Hooch cooling system pushing out water from cap

[DaveKamp]

Clearly Joe is determined to predispose the problem to fitment of a theory, rather than apply wrenches, perform tests, then open it up, and look for bona-fide real-world proof.

Until the latter is done, this will continue to be nothing more than fruitless banter.

 

[dan filipi]

i Just think simply that with the mods Joe has done to this motor, the reliability of the stock form is thrown out the window.
I’m also starting to loose sight of what the “Hooch bike” is suppose to represent.
Maybe Joe can explain.

 

[joedrum]

Well I’ve been doing a lot of reading ...and it’s just like I said in the beginning...the stock gasket are ok in economy stock use...pass that that ...they won’t last in a hi performance or boost type situation ...and the culprit is heat and pressure ...basically heat degrades the composite gasket around the fire ring and failure ...I’ve about givin up on the two gasket copper sandwich .... parts should be in ..in a day or two hopefully

 

[DaveKamp]

Pull the plugs, take pictures of 'em, identified by the position... and give it a leakdown test, watch for bubbles at the radiator cap... that will help you narrow down the location of the problem.

I believe that the problem you're experiencing, IS a heat/pressure situation, but more than likely, it is combustion pressure leaking out into the cooling system, but not cooling leaking INTO the combustion chamber. Understanding this is of paramount importance, because the TYPICAL blown-gasket situation is visually revealed as a 'cleaned' spot where coolant is being pushed through. In your case, I don't believe it is. I suspect you're developing enough combustion pressure under load, that one tiny spot somewhere is JUST weak enough... like... just a little too light on gasket force, either due to bolt torque, or a yielding fastener, or a REALLY slight warp, so that your 250ish PSI chamber pressures are leaking by, but the 16ish psi of cooling system pressure will not come backwards.

Take good, clear pictures... they MIGHT show it... and they MIGHT not. The leakdown is your best first clue.

 

[dan filipi]

Hasn’t been mentioned, but preignition being a violent uncontrolled explosion is plenty to blow a head gasket. I know that your C5 ignition is programmed with a lot of advance, making preignition especially possible.

 

[joedrum]

I also have the stock curve also as my lowest setting out of the 4 curves I got ...it remains to be seen what things look like ...and what I’ll do...

 

[saganaga]

I'm still encouraging you to check everything.

This is 40 year old engineering. Sure, it could be gaskets blowing because its just too much, but IMO, a lot of old engineering has a pretty good safety factor. No modern material science, which may mean a flaw, but more likely means larger safety margins. And gasket tech is more or less the same for different reasons - they are probably pulling materials designed for high compression, high hp automotive engines.

 

[joedrum]

Pic

Got the gaskets today ...first time ever seen them looking like this ...they seem to be more paper like in the composition and the fire ring is a bit wider and seems to have a step up in it where it gets fatter ...hmmmm strange first I’ve ever seen like this :headscratch:

 

[dan filipi]

Who is this gasket from? Maybe get lucky and it's a better design.

 

[joedrum]

They were 15.88$ for two gaskets ...free shipping. Made in China is all the brand name there is ....they are certainly different from the others I’ve seen

 

[Two85s]

Maybe changed to avoid copyright?

 

[DaveKamp]

they seem to be more paper like in the composition and the fire ring is a bit wider and seems to have a step up in it where it gets fatter

Okay, so if you look extremely close at the fire ring, you'll see that there's no seam anywheere. That's because when that fire ring is made, it's a copper sleeve... and they 'spin' form a flange on one side.

Here's a neat look at how spin-forming works... on copper, and this one is a CNC machine...

The gasket material is a sheet that comes off a roll. A cutting die punches the two bore holes, and a square, then the punch retracts, they place two copper rings into the holes, then cycle the press again, with a secondary die from below that comes UP, and forms the lower copper of the sleeve into a flange... then continues upward, curling it inward, and then flat against the gasket material.

What you're seeing as being 'fatter', is just the area of the formed copper as it transitions from being flat against itself, to being crimped over the gasket material.

 

[dan filipi]

Is there more goo or less goo, or same goo?

 

[joedrum]

Yes this is usually not like that on goo gaskets ..the other deal is the fire rings on oldwing gaskets are not copper there steel ..I’ve seen head gaskets made by smart hands a gigs fire rings and all ...I’m not to impressed with the gasket ...it does appear to have metal center ...so I’m looking at coating ...the problem here is there no block deck ...and the gaskets are exposed to moving coolant always ...I’ve never seen a oldwing head gasket yet that didn’t show signs of degrading from where coolant was expose to the gasket ...

There’s seems to be less goo dan ...so I’m just doing a lot of thinking right now ...looks like fire ring over pressed and not very V like ...gasket does not look like it can handle coolant bath to me

 

[joedrum]

Pics

Check the fire rings out and gasket coating

 

[dan filipi]

Is there metal sandwiched between the paper?

I'm not sure what to think of those gaskets. Just because it appears to be paper doesn't mean it won't hold up to coolant. Considering the source, who knows what material they used . May be the only way to know if it will hold up is to run it.

 

[joedrum]

Yes there is metal in the middle it seems dan

 

[joedrum]

Well if the day is ok I’ll work on the bike ....

 

[ekvh]

My bike was doing this also, puking cool, not scalding hot, coolant under heavy throttle. My overflow bottle is on the right front down tube and has no overflow tube, so it flew all over my right leg. Scared me. I chased the gaskets a few times. My heads were shaved around 0.025”. Then I used copper gaskets. I found an issue with the way the way the head was shaved. Fixed that, Still puked coolant.

One time, when I still had OEM gaskets, it was bubbling , so I know it was a head gasket, but I also know I ran it low on coolant and probably cooked it.. With the copper I think it was just pushing it out, and therefore not able to return the same amount as it cooled down. Soon you’re low on coolant. The same thing happens if your reservoir line has a crack in it, the coolant won’t go back down into the radiator. I tried new radiator caps, old caps from different bikes. I found the top of my filler neck was bent a bit which probably didn’t help, but it still puked.

My issue was resolved by adding more volume to the coolant overflow. I had a small container. I used an old thermos, so I drilled holes in the liner and probably doubled the volume. A thermos isn’t a great choice because you can’t see through it like plastic.

I also installed a clear piece of tubing to watch it when it pushes coolant. When you really get on it, it pushes a surge of coolant out. I am still a bit leery that it will come flying out on me, but so far it hasn’t. Or it didn’t. It also was never scalding hot.

I’m back to the 1200 heads now and can’t remember if it does it with them or not. I’m going to say no, but can’t remember for sure. The other change I made was going to my 83 radiator. I did it because the 1000 had a leak. I think they’re the same size. I’m still using copper with aviation sealant.

The 1000 cams are higher revving, so could it just be the volume and sudden expansion of the coolant from the added heat overwhelms the system? Water pump pushes it through, but radiator won’t pass it back fast enough. It has to go somewhere.

If you still have your bike together, it might be worth investigating this using a larger overflow.
If you don’t, maybe when it’s back together if it still does it.

 

[joedrum]

Well Eric I’m thinking a lot like you ...people just don’t understand how vicious the rpm rise can be ...and I’d say the radiator can get overwhelmed with flow ..I’m sure with a motor like this more radiator is absolutely a good thing ...they make rather small oil coolers that could be added ...I appreciate your post Eric ...it confirms a lot of things ...on a very similar bike ...I will be pulling heads today to look at things :builder: