Author Topic: Small Block Chevy Oiling System  (Read 5968 times)

dans67camaro

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Small Block Chevy Oiling System
« on: December 05, 2006, 01:01:17 PM »
Does anyone out there know where I can find articles on how the GM sbc oiling system works for a 67 - 350cid engine. Thanks!

JohnZ

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Re: Small Block Chevy Oiling System
« Reply #1 on: December 05, 2006, 04:18:30 PM »
The GM 1967 Chassis Overhaul Manual has excellent full-page illustrations of the complete oiling system; the same diagrams are in the "Chevrolet Power Manual".
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rich69rs

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Re: Small Block Chevy Oiling System
« Reply #2 on: December 05, 2006, 10:25:28 PM »
See the following, 283, 327, 350, all the same:

« Last Edit: December 05, 2006, 10:28:08 PM by rich69rs »
Richard Thomas
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rich69rs

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Re: Small Block Chevy Oiling System
« Reply #3 on: December 05, 2006, 10:27:32 PM »
....and
Richard Thomas
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dans67camaro

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Re: Small Block Chevy Oiling System
« Reply #4 on: December 06, 2006, 04:20:07 PM »
Gee thanks... Does anyone know the purpose of the angle hole shown in the "distributor oiling system" cross section view?? My hole is plugged and I don't know if I need to open it up! Thanks.. Dan

JohnZ

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Re: Small Block Chevy Oiling System
« Reply #5 on: December 06, 2006, 05:42:07 PM »
Gee thanks... Does anyone know the purpose of the angle hole shown in the "distributor oiling system" cross section view?? My hole is plugged and I don't know if I need to open it up! Thanks.. Dan

Some distributors have a hole in the distributor housing between the machined rings above and below that hole in the "tower", so it apparently provides some splash or mist lubrication that dribbles down to the lower mainshaft bushing. Photo below of that hole in the passenger side of the "tower" in my 657 block.
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dans67camaro

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Re: Small Block Chevy Oiling System
« Reply #6 on: December 08, 2006, 12:55:25 AM »
I agree with you on some sort of oiling scheme for the lower dist. bushing/bearing! But, my distributor housing does not have a cross drilled hole. So the only lube it will get is from splash off the cam/crank or leak down from the oil galley hole which intersects with the dist. hsg. So I'm wondering if I need to worry about the hole (which your picture shows) in my ..2657 block which is plugged?? If pressurized oil from the oil galley would work it way up (or down)  the distributor housing, it would overflow the top of the cast tower in the block. Hmmmm..... Does your distributor have the cross drilled hole? Does anyone else have a distributor housing w/o the cross drilled hole shown in on of the above pictures? ... Thanks... Dan

JohnZ

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Re: Small Block Chevy Oiling System
« Reply #7 on: December 08, 2006, 03:46:19 PM »
The only pressurized oil in that area is inbetween the two lower annular rings, which form an oil gallery to feed the lifter galleries. The upper distributor shaft bushings are lubricated by the grease well below the breaker plate, and the lower bushings are lubricated by splash and by oil dribbling down the shaft. Corvette distributors have a 3/8" hole in the housing just above the upper of the pair of annular rings - not sure about passenger car distributors. It wouldn't surprise me if the hole in the side of the tower was also there to bleed off any oil back into the lifter valley that gets past the upper of the two annular rings so it doesn't work its way up into the breaker plate area inside the distributor.
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dans67camaro

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Re: Small Block Chevy Oiling System
« Reply #8 on: December 12, 2006, 12:59:00 PM »
Does anyone know what the hole size should be for the machined hole in the rear of the engine block that the distributor housing slides into??? I want to be sure I have the correct slip fit with the distributor housing. I believe its specification is 1.2485/1.247.

JohnZ

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Re: Small Block Chevy Oiling System
« Reply #9 on: December 12, 2006, 04:45:27 PM »
I don't have the hole diameter handy, but I do have the distributor drawings, and the finished diameter of the annular rings is 1.2475"/1.2490".
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dans67camaro

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Re: Small Block Chevy Oiling System
« Reply #10 on: December 13, 2006, 12:29:39 AM »
That agrees with my measurements of my distributor housing. If you come up with the hole size, please let me know.. Thanks.. Dan

cib12

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Re: Small Block Chevy Oiling System
« Reply #11 on: December 15, 2006, 05:11:51 AM »
if i remember correctly small block dist with the point and condenser system would interchange-i believe there was a short and longer shaft dist but that was in the 1950s-that was a cast iron housing version.  even an early corvette dual point dist fits- they had a snap on cap (no window or the newer two screw cap with 2 windows). best way to get correct part number for year and motor-then set up timing curve on dist machine if you can find an old sun dist machine