Cylinder head questions.
 

I am in the process of replacing the cylinder head gasket on my Model A speedster, 1928 engine. In the water passage next to no. 3 cylinder, passengers side there are 3 or 4 loose objects. They are metallic, shaped like 3 dimensional stars and are too large to be retrieved through the passage. Any ideas what they are? I will be using a copper gasket. Should crimped side be up or down? I have seen both recommended. I will be replacing studs and nuts. Should some type of sealer be used on studs before installing in block? Should anti-seize or some other lubricant be used on studs before torquing the head. I have 4-5 thousandths of warpage in the head. How much is allowable before remachining. Thanks for help and advice.

Re: Cylinder head questions.
 

The most sensible recommendations I've seen are that the coarse threads on the studs should get a light coat of RTV, which will discourage seizing but also help to slow or block any migration of coolant due to microscopic cracks or rust-through. Care should be taken not to apply the RTV to the bottom of the stud. The fine threads can get oil, or be torqued dry, it's been done both ways and it's worked fine both ways.

My personal opinion is that if you've got warpage in the head, you should have the head resurfaced. It's relatively cheap and it's not a big production to take it to a shop. I have heard that there's a right and a wrong way to secure the head in the mill, others may know more about that. A good shop can also mill the head with the correct RA value for surface roughness, which will help the gasket adhere properly.

The other reason to have the head milled is that you likely also have warpage somewhere on the deck, so putting two warped parts together increases the risk of leakage.

Re: Cylinder head questions.
 

Re: Cylinder head questions.
 

I filled my cooling system with RUST911. It dissolved absolutely every speck of rust. After letting it sit for 24 hours I drained and rinsed it. The mixture that was clear when poured in came out absolutely black. I left the second dose in for another day. When drained it was grey. Rinse and refill again. This time when drained the mixture was clear. The radiator was absolutely spotless and the water passages in the block were squeaky clean. a two gallon bottle of the concentrate will last you for a very long time and is handy for cleaning rust from parts. https://www.amazon.com/Rust911-Ultra...s%2C233&sr=8-2

Re: Cylinder head questions.
 

Original block had blind stud holes, they didn't go into the water. 90 years later this may not be so. I use anti-seize on the coarse end of each stud, and either oil or assembly lube on the top threads. Studs, nuts and bolts should never be torqued dry!

.006" has been the standard limit on warpage for many years, you should be fine at .004".

Re: Cylinder head questions.
 

Do NOT chas the threads in the block ! ! !
Paul in CT

Re: Cylinder head questions.
 

Over at FORDGARAGE.com there are a couple articles by Larry Brumfield (Brumfield Heads) that will answer your questions.

http://www.fordgarage.com/pages/brum...structions.htm

http://www.fordgarage.com/pages/tighteningsequence.htm

I have found his suggested methods to work except that the local supplier told me that the newer copper gaskets have a tendency to blow when using high compression. He suggests the composite gaskets for high compression and I have not had a problem.

Re: Cylinder head questions.
 

Why not?

Re: Cylinder head questions.
 

Probably he means don’t chase them with a tap.

Re: Cylinder head questions.
 

I assumed that's what the OP meant, but, "why not"?
What's wrong w/a bottoming tap to chase/clean the threads?

Re: Cylinder head questions.
 

Re: Cylinder head questions.
 

The tap may cut away some of the metal and weaken the threads. It is best to use a thread cleaning tool. It looks somewhat like a tap but is designed for its specific use...to clean the threads.

Re: Cylinder head questions.
 

Thanks to everyone for all the good information. Howie

Re: Cylinder head questions.
 

It wasn't all good.

Re: Cylinder head questions.
 

I know where you are going but that is kind of a 'Misconception'. A tap doesn't necessarily remove metal. I use a tap to chase threads all the time as I am interested in removing damaged threads and/or rust. The reason why this myth about not using a tap is often mentioned is because most mechanics do not understand about classification of threads. Since I purchased the print of the engine block, it provided the class of threads. I ordered the matching class of bottoming tap, and it works perfectly.

Re: Cylinder head questions.
 

Will you share with folks what class to use, or is that, er, classified?

Re: Cylinder head questions.
 

Sent you a p.m.

Re: Cylinder head questions.
 

Here is a chart about classes: https://www.natool.com/wp-content/up...atp101-102.pdf

The right one for each spot would be defined on the factory drawings, but I don't remember what I have read about how to see the drawings.

I use these, instead of standard taps & dies, but I don't know if they would harm good block tapped holes: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Re: Cylinder head questions.
 

I use ⁷⁄₁₆-14 H1 tap. Print called for a ⁷⁄₁₆-14 NC 5 tap with .3917-.3929 pitch diameter.

Re: Cylinder head questions.
 

There have been several threads EXTENSIVELY covering all of this in the past both here, the early V8 forum and the HAMB, including how to make a test tool for the block threads.