Head Removal: Tips 'n Tricks

[P.S.]

Originally Posted by katy

For the "rope trick", never heard of using the starter, used a socket and breaker bar, gently on the crank (ratchet) nut.

I know there's a lot of people who cringe at the rope method, but it's actually quite safe.

Here's how it is done (fast forward to about 7:30)- https://www.youtube.com/watch?v=du1AZS5y3r8

Here's the full explanation of how and why the rope trick works so well- https://www.youtube.com/watch?v=4M7o5v_exXE

Easy, safe.

[Brendan]

Originally Posted by alexiskai

Have you ever seen that actually happen? What makes you think the weak torque applied by the starter motor is capable of bending a rod?

i think that is a bad idea,The rope, mabey a head that has resently been off. i used the chain trick on my car , lifted it off the ground. did not budg. i used a head puller, heat penatrating oil ans wacked the studs with a body hammer, use more heat then a propane torch, repeated the prosess over a 3 weeks, the head finly gave free, take your time

[Bruce of MN]

Originally Posted by 1crosscut

You can use an engine hoist to apply lifting force but be very careful because if the head does come off when doing so the head can and will come up quickly and damage (destroy) your junction box.

Very good point!!

[Ayers1]

As has been suggested above, lots of penetrating oil. May take a few squirts a day for a week. I bought the head remover kit from Snyders that is similar to the angle iron above. The kit is a pair of plates that puts pressure on the studs to lift the head. If you have to, you can torque it down a little, let it set for a while and come back to it. A lot of times it will have raised up with the constant pressure.

Here's the link,

Snyders - Product Cylinder Heads HEAD PULLER KIT A-6010-PX https://search.app/kB3SUd7gnxCwHduNA

[Brentwood Bob]

Hard plastic wood splitting wedges have helped.

['29 Pickup]

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I'm starting to favour the plate and bolts method as in George's video in the first post.

A pain in the neck to set up but looks like it solves all the issues and problems people have brought up and George says he has never known it not to work. It provides a nice slow even pressure on ALL the studs at more or less the same time and no chance of the head suddenly hitting the roof.
The other thing I like about it is that I have seen the commercial tools ( and the rope trick) really only do either a couple of studs at a time or they are only able to lift up to about an inch or even less. Plenty of times I have seen that the head starts to lift a few mm and then stops, still stuck....it still has another few inches to go but the commercial tool or using compression, 'aint gonna get you there. George's design eliminates all those issues.

Now, where do I get 7/16"x9" coach/carriage bolts....hmm, I can't, so I am going to use all thread for all of them 10mm which is about 1mm less than 7/16".....as I will be using that American miracle whip, JB Weld for the spark pug holders and it only sits on top of the studs without threading in, the size doesn't matter.

PS: Please excuse the use of mixed measures, sometimes it's easier to visualise a few mm and sometimes it's easier to visualise an inch....we still do that a lot in Oz.

['29 Pickup]

Is there a way of being able to mark the positions of each stud on a steel plate ready for drilling without having a head gasket available as a template to mark it up with accurately. The gasket I want isn't available here and I'm not ready to make my big order in the US....(small orders work out way too expensive for international shipping per item).

[alexiskai]

Originally Posted by '29 Pickup

Is there a way of being able to mark the positions of each stud on a steel plate ready for drilling without having a head gasket available as a template to mark it up with accurately. The gasket I want isn't available here and I'm not ready to make my big order in the US....(small orders work out way too expensive for international shipping per item).

Use bluing to mark the tops of the studs and then put the plate on top.

https://en.wikipedia.org/wiki/Engineer's_blue

['29 Pickup]

Originally Posted by alexiskai

Use bluing to mark the tops of the studs and then put the plate on top.

https://en.wikipedia.org/wiki/Engineer's_blue

Would the plate rest flat on all the studs at the same time? (excluding the water inlet studs of course).

[alexiskai]

Originally Posted by '29 Pickup

Would the plate rest flat on all the studs at the same time? (excluding the water inlet studs of course).

