Is this clean enough for an MLS gasket
Joined: Apr 2006
Posts: 3,909
Likes: 1,158
From: Grand Rapids, Michigan
Regardless of how well you tape things off, particles are bound to get where they shouldn't go. You can certainly get the surface looking cleaner by scuffing it with scotchbrite, and if you're careful, you can minimize any abrasive residue getting into the engine, but with how much engines cost and the labor involved to swap one out, I'd rather spend a couple hours cleaning than worry I missed a spot taping. My pic doesn't show it well, but the deck surface is clean down to the original machining marks from GM. Any stains from coolant are superficial and won't cause any issues. I know many people have used scotchbrite with zero problems, it's up to the OP if they want to use it or not. I also know that people have done head/cam swaps and a year down the road they have a spun bearing. Was it due to abrasives making their way into the engine? Who knows, right? I'm not one for taking those risks, myself. The OP is well informed and can go from here.
btw. I work at a dealership and we used to (no me, ever!) copper coat head gaskets. I kept telling the guys stop that **** but they didn't listen to me until cars started coming back with repeat head gasket problems. I specifically remember an S2000 that had head gaskets problems twice and to told them stop copper coating it... its coated from the factory and the copper **** does not stick to it. The last repair they listened and the car never had an issue again. I know alot of people get away with it, but its not right to do. People get away with reusing head bolts and crank bolts that are one time use all the time... but thats probably the same people that are pulling heads off and having to fix it after a short time.
Last edited by Kfxguy; Jul 20, 2024 at 08:56 AM.
Another excellent way to do this is to go to Grainger or similar supplier and buy a Norton or like brand flat honing brick/stone. They measure about 6"lg.×2"wd.×1-1/4" thick, IIRC. Most are black on one side, tan on the other, thiugh some are all black. Different colors denote 2 different grits. Black is coarser, tan side finer. Before I retired I put my honing brick into a milling (Kurt) machine vise and surface ground both sides dead nuts flat. We were taught in apprentice class to use them in a figure 8 pattern when possible. As stated, using WD-40 or similar oil will help keep the stone cut and help keep it clean.
