Thread: S1 2L Spread Bore Oil Galleries

He has sent me this image just now there is something in the large hole arrowed that he says he can lift up with his finger but will not go down , wondering what it could be , could this be causing the loss of oil pressure , it is above the drive gear from the cam shaft . I was thinking the bush in the bottom of the alum distributor tube but it dose not seam to have the bottom flange on it. Also there seams to be a lack of oil in the side cover so oil loss is before it get's to the rockers. IMG_9646 (1)_LI.jpg There are no external oil leaks showing .

I assume it has a bypass filter. This should have a restrictor in the oil supply to it. If this is missing or too big, or the filter is one designed for full flow, this could result in the low oil pressure. The other thing to look at would be the clearances in the pump, or possibly a badly blocked screen on the intake.

Originally Posted by JDNSW

I assume it has a bypass filter. This should have a restrictor in the oil supply to it. If this is missing or too big, or the filter is one designed for full flow, this could result in the low oil pressure. The other thing to look at would be the clearances in the pump, or possibly a badly blocked screen on the intake.

No full flow , filter is on the drivers side , books I have are for engine with by pass filter so don't show later type of filter . He has checked the pump clearsnces & pick up.

Originally Posted by 1950landy

Asking for a friend in NSW & I am in Qld
Friend is restoring a 1956 LR S1 with a 2L spread bore motor . The engine has been rebuilt with all new parts including new gears in the oil pump. He started it the other day after fitting a external new oil gauge & has very low oil pressure (5psi) He has screwed the relief valve fully in with no change & dose not have anything under the ball & valve has all it's components , He removed the oil filter & it has filled with oil , also checked the restrictor is in the banjo bolt in the back of the head. The plug is in the front of the exhaust rocker shaft.
Dose anyone know were else he can look for loss of pressure. Dose any one know were the gallery runs from the oil pump to the oil pump to the full flow filter. Would anyone have a oil gallery chart for the 2L with full flow oil filter. Would there be any other gallery plugs the engine shop could have taken out that he dose not know of releasing the pressure internally. He has also checked all the bolts are tight on the pump body.
All the books I have show engines with by pass filters or do not show oil galleries, LR workshop manuals fall short some times I find.
Any advice would be appreciated .

Is your friend using a suitably high viscosity engine oil? Modern low viscosity oils don't work well in older high clearance gear oil pumps. Also, most old gear type oil pumps don't self prime very well (RRC in particular) and can suffer from lack of priming suction if assembled dry or with light oil in between the gears. Did he pack the oil pump gears and housing with gease at assembly? If the pump has an air lock it won't do much oil pumping. I have primed air locked gear pumps in the past by pumping grease from a grease gun in through the pressure relief valve hole (remove ball , plunger and spring). It helps if you can turn the engine backwards a few turns while pumping the grease in. Also the main oil gallery pipe (a steel tube) running parrallel to the crank can clog up with sludge, especially if it hasn't been scrubbed and flushed out thouroghly during a rebuild and the gallery plugs screwed back in tight. There is an oil feed to the timing chain tensioner. If the plunger is not right, there is pontential for an internal oil leak
Is the oilpump pressure relief spring too short or weak? The plunger is between the spring and the ball? The oil pump driving gear cross pin can shear. If all else fails, re- check the pump/distributor drive and relief valve for missing/ incorrect parts or assembly problems.

Good luck.
5380

Originally Posted by 5380

Is your friend using a suitably high viscosity engine oil? Modern low viscosity oils don't work well in older high clearance gear oil pumps. Also, most old gear type oil pumps don't self prime very well (RRC in particular) and can suffer from lack of priming suction if assembled dry or with light oil in between the gears. Did he pack the oil pump gears and housing with gease at assembly? If the pump has an air lock it won't do much oil pumping. I have primed air locked gear pumps in the past by pumping grease from a grease gun in through the pressure relief valve hole (remove ball , plunger and spring). It helps if you can turn the engine backwards a few turns while pumping the grease in. Also the main oil gallery pipe (a steel tube) running parrallel to the crank can clog up with sludge, especially if it hasn't been scrubbed and flushed out thouroghly during a rebuild and the gallery plugs screwed back in tight. There is an oil feed to the timing chain tensioner. If the plunger is not right, there is pontential for an internal oil leak
Is the oilpump pressure relief spring too short or weak? The plunger is between the spring and the ball? The oil pump driving gear cross pin can shear. If all else fails, re- check the pump/distributor drive and relief valve for missing/ incorrect parts or assembly problems.

Good luck.
5380

Yes to filling oil pump with petroleum jelly , relief valve is assembled correct, oil galleries should be clean as gallery plugs had been removed before chemical bath by engine shop & dist drive shaft is fitted correct . I don't know what oil he is using & he has not pulled the timing cover off yet because he wants to exhaust all other potions first. I have sent him an old shaft , he is going to extend it so he can drive the oil pump with an electric drill to see what he can see with rocker covers off & hopefully prime full system . I think the problem has something to do with what ever is in the large hole in the alloy tower , there is something in there he can move up with his finger & then it falls back down.IMG_9646 (1)_LI.jpg

Originally Posted by 1950landy

Yes to filling oil pump with petroleum jelly , relief valve is assembled correct, oil galleries should be clean as gallery plugs had been removed before chemical bath by engine shop & dist drive shaft is fitted correct . I don't know what oil he is using & he has not pulled the timing cover off yet because he wants to exhaust all other potions first. I have sent him an old shaft , he is going to extend it so he can drive the oil pump with an electric drill to see what he can see with rocker covers off & hopefully prime full system . I think the problem has something to do with what ever is in the large hole in the alloy tower , there is something in there he can move up with his finger & then it falls back down.IMG_9646 (1)_LI.jpg

I think I know what the problem is. I have stripped a few comletely clapped out engines with all friction sufaces badly worn from poor lubrication. The top casting of the oil pump has a long stem that was cracked up inside the block in 2 of the spread bore engines allowing oil to escape before getting to the galleries. The way to check this is to remove the sump and grab hold of the oil pump gear housing body and give it a wriggle. If it moves in the slightest, the long stem of the oil pump that slides up inside the block is broken. The pump is easily broken if is bumped while the sump is off or something nasty whacks the sump in the wrong place (rock? tree stump?)
I hope I am wrong, but it appears they you have checked most of the other causes. If the floating bit in the hole is cast iron (magnetic) that would be confirmation.
Have a look at a picture of the oil pump and you will see what I mean about the vulnerability of the long cast iron pump drive shaft housing. There are two location screws on the housing, a small 1/4" lower one and a larger one up further with a lock tab. Check them out.
Keep us informed. Good luck!
5380

Why priming? Or do I miss something?
My 56 pump is submerged and build up straight perfect pressure at the very first crank. m

Originally Posted by 100inch

Why priming? Or do I miss something?


My 56 pump is submerged and build up straight perfect pressure at the very first crank. m

He is going to use a drill to turn the pump so he can look to see where he is loosing pressure not to prime the system. He dose not want to run motor with low oil pressure .