I've always wondered what keeps debris from getting sucked into those horns?
Just drive fast enough that the debris doesn't have time to get up there.
'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.
Mark, Like everything else on your build, outstanding workmanship! Going to be a very high HP work of art when finished. Can't wait to hear it roar!
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
I realize this engine is not stock but how did you get the spark plugs and exhaust reversed? Did you manufacture your own head?
Last edited by Otto Skorzeny; 12/15/20241:36 PM.
1950 Chevrolet 3100 (Ol' Roy) 1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1956 Cadillac Sixty Special Fleetwood (The Godfather) | 1966 Oldsmobile Toronado (The Purple Knif) | 1966 Ford Mustang (Little Red) | 1964 Ford Galaxie 500 coupe | 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
12 port heads (6 intakes on the driver's side, 6 exhausts on the passenger's side) were a Southern California hot rod thing in the very early 1950's. The first were cast by Wayne Horning for Chevy, followed shortly with heads for GMC engines.
If you'd like the early history, seek out "The 12 Port Story" written by Herbert Hall, a series of 9 articles in "The 12 Port News" in 1981-2.
'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.
Flywheel installed. Clutch plate installed. No pictures of the clutch plate and I don't feel like crawling under there unless I have to. Working on fitting a hydraulic throwout.
Hydraulic throw out installed. That created a few issues. McLeod requires a 0.100 - 0.250 gap between the bearing and the pressure plate fingers. The standard piston was too short. To remedy that, they sell a tall piston. After I installed the tall piston, I had less than a zero gap. To fix that, I needed the trans moved back 3/16". Which would now get me past the minimum and give me the 0.100 and some change. That would still leave me with enough pilot bearing interference and full spline contact on the disc. So that nice 9/16" thick adapter I bought now needed to be 3/4" thick. Off to the mill I went.
Next issue, the throw out bearing stack is too short to pilot into the bellhousing. So I made some bolt-on line-up blocks that are bolted on top of the throw out bearing base. Leaves me with an extra 1/8" protruding from the adapter to keep things lined up in the bellhousing. Makes me feel better about the driveshaft since it was built slightly shorter than I wanted.
Intake gasket being made, or was, 11 quarts in the pan, one in the filter. Being the military pan and pump, it takes 1/2 quart more or so. Still nowhere close to the crank. Found out I didn’t have the correct exhaust manifold gasket. Gotta make one of those. Still need to prime it and verify I have oil going to the top. Check for leaks. Put some gas in the tank. Check for leaks. Maybe rough in the pressure. Still haven’t figured out where to mount the battery, but that won’t stop me from trying to fire it up. Many five minute jobs still left to do.
MNSmith: This is way beyond excellent. I would submit an article to some magazines. They will love a build like this.....and they pay for them. Your quality is uber. This is soooooo SoCal. I don't see a like button.
"We are not now that strength which in old days Moved earth and heaven; that which we are, we are"
1948 International Farmall Super A 1949 Chevrolet 3804 In the Legacy Gallery | In the Gallery Forum 1973 IH 1310 Dump 2001 International/AmTran RE3000 "Skoolie" 2014 Ford E-350 4x4 (Quigley)
Latest issue to deal with. Didn't think there was a water jacket that close to this head bolt. Maybe a casting anomaly? Gotta figure out how to seal that. Seems it's between the head of the bolt and the top of the block. I might be able seal it under the bolt head shoulder? We'll see.
Does the head of the bolt tighten against the cast surface above the hole, or is it a socket head bolt recessed into the opening? The cast surface is going to be hard to seal but if the counter bore is just bolt clearance you could use a bolt to ensure clearance and fill the cavity with an epoxy material to seal the opening.
As far as I know and correct me if I'm wrong, but they don't make a split neoprene seal for the GMC. This poor little guy didn't touch the crank. At least not by much. Found my leak, I guess!
As far as I know and correct me if I'm wrong, but they don't make a split neoprene seal for the GMC.
Not yet, but I haven't started whittling yet. I've got an idea in the "dreams and schemes" stages right now to make the block and the crankshaft compatible with a big block Chevy V8 split seal. It will be a similar procedure to what I do on Chevy engines, but there will be an aluminum, or maybe steel seal holder pinned or bolted to the block and the rear main bearing cap. The seal surface on the crank will have to be ground to a slightly smaller diameter. 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!
"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!
That is just plain ugly. What's the plan on fixing that?
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum