Cylinder Head Gasket Weeping Oil? Here's A .32 Cent Bandaid

[ace.cafe]

There are times when things need to be changed, and other times which just require things to be put together the way it was intended.

This is one of those times when it just needs to be put together as it was intended.

[cyrusb]

Ace, not trying to be an ass pain, but, where does it actually say that? I have never seen a real (not snidal's) RE engine manual. Does anyone have one? It just seems like an engineering "don't" to make two surfaces seal perfectly in that manner. And certainly not a 3rd world process.

[ace.cafe]

Ace, not trying to be an ass pain, but, where does it actually say that? I have never seen a real (not snidal's) RE engine manual. Does anyone have one? It just seems like an engineering "don't" to make two surfaces seal perfectly in that manner. And certainly not a 3rd world process.

I'm just discussing the head gasket sealing procedure, not the "lapping the head to eliminate the head gasket" procedure.

With the spigot too high, it's apparent that the gasket can never seal, so we know that has to be short enough to let the head crush the head gasket to seal the oil.

With the spigot too short, the gap above the spigot in the recess around the combustion chamber permits hot combustion gases under pressure to get into that area. The only place that spigot can seal is at the top, against the head.
If that doesn't seal at the top, these hot gases can, and often do, go over the top of the spigot and down to the head gasket itself. As this happens, flame cutting takes place and erodes the head recess and spigot until the area of cutting gets big enough to compromise the integrity of the head gasket and the head gasket blows. If any detonation is happening, it happens even worse. When it does this, it often blows to the pushrod tunnel, and causes very high crankcase pressure, which is often the first indication to the owner that something is amiss. Upon disassembly and examination, this flame cutting damage has been seen to be the cause.

The higher the compression in the engine, or the worse the detonation problems, the more likely we are to see this problem. However, it is even seen on stock engines from time to time.
So, the answer is to fit the parts so that the seals work properly, and no problems.
We have a "hard surface seal" on top of the spigot, and a "soft crushable seal" on the head gasket. All that's needed is to set the height of the spigot to handle both seals at the same time. It's simple, really. We do it on every engine we build, and if we don't do it ourselves, we instruct our clients how to do it themselves. I have instructed people in India how to do it, by email.


Additionally, just looking at a combustion efficiency point-of-view, the crevice that might be left above the spigot on a non-sealing spigot/head interface would be included in "parasitic crevice volume" problems that should be avoided in combustion chambers. Areas like that which can get the fuel pushed into them and not have room to properly ignite can cause poor combustion because that fuel which is intended to mix with a certain amount of air is pushed into that crevice by compression pressure, and then the remaining mixture in the chamber has lean spots because that fuel is hiding in that crevice volume. This causes poorer combustion, excess heat, loss of power and fuel economy, etc. The same can be said of the volume around the top of the piston, above the top ring, which gives similar problems, and which is why people try to place the top ring as high as feasible, trying to minimize that parasitic crevice volume.

The Bullet already has very challenging combustion problems from the initial design, and really needs all the help it can get. So, dealing with this parasitic crevice volume, and sealing the combustion chamber at the spigot properly, can help both of these issues, and also be done in a way that the head gasket seals the oil around the pushrod tunnels too.

I have had people who could not solve their oil leaks after many tries, send me their heads and barrels to be properly set, and their problems were solved in our first try, because we have done this so many times that we know the procedure. We can run any compression level we want, and have good combustion, and never have oil leaks at the head joint.

So, it's really just a matter of knowing what the ideal arrangement should be, and accomplishing it to solve the problems. It's more than just reading a manual. The manuals are the most sparse information available, and primarily centered on repair, and not necessarily focused on correcting the factory shortcomings, or understanding proper engine building techniques.

Regarding the process being too much for "3rd world", I have accomplished it with a hand file on more than one occasion. If you understand the goal, and are careful with your work, it can be done by hand.

[cyrusb]

There are times when things need to be changed, and other times which just require things to be put together the way it was intended.

This is one of those times when it just needs to be put together as it was intended.

