Head gasket now!!?

FiatFunk

FiatFunk

True Classic
I thought I'd be driving next week. Just fixed a couple coolant leaks on the t-housing and water pump, put electronic ignition and fit a couple hard brake lines in yesterday, working on a gm alternator fit today, a few little parts arrived from Midwest today. Still lots of bodywork to be done but was hoping to at least go for a test drive next week.
I topped up the coolant and bled the radiator, and it wasn't long before I saw another coolant leak. Investigate and it's coming right out of the exhaust! I couldn't believe it. Didn't cry but did swear. And then got right into it. Exhaust port 3 and 4 were wet, 2 was dry, and 1 was oily. Pull the head and it didn't take long to figure out what had been happening. I am 100% certain I torqued those head bolts down properly but as you can see the head gasket did not seal along the front edge. Bad gasket or my fault? I don't know. Measuring gasket thickness and it is approximately 2mm along the front edge and 1.8 along the back and over 2 around the fire rings.
The engine did get hot on the first startup, not too sure how hot as I couldn't get the temp gauge working then (does now) I was a little worried about this but on two subsequent start ups and very brief runs there were no noticeable leaks, although it was difficult to start once, possibly due to coolant in a cylinder.
At least these heads come off easily.
Now, what is the best way to clean the surface of the block and head? I don't have a machinists straight edge but better pick one up asap. Hoping the head is still flat enough.
Any head gasket recommendations? This one was from Vicks, I'll spend more on one this time around and want as thin a gasket as possible.
Sigh, didn't need this!
 

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JimD said:
Did you change the t-stat gasket? Depending on the head you have, there is a chance you got the wrong gasket. If your engine had the EGR passages in the head, there is one that can be left open to the coolant flow.
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This thread has dome of the gasket problem info.

86 X - thermostat housing to head gasket

Hi all, I'm putting the head back on my X after upgrading the cam. I now realize that the thermostat housing to head gasket I have must be for an older model as it is not quite the same as the one that came off the car (it doesn't have the same cutout shape nor the extra hole). Though the...
xwebforums.com
 
jimmyx said:
If you decked the block or shaved the head make sure you shorten the two dowels a corresponding amount. Edge leaks are almost always caused by a dowel issue.
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Oh crap I bet that's the problem! I didn't realize that had to be done. Although I vaguely remember checking the depth available for the dowels on the head
 
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JimD said:
Did you change the t-stat gasket? Depending on the head you have, there is a chance you got the wrong gasket. If your engine had the EGR passages in the head, there is one that can be left open to the coolant flow.
Click to expand...
I did change the t housing gasket. The old one didn't come off clean (now I'm not sure if it blocked that hole or not). I had a paper gasket for the t housing which partially blocked that hole, I cut it so it didn't obstruct that hole at all and put it together. That sounds very likely to be the issue. It gushed out the exhaust. But also I think it was the dowels, tho I vaguely remember checking the depth on those. And this gasket issue wouldn't explain the oil in exhaust port 1

*Edit- most of the links in that old thread don't work anymore, but it sounds like that hole must be blocked. The other gasket must have blocked it off, and that is why it was such a sudden flow today. Possibly I rushed into taking the head off, although as I mentioned oil in port 1 isn't good or explained by the t housing gasket. I'll tap and plug it tomorrow
 
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JimD said:
Did you change the t-stat gasket? Depending on the head you have, there is a chance you got the wrong gasket. If your engine had the EGR passages in the head, there is one that can be left open to the coolant flow.
Click to expand...
Yes...THIS (above).

Water coming out of the exhaust after a rebuild is 99% of the time due to using the wrong thermostat housing gasket.
 
I made the same mistake 20+ years ago when swapping a 1300 engine into my early 128 Wagon. Scared the crap outta me at first. 😄
 
I suggest plugging that hole behind the T-stat in addition to using the right gasket.

For a much better head gasket I like the multi layer steel (MLS) ones from Cometic. Available for both 10 and 14 bolt heads, any thickness desired, not that expensive and I believe offers the best chances of no leaks....assuming the head and deck are flat and the dowels are not too tall.
 
FiatFunk said:
I think so, doesn't retorque come later? After a few hundred km?
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Head retorque is after 1 heat cycle. Then again after a few hundred miles... This was my mistake on the last rebuild, I didn't do the first heat cycle retorque and I suffered a slow gasket failure after 4 months of driving.. This is, if regular bolts or studs are used and a standard style gasket. I don't know anything about TTY bolts....
 
Ok so just got back to the car now.
The dowels are pressed into the block far enough, possibly it was that I neglected retorquing the head bolts. But I don't think this would explain how the head gasket is more crushed in the back edge. It is possible tho unlikely that I didn't torque the head down properly. I replaced the head bolts but can't remember who I got them from but here is a photo, maybe that helps. Also a photo of the t housing and gasket, clearly the wrong one. I really do have to be more thorough when building an engine. Wrench slow to drive fast.
Not sure if I should get that head skimmed. I think cleaning it up with red scotchbrite and checking with feeler gauges and a straight edge should be a good enough inspection. MLS would be a good way to go if it's flat enough, if it needs a skim it will pretty much remove what's left of the decompression rings.
 

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bruinbro said:
My bad. I made the assumption that you are using “standard” head bolts, not torque-to-yield bolts. Happen to know which you are using?
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The head bolts are not the originals, but not sure what kind they are and can't remember who I got them from. See photos below
 
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