tomkite
Registered user
Hi all,
I hope someone might be able to give me some idea of where to go next. appologies for the essay but i figured you'd need the info.
Bike - 1983 R65
Problem - intermittent low oil pressure after engine rebuild.
notes - Siebenrock 846cc kit. engine stripped to bare block. crank, thrust washers, main bearings, cam shaft and conrods are original. new seals and stretch bolts throughout. 20w50 oil. Mahle filter. No oil cooler.
i stripped the engine getting on for 2 years ago to the bare block, which i sent away for aqua blast cleaning along with the heads and engine covers. I then proceeded to rebuild the engine with new gaskets and seals throughout. Now because of the 2 years between rebuilding and actually firing the bike, i cannot for the life of me remember what i did internally regarding checking end float of crank and cam although i cant see how either would attribute to the problem i have.
I do remember visually inspecting the big ends as they appeared like new, i also bolted them upto the crank on the bench and the operation was smooth and im pretty sure i would have checked the clearances too.
all components were manually oiled on rebuild.
The problem i have is that it takes 20-30 seconds of turning or running the engine before i get pressure registering on my oil pressure test gauge. Then, when i do get pressure, (which is good at around 30psi at 1000rpm tickover rising cleanly with revs upto approx 85psi), it cuts drops off a cliff at around 90psi, which i could attribute to one of the pressure release valves opening, but then it doesnt come back!
i have spun the engine 3 ways;
1 - actually running the bike (which alerted me to the problem initially as dash oil light came on).
2 - plugs out, fuel off, turned with starter.
3 - timing chain off, turn the cam only with a cordless drill.
i have turned the engine with the drill with the oil filter out and oil absolutely floods into it, I have also checked all oil pump clearances which are perfect so i have eliminated the pump itself.
I have removed the pressure release valve in the canister and cleaned and inspected. the spring is in decent condition, no pitting to the ball bearing and the screw is good. however, to eliminate this as the weak point, i have screwed the cap down till it lightly seats on the bearing.
the pressure release valve by the timing chain has also been checked and passes.
the canister depth is 0.188'' / 3mm . i use a new white oring and one shim. no gasket.
i have a siebenrock deep sump kit with the strainer extender. i removed this and checked for correct installation and a clear pipe. all is good.
Oil level covers the strainer by at least 50mm. (i have turned bike over with starter with sump dropped and can see the level drop once pressure gets up)
oil has got up to both sides rockers although less to the right than left.
no external oil leaks are apparent.
engine is currently stripped with only conrods and crank left attached, i have checked everything during strip down thus far and can find nothing of note.
Any pointers on where i can look? i am stumped!!!
I hope someone might be able to give me some idea of where to go next. appologies for the essay but i figured you'd need the info.
Bike - 1983 R65
Problem - intermittent low oil pressure after engine rebuild.
notes - Siebenrock 846cc kit. engine stripped to bare block. crank, thrust washers, main bearings, cam shaft and conrods are original. new seals and stretch bolts throughout. 20w50 oil. Mahle filter. No oil cooler.
i stripped the engine getting on for 2 years ago to the bare block, which i sent away for aqua blast cleaning along with the heads and engine covers. I then proceeded to rebuild the engine with new gaskets and seals throughout. Now because of the 2 years between rebuilding and actually firing the bike, i cannot for the life of me remember what i did internally regarding checking end float of crank and cam although i cant see how either would attribute to the problem i have.
I do remember visually inspecting the big ends as they appeared like new, i also bolted them upto the crank on the bench and the operation was smooth and im pretty sure i would have checked the clearances too.
all components were manually oiled on rebuild.
The problem i have is that it takes 20-30 seconds of turning or running the engine before i get pressure registering on my oil pressure test gauge. Then, when i do get pressure, (which is good at around 30psi at 1000rpm tickover rising cleanly with revs upto approx 85psi), it cuts drops off a cliff at around 90psi, which i could attribute to one of the pressure release valves opening, but then it doesnt come back!
i have spun the engine 3 ways;
1 - actually running the bike (which alerted me to the problem initially as dash oil light came on).
2 - plugs out, fuel off, turned with starter.
3 - timing chain off, turn the cam only with a cordless drill.
i have turned the engine with the drill with the oil filter out and oil absolutely floods into it, I have also checked all oil pump clearances which are perfect so i have eliminated the pump itself.
I have removed the pressure release valve in the canister and cleaned and inspected. the spring is in decent condition, no pitting to the ball bearing and the screw is good. however, to eliminate this as the weak point, i have screwed the cap down till it lightly seats on the bearing.
the pressure release valve by the timing chain has also been checked and passes.
the canister depth is 0.188'' / 3mm . i use a new white oring and one shim. no gasket.
i have a siebenrock deep sump kit with the strainer extender. i removed this and checked for correct installation and a clear pipe. all is good.
Oil level covers the strainer by at least 50mm. (i have turned bike over with starter with sump dropped and can see the level drop once pressure gets up)
oil has got up to both sides rockers although less to the right than left.
no external oil leaks are apparent.
engine is currently stripped with only conrods and crank left attached, i have checked everything during strip down thus far and can find nothing of note.
Any pointers on where i can look? i am stumped!!!