I am currently putting together an engine for my 2002 Explorer. This one is a cast iron Romeo "W" block out of a 2003 Mustang GT.

I am having a real difficult time with getting the head gasket mating surface smooth. Everything that I read, whether it is from the Ford Service manual, Engine Builder magazine, and aa1car.com, they all say that these modular engines with the MLS type gaskets and aluminum heads have to have a very smooth finish or else I will have to open it back up for a "do-over."

I have tried using acetone, lacquer thinner, and Permatex Gasket Remover. Along with that I have best plastic scrappers on the market from jusntyme tooling that are used by aircraft mechanics.

I have also used a Dremel 3000 with steel brush 428 with no luck. The carbon build-up is on there very tough.

Any other suggestions on how to get this surface smooth? I was thinking of trying a belt sander with an 80 grit belt. I don't want to have to get the block milled down since that can lead to other issues such as retarded cam timing or head bolts bottoming out.

I bought the FRPP head gasket changing kit that I was planning to use. However, I have been reading that aftermarket MLS gaskets do not require as smooth of a finish as the OEM gaskets. Should I just get some gaskets from Felpro or something and throw it on there and call it a day?

Thanks,

jayton4

 

Just to clarify, I would like to be able to do this here in my shadetree garage. Moving it to a machine shop is a hassle that I would rather avoid if at all possible. I do not have a big oven to warm it up here.

What is this metal surface cleaner the Ford Service manual speaks of? Part # F4AZ-19A536-RA. Is this stuff any good?

Here are pictures of the right side:

Head gasket mating surface pictures by jamesayton - Photobucket

 

The pictures look good to me. The raised deposits are in the coolant passages and will not affect sealing. I use 3M Roloc discs to clean the block and heads. I use a new one on the block and by the time I'm done with the block the disc is worn enough to not damage the heads. DO NOT apply any pressure when using the disc or you WILL remove metal. All you want to do is scuff up the surface and remove all traces of the old gasket. The metal does not have to be shiny to be clean. When done thoroughly clean the debris off with brake cleaner and wash out the oil drain back holes. Then change the oil before you start it up.

 

Thanks partner! Just the kind of info I was looking for. I was thinking that it didn't have to be shiny, but the parts that feel rough to the touch were what was worrying me.

I'm going to look into these Roloc discs. The heads are already clean enough with just the plastic scrapers, so I don't have to risk scoring those up.

As you can see, the Permatex Gasket remover overspray left some orange discoloration inside the cylinder walls. Is brake cleaner ok to use to clean in there?

As I was scraping, the debris was falling into the coolant passages and in between the pistons and cylinder walls where the rings are. I was thinking about rolling it out into the drive way to hose everything out and maybe scrub with some Dawn dish soap. Would there be any issues or reasons why I should not do that? It had orange coolant in it before, which caused a lot of gunk to build up in the coolant passages, and I was planning to do a coolant flush in addition to an oil change right after I get it going. It is weird to see the coolant passages in my 186000 mile engine look brand new clean and then look at this low mileage engine with all the gunk.

 

This morning my father (an airline mechanic) brought me some things that his crew uses to remove sealants. In the bottom of the bag were two 3M Roloc discs with the shank/screw. He also said don't use them on the aluminum. At first, I thought, "Wow, what a coincidence!" But if you and my father are both telling me that this is what I should be using, it just confirms even more that this is the way to go, and not so coincidental after all.

I'm just surprised that with all the searching and reading I did all over the web that I didn't come across this product before.

Thanks!

 

And I beleive the "service gasket" is a little more forgiving on the surface finish than the ones they use at the factory.

 

I spray the cylinders with brake cleaner and wipe up most of the debris from cleaning. Then I take a air nozzle and go around each piston and blow any remaining stuff out. Then I wipe that out and then apply a film of engine oil to the cylinders. I guess you could use soap and water just make sure to dry it all out and then oil the cylinders. The stuff getting into the coolant passages really won't matter.

 

Soap and water is not acceptable. You will get flash rust. The ALU cylinder bores, you just might be able to use soap and water, but no needed. A light solvent on a blue shop paper towel is just fine.

 

OP is using a cast iron block engine and soap and water wont hurt anything if it gets dried out and then oil applied to the cyl walls. Even if it does get a little flash rust the rings will take care of it once the engine is started.