Putting in the rods and pistons into the 4.7L last night, my son asked quite innocently, Is that scratch on the cylinder going to make any difference? I was heart broken. A 1 inch long deep gouge, not scratch, in the # 6 cylinder wall. How in the hell did I miss that? When I dissassembled it, the pistons and rings were unremarkable. I inspected/measured every cylinder. It is so deep, I don't think it can be bored out and saved. Now I have a bum 4.5L and 4.7L block. I'm thinking the most economical thing to do now is to call 928 Intl. and buy a 5.0L short block and put my rebuilt Euro heads/cams/intake on it to make a Hybrid. All ideas suggestions welcome.

 

An anonomous Guru says "Run it anyway".
Full Speed Ahead!

 

Damn sorry to hear about your block. I'm sure 928 Intl would have what you need, there is always that '86 on e-bay, grab it for the engine and a few other parts upgrades and sell the rest.

 

Nikasil it?

 

Yeah... It all depends on your budget, and intentions.
If you just had a bum engine, and wanted to rebuild it yourself,
you might be able to just put it all back together, and still be
running at 95% efficiency. A little blowby, but not the end
of the world. Or just swap in a used engine from a parts car.

OR

You were trying to rebuild your engine right, to last another 20 years.
If that is the case, then yes, why not do it right? I have heard that
if you want to use the 5.0 block, you have to machine the pistons.
So if you are going to think about nikasil, or machining pistons,
why not just build an engine for supercharging? Nikasil, low-compression
pistons, etc...

 

I still have the '85 EURO Engine for sale! Complete with both brains!

 

Get with me if you need details on the Nikasil. If that scratch is less than 0.010" deep you can easily nikasil the thing and open up a lot of options. It is very cost effective.

 

Thanks for the suggestions. The cylinders are within spec, other than the described malady. I had the heads reworked, guides, ect. I definately wanted this engine to last awhile. New rod and crank bearings, rings and so forth have been installed. Initial cost of the M28/11 was $1200.00 and I'm right at 3.5K now. The additional cost of boring it out and new pistons is down right depressing. The scratch is at least 0.010+, but I've read some good things about nikasil here and will seriously consider it. Unfortunately, we are limited to how much we can bore these engines out. The 5.0L block would require the pistons to be modifed and still would not just be a bolt on. US 4.7L pistons have the cut outs, but the Euro heads have slightly larger valves and the pistons may have to be reworked also. I'm already beyond the point of no return on the 79. Damn good thing I love this automobile.

 

I have brand new pistons rings and pins for your motor, they are oversize and are the Mahle high comp euro pistons, PM me if you are interested.

 

I have a set og 91 GT rods and pistons with the block I'll sell you for $1000. Also comes with cross drilled 91GT crank.

Guy

 

Greg Your offer of new matched Euro pistons/pins and rings is more than a fair price even in USD.

Mark, I would prefer to stay CIS. Just call me crazy.

Wild Guy, That price on the 91 GT block/pistons, rods and crank is WILD!

If anyone on the board needs these parts, the prices are more than generous. I however, after thinking about over the last 24 hours, am reminded, my son is starting at Texas A&M (Kingsville) at the end of August. Guess what my priority should be? He did finish in the top 10% and was a 4-A All-District Left Guard this year for the Rockport Pirates.

Thanks anyways guys, your generousity is typical for the 928 list and I'm proud to be a part of it.