Cleaning a NASTY W58 head

[PdidD25]

Hey all, I was wondering if any of you have ever had to clean a terribly nasty head before. I have already removed the valve cover, valves, springs, rocker arms, some smaller pieces I assume are the lash pads, etc. and organized them in baggies. But what I'm really concerned with cleaning are the rusty water jackets and grimy chambers. I just wanted to know of ways to clean an aluminum head. I understand that one can use a soda blaster on aluminum and valve covers for sure, but any other cleaning methods you might suggest? Thanks i advance. Pics to come.

[okayfine]

Find a head rebuilder, or an engine builder/machine shop (maybe even a radiator shop if they're nice) and have them hot tank the head. That's not going to fix corrosion (aluminum doesn't rust) insofar as the material that is already gone is gone, so best to get the head evaluated to make sure it's worth the money and effort you'd put in to refreshing it.

But, depends on what you want to do with it, and it's actual state. Maybe it just needs a can of Gunk, some hot water, and a stiff Nylon brush? I'd avoid anything too abrasive, especially on gasket and machined surfaces.

[PdidD25]

[okayfine]

The ol' round-port peanut head. Do you have the exhaust manifold/header for that head, 'cause it's different from the usual L-series square port.

That said, it doesn't look bad from the pictures provided - heads have corroded much worse. The rusty bits in the combustion chambers are the valve seats, so you'll want to get them replaced, which basically means getting the head rebuilt (new seats, valve grind, etc.) which means they'll clean it up while they're at it.

You're probably not going to be able to fix that on your own. Those valve seats look a little too far gone to be able to just wire-wheel the ports and lap valves in.

[PdidD25]

Thanks! I know of a shop in town that can do the hot tanking and I can probably get that done with my block next week. And if that guy can't rebuild the head, I know TEM in Napa can.

Thanks for the heads up on the manifold too, I still have it.

[McShagger510]

Ultrasonic is better for aluminium as the hot tank chemicals are mainly for cast iron and can etch & discolour your head. Any engine shop will take care of that for you.

James

[defdes]

What about the removal of those exhaust liners too?

[PdidD25]

Cool, thanks James, will have to see who can treat the head with ultrasonic or however you say that hahaha.

I may keep the liners in if the work costs too much. Right now, I'm more concerned with getting the engine assembled again.

If it is affordable, I would need to have the exhaust walls smoothed out for smoother flow post liner removal, right?

[okayfine]

Have only heard third-hand wisdom regarding the liners, which says not to remove them. Mainly due to the work necessary to smooth the ports afterwards, the possibility of punching through to a water jacket, etc. Apparently some of the Z crowd has gotten good power with their version of the smog head.

Depending on the overall build of the engine, you might not benefit for the $ needed to do it.

[PdidD25]

Well, I think the way to go would be to simply overbore the L20B block to 86mm bore (is that correct?), get oversized pistons to match, bearings and seals, and have the crank assessed for straightness then reassembly.

I don't need it to be a beast, just running.

I did some forum research before and found the same stuff as you, okayfine.

[okayfine]

Stock L20B bore is 85mm, what you need to overbore it to depends on the condition of your block. A running L20B (versus a beast) doesn't need the liners removed from the head.