head gasket/6:1/mystery?

G

Growley bear

Well-known member
I am not trying to hijack any posts or bash any parts vendors here.
This is an on going problem at my club in Coos county, OR. Two members same problem. 6:1 Snyder cylinder head premium head gasket and the fiber gasket also from Snyder's pictured here. One owner had this happen twice; he owns a machine shop and is a first class machinist. He switched to a Lion lll speed head and has had no more problems. The other engine, same thing only three gaskets blown at less than 500 miles each. At this time a 5:1 Snyder head has been substituted for the 6:1.
I also need to mention that both engines have been using 9lb pressurized cooling systems.
No one seems to understand what is causing this. To my knowledge not even Tom or his engineers. Has anyone experienced this and if so did was it repaired?
This erosion has taken place from the inside out toward the combustion chambers on cyls 2&3 every time and has been the same with all gaskets used. Any help or suggestions are of great importance and would be much appreciated.
The head gasket here is P/N B-6051-C. I don't have photos of the other gaskets. I wish I did.

Chet
 

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Copper gaskets!!! only way to go. properly torqued and using the correct process.
 

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Check the gasket fire ring fit on the head, I had a similar problem. It seems the mold slipped during casting and the head was not completely clapping the fire ring.

A copper head gasket made by "The Best Gasket Co." worked good for me.
JB
 
Thanks, I'll check on the copper. I don't know if a copper gasket was tried or not. I'll look into that. I know the heads were torqued properly and the block deck is in top notch condition.

Chet
 
Have the heads in question (and the block) been checked for flatness? It is very easy to instill a torque on a part while clamped for machining. The result is a distorted planar surface that may NOT be detectable with a straightedge! Below is an example:
twisted+plane+-+gnuplot.png

This distorted plane will measure perfectly "flat" with a machinist's straightedge along any point perpendicular to any edge AND across opposite corners. This is extremely deceiving and can only be detected with a surface plate or more advanced electronic measuring that 'feels' or scans the entire surface.

It is also possible that several heat cycles with applied head stud torque (clamp pressure) over differential gasket surface areas created uneven gasket compression that the head and block are too rigid to comply to. In essence, the gasket itself goes from planar to a compounded version of the above illustration in sections. In this case, the head may be too stiff to bend slightly while torqued down!

You can't go back and re-engineer the A block like a modern design, with stud placement calculated to present equalized gasket compression surface area to each head stud. How to address the difference in compressibility constants with gaskets and variances in rigidity of different heads could be beat to death in a forum with testimonials, but only real engineering data will prove out the best gasket for a particular application.
 
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Curious as th which head studs were used? The grade 5 that are made to look like originals or the grade 8 which are recomended for the high compression heads? Rod
 
The best way to go is with a copper head gasket, sprayed with Copper Coat, and most important, torque the head down in increments starting at 35# then 45# and then 55#, unless you have grade 8 studs and a good block then to 60# hot.
This works for me with a 8.5-1 head.
 
The 6:1 head was twisted and resurfaced twice between two blown head gaskets in the same location.
Grade 8 studs are being used. And I don't understand the need for a pressurized system in a Model A either. They aren't my cars though.
A copper gasket is now in use with a new 5:1 head and already torqued 3 times but not enough miles to tell yet.
Thanks for the comments and suggestions, all welcome and appreciated.

Chet
 
We have used for several years, the "Best" brand grey gasket with Copper Coat sprayed on both sides, on every engine we build and every head we install , and they never even seep. Most are Snyders 5.5 and 6.0 heads.

Never used pressurized radiators either. Don't see the need.

Steve Becker
Berts Model A Center
 
SteveB31 said:
We have used for several years, the "Best" brand grey gasket with Copper Coat sprayed on both sides, on every engine we build and every head we install , and they never even seep. Most are Snyders 5.5 and 6.0 heads.

Never used pressurized radiators either. Don't see the need.

Steve Becker
Berts Model A Center
Click to expand...

Steve, thanks,
I'll forward the information.

Chet
 
Hey Chet,
I'm presently also using the 6:1 variety head you mention. BEST 501C copper with copper coat both sides and torqued as required..no seep at all. I had the head milled flat, just prior to installation. Just because I like to experiment and hate seep/weeping, I used a few pieces of copper wire for 'reinforcement', with normal torque, i.e.- 55lbs. Best head gasket seal job that I've ever had on a B. I'm going to try same procedures with next head super Winfield at 8.5:1 !
 
Purdy Swoft said:
The 9 lb. pressurized cooling system is more than likely the problem.
Click to expand...

