Hi everyone. I could use a little help on my 270 assembly. I had to leave my 270 engine project for over a year for a number of reason. It was completely disassembled. Now there is a little brass tube I believe that oils the crank and cam gears. I have seen pictures of some that where pinched with holes drilled in the side. Mine is wide open on the end. But I seem to have an extra one that looks like it was a restrictor possibly of some kind. I can not make it work with the other one. So I am at a loss as to where this other one goes. It is also brass and is swelled on one end. Maybe it was in one of the old rotted oil lines, some place in the head I have missed maybe in the block. It has been so long that I can not remember. Everyone I know is not that familiar with these engines. I could really use the help. Or lead me to some research material. So far nothing in the motor manuals I can find. I would hate to put this very expensive engine together just to have it go boom. Thank you one and all. Davie
Take a close look at the area where the camshaft and crankshaft gears mesh under the timing cover. You should find a hole that aligns with an oil gallery. The pinched-off tube with a small hole in the side should press fit into that hole and squirt a small stream of oil onto the timing gears. I'm not sure about the location of the other tube you mentioned. 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!
Look for an oil passage in the cylinder head that would be used to provide lubrication to the rocker arm shaft. There might be a tube that joins a port or an oil gallery in the cylinder head to the shaft. I haven't built enough GMC engines to have the oil circuits memorized. 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!
The passage between the oil gallery in a GMC six cylinder head and the first rocker arm shaft bracket has a small copper washer used as a seal. No tube there.
And the funny part is the washer is shown in the 1955.2-1960 GMC Master Parts Book drawing, but has no reference number. (See ^ on page below.) It isn't shown at all in the 1939-53 GMC Master Parts Book.
My 302 has a "pinched down" oiler tube for the crank to cam gears.
'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.
And the funny part is the washer is shown in the 1955.2-1960 GMC Master Parts Book drawing, but has no reference number. (See ^ on page below.) It isn't shown at all in the 1939-53 GMC Master Parts Book.
It’s in group 8.0955 (A) 105451. Check out that group in your 1939-53 GMC Master Parts Book. My 1939-1954 book shows “SEE 20.0340” which is a Fuse.
Ok in the upper photos are the two pieces in question. The one in the right is the cam and crank gear oiler. The one on the left is what I do not know where it goes or if it is needed. Thank you Davie
Jim: My 39-53 (not 54 like yours) book does not show the copper washer nor does it list a 8.0955. Your book is better than mine.
But none of this is helping Davie figure out what the second part is for. I'll check with the guys on OldGMCtrucks and see if they recognize it.
Davie: I'm guessing the unidentified part is about 5/16" OD and 3/4" long?
Last edited by Bill Hanlon; 10/09/20234:22 PM. Reason: additional info
'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.
Any chance you have a good buddy who likes practical jokes? He could have brought that piece from who knows where and mixed it in with your parts. I have friends like that.
'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.
Lol, no I do not think so. The problem is it was just as oily as the other one. I was out in the shop and went through all the oil lines from the filter housing line and every oil orifice I could find to the rocker arms. I can not find a place where you could reasonably think it would go. It certainly did not fit anyplace. Old age is setting in on me. I thank you for your help. Ever need anything let me know. Thank you Davie
A suggestion from one of the guys over on OldGMCtrucks is:
To me it looks like a cap that would put on the end of a cable sheath, like the end of a park break cable. I remember my stock ones had a cap that looked like that and fit into the bracket on the frame. Not sure about the dimensions but I think it would be close.
'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.
