Need Advice on Purtyin' Up A Fugly Engine

[Shawn D.]

If Y'all will recall, I recently purchased an M30B35 and knew when I bought it that it was fugly. However, until starting the disassembly/tidying-up process this weekend, I didn't know how fugly it really was. Now that I've seen more pics of fastpat's tidy new engine, I'm quite jealous!

To get the pressure plate off the flywheel, I had to cut the heads off the bolts with a die grinder; once the tension was relieved, many of them were removeable by hand. The exhaust manifold studs (the ones that were still intact) were much less of a "problem" as they snapped off easily (one will have to be drilled, as it broke inside its threaded hole). I'll have to replace many of the other fasteners as well, mainly due to appearance issues. That's not my real problem, though.

What I need advice on is how to remove the scaly rust that's on the block. IMO, wire brushes are out -- my experience on other cars says that they mainly remove some loose flaking and then merely polish the remaining rust. I want to remove as much as possible, so that when I paint the block it'll look decent. I'm considering using 3M bristle discs and/or the more traditional cleaning discs (both in 50-grit):



Does anyone have any experience with these? The bristle disc supposedly conforms to irregular surfaces well, so it might be the better bet even though it's more expensive than the traditional disc. It appears that the bristle disc will be easier to use, and they come in 1, 2, 3, and 4-1/2" diameters.

As for what to paint with, I'm considering a POR-15 product. For those of Y'all who have used POR-15 stuff on engines, which product did you use? Nowadays, they have a multitude of new products and I'm not sure which would be best (many also require you to use the original stuff as a basecoat) and how much I'd need. Any advice on this? Yes, I know some of Y'all have said that this stuff costs them little to produce and the price is a ripoff, but are there decent alternatives with equivalent longevity?

Any advice on cleaning up slightly-corroded aluminum? It's not badly pitted, but is a bit "dusty" with white corrosion.

NOTE: I do not want to disassemble the engine and have stuff tanked, nor do I want to have to cart the assembly to a commercial blaster (and buying a setup to do the blasting isn't a realistic possibility for now), and while disassembling, blasting, and powdercoating is tempting, it ain't really an option either.

At least I can take solace in the fact that when I removed the intake manifold, it looked as if the engine had less than 1000 miles on it, despite its 122K age -- it's extremely clean inside.

TIA!


[Edit by Shawn D. on [TIME]1109600111[/TIME]]

[Madhungarian]

If you have the block completely disassembled I would take it to a machine shop and have them clean it in a dishwasher like contraption they have with the solutions they use. It also gets to places you can not wita any mechanical device. I have just done that to my block and while not perfect, came out pretty good. The detergent they use has some rust preventive stuff in it. My shop only charged me $50.00 for it too!

[Velocewest]

[QUOTE="Shawn D."]NOTE: I do not want to disassemble the engine and have stuff tanked, nor do I want to have to cart the assembly to a commercial blaster (and buying a setup to do the blasting isn't a realistic possibility for now), and while disassembling, blasting, and powdercoating is tempting, it ain't really an option either.[/QUOTE]

You really don't want to use abrasive blasting on an engine anyway. Too much risk of grit getting inside. I'd just pick up some rust converter from the paint store, like Naval Jelly or whatever. Give it a few rounds of that, scrub it down well with acetone, then paint it with engine block paint or Rustoleum. I don't think it's worth the money for POR-15.

[Shawn D.]

[QUOTE="Velocewest"]I'd just pick up some rust converter from the paint store, like Naval Jelly or whatever. Give it a few rounds of that, scrub it down well with acetone, then paint it with engine block paint or Rustoleum. I don't think it's worth the money for POR-15.[/QUOTE]

Good points -- it'll take a bit more than Naval Jelly on this baby, though! I've used Rustoleum inside my small-block Chevy, but hadn't considered it for the outside -- it's on the list now.

[fastpat]

Consider this as well. BMW engine blocks, the iron ones anyway, arer painted black. Leaks don't show up well on black. If I rebuild an M30 engine I'll probably paint it gray so that oil leaks will show up sooner.

Now, I know that some folks can put together an engine that will never leak, but I'm not one of them. :p !@#$

[booker]

Shawn, in my recent battle with rust, I used some stuff called One-Step. I got it at my local body shop supply store. It is essentially the same as POR 15. In fact, the guy at the body shop supply told me they had the formula first, and POR 15 ripped em off. I don't know if it's true or not...

We used to use it on the tugs I worked on (never ending battle with rust), but it was called Endrust.

It's a thin, white liquid, and it works very well. Just don't take all the rust off before you use it. It need some rust to work. I would chip off any scale, brush off any rust dust, and paint it on. You need to apply a second coat within 20 minutes.

I wouldn't use naval jelly, but that's just me. I don't mind spending the extra dough on a quality product.

[Rich in Tupelo]

Shawn,

I think I have an extra can of POR-15 lying around in the garage that I most likely will never use. If you want, I can bring it this weekend.

Rich

[Shawn D.]

[QUOTE="booker535"]Shawn, in my recent battle with rust, I used some stuff called One-Step. I got it at my local body shop supply store.

We used to use it on the tugs I worked on (never ending battle with rust), but it was called Endrust.

It's a thin, white liquid, and it works very well. Just don't take all the rust off before you use it. It need some rust to work. I would chip off any scale, brush off any rust dust, and paint it on. You need to apply a second coat within 20 minutes.[/QUOTE]

Ah, yes, Mar-Hyde One-Step. In aerospace circles (and others, probably) that's called a "chemical conversion coating." I've used the similar Loctite Extend Rust Converter. AFAIK, all of these require topcoating with an oil-based or lacquer paint (which I was gonna do anyhow).

[Shawn D.]

[QUOTE="Rich in Savannah"]Shawn,

I think I have an extra can of POR-15 lying around in the garage that I most likely will never use. If you want, I can bring it this weekend.

Rich[/QUOTE]

Thanks, man! I'll take you up on that!

[Madhungarian]

Sorry, missed the part about complete teardown not beeing an option.
I think you mean something like this as the goal??

[Shawn D.]

Madhungarian,

That's pretty sweet! No, mine won't come close to being as nice, though. :

-Shawn

[booker]

[QUOTE="Shawn D."]Ah, yes, Mar-Hyde One-Step. In aerospace circles (and others, probably) that's called a "chemical conversion coating." I've used the similar Loctite Extend Rust Converter. AFAIK, all of these require topcoating with an oil-based or lacquer paint (which I was gonna do anyhow).[/QUOTE]

Yea, I forgot to put that in. You must use a top coat.

[spinedocab]

FWIW I don't think naval jelly is a rust converter. IRC it's strictly a rust remover of a very caustic nature, and care must be taken in it's use, and removal of excess after the job is done. BUT, naval jelly with an abrasive scrubbing could very well be an effective down-to-the-metal method.

[Shawn D.]

[QUOTE="spinedocab"]FWIW I don't think naval jelly is a rust converter.[/QUOTE]

You're right -- it isn't.