Helping a friend on a motor problem in his jeep, while we are having good weather! We knew he had lost a head gasket, so today was exploratory surgery.
We started with this:
Everything must be labeled, so it can go back right.
This is the secret of repair work, anyone can do significant repair work; if everything is labeled as it comes apart!
It also helps to put the screws back in place by hand as you go. That way, when you reassemble them, you have the right screws, in the right place....
After we played for about 4 hours we had this:
And yes, the green in the back cylinder is antifreeze, it drained out of the head when we tilted it up for removal. The second cylinder is rust in water from the failed head gasket, which we expected from the dry / wet pressure testing.
The head doesn't show obvious cracks:
But it did show valve damage caused by towing above rated Loads! This was unexpected, and may have destroyed the valve seats in this head....
They look like this:
And this:
You can see a burn on both valves, with one burned on opposite sides. This is caused by heavy loads and rich mixtures raising the EGT (exhaust gas temperature) beyond safety limits. The aircraft actually have an EGT guage specifically to allow the pilot to avoid damage by this same scenario, by leaning out the mixture in flight. We'll need to remove the damaged valves to inspect the valve seats, to decide if this is a usable head, or scrap!
The other unexpected problem is here:
The intake manifold lost an ear just like Van Gogh! This one is easier to fix with a heli-arc welder, which will allow this manifold to be as good as new soon.
The outcome is dependent on the condition of the valve seats. If they are also repairable, he may decide to repair this motor; if not, it will need to be replaced. He is leaning to putting in a V-6 so he can tow without burning valves.
I'll let you know what he decides to do, and show the final repair! Hope you enjoyed the look inside this engine.🚂
💗🤠💙👍
Be blessed!