I'm starting on the 62 fuelie motor and the machine shop that I've used for years no longer vats blocks to clean em, saying that now they bake em for several hours to burn everything off, then put em in a shot blast cabinet. He didn't have anything done that I could look at that hadn't been decked anyway. Anybody have any experience with this process. I'd hate to cause an original engine to start raising eyebrows after all these years.
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Re: Effect of shot blasting engineblocks on pad fi
Media blasting is very likely to alter the pad surface texture. Also, media blasting will only clean accessable surfaces. The most important surfaces to clean are the internal water jacket surfaces.
Many shops are now using ultrasonic tanks, which are very effective and will clean the interior surfaces of the water jacket.
My recommendation is that you shop around for a shop with an ultrasonic block/head cleaning tank.
Duke -
Re: Effect of shot blasting engineblocks on pad fi
I've also been to shops that have huge "dishwasher" like machines to clean blocks. The block is hung in the machine with chains. You close the door, and turn on the water. I wouldn't shot peen or blast a block. Chuck1963 Corvette Conv. 327/360 NCRS Top Flight
2006 Corvette Conv. Velocity Yellow NCRS Top Flight
1956 Chevy Sedan. 350/4 Speed Hot RodComment
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Re: Effect of shot blasting engineblocks on pad fi
Norris:
The pad can be protected from media blast by a stick-on rubber patch. If your machine shop does not have this, see your local tombstone dealer.
I'm not familiar with the cleaning ability portion of your question.
MikeComment
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Re: Effect of shot blasting engineblocks on pad fi
Chuck - All the shops I have worked with use the jet spray cabinets. The chemical in the cleaner really cuts grease, doesn't hurt aluminum, and obviously doesn't hurt any finish. Dukes comments sound interesting though as the ultrasonic would really de-scale the jackets better than a jet spray cabinet....CraigComment
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Re: Effect of shot blasting engineblocks on pad fi
The local machine shop does a lot of differentials, steering boxes, and other cast iron parts for a local restorer. They use a high pressure wash then shot blast. I have seen the differentials before and after. Some of them are so pitted and rusty you wouldn't want them in a Flight judging car but they are perfect candidates for someone wanting a "spare" differential or one for swapping out. The after product looks great but it is definetly different than what I think original cast iron would look like. Btw, I just saw my first photo of the shot media. Now, I was thinking large ball bearing type shot (duh!), but this stuff was almost powdery! Still, I wouldn't do this to my original engine.
GaryComment
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Re: Effect of shot blasting engineblocks on pad fi
Gary - while I haven't used it myself, I have seen blocks that came out of a shot cleaner. It is probably the only way to go on a block that has been laying around and rusted inside and out...but I would, like you, avoid unless necessary especially on a known original block. To me, the iron almost looks like it is "steel coated" with more of a sheen and a color change. If I had to do this to an original engine, I would bond a piece of 1/8" rubber over the stamp pad, like used at a gravestone blaster, to protect the pad. I believe this was mentioned above, but the block may still have a texture change after this operation that is discernable from original. I still like Dukes idea of ultrasound, my shop has jet spray but the inside of my 66 427 block doesn't look to be very scaled so I may just use his jet spray tank. I used Jasco stripper (what a mess and pain, but it worked well) to get all the paint layers off down to the cast iron. The remaining residue will come off fine with a thorough trip through the jet spray cleaner...CraigComment
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