The question was simple "Intended by who?". If you prefer your theory as to why that spigot is there, fine. But as I asked, Where is it written? If you are going to be speaking for RE 's "intentions" you need RE's data to back that up. Cheers, cyrus

[ace.cafe]

The question was simple "Intended by who?". If you prefer your theory as to why that spigot is there, fine. But as I asked, Where is it written? If you are going to be speaking for RE 's "intentions" you need RE's data to back that up. Cheers, cyrus

I don't speak for RE. But I do clean up a lot of their mistakes.
And their manual is by no means complete, nor without omission, about many things.

Here's a technical drawing of a VW aircooled engine which uses the same type system that might help to visualize the concept.


And one of a Lycoming aircooled aircraft engine, using the same type system.


Here's a 356 Porsche





They all show the same thing. The spigot goes all the way to the top inside the head recess.
It's just the way it's done. I provided the reasons in my other post.

So, to answer the question about "Who intended it?", the answer would be "the people who understand the design, and who know what they are doing, and who care about getting a good result, intend it."

[72westie]

Mmmmmmm....Volkswagens.... 

[baird4444]

" It's just the way it's done. I provided the reasons in my other post.
So, to answer the question about "Who intended it?", the answer would be "the people who understand the design, and who know what they are doing, and who care about getting a good result, intend it." "

    I think what ace is saying is "Because I say so..."
"the people who understand the design, and who know what they are doing"

   Now I feel like the lowly serf,
        being told what is right and how to think...
                     and that I'm not as good as....

 

[ace.cafe]

" It's just the way it's done. I provided the reasons in my other post.
So, to answer the question about "Who intended it?", the answer would be "the people who understand the design, and who know what they are doing, and who care about getting a good result, intend it." "

    I think what ace is saying is "Because I say so..."
"the people who understand the design, and who know what they are doing"

   Now I feel like the lowly serf,
        being told what is right and how to think...
                     and that I'm not as good as....

People are free to do it any way they want.
I'm not forcing anybody to learn anything, and I backed up my statements with real facts, not just "because I say so".
People can always go and do it like the manual doesn't instruct, if they can decide on a method that's not in there. Or they can take the advice of somebody that does this work regularly and knows how to do it, and has solved a lot of problems for Bullet owners in this oil leak issue and other things. And incidentally, I described a way to do it that they could do themselves, and wouldn't cost them a penny to do it.

[Blltrdr]

The first time the light lit was reading the article below. Problems with fitment have occurred on British designs according to this article ever since there machines started wearing out. So you take the same problem to India with machinery provided to the factory from England and run it non-stop for say 50 years and you are definitely going to end up with the same problems the Brits had years earlier. It is up to the end user to rectify this problem just as Tom has laid out. Now granted, this article is about doing away with head gasket but the article also makes very clear of the problems with the spigots mating correctly, not only on RE's, but on most other Brit brands. Who woulda thunk!

[baird4444]

and let's go one better....
     the composit head gasket IS the fix. I don't think there have been any
reports of it not sealing...

[Arizoni]

For what it's worth Ace, I appreciate you taking the time to explain how to assemble these engines.  Experience beats speculation every time.

I know it takes time to write these things up and I think I can speak for many of our viewers, your time is not wasted.

[ace.cafe]

For what it's worth Ace, I appreciate you taking the time to explain how to assemble these engines.  Experience beats speculation every time.

I know it takes time to write these things up and I think I can speak for many of our viewers, your time is not wasted.

Thanks, Jim!

[cafeman]

and let's go one better....
     the composit head gasket IS the fix. I don't think there have been any
reports of it not sealing...

That's what I've read, but when the time comes to install it I will be checking the gap with the head installed on the barrel just to make sure all is good.
But in the meantime, the rope around the perimeter will suffice ........................for as long as I'm lazy  

[Arizoni]

As long as your using the "rope" trick to fix your problem I think you will have to know the old British Motorcycle rule.

"When no oil leaks are detected your motorcycle is out of oil.  Top up as soon as possible."   

[mrunderhill1975a]

I have  been lurking on this thread for some time and have learned a great deal from this discussion.  I now have a question........If I were to lap the head to the barrel myself, how long would this process take?  One hour, 10 hours of lapping or more?