Graham Baggaley Posted October 14, 2023 Report Share Posted October 14, 2023 Well I wanted to try and solve my oil pressure issue on my 3a with a recent rebuild. I had an oil leak on the sump so I swapped out the oil pump whilst I solved that. What I hadn’t bargained on was that my car was still leaking oil from somewhere, the oil pressure still wasn’t resolved by swapping the oil pump (it still dropped oil when the car got to temperature) but worst of all the car has now trashed the big ends. I’m likely to take the engine apart in the next month so will be looking for clues whilst I do. I can say that it trashed the big ends (diagnosed by noise and by bearings in the drained oil) but also that the oil had been superheated. So much so that there was steam (cooked oil not water vapour) coming out of the dipstick. when I drained the oil the stench of burnt oil was very pronounced. The cooling system however was still in tact. I am going to pull the engine and strip it and hopefully it will become obvious what has happened but very interested to hear from the knowledge bank of the forum for things to consider or look for whilst stripping it. This engine only had 1500 miles so I’m really surprised this has happened. The engine was rebuilt my father in law a precision engineer with very many successful engine rebuilds over a great many years though no specific Tr3a 4 pot prior experience. Thanks so much Interested to hear any theories. Quote Link to post Share on other sites
RogerH Posted October 14, 2023 Report Share Posted October 14, 2023 Hi Graham, is this the car you did the RBRR in - if so how far did you get. When you take the head off DO NOT rotate the crank unless the liners are clamped tight. Check the cam bearings. Piston rings Could the hot oil be due to seized pistons as it is a new build. Roger Quote Link to post Share on other sites
iain Posted October 14, 2023 Report Share Posted October 14, 2023 So many issues to look at. As Roger intimates strip it down slowly and methodically. Follow the WSM. Were all the components machined before rebuild.? Crank? Rods checked for trueness and ovality. Small ends ream to correct clearance Ring gaps correct? Thrust washers correct size and facing the correct way……yes it’s easy done….. Block thoroughly cleaned, end caps all matching? The list goes on , but all needs to be checked. Oil that got that hot did so for a reason and one can only guess it was a clearance issue somewhere. Quote Link to post Share on other sites
John McCormack Posted October 15, 2023 Report Share Posted October 15, 2023 Were you running waterless coolant? We have had a few cases of cars overheating to the point the oil cooked and it not being noticed because the engine didn't boil. Trashed bearings were the result. Quote Link to post Share on other sites
Graham Baggaley Posted October 15, 2023 Author Report Share Posted October 15, 2023 14 hours ago, RogerH said: Hi Graham, is this the car you did the RBRR in - if so how far did you get. When you take the head off DO NOT rotate the crank unless the liners are clamped tight. Check the cam bearings. Piston rings Could the hot oil be due to seized pistons as it is a new build. Roger Hi Roger. I made it up to Scotland but the rain was driving horizontally into the car do in the name of safety we stopped our entry in the RBRR. We stayed in Berwick. The following day we headed south away from the rain. We had a great drive through the b roads of Yorkshire. Around Northampton the big ends went. We stopped immediately. it’s defo not a seized piston. I will be taking everything apart to find the failure. The oil leak and the reduced oil pressure are the clues I think. great to see you at the RBRR Roger. Graham Quote Link to post Share on other sites
roy53 Posted October 15, 2023 Report Share Posted October 15, 2023 Were the bearings caused by the oil leak therefor low or no oil ? the last thing that you touched was the pump so a good starting point. Burnt oil can only mean that it's been on top of pistons so rings or hole. Just thoughts Roy Quote Link to post Share on other sites
Andy Moltu Posted October 17, 2023 Report Share Posted October 17, 2023 Oil will get cooked in a seizing engine. You wonder if your new oil pump failed catastrophically, was the drive intact when you stripped it down? A few moments of no oil pressure can be engine trashing and the absence of a warning light means this isn’t spotted until too late unless you were staring at the pressure gauge at the moment of failure. One of our group had this happen driving along and then lost power as his engine seized. When stripped down we found a fragment of metal had made it through the oil pump strainer, locked it and sheared the pump drive. it looked like a bit of piston ring but the strip down showed the present rings to be intact so may have been from somewhere else or an old ring. Was your low pressure symptomatic of worn bearings rather than the old pump failing? My experience of repro pumps (and repair kits) were that they were worse than the one I took out so built mine with the old pump. If you fitted a new (but rubbish) pump to an engine with already worn bearings the further drop in pressure may have been the death, but worn bearings tend to rumble and knock more as they wear. Realistically you will need to strip down an check it out taking care to clean out any debris and the like from the oilways. As roger said, don't disturb the liners (unless you are planning to remove them to fit new liners and pistons) or you will have to faff around replacing the FO8 gaskets and setting the cylinder protrusions. Quote Link to post Share on other sites
Nigel C Posted October 17, 2023 Report Share Posted October 17, 2023 Isn't there a trick to setting up an oil pump? bottom plate/face/clearance etc? (I can't remember!) Quote Link to post Share on other sites
Motorsport Mickey Posted October 17, 2023 Report Share Posted October 17, 2023 That sounds like our old friend of a seized oil pump vane. Check the oil pump vane on strip down, there was a bunch that were "staked" rotor to shaft which after a while in use became loose causing the rotor to spin on the shaft giving low pressure and then an engine seizure. I always drill and pin (small dia c pin is fine) through the rotor into the shaft for safety. Mick Richards Quote Link to post Share on other sites
Lebro Posted October 17, 2023 Report Share Posted October 17, 2023 2 hours ago, Nigel C said: Isn't there a trick to setting up an oil pump? bottom plate/face/clearance etc? (I can't remember!) It's all detailed in the workshop manual. Bob Quote Link to post Share on other sites
