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Any of you folks experienced corrosion damage on models with the 16 valve engine design? Thinking about this issue in general I realised that I had no recollection of ever seeing a post about any such damage on a 16 valve head. I am sure it must happen but....?
I did a comprehensive search and could only find one example and it seemed minor compared to what we all too often see on 32 valve heads. If you have any photos of such 16V head damage much appreciate if you can post about such example together with any recollection about the state of the head gasket adjacent to where the damage took place..
Sorry to say my cylinder heads (1978) have some. But only on the water channels. Not on the rings that touch the barrels.
Photo's? The tops of the cylinders have been known to corrode but that is another matter. I have never seen the cylinder head corrode where the fire ring sits but have seen it abutting such.
Greg did a long thread about rebuilding an 84 for his son a few years ago. Had a lot of discussion and maybe pics of what he was finding inside potential donor engines.
Greg did a long thread about rebuilding an 84 for his son a few years ago. Had a lot of discussion and maybe pics of what he was finding inside potential donor engines.
This is only going to get worse for ALL "stored" 928 engines......especially ones sitting with coolant on a shelf somewhere. The $300 engine I bought for the Lemons racer was SO BAD.....it corroded new cooling passages in the head, the head gasket was almost totally gone except for fire rings. If your gonna store a 928 (or any engine) for a while, be sure to drain all the coolant out
Any of you folks experienced corrosion damage on models with the 16 valve engine design? Thinking about this issue in general I realised that I had no recollection of ever seeing a post about any such damage on a 16 valve head. I am sure it must happen but....?
I did a comprehensive search and could only find one example and it seemed minor compared to what we all too often see on 32 valve heads. If you have any photos of such 16V head damage much appreciate if you can post about such example together with any recollection about the state of the head gasket adjacent to where the damage took place..
Not sure why you would expect these engines to be any different.....
If anything, they are worse, simply because of age.
I've spent days, literally days, trying to get the heads off of some of these engines....the coolant will get past the head gaskets, into the areas where the head studs are, and corrosion will occur so badly that the head will be "locked" in place onto that stud. Soak, wiggle, heat, jar the stud while pulling....rinse and repeat for hours on end. One head I literally ended up "cutting" off off the stud, once I got the head up a few millimeters.
On engines that people want to retain the same serial number, I've been putting in sleeves, to salvage the blocks.
Very difficult to find a used 16 valve engine that doesn't have corrosion damage so bad that either the heads or block are usable.
When I start looking for a used engine, I plan on taking apart several, to find one that is usable.
Not sure why you would expect these engines to be any different.....
If anything, they are worse, simply because of age.
.
I have no idea how you might have concluded I expected the 16V engines to be any different when my "logical" expectation is that they should be worse given the aging factor.
It struck me that all the examples I had seen mentioned on the list were 32 valve motors so I did an archive search and found virtually nothing about such on this class of engine. This made me wonder if it was coincidence, poor search technique or perhaps by some weird reasoning a factual occurrence. Needless to say 32 valve motors are pertinent to my specific interests and it may just be that I simply gloss over threads to do with the 16V motor that to be fair, I know squat about.
On a side note I took a look at your thread that Seth linked last night but unfortunately the photos would not download for some reason.
On a side note, I also did some investigation about their head gaskets on the Victor Reinz website noting that I am more than intrigued as to why their head gaskets are seemingly "falling apart" as you have mentioned on several occasions. I found they offer a 968 gasket presumably like the one fitted to Jim's motor- I think it said they were 106mm bore. Surprisingly they did not list a head gasket for the stock 928 at all! Whether this is a website glitsch or a technical reality I have no idea.
Further research on the VR website suggests they only use one specific material for their composite head gaskets outboard of the fire ring and the fibrous material is aramid [part of the kevlar family] - this was heavily marketed some 40 [?] years ago as the alternative to compressed asbestos gasket sheeting material. The stuff they use appears to be referred to as AFM22 and is also offered as a sheet material to those wanting to make their own gaskets - it seems they use this on all their composite head gaskets with no spec changes for different coolants. Bottom line- this material is formed from galvanised mild steel with tangs that the fibrous material is pressed onto from both sides so presumably not bonded. I could find no info about the fire rings but suspect they will be SS316. How the fire rings are retained in the head gasket I do not know- perhaps they have an external groove that engages when pressed into the sheet material that is stamped out with a small interference - any offers anyone?
Here are mine. Appx 80,000 miles. For the past 5 years, the car has sat for 11 months out of the year.
Scott,
Thanks for sharing the pics. Signs of minor corrosion damage having been initiated but nothing of significant consequence. Looks as though you have been going some with the wet and dry to clean up the faces- not sure how sound that is given the surface finish has a controlled roughness factor [50RA?].
- both sides
Much appreciate if you can offer some insight into yearly mileage and whether the coolant was changed at all in those 5 years, or more to the point when was the coolant last changed? If you have the gaskets and if it is not too much trouble maybe you can post some pics of the gaskets or at least one of them both sides.
Yearly mileage is less than 1,000. All my cars are stored in Baltimore. I get back there once a year for maybe a month. Ive got 4 toys there, so they dont get driven much. Most of that time is spent wrenching.
