Hi all,
I haven’t posted in a while as I have been busy working on my 1983 Jaguar XJS. I last posted that I had a noise in the engine I had recently swapped into my XJS. I pulled the heads and it was actually not a dropped valve, but a washer that had somehow found its way into the engine (cautionary tale for anyone who has their intake manifolds off). It had embedded itself into the piston and was whacking the head. That will make noise. On a brighter note, the number 12 piston actually had an exhaust valve seat that had fallen about halfway out, so I was on my way to detonation one way or another.
I fabricated up a custom head puller and it has been working great. I first pulled the heads off the poorly running motor I had already pulled out of the Jaguar as a head puller test bed. Those heads were stuck good, but the solid plate head puller did its job. After I got the heads off, I was shocked to find that the head gasket had degraded severely and the inside of the water jackets were literally filled with rust and garbage. The heads initially looked okay and I took a pressure washer to them. Unfortunately after pressure washing, severe pitting was evident to the point that I would suspect head gasket failure at some point if I tried to reuse them. Interestingly, I also found that at some point in the engines life a bolt had found its way into the engine and had left its imprint on the piston and the head, but had somehow been ejected out because damage was limited to the imprint (I guess someone could have dropped a bolt into the intake and it seized and they yanked the heads before it did real damage). However, based on the poor shape of the gaskets etc., it must have been a long time ago.
When I pulled the heads off the swapped motor in the car, that is when I found the washer damage. Interestingly the inside of this engine looked a lot better, but I still can’t understand where all the sand and garbage is coming from, no wonder everyone’s radiators get plugged without filters
I decided to not pull the motor, as if I pulled the motor, I might as well do the whole bearing thing etc. and I had already been in there and resealed the entire bottom end and the bearings looked fine. Instead, I pulled the piston liner out (it didn’t come easy) and used a dremel to clean up the small amount of damage to the piston. I then purchased some new rings (These are getting hard to find). I honed the liner, installed the new rings and was able to get the liner over the new piston rings from the top. This involved a chunk of 1 liter diet coke bottle and two large zip ties, and about four hours of trial and error (with a large amount of swearing) P.S., you cannot allow the coke bottle plastic to go into the liner with the rings, there is not enough clearance. I had to snip some wings into the top of the coke bottle spring compressor (4th try) so it would slide down with the liner and not get jammed up in there, then I snipped off and pulled out the zip ties and the liner slid down the piston. I obviously cleaned and resealed the liner before sliding it into place.
On the heads, I spent a couple of days disassembling them and cleaning them up. I was able to knock the offending valve seat back into place and I pinned every valve seat in both heads by simply whacking a divot into the aluminum on two sides of the seat. Hopefully this prevents a future drop episode. I cleaned up the valves and then lapped them in the heads. I had started out with a stupid suction cup tool and lapping compound you can buy at any auto parts store. The suction cup tool is a waste of time. I had a bit of insight after the first two valves; I gooped up a valve and simply hooked my drill to the valve stem on the other side of the head and spun it back and forth about ten times. It worked fantastic and saved me countless hours of time.
So, I am finally on the home stretch so to speak. I need to reinstall all the valves, check clearance, adjust accordingly, then reinstall the heads. I spent a lot of time cleaning the surface of the heads and thought they are not perfect (water jacket area is still discolored), I don’t suspect I will have a seal problem. I carefully scraped the corrosion off with a scraper/razor tool, being careful not to work in the piston seal areas. I then used steel wool to clean off the entire deck of the head. All seal areas are smooth and shiny.
On another note, I am sitting here looking at the new metal head gaskets and am thinking, these are going to inevitably corrode, especially in the water jacket area. Why not use stainless steel on the head gasket and the head studs? Or at least make them corrosion resistant?
I realize that this whole project is kind of a complete backyard throw together job and could fail spectacularly, (probably will have higher compression in the cylinder with new rings, gaskets could fail, etc.) but, I am only into it for a head gasket set and a set of 12 piston rings (if anyone needs a single set of rings, I have 11 spares) Thanks for reading