Graham Baggaley Posted January 18 Author Report Share Posted January 18 There’s some really interesting comments in here. Thanks everyone. I finally pulled the engine and started the strip down. Sure enough big end bearing on pot number one was trashed. I think that a complete strip and measure is necessary however my first port of call will be to check the oil path through the crank. I will try to remove the slot headed plugs in the crank first. so much to look at!!!! certainly going to look at the oil pump as well now to start looking at that manual. Quote Link to post Share on other sites
iain Posted January 18 Report Share Posted January 18 (edited) 22 minutes ago, Graham Baggaley said: There’s some really interesting comments in here. Thanks everyone. I finally pulled the engine and started the strip down. Sure enough big end bearing on pot number one was trashed. I think that a complete strip and measure is necessary however my first port of call will be to check the oil path through the crank. I will try to remove the slot headed plugs in the crank first. so much to look at!!!! certainly going to look at the oil pump as well now to start looking at that manual. Those plugs can be pita’s, go careful and/or get and engineering shop to help. Edited January 18 by iain Quote Link to post Share on other sites
RogerH Posted January 18 Report Share Posted January 18 Hi Graham rather than take the plugs out (can be very difficult or even impossible) use a pressure spray in the gallery into the blind bore towards the plug. Use a magnet on a stick to pull out any ferrous particle. Usually there is nothing to wash out or attract. Roger Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 18 Report Share Posted January 18 (edited) 1 hour ago, RogerH said: Hi Graham rather than take the plugs out (can be very difficult or even impossible) use a pressure spray in the gallery into the blind bore towards the plug. Use a magnet on a stick to pull out any ferrous particle. Usually there is nothing to wash out or attract. Roger +1 Fairey liquid bottle filled with degreasing fluid squirted into the main bearing oil gallery holes of the crank should see a steady stream exiting the crank pin con rod bearing journal oil holes. Poke through with pipe cleaners. If the crank is going for a regrind maybe worth asking the engineering shop to remove the plugs for you. Did the engine get over revved? Check the con rods for bend and twist. Edited January 18 by BlueTR3A-5EKT Quote Link to post Share on other sites
Trumpy3 Posted January 18 Report Share Posted January 18 Graham Don't forget to remove the two aluminum main oil gallery plugs in the block to ensure all oil galleries are thoroughly cleaned. New plugs are available, or at least were. I machine up my own. Brian Quote Link to post Share on other sites
iain Posted January 19 Report Share Posted January 19 10 hours ago, Trumpy3 said: Graham Don't forget to remove the two aluminum main oil gallery plugs in the block to ensure all oil galleries are thoroughly cleaned. New plugs are available, or at least were. I machine up my own. Brian +1. Revington supplied mine, I’m sure others do them as well. Quote Link to post Share on other sites
RogerH Posted January 19 Report Share Posted January 19 The plugs are readily available https://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/engine/engines-components/external-engine-tr2-4a-1953-67.html Roger Quote Link to post Share on other sites
EliTR6 Posted January 19 Report Share Posted January 19 16 hours ago, Graham Baggaley said: There’s some really interesting comments in here. Thanks everyone. I finally pulled the engine and started the strip down. Sure enough big end bearing on pot number one was trashed. I think that a complete strip and measure is necessary however my first port of call will be to check the oil path through the crank. I will try to remove the slot headed plugs in the crank first. so much to look at!!!! certainly going to look at the oil pump as well now to start looking at that manual. Would be great if you could post some photos of the strip down and the parts you're checking as you go along. Thanks! Quote Link to post Share on other sites
Trumpy3 Posted January 19 Report Share Posted January 19 If only No1 big end is shot and the other bearings are OK except maybe for some damage that can be attributed to debris from the failure then my first approach would be to concentrate on No1. Oil flow,mechanical or assembly issues. If all bearings show distress from lack of oil flow then the lube system is more likely the issue. Remember that if there is a general problem then there will be one item that will fail first. At least this will keep you out of trouble for a while. Brian Quote Link to post Share on other sites
Graham Baggaley Posted January 20 Author Report Share Posted January 20 11 hours ago, Trumpy3 said: If only No1 big end is shot and the other bearings are OK except maybe for some damage that can be attributed to debris from the failure then my first approach would be to concentrate on No1. Oil flow,mechanical or assembly issues. If all bearings show distress from lack of oil flow then the lube system is more likely the issue. Remember that if there is a general problem then there will be one item that will fail first. At least this will keep you out of trouble for a while. Brian Hi Brian, the strip down started. The result of the failure was found to be a big end bearing on pot 1. The cause is yet to be to be found but clearly it’s oil related. The car was suffering with low oil pressure when warm and was losing oil I suspect through the breather so I’m presuming the crank case was somehow being pressurised. on start of strip down you can see all the bearing shards but also one of the big end cap tab washers has broken in half and I suspect had destroyed the oil strainer. next step is to remove the crank and check it’s all path. Quote Link to post Share on other sites
roy53 Posted January 20 Report Share Posted January 20 What are all those bits in the sump picture ? Quote Link to post Share on other sites
Hamish Posted January 20 Report Share Posted January 20 That’s a proper skinny lightweight flywheel. is it a high performance engine ? Quote Link to post Share on other sites
RogerH Posted January 20 Report Share Posted January 20 (edited) 29 minutes ago, Hamish said: That’s a proper skinny lightweight flywheel. is it a high performance engine ? Not at the moment Roger Edited January 20 by RogerH Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 20 Report Share Posted January 20 29 minutes ago, Hamish said: That’s a proper skinny lightweight flywheel. is it a high performance engine ? Beat me. I was going to ask where the rest of the flywheel had gone. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 20 Report Share Posted January 20 What oil was this engine running with? Quote Link to post Share on other sites
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