Some time ago, a forum lister on Jag-Lovers Forum published a video of his Nikasil block resleeving project. It worked fine for about three months and then failed. Sleeving an aluminum block is not for the faint-hearted or inexperienced. No matter how good a machine shop is, they need experience in this engine to resleeve it dependably. The factory did a lot of them and sent them out as rebuilt. I have not heard of them failing, so it may be possible.

 

Something I meant to mention, if you reuse the systems from the original engine at all, be sure to find out why you got holes in your pistons before starting up the new one. You might have a problem that will reoccur in the engine management or fuel delivery systems.

 

I too need some engine work. I have high blow-by. I am an old guy who has rebuilt a lot of engines. Never a Jag. One thing I learned over the years and am quit firm on is that it is better to rebuild the block you have, unless there is a strong reason not too. Why? I have had at least two cases where the used block had warpage or hidden cracks. I'm sure guys will write in and say, not problem. The block and heads will be magnafluxed or die penetrant tested. Mine were also. There is notheing more frustrating than haveing a new ingine with an overheating problem. There aren't many people around that are good at trouble shooting overheating problems, or other problems caused by warped cylinders. You know the history of the engine you have, and can be more confident in the outcome. If you find someone to do the job that has worked on Nikasil engines I think you will be happy with what he tells you about the good results of a Nikasil overhaul. I am not going to change engines. I would even pay a little extra to keep my old block and heads.

 

As an update:

The original, plastic tensioners are in perfect shape. No sign of wear or breakage. In fact, the entire timing system looks perfect.

There are no holes in the pistons and after a wipe off, they look to be in perfect shape.

What appeared to be a hole was apparently part of a piston ring or some other foreign body. Five out of eight cylinders had rings that were shot, pretty close, or virtually non-existant.

On a related note, new engine installation is not going so well.

 

sorry to hear about your difficulty, hang in there, and have faith!

 

Brief update: better late than never I suppose.

New engine was installed, went in perfectly.
New engine started, coughed and died.
Hillbilly mechanics gave up. Told me to get rid of the car because there was nothing else they could do with it.
Unfortunately by the time they did that, the warranty was up and I was...

They dropped it off to my regular guy who played around with it for a bit and discovered a few valves were stuck.

So it has been sitting since then. I've found a new engine, a reman with 22k miles on it for around $4000. By the time I get everything done, it'll be a $7000 job. Not really looking forward to it.

Don't really have much of a choice at the moment. Decent engines (guaranteed decent) are hard to find.

Can anyone point me to the right threads that have done valve replacements?

 

I would pull the heads and replace the bad valves, it will be easier than finding an engine in your parts I gather... I have done it a few times now without incident. if the engine is already out, it is a pretty simple job for a mechanic to do.

 

I've neglected an update. The 'replacement' engine has mashed heads, damaged pistons and the scored cylinders.

The previous engine appears to be in decent shape... aside from the weathering. If I had gone to see the guys that currently have my car first, I could've saved a ton of money and time... but alas, I did not know about them.

At the moment, I have two totally unusable (though rebuildable) engine. This has become a complete cluster...

I'm giving it one more shot to get a working engine before the end of next week... otherwise the car is being sold to a guy who will gut it, put in a built 350 and drive 1/4 mile at a time.

 

Can't find an engine from a reputable source.
Can't rebuild either of the junkers I have without significant cost and time.

I'm packing it in.

Any idea what an XK8 in decent shape is worth without an engine?
Any idea what I can do with the engines I do have?

 

Sorry to hear- If you were closer I would consider it myself. You have a car worth 1K which would be worth 8K with a 1.5K parts investment. Maybe if you wait a bit and watch the classifieds you can find a wrecked XK8 or a good engine?

You can part the engine and maybe recoup some costs... The car itself without ANY engine is not worth much as a whole- ($1000us?) if you part it out you are looking at over $5k, but there is time and effort involved stripping it. Take a look at ebay for values on used parts.

I would keep it and wait for the right engine opportunity if it were me. An eternal optimist, I rarely "pack it in" the exception being one Alfa Quadrofolio that had an engine fire and was a salvage title- the time/cost benefit ratio didn't add up.