;Please explain how 9 lb. of water pressure will erode a properly installed head gasket If both surfaces are true and the correct studs are used and installed correctly.
I believe there is a problem with the head in that area (soft/ thin spot /weak casting. Bill



Where is Larry Brumfield when you need him
 
"I believe there is a problem with the head in that area (soft/ thin spot /weak casting"

maybe. but the fiber gasket is junk.

Felpro copper 7013 non-silicone works well in this shop. Re-torque at least 3 times. There is no such thing as checking the torque too many times. We torque initially; then after 10 min of running, then after another 30 min, then at 25, 50, and 100 miles.

I have looked at Best gaskets and I am glad they are working for people, but the ones I looked at had very poorly made fire rings and I would not use them

also agree pressurized system not needed at all

"If it ain't broke fix it until it is" applies to pressurizing
 
bbrocksr said:
;Please explain how 9 lb. of water pressure will erode a properly installed head gasket If both surfaces are true and the correct studs are used and installed correctly.
I believe there is a problem with the head in that area (soft/ thin spot /weak casting. Bill



Where is Larry Brumfield when you need him
Click to expand...

The cylinder head is definitely suspected of being flawed. I don't see how 9 lb pressure can cause this either; it may add to the relatively short period of time for the erosion to occur. 100 miles in this last instance. Thanks for your assistance,

Chet
 
tbirdtbird said:
"I believe there is a problem with the head in that area (soft/ thin spot /weak casting"

maybe. but the fiber gasket is junk.

Felpro copper 7013 non-silicone works well in this shop. Re-torque at least 3 times. There is no such thing as checking the torque too many times. We torque initially; then after 10 min of running, then after another 30 min, then at 25, 50, and 100 miles.

I have looked at Best gaskets and I am glad they are working for people, but the ones I looked at had very poorly made fire rings and I would not use them

also agree pressurized system not needed at all

"If it ain't broke fix it until it is" applies to pressurizing
Click to expand...

I have been informed by the owner of the problem that the first gasket to go was a copper gasket that was only leaking on an outside area of the head. I also torque until there is no noticeable movement at ant of the head nuts. I torqued my stock head at least five times and recheck every 500 miles.
I was also told that the reason for pressurizing the system and installing a thermostat is to aid in faster warm up time. I know that a pressurized system will operate at a higher temp. before boiling. At this point the theory of operation tends to drift away from Model A to the more modern technology used in vehicles of the past 30 or so years.
I agree with principle of, "if it ain't broke don't fix it."
I'll keep this Fel Pro P/N and pass this info on to the owner. Thanks for your help,

Chet
 
Regarding the failure of the head gasket in this thread: I don't think the pressurized system had anything to do with the failure other than it likely made the failure progress at a faster rate. I believe there is some other problem causing the failure. Studying the photos of the composite gasket, there is what appears to be a "carbon track" on the fire rings adjoining the failed area. It is likely that the escaping combustion gases eroded the composite material and the coolant leak followed. This area on used original or replacement stock heads is often collapsed when I surface them. It is not uncommon for this area of the head to be from .008" to .012" off from the rest of the head. I have not surfaced many new Snyder's heads so I have not noticed a pattern of similar collapse. I did have one new Snyder's head that would not hold gaskets (purchased in 2012) and I found this area collapsed as previously described after two gasket failures while running dyno tests. A second Snyder's head had a variation from normal on the combustion chamber that would not properly cover the fire ring...I substituted a gasket that better fit the chamber design and the problem ceased.

Pressurized system the cause of the failure...from my experience…I don't think so. The general consensus of the previous posters is a pressurized system is not necessary...and I agree: For the Model A that is maintained and driven like Ford envisioned, a pressurized cooling system is not needed. But...there are always a few that do not follow the norm and I happen to be part of this latter group. I drive most of my miles within Ford's design limits but I often get on the freeway and keep up with the traffic in the right lane. I have an inserted, counterweighted and balanced engine with a Mitchell overdrive. I have had a 3# pressurized system for 11 years and during that time driven over 70,000 miles. I have only changed the head gasket one time during that period...and that was because I wanted to check the head for carbon build-up...not because it had failed.
Regarding the type of gasket I have used during these miles: My first gasket was copper (19K miles). The second gasket is a Snyder's Premium B gasket with the silicone seals (52K miles). Both of these gaskets have worked fine under some pretty hard driving at times.
From my experience, a 3# pressurized system has its advantages if you often run at freeway speeds, primarily the coolant stays in the system and your hood and the highway remain dry. Before adding the pressurized system with expansion tank, I was washing my hood and adding coolant on a regular basis. With the pressurized system, I often go an entire season of driving without needing to add coolant. Just my experiences and opinion…formed over 70K+ miles.
I hope your search for answers is a short one!
Good Day!
 
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