Hi guys, Could use some advice on a GMC 228 exhaust manifold I purchased on eBay. I cleaned it up and found the mount flanges considerably corroded (see attached photos). Can these faces be machined to clean up? If needed can they be weld repaired to build up the faces, then be machined?
A machine shop where I worked part time had a BIG belt sander- - - -like 12" wide and over 3 feet long. We would use it to clean up manifold flanges like that. It would also be possible to set it up on a mill like a Blockmaster and machine the pits away. As long as there's a little bit of the flange standing proud of the manifold runners, you'll be good to go. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I recently repaired a '56 Cadillac exhaust manifold in worse shape than that by taking off just enough to get all the ports smooth and in the same plane. A little bit of Yale Muffler Cement between the manifold and gasket on areas that are too deeply pitted to machine out works wonders, too.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
If you are going to repair that exhaust manifold, loose mount it and the intake manifold to the head (don't forget the alignment rings in the intake ports) with an 838290 gasket (Victor # 17473, old Chevy six engines use the same part) between the two manifolds. Once you get all the bolts snug (but not tight) tighten up the intake to exhaust bolts and then remove the manifolds as one piece. Take the assembly to the machine shop and have them make the surface of both manifolds flat and in the same plane at the same time.
Ask me how I know.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
