Head gaskets---again

[gltriker]

Ahhhhh...... no machining involved. Just ticky-tacky.

[desertrefugee]

Yeah, and confession time here. Talked to my buddy and it was, in fact .002-.003" he shaved off. Mainly because I stressed to just take enough material off to get them coplanar.

So...that suggests that I must've screwed up the first go-round. If the OEM gasket should have compensated for that small amount, I'm not really sure what happened as I didn't do anything any different the second time. I have done a bunch of them (many, many cars), but this is only my 2nd 'wing head job. (I did head gaskets on the 1200 once).

The machine carried me up the hill to Prescott Saturday afternoon without a hitch. 180 miles. Life is good.

I think the basics are the crux and have been offered in this thread:

1) Flat surfaces - head and case.
2) Surgically clean mating areas.
3) OEM gasket (for stock builds)
4) Clean bolt threads and threads in case. Tap if needed.
5) Moly grease on bolt threads and under head/washer
6) 45ft/lbs (using Honda recommended sequence)
7) No re-torquing should be necessary.

[robin1731]

Robin, any experience with aluminum head gaskets? I'm wondering about them using the stainless steel rings as Irishcarbomb used.

I've used aluminum spacers under cylinders. Too lower compression. And they have a fiber gasket on each side to seal them. But not for head gaskets. I don't think it would work. The only thing I've ever used or seen used in race engines is copper.

Power rings would work on a GL engine. I think that is what Irish used. I wouldn't want to risk o-ringing the sleeve on a GL engine. Too much chance of it moving. If I was doing it I would get the heads o-ringed. Would take a good shop to do it but it could be done.

[Old Fogey]

Robin, I think the 'sleeves' are not really sleeves, they are cast in liners. If so, not much chance of them moving, but equally not much material to put a groove in either.

[robin1731]

I'm just thinking of a machine cutting a groove in the top. You're right, not a sleeve like on an inline engine. But also not supported the best for cutting in to them. While an o-ring groove isn't very big or deep it is still a machining process that has the potential to cause vibration. Another advantage to doing the heads is you could use them on any block of the same size.

[olchris]

I dont trust many head gaskets anymore because one thing is for sure there not all the same..... That why i posted this....

http://www.ngwclub.com/forum/viewtopic. ... re#p642383

[gltriker]

Yeah, and confession time here. Talked to my buddy and it was, in fact .002-.003" he shaved off. Mainly because I stressed to just take enough material off to get them coplanar.

So...that suggests that I must've screwed up the first go-round. If the OEM gasket should have compensated for that small amount, I'm not really sure what happened as I didn't do anything any different the second time. I have done a bunch of them (many, many cars), but this is only my 2nd 'wing head job. (I did head gaskets on the 1200 once).

The machine carried me up the hill to Prescott Saturday afternoon without a hitch. 180 miles. Life is good.

I think the basics are the crux and have been offered in this thread:

1) Flat surfaces - head and case.
2) Surgically clean mating areas.
3) OEM gasket (for stock builds)
4) Clean bolt threads and threads in case. Tap if needed.
5) Moly grease on bolt threads and under head/washer
6) 45ft/lbs (using Honda recommended sequence)
7) No re-torquing should be necessary.

Yep, I'm still here! I can't get out riding, so I sit and ponder, to some folks profound dismay, instead.

desertrefugee has presented an excellent checklist for new, cylinder head gasket pre-installation requirements!
BUT, How do we know the 'head and case' are, in fact, flat surfaces before installing a new compression sealing component between them?

From the very first post in this topic, there hasn't been any discussion of how the head gasket's sealing surface of the cylinder block and its cast in 'liners' would have been technically corrected from the errosive after effects of a failed cylinder head gasket's combustion blow-by gasses. There's typically also a complementing witness of coolant corrosion effects on the top edge of the cast in 'liners', as well.
Both destructive forces will inevitably cause some level of undesirable dimensional surface defects, which may ultimately contribute to repeat head gasket failure scenarios. There may be, as well, thermally induced deviations from designed and manufactured dimensions.
I want to believe there isn't sufficient dynamic cylinder combustion gas pressure generated in a normally aspirated GL1000 engine, to cause an OEM Honda cylinder head gasket sealing failure, when an engine is properly and completely examined and prepared prior to reassembly, per factory service manual prescribed procedures, and specifications.
Respectfully, Alternative cylinder head gasket materials seem to be an expensive band aid to hopefully compensate for faults in remedial preparation prior to the re-assembly of engine components.

Actually, after searching for desertrefugee's term, "coplanar", and seeing an illustration which exceeds my understanding of its geometric importance, I then processed parallelism is more specific to the topic we are discussing.

So......Thanks to a Google search here's what I discovered, which better describes what we sorely long for.

"Surface Parallelism is a tolerance that controls parallelism between two surfaces."

Professionally machining the sealing surface of the Cylinder head, 'flat', hopefully fulfills that component's opposing surface minimum dimensional tolerances requirement, towards adequate Surface Parallelism alignment with the cylinder block and its cast in 'liners'.

Subsequently, how will the cylinder block and its cast in 'liners' be correctly and completely prepared in our typical work space to its sealing surfaces, as required to meet its minimum dimensional tolerances for Surface Parallelism requirement, too, eh?
Having its complementing sealing surfaces-the block and its cast in 'liners'-- professionally machined, 'flat', as well, is obviously the answer.
Taking into account, though, being that judicious "decking" of the cylinder block, although yet another detail not approached in Honda Service Information as prescribed remedial procedure, may well produce interference of the piston dome and cylinder head combustion chamber components, an alternative cylinder head compression sealing gasket with additional thickness to compensate may indeed be necessary. Maybe o-rings annular grooves cut into the top of the cast in liners isn't such a bad idea, after all? hmmmmm....... I'm opening yet other proverbial cans of worms.
Anyway!

We've all heard 'Blueprinting' a 'seasoned' engine block and cylinder head are quite desirable, for building a high performance automotive engine; that is assuming a qualified, detailed examination of all components is performed, first.
That certainly pertains to our motorcycle engines 'seasoned' components, too. Details, details, details.

I need a couple of Extra Strength Excedrin tablets and a good nap now......

[Old Fogey]

Cliff,
You are absolutely right. In an ideal world the block would be machined too.
But now you are talking not just removing a couple of heads and easily transporting them to the machine shop for skimming, but draining everything, removing the the engine from the bike and stripping it down completely.
A decent machine shop will soon have the head surfaces flat, then you have the job of washing the two halves of the block thoroughly to remove all the residue from the machining.
I've just had this done, on a block that had to be bored and a sleeve fitted due to a piston ring scoring the cylinder. Trust me, getting all the muck out was a big job.

[gltriker]

John, Perzactly!
For the sake of all our collective sanity, I won't belabor this topic anymore!
Incidently, I think looking for definition of the word, 'coplanar' got me all wound up.

[robin1731]

Yeah, even cleaning the heads after you get them back from a machine shop takes time. They are not clean enough to reinstall when you get them back.

[ericheath]

Sooooooo, besides sloppy mechanics on the last gasket change, I went out today and looked a bit more at the coplanar parallelism of the cuboid assembly. I have a large jack plane that my Dad would smack me for using it as a straight edge, but just the edge, Dad, jest the edge. I also used a large flat file and as near as I can tell, the block is conplane flat. I checked a bit more around the bolt holes to see if they had been pulled outward. They hadn't.

I began to get ready to pull the 1200 heads off my 87 donor when I decided to compare how much the Pistons stand proud from the block, pics to follow. When I did all the work on this engine a few years back, I noticed the 1200 Pistons come about 0.040" out of the block while the 1000 piston rim stays about0.040" in the block. It made it difficult to come up with compression estimates. So I rolled up my number one piston, and---what do you know, it's down in the block just a bit. I was sure it was above the deck before, so what gives???? This pic is looking down the edge of the block and you can make out the liner and see the piston is definitely in the block.

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And now, Paul Harvey, RIP, for the rest of the story.
Story number 4

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Story number 3

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And story number 2

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I hope you can all clearly see that Pistons 2-3&4 all are above the deck and piston 1 is clearly not. I would looooove it if someone could tell me that that is not a bent rod. I'd just love it, but even a rookie like me thinks it is. This is also the cylinder that was leaking coolant. I do remember it being hydrolocked once last summer and when I hit the starter, it turned over quite a bit before it stopped and it gave a "WHACK" this time. I'm pretty sure that is a parts motor or a rebuilder.

I pulled the heads on the 87 and all four Pistons come above the deck. Yay!

If I can get myself organized later this summer I'll pull the old one apart and see if it is a bent rod for sure.

[82aspy]

was not shutting off the fuel part of this hydrolocK?

[ericheath]

My fuel shut off is a pair of vise grips on the bike. I need to pull the tank and weld one in or find a good inline petcock. The one I had began leaking in no time.

[robin1731]

That is not a bent rod. There, I told you. Now get that engine out and replace with one that has 4 straight rods in it.

You do know you can buy plastic inline fuel shutoff valves right? I know Oreilly's carries them in stock for lawn mowers.

[ericheath]

Line isn't big enough for my bike. Well, it is right now.

I know it was good, and after hydro locking several times I didn't think it was possible to have the starter actually bend a rod, but I guess it's all about how much momentum the piston has before it goes up to compression. Then if one cylinder started to fire, there's that much more force.