She's done, selling her for parts

The engine I'm rebuilding is almost exactly like this one. Except I've got the bottom end open too. So what do I do? Can anyone point out a good post?

 

If it's your 1980 in your sig, then you need to fix the tranny, replace all the chain guides, buy a gasket set, rings, replace burnt pistons, might as well do a valve job, valve seals, re-shim, "blueprint" the oil pump, and soda blast the motor.

Or buy a "ready to go" motor that passes a compression test, with low miles. Upgrade to a 750.

Get the nicest, lowest mile motor you can afford, and amazingly, they are all about the same price anyway !!

 

When I did the valve work on mine, I got sick and tired of trying to scrape bits of old head gasket and carbon off the head, block, and pistons with tools that I could trust not to scratch alumimum.

To solve this, I went to Harbor Freight and picked up one of their smaller blasting guns and a bag of blasting soda. I did this the cheap/messy way in a plastic storage bin with the cover mostly closed, while wearing a dust mask and safety glasses. But, despite the mess, it was pretty easy and the results were great. If you have a number of surfaces to clean of old gaskets or carbon, I highly recommend it.

Total cost (already had the compressor and storage bin) was about $65. I had about a lifetimes supply of soda still left afterwards.

Cylinder head before soda blasting:


And after:


And a closeup of one cylinder before:


And after:


Cheers,
Paul

 

My buddy has a sand blasting chamber. Will that work? Too harsh?

 

Exchange the sand/garnet he uses for soda powder and you should be good.

 

I use these for removing old gasket material of aluminun engine parts, they are made to not remove aluminum or gouge it. 3M bristle dics

http://multimedia.3m.com/mws/mediawebse ... 6E666666--

 

Where does one buy soda powder?

 

Guys Guys!

The brighter side of this is the circle of life. The spirit “parts” of this XJ will keep who knows how many other XJ’s on the road. My Seca is the combination of two bikes, neither was any good on there own.

 

50lb bags are about $40 at Harbor Freight. I think you can use the regular grocery store baking soda if you don't need so much... though it's probably a bit finer than the blasting stuff.

 

Hey SQL Guy,
You didn't back-cut your guides any, or round a few edges?
I think I'll open up a motor this winter.

 

No, not at all. The soda takes off dirt, silicone, carbon, paint, etc, but it doesn't hurt the metal at all. And, it washes off and dissolves with water, so you don't need to worry about bits of it being left over in small places.

The soda is rated 2.5 for Mohs hardness. Aluminum is rated about 2.5 to 4, so it may sound a bit risky, but the cast aluminum of these parts is not the softest aluminum, and all exposed aluminum will be covered with a layer of aluminum oxide, which is 7 on the Mohs scale.

The valve guides are bronze, they're a bit harder still than either aluminum or the soda.

Of course, even water will wear through rock eventually, so I suppose some damage could be caused if you kept blasting away long after the parts were clean. I measured my valve guides for side shake after cleaning, and they were fine... and you can see what the seats look like.

One other alternative, though, is crushed walnut shells. They are really safe for aluminum, but they're much harder to get out of places where left overs will get trapped.