned that he used some aluminum tubing for the initial alignment of his "pin jobs". This got me thinking, so I ordered a couple of pieces of 1/2" aluminum tubing in different wall thicknesses.

One sample had a wall thickness of about .030" and when compared to the bare bolt hole has a clearance of less than .010" (rather than .075"). This seemed about perfect, so I cut a couple of lengths, and they slipped right into the bolts holes in the heads, needing to be tapped in about the last .020" or so. When I installed the heads on the block, I had to wiggle them a little to get the head bolts started, but they went in by hand and when installed, the head could not be moved. I was going to counterbore the heads and install the "step-washers" on top of he aluminum tubes, but when I measured them, they had an inside diameter of .440", which is .005" bigger than the aluminum tubing, so I thought why bother? I think keeping the heads from moving around on the block will be helpful to improve head gasket seal and will save some trouble down the road. There is also he possibility of using more than two sleeves per head, or even using the "step-washers"; I'll have to see how this turns out.

The first picture shows the tubing and a "step-washer" lying, in the head, the second shows the tubes partially installed, the third shows the tubes fully installed (it's kinda hard to see), and the fourth shows the head bolted to the block. This was cheap and easy and I hope it does some good.

john in illinois · 07-30-2016, 05:43 PM

Thanks for posting this. It looks like a simple way to make flathead a little better.

John

Ol' Ron · 07-30-2016, 06:42 PM

Tubman, keep up the good work, figgering out how to fix these problems makes you a "Master putzer", I just love to putz, makes getting up in the morning very easy, when you have something to putz about.

BillM · 07-30-2016, 07:24 PM

I like it. It looks to me that the only advantage the dowel pin method would have over this would be to lock the gasket to the block. How do the bolt holes in your gasket fit the bolts?

tubman · 07-30-2016, 07:33 PM

Ron,

Though I'm not quite as old old as you (in years at least), I'm old enough that my major function is "putzing". Luckily, I've got a "young guy" (who's 56) to do the heavy lifting.

Twenty years ago, I would have just bolted a set of new aftermarket heads on, and then wondered why they didn't make much difference and caused some problems. "Putzing" has it's moments; just ask me how long it took to get the aluminum timing cover on this engine "just right".

Oh, and I wonder; do the new aftermarket heads for sale out there have this (in my opinion) huge tolerance with the head bolt holes? Somebody got a pair they can check?

Tubman

JSeery · 07-30-2016, 07:36 PM

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Tubman I wouldn't think there would be any need to do all of the holes. Something like say four corner ones should hold it in place and would make take the head on/off a lot easier. If your using bolts (which you appear to be) then it's not that big an issue, but with studs it might be.

tubman · 07-30-2016, 07:39 PM

Quote:

Originally Posted by BillM

I like it. It looks to me that the only advantage the dowel pin method would have over this would be to lock the gasket to the block. How do the bolt holes in your gasket fit the bolts?

You know, with all the measuring I did, I never checked the gaskets. I have "Fel-Pro"'s and a set of "Best" gaskets; the "Fel-Pros"s seem to be about .050" thick ) uncompressed", while the "Best's" look to be about .070". When I go to the shop tomorrow, I'll measure the bolt hole diameter. If I had to guess right now, I'd say the bolt holes were .500", like the heads.. I figure if you can keep the heads from moving around, the battle is mostly won.

JWL · 07-31-2016, 07:20 AM

In what location were the heads when the squesh dimensions and valve clearances were measured???? If this new centering system differs from the procedure used to establish the desired clearance those old measurements might not apply. This is especially true if the heads are shifted upward toward the intake manifold.

tubman · 07-31-2016, 07:27 AM

Ideally, the alignment should have been done before the combustion chamber checking. Unfortunately, I didn't realize than the head bolt holes were as large as they are until I was getting ready to install them. I rechecked the squish, and luckily, it is still OK. As to clearance over the valves, that was always more than adequate (I'm running a stock Merc cam).

GOSFAST · 07-31-2016, 09:12 AM

Quote:

Originally Posted by tubman

Now that I've got the chamber volumes and squish where I want them on these heads, it's time to install them. I was getting all set to do this when I noticed that the head bolt holes seemed to be quite large. A little measuring and I found that while he head bolts are .425 inches in diameter, the holes in the heads all run about .500". That's a difference of .075, which to me is quite a bit. I put a head on temporarily with 4 bolts, and was able to move it around a surprising amount. It seems to me that this movement could be conducive to head gasket problems. What to do? In a perfect world I'd send the whole engine out and have locating pins installed, but this is already assembled and almost ready to go. Since I am using aluminum heads, I had already purchased a set of special head bolt washers from Gary ("GOSFAST"), so I pm'd him to see what he had to say. He pins the heads on all of his builds, but as I said, that is impractical for me at this juncture. I was thinking that special "step-washers" might be the answer, so I ordered a set from Jegs's. Gary didn't seem to think much of this, and mentioned that he used some aluminum tubing for the initial alignment of his "pin jobs". This got me thinking, so I ordered a couple of pieces of 1/2" aluminum tubing in different wall thicknesses.

One sample had a wall thickness of about .030" and when compared to the bare bolt hole has a clearance of less than .010" (rather than .075"). This seemed about perfect, so I cut a couple of lengths, and they slipped right into the bolts holes in the heads, needing to be tapped in about the last .020" or so. When I installed the heads on the block, I had to wiggle them a little to get the head bolts started, but they went in by hand and when installed, the head could not be moved. I was going to counterbore the heads and install the "step-washers" on top of he aluminum tubes, but when I measured them, they had an inside diameter of .440", which is .005" bigger than the aluminum tubing, so I thought why bother? I think keeping the heads from moving around on the block will be helpful to improve head gasket seal and will save some trouble down the road. There is also he possibility of using more than two sleeves per head, or even using the "step-washers"; I'll have to see how this turns out.

The first picture shows the tubing and a "step-washer" lying, in the head, the second shows the tubes partially installed, the third shows the tubes fully installed (it's kinda hard to see), and the fourth shows the head bolted to the block. This was cheap and easy and I hope it does some good.

Hi "D", nice job, really! Trying the c'bore fix I believe would have opened the proverbial "can-of-worms" for sure.

Don't make more work for yourself, just 2 of the sleeves will maintain control of the head "movement", this in itself will also help keep the gaskets more stable. Looks like you did a nice job so far?

(Add) On a side note, if the head bolt holes are still in the correct position, meaning they haven't been moved during any type of drilling, using 2 locating sleeves should put the head back in the exact spot it would have been with the correct size holes?

Thanks, Gary in N.Y.

P.S. I would just add this, for some years now we've found the newer mfd aftermarket castings ALL make the head bolt holes way too big. Their argument, as explained to me by Edelbrock for one, claimed there were too many customers calling in and "complaining" they had trouble getting the heads in place with the existing head studs were in position. Their "fix", simply make the head bolt holes larger. Over here (as mentioned above) we now dowel-pin the entire setup during all the basic machining. I know it can't be done on built units, so the sleeve modification seems appropriate?

tubman · 07-31-2016, 10:42 AM

Thanks for the kind words, guys. If what Gary is saying about all heads being this way, I think this should be a "no-brainer" on all head installations. It was super easy to do, turned out great, and the material was less than $10 including shipping. I probably would have done four bolt holes per head, but I only had enough material for two. If you think about the geometry of this, two should be sufficient. I only considered using the "stepped-washers" on the holes with the tubing in them, figuring that they would reinforce the tops of the holes, but after I got the special thin washers from Gary, it became obvious they would just be more work and require cutting the head. Using this method and the special thin washers, I didn't have to cut the heads at all.

JWL is right; I should have done his before I measured and modified the combustion chambers. In this case I just got lucky. If you think about it, the most the head could have moved is about .030".

Juergen · 07-31-2016, 10:54 AM

Question: If you are using the step washers, don't they position the heads? If so are the dowels redundant? With electrolysis between the aluminum heads and iron studs, it would appear that the dowels would weld together over time and not be easily removeable, hence the new design for bigger stud holes.

tubman · 07-31-2016, 11:20 AM

I hadn't thought about electrolysis because the sleeves are aluminum, just like the heads. Wouldn't any electrolysis be between the sleeves and the bolts? Like Gary said, I can see a possible problem with head studs, but not with bolts.

The step washers would position the head, but when I measured them they had .005" more "slop" than the tubes, plus I would have had to counterbore the heads (the body of the washer is .529" OD).

