How to prepare the block for a new head gasket

[SHOtimer]

I have the heads off and at the machine shop at the moment. My 3.2 is sitting on an engine stand with a huge amount of gasket crude left on it. I can remove a large portion of it with a razor blade. But, the block is not left perfectly clean, which I assume it needs to be in order to properly install a new gasket. What have you guys all used to prep the block?

Suggestions?

Thanx, Doug

 

[LOUDSHO92]

Well for my motor I had used heads so to clean them I just used a steel wool pad. It worked pretty good but make sure you go in a circular pattern so you dont make any depressions. Since the block is iron you may be able go with a high grit sand paper.

 

[Mr Anonymous]

Blue (fine) ScotchBrite and Brakleen.

 

[Devin]

I used a soft wire brush on the lowest speed setting with a rotary tool. It doesn't pickup any metal, so I'm pretty sure it's safe. Polishes it damn nice though.

 

[SHOtimer]

What should I use to cover the cylinders with? Should i cover up any of the coolant or oil passages?

Doug

 

[SASHO91]

is the motor still "together" ??

if it is, i would close the oil ways, and water ways up... maybe a small piece of tape...
but if the motor is apart, just let loose, then get the block dipped....
but from what it sounds like, the motor is still "together"
i would tape off all passages... and have a shop vac handy....

 

[yamahaSHO]

I use a razor blade to get most of it and them carb cleaner on a rag to get the rest. I don't bother covering the coolan and oil passages because I go at it with a vacuum cleaner afterwards (and I also am carful at where I let the material go when I scrape it off). You'll suck up coolant if you do that... It makes for an interesting smell in the vacuum cleaner.

 

[Devin]

What should I use to cover the cylinders with? Should i cover up any of the coolant or oil passages?

Doug

Playdoh. Seriously. Best masking material ever made.

 

[yamahaSHO]

If you're that worried... A few rags will be fine.

 

[SHOtimer]

I use a razor blade to get most of it and them carb cleaner on a rag to get the rest. I don't bother covering the coolan and oil passages because I go at it with a vacuum cleaner afterwards (and I also am carful at where I let the material go when I scrape it off). You'll suck up coolant if you do that... It makes for an interesting smell in the vacuum cleaner.

So, it needs to be good and clean and smooth. But, it doesn't need to be perfectly bare metal without any trace of the previous gasket, correct?

Doug

If a single edge razor blade is used, you will have it down to bare metal. It doesn't have to be polished metal. We used to use a large flat file wrapped in 600 grit sand paper to do the final topping of the decks. If you're worried about stuff falling into the oil and coolant passages, rotate the block on the engine stand so that it's upside down.

I wouldn't use a power tool unless you're going to vat the block afterward. Rotary tools, like wire wheels, throw bristles all over the place.

There is a rotary tool that is made out of rubber impregnated with grit that is specifically made for removing head gasket material. Don't know where you would get one though.

Tom

 

[Mr Anonymous]

So, it needs to be good and clean and smooth. But, it doesn't need to be perfectly bare metal without any trace of the previous gasket, correct?

Doug

Right. It's pretty common for the old gaskets to leave stains on the mating surfaces, but as long as the surfaces are smooth and clean you shouldn't have a problem.

 

[shojuan]

Permatex gasket remover might come in handy. It works well. Also good for taking carbon off piston tops. Just be careful to not flush gunk down the sides. Get some "Goof Off" from the paint section of Osh, the despot, or walmart while you're at it. Just finish clean with brake cleaner.

Turning the block upside down like Tom suggested should alleviate most of your worries.