headgasket time....

[Raze]

So I went to take the Fiat for a drive yesterday and popped the coolant to ensure it was topped off (I had flushed it and bled it but noticed it slightly below the filler neck the last time I took it out) and noticed a couple black globs floating on the top, I immediately suspected headgasket or the like (no overheating problems) so I fired her up to see. When I cranked her up she started spitting what can best be described as globules of oil in clear water out the tail pipe, shoot. I then drained the oil, sure enough it was milkshake, and had a greenish tinge to it, shoot. I drained the coolant and could basically make out a faint oil slick on the top (you know, the rainbow of oil on water). I haven't overheated the motor, though the engine's history is a total mystery so I'll be measuring the deck and head for flatness.

What I want to know is besides the HGs, are there any other places / connections / gaskets on these motors where oil and water can mix? Is it worth redoing all the gaskets, valve stem seals, etc? The only gaskets I can see leaking some are the lower cam/valve gaskets. Also, are headbolts TTY or reusable? Anyone have problems stripping headbolt holes in the block upon removal? Standard battery of questions I'm sure and I have the Haynes manual, so if there's something in there or not let me know.

-Jeff

[124JOE]

i once heard on here to tighten your bolts to tourq spec.when ever you dont the history just double check.

sorry to hear that.i hope it all goes well

[vandor]

Hi Jeff,

> so I'll be measuring the deck and head for flatness.

Yes, do that for sure! Remember, if the head is warped, the camtower surfaces will be warped aswell.

>What I want to know is besides the HGs, are there any other places / connections / gaskets on these motors where oil and >water can mix?

No.

> Is it worth redoing all the gaskets, valve stem seals, etc?

Definitely! You don't want something else start to leak after you put it back together. Just buy a head gasket set and replace everything, cam seals, camtower gaskets, etc. Might not be a bad time to check the valve guides, maybe do a valvejob. Oh, and either way check the valve clearances. Talk about project creep

> Also, are headbolts TTY or reusable?

In theory they are reusable, but they are old enough that sometimes they start stretching and won't torque down.

> Anyone have problems stripping headbolt holes in the block upon removal?

I've never heard of that on these engines.
BTW, when reinstalling headbolts the threads are supposed to be lightly lubricated with engine oil. Antiseize would probably work too, as long as they are not dry.

[fiatfactory]

.

[Raze]

Thanks guys, all the answers I needed. Valves are good, I checked the clearances after I got the car and they're perfectly in-spec, the shims look almost brand new so I'm guessing it had some love at some point. I'm actually more interested in checking the head for cracks or some other problem with why i'm seeing oil in the radiator. That is the part that bothers me as I've blown headgaskets on several cars...

[vandor]

Yes there is... the thermostat recess in the head, behind it is an oil passageway that balances the oil drain level under the camboxes, the thermo recess can corrode thru to the oil passageway...leading to oily milkshake in the crankcase.

Dang, there must be a lot of corrosion to eat through that much metal! I've never seen that happen, but I've seen the coolant outlet T's just about disappear from corrosion, so I suppose if the coolant is not changed for a long time some pretty nasty things can happen.

[Raze]

Got the head off, will post pics tonight, headgasket was in sorry state, with most of the coolant passages badly corroding in the gasket, the rings between 3 and 4 cylinder looked like they were starting to share the love between cylinders. Have alot of indication #1 cylinder is where the water is coming from as all the corrosion on the piston wiped off clean in one shot, plus i have some nice rusting on the exhaust manifold on #1 that wasn't there when I rust treated the header and painted it. This gasket looks copper sprayed and was pretty flimsy. I couldn't make out any manufacturer mark on it. I'll be swapping in a Fel-Pro and redoing all the seals on the head while I'm at it as others have suggested. The deck is flat save a small coolant passage spot that seems low, as if it's corroded some of the block material, but it won't affect sealing, and it wasn't one of the cylinders affected so I'm not concerned.

I have some questions:

1) the carbon deposits on the piston tops (non-leaking ones) is hard as all hell, what's a good product besides throwing coolant on there to loosen it up? Same goes for the valves, the deposits are like concrete, I've seriously never seen anything like it before, anyone have any ideas?

2) how can I check what pistons (high compression / high dome)? I can measure the bore with some calipers...

3) cams, how to check what cams are in there, lobe measurements of a stock 1608, etc.?

[vandor]

I usually wire brush the valves, not sure about the pistons, maybe carb cleaner and a wood scraper?

If you measure the height of the piston dome we can tell you what CR it will likely give.

For cams you should measure the lift, that may give an indication. Most aftermarket cams have some stamping on the back surface, or numbers stamped (not cast) in to body. A pic might help. Of course they could also be reground stock cams, that would be hard to tell. FWIW all US stock cams had the same timing.

[Raze]

Pics as promised:







There is writing on the tops of the pistons:

80.8 55705/A with a small B3 below it. Everything I can find on a 80.8 for the 1438, but since the 1608 block is the same this is the same compression or does this bump compression?

[majicwrench]

There is really no need to clean the top of the pistons, it will look that way again soon enough. If you want to loosen it, go to the local GM dealer and pick up a can of Top Engine Cleaner. TEC is very bad for you, use it in a well ventilated area. ANother product is Sea Foam, available at auto parts stores, is not near as effective as TEC tho.
Keith

[Raze]

yeah I've used GM TEC and Seafoam, I've got a bunch of it laying around, though I have this idea to get a 5 gal paint bucket and fill it with a gallon of heavy duty degreaser from HF given how cheap it is, dilute it out a bit 4:1 (I've read this works well), disassemble the entire head and let it soak for a day. I'm thinking that might do what I'm looking for without much effort...

[vandor]

80.8mm is the diameter of the pistons, 0.8mm oversize. This has nothing to do with the compression ratio.

The stock 1608 pistons had about a 2mm done, the one on your pistons look noticeably larger than that. I bet that those are "9.8:1" compression pistons.

That headgasket sure looks hammered!
bye,

[Raze]

80.8mm is the diameter of the pistons, 0.8mm oversize. This has nothing to do with the compression ratio.

The stock 1608 pistons had about a 2mm done, the one on your pistons look noticeably larger than that. I bet that those are "9.8:1" compression pistons.

That headgasket sure looks hammered!
bye,

How high are the domes on the higher compression pistons? I knew they were larger bore, but I didn't know if you could get larger bore in stock CR or if it was performance only kind of thing. Was also wondering based on the numbers (not the 80. if they meant something...

[vandor]

>How high are the domes on the higher compression pistons?

There were several brands, etc, so it's hard to say. My guess is 6-8mm.

> I knew they were larger bore, but I didn't know if you could get larger bore in stock CR or if it was performance only kind of >thing.

In the past all kinds of variations were available. Today the selection is nearly non-existent.

>Was also wondering based on the numbers (not the 80. if they meant something...

They are the manufacturer's part number. Doesn't really matter, as none of the manufacturers that used to make these pistons (Mondial, AE, etc) make them any more.

[So Cal Mark]

I'd like to see a pic of the underside of the cyl head