Probably not, you’d probably have to do multiple passes. It’s not a great solution, I was just trying to offer an idea that would work within your stated constraints.

['29 Pickup]

Originally Posted by alexiskai

Probably not, you’d probably have to do multiple passes. It’s not a great solution, I was just trying to offer an idea that would work within your stated constraints.

Thanks
I think it really needs the gasket to do it spot on.
This is why I didn't like the plate and bolt idea from the get go....too fiddly.

But I think it is probably the best approach.

[johnbuckley]

When rebuilding is there an engineering reason for not replacing the studs with bolts, like modern car? This would surely make life easier for the next person to remove the head.

[alexiskai]

Originally Posted by johnbuckley

When rebuilding is there an engineering reason for not replacing the studs with bolts, like modern car? This would surely make life easier for the next person to remove the head.

Studs provide much more consistent clamp force. Since the A head already doesn’t have as many fasteners as it should, switching to bolts would increase the risk of head gasket failure.

[johnbuckley]

Originally Posted by alexiskai

Studs provide much more consistent clamp force. ....

Why? If the nuts/heads of the bolts are the same dimension, and the diameter of the bolts/studs are unchanged , I can't understand why it should make any difference... though presumably it does

[alexiskai]

Originally Posted by johnbuckley

Why? If the nuts/heads of the bolts are the same dimension, and the diameter of the bolts/studs are unchanged , I can't understand why it should make any difference... though presumably it does

To understand why, we have to think about the nature of the materials being used.

When you fasten a cylinder head to a block, particularly with flathead engines, your main objective is to create a perfect seal around the combustion chamber. After ignition, the expanding combustion gases will try to escape the chamber. We want to force them to push against the piston, which means we need to seal off other avenues of escape.

Head gaskets are weak and fragile things relative to the other materials in the engine, so the combustion gases will try to displace the gasket and escape into the water jacket. The only way to prevent that is to make it impossible for the gasket to be displaced. To do that, you have to clamp the gasket between the block and the head in such a way that the force on every point in the gasket is as strong as possible.

Cast iron is a very strong, rigid material, so we can put clamping force on the gasket by placing fasteners at key points around the head and tightening those fasteners down. The cast iron in the head will take the clamp load applied by the fastener to a very small area (the area under the bolt head/nut) and distribute it across a wide surface. This lets us use a small number of bolted joints to apply clamping force evenly across the surface of the gasket. By tightening the fastener above a certain threshold, we prevent the gasket from being displaced, which would induce head gasket failure.

However, cast iron is not infinitely rigid. If you apply too much clamping force, it will flex/warp around the bolted joint. Some parts of the mating surfaces will deform toward each other and other parts will deform away from each other. In any spot where the head and block deform away from each other, the clamp load on the gasket will be decreased. This introduces the risk of head gasket failure again.

Therefore the clamping force applied by the cylinder head fasteners must be inside a particular range. Not so light that the combustion gases can overcome the force and displace the gasket, but not so heavy that the mating surfaces become distorted, disrupting the gasket seal and allowing displacement.

We now come back to your original question of bolts vs studs. On a Model A, the threads in the block are 7/16-14, coarse pitch, while the threads at the top of the stud are 7/16-20, fine pitch. The block threads are also class 3 fit. Class 3 joints have very close tolerances. You will notice when threading in a cylinder head stud by hand, there is a fair amount of friction in the turning even though there is no load on the stud.

If you were to use bolts to seal the head to the block, and particularly if you did it without lubrication, a very high proportion of the torque applied in the tightening would be used simply to overcome friction in the joint. The pitch is coarse, so a given amount of rotation on a bolt tightens the joint more than the same rotation on a head nut, and the tolerances are very close. Furthermore, these engines are 90 years old, so the threads are likely already torn up a little bit from prior wear and tear.

It has been clearly established in engineering science that the more friction there is in a bolted joint, the more variance there will be in the exact value of the friction. So across the 14 fasteners in the cylinder head, you might get friction resistance that varied by 20%, 30%, or even 40%. If you are applying identical torque on each fastener, this means the actual tightening force on those fasteners will vary by up to 40% as well.

