Cleaning the cylinder head gasket surface

[jeffclark42]

I am in the process of cleaning and rebuilding my cylinder heads. After having thoroughly cleaned the heads with carb cleaner, solvent, etc. I'm reasonably certain the heads are clean. However, the head gasket surface still has a "waffle pattern" left on it from the gasket even after scraping with a putty knife. What do you think about cleaning the head gasket surface with a scotchbrite pad? Yes or no?

Thanks for any help

Jeff

[Barry Nave]

I have used a brass wire wheel on a drill and works good. You can use the pad also or even a wet/dry sanding cloth paper. 300-400 grit with WD45,paint thinner.
Remember to use new head bolts. Sealer on threads where needed and oil the threads on the rest.
ARP would me my only choice. ARP has a Tech addvice of toruqe the bolts,back off, retorque and repeat steps at least three time up to the finel rating.
Seen this on "Two Guys Garage"

[Kennedy]

I would use a large, flat body sander and never anything rotary. You can use some pretty coarse grit w/o hurting anything.

I believe my guys use like 80 grit diagonally on the deck and head surfaces after machining.

[ 01-26-2006, 05:39 AM: Message edited by: kennedy ]

[ueckebes]

done several 6.2/6.5 head gaskets,some were blown,some just as part of a rebuild.i like to scrape the surface with a blade,then use the 80 grit sand paper on a sanding block.powertools are great,but there is a roon for error.i also like to clean the surface latter with brake cleaner,then re tap the holes in the block for a more consistiant trq reading[highly recomend].then new bolts as mentioned.

[jeffclark42]

Guys,

Thanks for all the great information. I had a feeling it would be alright, but wanted to make sure.

Jeff

[john8662]

I second the wire wheel on a drill and light pressure, not concentrating on any one location long. This works really well.

I used a good stiff razor blade to take off the initial gasket, as well as any parts of the old gasket that were stuck good. This is done on both the block and the heads.

As for tapping the holes, make absolutly sure you don't use a tapered tap, only use a "bottoming tap" because you do NOT want to take any material off the threads. Otherwise, you'll get into the pulling threads situation. I would almost go as far to say that you can skip using a tap and use a good clean old head bolt, run it into every hole until it stops (because the bolt is streched at one point) and repeat on every hole. The bolt trick mainly works on engines that have been baked and vatted and really don't have any debris/sealant left in the threads.

My next engine is getting studs...

[G. Gearloose]

One can use a cut-off wheel to put two grooves in an old head bolt that are square to the threads, and use it like a cleaning, bottoming tap.

Some oven cleaner softens residual gasket material. Permatex makes a special spray.

[Hubert]

Sounds like all good advice and you are covered. Just another related tip. I try to sand in figure 8's and mix in orbital moves to help minimize any directional low tracks when trying to keep something flat and square. Staple some good quaility sandpaper to a block of wood and or use some of that layout glue stick too if you want on back of sandpaper.

[jeffclark42]

Wow! Again, many thanks for all the great advice.

Jeff

[tom.mcinerney]

As regards the nylon scrub pads:
At least one OEM {i think i saw the caution in my Saturn manual} strongly advises NOT to use nylon scrub pads for engine work, as very fine abrasive particles will remain....which are too small for the (lube) filter to catch. Soap/detergent is better than solvents for removal of abrasive/metal particles.