07-30-2016, 05:43 PM	#2
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,184	Re: More modifications to my Edmunds 8BA heads Thanks for posting this. It looks like a simple way to make flathead a little better. John

07-30-2016, 06:42 PM	#3
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,860	Re: More modifications to my Edmunds 8BA heads Tubman, keep up the good work, figgering out how to fix these problems makes you a "Master putzer", I just love to putz, makes getting up in the morning very easy, when you have something to putz about.

07-30-2016, 07:24 PM	#4
BillM Senior Member Join Date: May 2010 Location: Everett, WA Posts: 504	Re: More modifications to my Edmunds 8BA heads I like it. It looks to me that the only advantage the dowel pin method would have over this would be to lock the gasket to the block. How do the bolt holes in your gasket fit the bolts? __________________ My web page: http://myplace.frontier.com/~wgmumaw/

07-30-2016, 07:33 PM	#5
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: More modifications to my Edmunds 8BA heads Ron, Though I'm not quite as old old as you (in years at least), I'm old enough that my major function is "putzing". Luckily, I've got a "young guy" (who's 56) to do the heavy lifting. Twenty years ago, I would have just bolted a set of new aftermarket heads on, and then wondered why they didn't make much difference and caused some problems. "Putzing" has it's moments; just ask me how long it took to get the aluminum timing cover on this engine "just right". Oh, and I wonder; do the new aftermarket heads for sale out there have this (in my opinion) huge tolerance with the head bolt holes? Somebody got a pair they can check? Tubman Last edited by tubman; 07-30-2016 at 07:43 PM.

07-30-2016, 07:36 PM	#6
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: More modifications to my Edmunds 8BA heads Sponsored Links (Register now to hide all advertisements) Tubman I wouldn't think there would be any need to do all of the holes. Something like say four corner ones should hold it in place and would make take the head on/off a lot easier. If your using bolts (which you appear to be) then it's not that big an issue, but with studs it might be.

07-31-2016, 07:20 AM	#8
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: More modifications to my Edmunds 8BA heads In what location were the heads when the squesh dimensions and valve clearances were measured???? If this new centering system differs from the procedure used to establish the desired clearance those old measurements might not apply. This is especially true if the heads are shifted upward toward the intake manifold.

07-31-2016, 07:27 AM	#9
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: More modifications to my Edmunds 8BA heads Ideally, the alignment should have been done before the combustion chamber checking. Unfortunately, I didn't realize than the head bolt holes were as large as they are until I was getting ready to install them. I rechecked the squish, and luckily, it is still OK. As to clearance over the valves, that was always more than adequate (I'm running a stock Merc cam).

07-31-2016, 10:42 AM	#11
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: More modifications to my Edmunds 8BA heads Thanks for the kind words, guys. If what Gary is saying about all heads being this way, I think this should be a "no-brainer" on all head installations. It was super easy to do, turned out great, and the material was less than $10 including shipping. I probably would have done four bolt holes per head, but I only had enough material for two. If you think about the geometry of this, two should be sufficient. I only considered using the "stepped-washers" on the holes with the tubing in them, figuring that they would reinforce the tops of the holes, but after I got the special thin washers from Gary, it became obvious they would just be more work and require cutting the head. Using this method and the special thin washers, I didn't have to cut the heads at all. JWL is right; I should have done his before I measured and modified the combustion chambers. In this case I just got lucky. If you think about it, the most the head could have moved is about .030".

07-31-2016, 10:54 AM	#12
Juergen Senior Member Join Date: May 2010 Posts: 503	Re: More modifications to my Edmunds 8BA heads Question: If you are using the step washers, don't they position the heads? If so are the dowels redundant? With electrolysis between the aluminum heads and iron studs, it would appear that the dowels would weld together over time and not be easily removeable, hence the new design for bigger stud holes.

07-31-2016, 11:20 AM	#13
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,319	Re: More modifications to my Edmunds 8BA heads I hadn't thought about electrolysis because the sleeves are aluminum, just like the heads. Wouldn't any electrolysis be between the sleeves and the bolts? Like Gary said, I can see a possible problem with head studs, but not with bolts. The step washers would position the head, but when I measured them they had .005" more "slop" than the tubes, plus I would have had to counterbore the heads (the body of the washer is .529" OD).