Joined: Sep 2017 Posts: 51 Threads: 19
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While removing pistons from crank shaft, I was surprised to find underneath the middle bearing housing an empty female threaded hole. I was expecting to find a copper pipe oil feed etc.
The engine has covered many miles in this state without any apparent problem (the reason for current strip down is a porous block).
Anyone any idea why the middle bearing should have no oil supply.?
Joined: Aug 2017 Posts: 3,216 Threads: 100
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Location: Darkest Bedfordshire
Does it by any chance have a little blanking screw - 5/16" or so - right next to the oil filler spout, in between the two jet screws?
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Location: Deepest Frogland 30960
Car type: 1933 RP Standard Saloon
Photographs would help...
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I will try and get a photo on Friday. I will also check for blanking plate.....what's your thinking?
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Some three bearing engines were modified to take Reliant crankshafts. Part of the mod is usually to drill down through the main oil gallery at an angle to provide a pressure oil feed from above the centre bearing, via the old centre cam bush feed. In this case you would most likely find the two splash feed oil supply jets blanked off. As Reckless suggests, a few clear pictures should quickly clear things up.
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That's interesting, I will try to get some photos tomorrow. I guess if it is no longer splash fed, that might explain why when hot on tickover oil pressure is 8 psi or so, while on my RP tickover oil pressure is the more usual 1 psi or so.
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8 psi would be very low for a pressure fed engine, more like 25 - 50 when running.
Joined: Mar 2015 Posts: 5,196 Threads: 223
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Three bearing engines have smaller oil jets so as to raise the pressure to feed the centre main and centre cam bush appropriately.
They normally run at about 9psi warm.
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It's got a 0 to 10 psi gauge, anything above a tickover sends needle on gauge full scale.
It DID have a 0 to 100 psi gauge fitted, . But in my ignorance I replaced it because I EXPECTED oil pressure like my R P
Joined: Mar 2015 Posts: 5,196 Threads: 223
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Those type of engines would originally have been paired with a 0-20 gauge.
