Engine Update

[Superman]

I know some of you are losing sleep not kowing how my project is going, so here's the latest. John Walker is goingo to finish the heads pretty soon, and they will have all new valves, guides and seals. It was very interesting watching him replace the guides and I'll thank him publicly here for showing me that procedure. I am convinced the fresh valves and re-ground seats will seal much better than before, even though there was no severe leaking problems there.

A few of the cylinders were leaking between the head and the cylinder. After cleaning and upoin close inspection, it seems that a couple of the heads were banging against the cylinder tops. The heads and cylinders will be 'fly-cut' so that a nice seal can be achieved between these surfaces.

After looking at the cylinders, John thought that my engine is likely to accept new rings without smoking, though there are no guarantees. I am now planning to use new rings.

Yes, rods can be removed without splitting the case. We'll see if they can be installed this way too! The rod bearing journals look gorgeous, as though they had been micropolished yesterday.

The cylinders generally showed about .01mm of wear near the top and at least half of them showed around .02mm of wear near the bottom, at the widest point (where the cylinder wears into an oval shape). A couple of them showed as much as .04mm of wear at the widest point. Wear limit is .08mm, so these cylinders are still in spec.

The very, very interesting overall observation here is that almost nothing in this engine (aside from valve issues) is out of spec. The ring end gaps are close, but side gap is WELL within spec. Congratulations to those boys in Stuttgart....they must have been paying attention in those engineering classes!

Now, if I could just get over this extreme anxiety I'm having about polishing versus painting versus powdercoating, and which color or colors do I choose for these aluminum and magnesium engine parts.

[davis911s]

Great news Superman, but the big question is what do you expect this project to run you in $s? Just ballpark of course.

Oh and my vote would be for powdercoating the parts, colour is even more personal.

Thanks again

Shawn

[Superman]

We won't know the total cost until completion.

I had fantasized about $130 for twelve head studs and around $200 for a top end gasket set but I knew all along that I'd have serious 'as long as I'm in there' temptations. Still, the only major new parts will be valves, guides, seals...piston rings...plus head studs and gaskets and materials like Loctite. I'm keeping my clutch disk and other parts. I'll use factory one-piece oil return tubes.

I like powder coated surfaces too, but I'm afraid to try this on the magnesium fan and housing.

[Leland Pate]

COOL BEANS SUPERMAN!!!

Boy thats great news... course...you knew it already... aside from those pesky Dilvar headstuds...we SC owners rarely have problems with any rotating parts of our engines.

Boy, I bet she'll rip when you get her back together!
Thanks for the update.

Btw, it looks like we might be rotating out some time within...um...let's say...the next few weeks.. (Leland's comin' home) but get a load of this... apparantly big troop movements are a major OPSEC (security concern) so there's a good chance that we could have lke 24 hours notice to get our stuff on the plane and that they'll shut down our email before hand to keep people from blabing about it...so you might not hear from me for a few days until I'm already home!
Whoo hoo! It's most certainly time!

[Targa Dude]

Hello Superman, I agree with Shawn on the powder coating,
I had just about everything powder coated on my engine, Brackets, sheet metal and including the fan and housing housing.
I went traditional red for the 11 blade fan and the housing I bead blasted it and went with a clear powder coat. It looks sweet.
as for the colors that is personal preference, just make sure to clean everything else real nice paint alone will not win concours.

Jorge ( Targa Dude)

[Early_S_Man]

Super Jim,

It sounds like great news on everything except the heads, and if that is the only cost for nearly 200K miles of sevice, that seems pretty reasonable. The valves weren't sodium-filled, so a bit of wear-and-tear was understandable. The new Teflon valve stem seals will get you another 200K out of the top-end, and maybe a bit longer with Mobil 1! Seems like BA was mostly right about your engine! You are getting out cheaper than my brother-in-law did a week ago on his '87 Suburban 'work car' ... $2800+ to rebuild the engine with similar miles! No fun factor, either! Just an ugly gray Chevy truck!

Maybe a tube of $100+ Dow Corning RTV 730 is justified at this point, to keep all of the Mobil 1 in place for the future. After all, your Alusils came through shiny and proud ... and you aren't having to spend those big Mahle $$$. As you already know ... things could have been a lot worse!

[Superman]

Warren, tell me more about the $100 Dow Corning RTV. I thought the Loctite stuff was spendy enough at nearly $20! I'm so old-fashioned. But then, I'll do whatever it takes to build a dry engine. JW showed me some stuff in a copper can that he sprays onto gaskets to ensure against leaks. He also ran a few surfaces over the table/belt sander, so they are straight. I am hoping for a leak-free engine.

So, magnesium can be powder coated. Someone had said it cannot. The ends of the fan blades may need filing, but I am not sure any other coating will stand up on the fan. I need to talk to the other two PC places here in town.

You guys already know that a PC system can be purchased for perhaps less than $100, and an old oven might be $10. Hmmmmm.

[Targa Dude]

Hello Super Man, what I was told prior to powder coating magnesium was in the preperation on the magnesium do not use wire wheels, steel wool or anything that has ferous metals in it. this will contaminate the magnesium and cause corrosion later. Thats why I went out and purchased a 100.00 bead blast cabinet, This was one of the best investments I ever made.
my magnesium parts were powder coated 5 years ago and they still look as good as the day I picked them up. I can recommend a great Powder coating shop in the S.F bay area. just let me know.

[boyo]

The only worry I'd have about powder coating is heat - 300F is its melt point, so anything near the exhaust system may have problems. Should be fine for the top half of the engine tho.

-Boyo

[Early_S_Man]

The Dow Corning 730 Sealant has always been BA's favorite, albeit expensive, choice for sealing the 911 engine.

The following chart may be of some help to explain why ...
http://www.dowcorning.thomasregister.com/olc/dowcorning/aero.htm

[stormcrow]

I'll take WAG (wild a** Guess) and say when all is said and done about $1762.50 for the total rebuild. Any other takers?

I had fantasized about $130 for twelve head studs and around $200 for a top end gasket set but I knew all along that I'd have serious 'as long as I'm in there' temptations. Still, the only major new parts will be valves, guides, seals...piston rings...plus head studs and gaskets and materials like Loctite. I'm keeping my clutch disk and other parts. I'll use factory one-piece oil return tubes


Steve

[Leland Pate]

http://www.autometricsmotorsports.com
Check out this site!

Holy Wow, they powdercoated a WHOLE CAR!
never heard of that! Pretty neat, I think.

neat neat neat.... bet it wasn't cheap though.