Coolant is changed in all of them every two years. Here is the only pic I have of the head gasket.
there was evidence of coolant leakage on the paasenger side, as evidenced by the corroded stud.
Yearly mileage is less than 1,000. All my cars are stored in Baltimore. I get back there once a year for maybe a month. Ive got 4 toys there, so they dont get driven much. Most of that time is spent wrenching.
Coolant is changed in all of them every two years. Here is the only pic I have of the head gasket.
there was evidence of coolant leakage on the paasenger side, as evidenced by the corroded stud.
The mech used red and white scotchbright
Cannot read much into the gasket condition. If it is still around and can be cleaned up a bit it would be interesting to see what if anything can be read from it.
Well if nothing else your motor proves that the 16 valve motors can survive in reasonable condition on low milers.
If you do not mind me asking what caused you to pull the motor?
Well, this is the only car in my small collection I have not pulled the motor on, Im actually been putting it off for a few years. I have got 3 sailboats, and 5 sports cars (4, if you dont count an S600 Mercedes as a sports car). Everybody gets their engine pulled every 5 years for a checkup, cleaning and gasketing. And I am moving all the cars to Seattle, to be closer to where I hang out when Im stateside. Since I wont immediately have garage space when the cars get there, I spent November doing work on 3 of the cars.
Noticed what looked like a head gasket oil and coolant leak on the 928. And since the advice on the forum was to yank the engine for the 16v, out it came.
of course, while I was I was in there, it became a complete regasket job. But I had to leave Baltimore to head back to Seattle to get the parts for my sailboat engine there out of the machine shop before I headed back to Africa for the winter. So I didnt have time to stick around after we pulled the engine apart and cleaned up the heads.
So I am monitoring the re gasket effort from off site.
Well, this is the only car in my small collection I have not pulled the motor on, Im actually been putting it off for a few years. I have got 3 sailboats, and 5 sports cars (4, if you dont count an S600 Mercedes as a sports car). Everybody gets their engine pulled every 5 years for a checkup, cleaning and gasketing. And I am moving all the cars to Seattle, to be closer to where I hang out when Im stateside. Since I wont immediately have garage space when the cars get there, I spent November doing work on 3 of the cars.
Noticed what looked like a head gasket oil and coolant leak on the 928. And since the advice on the forum was to yank the engine for the 16v, out it came.
of course, while I was I was in there, it became a complete regasket job. But I had to leave Baltimore to head back to Seattle to get the parts for my sailboat engine there out of the machine shop before I headed back to Africa for the winter. So I didnt have time to stick around after we pulled the engine apart and cleaned up the heads.
So I am monitoring the re gasket effort from off site.
Hopefully you have an excellent motor there and your efforts will be well rewarded. If you have had a coolant leak through to a stud take a careful look at the gasket to see why and check there are no cracks in the head.
Not sure I like the idea of pulling a motor every 5 years but it seems as though head gaskets that have been in the motor for 20 years are by and large on "borrowed time". My [32V] motor is currently running at 14 years since I had the heads off. No intention of doing anything in that department for at least another 6 years unless circumstances indicate otherwise.
I checked the gasket carefully. We could see the path where the coolant was leaking. I didnt have time to have the heads magnafluxed, but a visual didn't reveal any cracks.
I also wanted a chance to check the clutch and assorted pieces, the TT bearings, and redo the bushes for the shifter. So this seemed like the appropriate time to yank the engine.
I am planning on loading the Baltimore cars and moving them to Seattle next spring. But, as I have several garages and a lift in Baltimore, I have nothing but a barn on the Olympic Peninsula. So now is the time to do all this sort of work.
I am giving up on Baltimore entirely. I got shot on one of my neighborhood strolls there last year. So I decided to sell my rental properties there and vacate the city. If you check the ‘MY 84 neighborhood find’ thread, Im the one that found the car that Steven now has. On one of my strolls. Ive survived living in Rwanda during the genocide, living in Mosul, Iraq for two years, and in South Sudan during the JajaWeed uprising. And I get nailed in Baltimore by some punk.
Last year I pulled the V12 out of my XJS to do the head gaskets and check for loose valve seats. As well as pulling the engine on my 1992 S600 to regasket that engine. This year was pulling the head on my Nissan 3.2L diesel in my Seattle based sailboat, as Im taking that to Alaska this season, and don't want any surprises. That engine is 45 years old, with the original head gasket. I did the head gasket in my TVR this fall, as it was last done 25 years ago. That one was stolen and hidden for 25 years, so I wasn't worried about wear, but time. Unfortunately, I didn't do the head gaskets in my Subaru Outback in time. Coolant got in the oil, and I threw a connecting rod in the middle of nowhere Montana. So I walked away from that car.
So color me a bit paranoid on head gaskets on aluminum engines.
Of all the toys, the 928 is my favorite. And I really want to keep it running. Bought it 6 years ago. Did a TB/WP, alternator, rotors, bearings and brakes, and tires. Took off from Vancouver, drove it 7,000 miles, thru Mexico, down to central America, back up through the Rockies and then to Baltimore. Never even hiccuped. So I figured I owed it some TLC.
01-12-2020, 04:58 AM
16V cylinder head corrosion damage