This is the key reason that bolts are not suitable for this application. It is not possible to ensure that the clamp load on all the bolts will be within that critical range I talked about earlier, where the gasket is clamped tightly enough that it can't be displaced, but not so tightly that the block or head deform.

['29 Pickup]

Originally Posted by alexiskai

To understand why, we have to think about the nature of the materials being used.

Do you consider copper spray on the gasket to be unnecessary snake oil or useful to help get a good seal?

[johnbuckley]

Alexiskai_ Thank you so much for explaining re studs vs bolts . I now understand; I have been struggling for years to comprehend the reason !!

[Afordman31]

Pictured are of the one I made to remove stuck and not stuck Model A heads.
I have used this on a couple of heads and have loaned it out to others with great success removing the head. The chain is hooked to bolts that go thru two old Model A spark plugs with the porcelain removed. The bolts pictured in the plate are half inch diameter with a nut on the back side. The bolts set on the head studs. It takes two wrenches one to hold the bolt and another to tighten against the bottom side of the plate thus lifting the head. A spare head was used to lay out the head stud pattern.

[Marshall V. Daut]

For what it's worth, from October, 1908 until May, 1927, fifteen million Model T Fords used 7/16" hex head bolts to secure the cylinder head to the block. The threads in the block and on the bolts were coarse. The compression ratio of Model T is only slightly lower than the Model A's, negligible actually. Bolts seemed to have done the job for those many years, at least good enough for Henry to stick with them for 19 years or so without changing to studs and nuts. I wonder what made him ultimately decide to use studs and nuts in the Model A??? Cost? Engineering discoveries? Also for what it's worth, being in the antique Ford hobby since 1966, during those years I have heard of (and experienced!) more Model A head gasket failures than Model T. 'Not taking sides which is better - studs or bolts - but draw your own conclusions from the Model T's "fairly" successful history.
Besides helping to seal the head gasket from leaking, copper head gasket spray also keeps the gasket from minute shifting, which can lead to blowouts in the narrow sections between cylinders. The late great expert engine builder Ron Kelley advised me to use copper spray for that purpose when I had him build a banger for me.
Marshall

[alexiskai]

Originally Posted by Marshall V. Daut

For what it's worth, from October, 1908 until May, 1927, fifteen million Model T Fords used 7/16" hex head bolts to secure the cylinder head to the block. The threads in the block and on the bolts were coarse. The compression ratio of Model T is only slightly lower than the Model A's, negligible actually. Bolts seemed to have done the job for those many years, at least good enough for Henry to stick with them for 19 years or so without changing to studs and nuts. I wonder what made him ultimately decide to use studs and nuts in the Model A??? Cost? Engineering discoveries? Also for what's it's worth, being in the antique Ford hobby since 1966, during those years I have heard of (and experienced!) more Model A head gasket failures than Model T. 'Not taking sides which is better - studs or bolts - but draw your own conclusions from the Model T's "fairly" successful history.

Can't say why it worked in the T. Maybe because the engine operates at lower RPMs?

Even on modern engines that use bolts, it's common to switch to studs if you are tuning the engine for higher performance. On my '18 Accord with the 1.5L turbo, there's a design flaw that's known to cause a lot of head gasket failures, and one of the suggested steps when you replace the gasket is to switch to ARP studs, which can be tightened to a higher clamp load than the OEM bolts.

Originally Posted by Marshall V. Daut

Besides helping to seal the head gasket from leaking, copper head gasket spray also keeps the gasket from minute shifting, which can lead to blowouts in the narrow sections between cylinders. The late great expert engine builder Ron Kelley advised me to use copper spray for that purpose when I had him build a banger for me.

I've heard this as well and yet I have a hard time believing that the spray would exert enough adhesive power to prevent the siamesed portions of the gasket from blowing out, relative to the compressive force exerted by the head. Who knows, might be true.