Steve Hayden Posted April 20, 2023 Report Share Posted April 20, 2023 I have a Mk IV Spitfire with an unidentified engine (think 1300 from Dolomite) It was working fine but circumstances meant that it has been hidden in the garage for 7 years. I am just trying to recommission it for the road. Despite continued cranking there is no oil pressure (engine was drained and oil replaced as there was a suspected leak of fuel from the fuel pump (another saga in its own right). I have replaced to oil pump which turns with the engine, checked the pressure release valve, oil pressure gauge, and switch (substitution). There is no oil coming out of the ports when the pressure release valve and the switch/gauge are fitted and the new oil filter remains empty. Has anyone got any ideas as to what the issue could be, i'm at a loss now. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 20, 2023 Report Share Posted April 20, 2023 some remove the dizzy drive gear and prime the pump with a battery drill sounds like the pump is just not priming have you tried cranking it over with the filter removed to see if you get a good squirt ?? what filter are you using a good few that tried a more modern equivalent found the pump wont prime Pete Link to comment Share on other sites More sharing options...
JohnD Posted April 20, 2023 Report Share Posted April 20, 2023 Making sure there is oil in the pump is more easily done by removing the PRV and squirting oil into there. Replacing is a lot quicker than putting back the dizzy and check timing! Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 20, 2023 Report Share Posted April 20, 2023 Spin the oil pump by using the dizzy drive rod on a drill. Gets the oil circulating while the other parts of the engine aren't, so less chance of damage. Link to comment Share on other sites More sharing options...
Sandy Gibson Posted April 20, 2023 Report Share Posted April 20, 2023 You have to spin the distributor drive ANTI-clockwise to prime the system. You’ll hear the drill noise change when it meets resistance of the oil being forced through. Also, when you are ready to try and start again, give the engine a spin with the starter without the plugs in first. Link to comment Share on other sites More sharing options...
johny Posted April 21, 2023 Report Share Posted April 21, 2023 (edited) Quite a long thread but documents everything tried and what finally gave success.... Edited April 21, 2023 by johny Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 21, 2023 Report Share Posted April 21, 2023 as the 6 cyl was never designed with a anti drain spin on filter using a more modern with a higher degree of anti drain probably overcomes the pumps ability to re prime ive used club filters for 20years with never a problem you cannot uprate the filters ability without an upgrade to the rest of the system you are likley to create a "must have" headache i dont see using a high end filter without any change to the simplistic 50 yr old pump design the mismatch will catch you out as many have found Pete Link to comment Share on other sites More sharing options...
johny Posted April 21, 2023 Report Share Posted April 21, 2023 20 hours ago, JohnD said: Making sure there is oil in the pump is more easily done by removing the PRV and squirting oil into there. Replacing is a lot quicker than putting back the dizzy and check timing! Looking at the manual certainly the sixes wouldnt benefit much from squirting oil in the PRV as it will tend to run straight back through the suction pipe into the sump. Better would be the plug immediately above it that leads directly into the pump discharge chamber... Link to comment Share on other sites More sharing options...
johny Posted April 21, 2023 Report Share Posted April 21, 2023 21 hours ago, Steve Hayden said: I have a Mk IV Spitfire with an unidentified engine (think 1300 from Dolomite) It was working fine but circumstances meant that it has been hidden in the garage for 7 years. I am just trying to recommission it for the road. Despite continued cranking there is no oil pressure (engine was drained and oil replaced as there was a suspected leak of fuel from the fuel pump (another saga in its own right). I have replaced to oil pump which turns with the engine, checked the pressure release valve, oil pressure gauge, and switch (substitution). There is no oil coming out of the ports when the pressure release valve and the switch/gauge are fitted and the new oil filter remains empty. Has anyone got any ideas as to what the issue could be, i'm at a loss now. Steve did you crank with the spark plugs removed and a good battery? These pumps need a bit of speed to suck the oil up from the sump and into the system... Link to comment Share on other sites More sharing options...
JohnD Posted April 21, 2023 Report Share Posted April 21, 2023 56 minutes ago, johny said: Looking at the manual certainly the sixes wouldnt benefit much from squirting oil in the PRV as it will tend to run straight back through the suction pipe into the sump. Better would be the plug immediately above it that leads directly into the pump discharge chamber... Johnny, I fear you misunderstand the purpose of 'priming'. A rotary pump compresses the oil between the lobes of the driven rotor and the cavities in the passive one, due to the offset. If those chambers are filled with air, as they may well be with the pump above the oil level in the sump, then against the resistance of the plumbing and filter the air is just compressed and released, and not driven into the system. Plus, without oil between the lobes and the rotors, air may easily leak around them and escape forward transmission. Priming should get oil into those chambers, where being virtually incompressible, it is driven forwards, wheras oil in the passages in front of the pump cannot do that. Even a little oil between the rotors to seal them will promote air pumping. The plug above might do, but IMHO the PRV is the one to use. I have seen it recommended in a rebuild to pack the pump with Vaseline! This will stay in the pump while the rebuild and installation is completed, and will satisfy the need for an incompressible medium in the chambers. Vaseline is suggested as it will dissolve quickly in engine oil, when proper grease may form 'clots' to block oilways. However, as Vaseline must be at least 200W/500, I would fear breaking the pump drive shaft and I've never done this! Instead, I use copious rebuild oil - Graphogen - on the bearings, and then turn over the engine without plugs until I see oil pressure, before I go for a start. On a six, with an oil cooler, this can take two or three minutes of churning, always a worrying time! Bests! John Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 21, 2023 Report Share Posted April 21, 2023 (edited) 2 hours ago, JohnD said: I have seen it recommended in a rebuild to pack the pump with Vaseline! Saw that back in the day, too, and remember a certain Triumph owner (who I've not seen in many a year!) packed the oil pump intake pipe; thankfully this was pointed out before use. Edited April 21, 2023 by Colin Lindsay Link to comment Share on other sites More sharing options...
johny Posted April 21, 2023 Report Share Posted April 21, 2023 3 hours ago, JohnD said: Johnny, I fear you misunderstand the purpose of 'priming'. A rotary pump compresses the oil between the lobes of the driven rotor and the cavities in the passive one, due to the offset. If those chambers are filled with air, as they may well be with the pump above the oil level in the sump, then against the resistance of the plumbing and filter the air is just compressed and released, and not driven into the system. Plus, without oil between the lobes and the rotors, air may easily leak around them and escape forward transmission. Priming should get oil into those chambers, where being virtually incompressible, it is driven forwards, wheras oil in the passages in front of the pump cannot do that. Even a little oil between the rotors to seal them will promote air pumping. no Im ok on the purpose of priming but its just if you look at the drawing most oil put in through the oil relief valve is just going to run straight down the inlet pipe that it discharges into. I suppose if you put the oil feed pipe right in some will get into the pump discharge chamber but as I say using the plug above it would guarantee this. Then once oil is in there it will run down into the pump discharge to fill the pump which, although not ideal, is the only way because theres no direct access to the pump inlet from outside the engine. This method needs a bit of time for the oil to purcolate through the pump interior (5 mins?) but as you say it only needs a little damping of the rotors to start to work... Link to comment Share on other sites More sharing options...
JohnD Posted April 21, 2023 Report Share Posted April 21, 2023 It's good to talk! 1 Link to comment Share on other sites More sharing options...
Steve Hayden Posted April 21, 2023 Author Report Share Posted April 21, 2023 Hi All, Many thanks for you help. I removed the oil filter used a small funnel to pour oil into the aperture below the threaded tube. Turned over the engine on the starter and a fountain of oil came out. I replaced the filter and turned the engine over, oil light went out and pressure gauge went up to 50 psi. I can now get on with the rest of the many recommissioning tasks. Thanks folks Steve Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now