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Hi all. After a restoration I am about to fire up the Twin Cam in my LeGrand MK6 FB. With the oil tank in the front and the oil lines carried through the frame tubes, what is the best way to get OP before the start up. I have tried cranking it over without the plugs in etc but can't get the OP to move. It is a long way from the oil tank to the pump and back so I am not sure the best way to do it. Any ideas. Thanks for any help in advance.
I race vintage Porsches that have a similar layout (engine in rear, oil tank in front). Usually by the time I've finished adding oil to the tank, it's made it's way to the engine and oil pump. Priming is usually as simple as cranking and waiting a few seconds to see the oil pressure gauge needle move. If you're not seeing that, maybe see if oil is getting to the pump? Could be a blockage, or it's sucking air for some reason. If that checks out, maybe check your gauge? Or try using a cheap mechanical gauge for comparison.
Scott
On Titan Mk 6 the tank is in the front of the car. Every race morning I would jack the up front of the car to the hight of a standard formula car jack. Let it sit for a few minutes then fire the car lowering it after a minute or two of running. When ever changed oil or engines it would sometimes not want to prime. With the nose up take an air chuck and a rag and add a little air pressure to the top of the tank.
Best of luck
Tom
Rowland’s method seems to be the better way.
The oil pump does not like to pump air. Jack up the front of the car until you are sure the oil level is higher than the oil pump. Loosen the inlet line from the tank at the pump and wait until you get a steady drip of oil. Tighten the fitting, leave it jacked up and spin the engine until you get pressure. You can also take the pressure line fitting to the gauge off at the block and watch for oil flow also. That usually helps.
Great tips guys. Thank you very much. Updates coming soon.
It can also help to back fill the pressure side of the oil pump by pouring oil down the output line of the pressure side. Once the pump actually has oil in it the suction will be established. I have a 2 qt accusump that I pre-load with a qt of oil under pressure and use a t-fitting on the pressure side of the pump. As soon as the motor starts I release the oil into the system.
Once steady pressure has been established the system re-pressurizes the accusump. I can close the valve and keep the oil stored for future use or leave it open after the motor has stopped to drain the qt into the car's oil system. I then remove the t-fitting.
Found with my Titan 6 once the system has been initially run for the first time I have not had to do anything special from then on, cranking gets the gauge to "move" after 15 to 20 seconds max and upon starting the pressure comes up instantly.
I have an aluminum vintage oil tank the the appropriate patina that likely had a "little more than a little air pressure" when trying to prime......Quote:
Originally Posted by marchsv
Oh yes. Do be careful about applying too much pressure into the tank. Be careful. I saw one fellow apply to much pressure when doing a track "fix." Blew the tank complexly apart. Day over (except for two hours trying to clean up several quarts of oil in the paddock.Quote:
Originally Posted by DanW
Had to cut mine out...Quote:
Originally Posted by DanW
Something I've done starting many different engines over the last 40 years. Take a normal oil can and fill all the oil lines; if you can get at the oil pressure switch, take it out and pump oil straight into the engine oil gallery. From your description I'm assuming you have a 'dry sump' system but still adding half litre or so directly into the oil pan will help to prime the pump.Quote:
Originally Posted by Earley Motorsports
Accusump is the best way to pressurize the system.
Oil can is a 'poor man's' accusump!:D
Thanks for all the suggestions thus far. I raised the nose of the car, cranked it over with he plugs out and the OP gauge moved a little. Put the plugs back in and it fired right up. OP came up to around 50psi so I am thinking good. Then it dropped down to about 5psi, went back up to 40 then dropped back down to zero. Turned it off. Left it for a bit then fired it up again. Zero. (This is all at idle 1200 rpm), waited again and fired it up pressure came up and went away again as before. Checked all the lines and frame tubes for blockage and they all appear good. All new braided lines. Pulled the sump plug and some oil came out but not much. What is strange to me is that before I pulled the motor to re-gasket it, I ran the motor and the OP was fine and constant.
I pulled the oil pump and took it apart to check for clearance between the rotors. I recall 10 thou being max clearance at the tip of the star to the outer rotor. Three of the tips are 5-6 thou and one is 10. The motor is more or less new and was only ran to fire up and the car never saw the track.
Does anyone know what the clearance tolerances in a Titan 4 port pump are supposed to be? This is starting to get a little frustrating :confused: but the thing is it had OP before being taken out. As always, thanks for any help.
I’m not familiar with the Twin Cam. What drives the oil pump? Could the drive system be slipping or skipping teeth?
Could your pressure gage be going bad? Is it a mechanical or electric design?
I find it odd that you’re seeing the oil pressure jump back and forth from 0 to 40/50 psi. A worn out pump wouldn’t do this, so I don’t think internal clearances are your issue.
The twin cam has a jack shaft ( half a cam). Gears are good, mechanical gauge is a new Smith’s.
Do you still have the old pressure gage? If so, install it and see if the oil pressure is stable.
Same gauge that was used before motor was pulled Jon. It was new then.
Seems like you are not getting all the air out of the lines. Personal preference I guess, but I've seen a lot of that problem with front-mounted tanks. I have a friend who is running an electric drill-driven primer pump on his FF1600. I believe it's a Peterson ( http://www.petersonfluidsys.com/filt...merRemote.html ), which is basically an oil filter mount with a small pump in the top. A bit pricey (~$400) but convenient. It won't clear the system of air but does give you a means of maintaining pressure while the system is clearing itself.
Here's a better picture: ( https://www.speedwaymotors.com/Peter...SABEgJlD_D_BwE )
The other trick I've used is to elevate the tank overnight and try again in the morning.
I'm guessing the engine is not noisy (or you wouldn't keep running it), try another gauge and lines!Quote:
Originally Posted by Earley Motorsports
Another idea; just spoke with one of our Lotus club members who had a similar problem with his Lotus 7 TC, it was the oil filter!!Quote:
Originally Posted by Earley Motorsports
My car developed a strange low pressure during a race earlier this year. It would start fine, have higher oil pressure at the start of a race, then start dropping to the low 30s after a couple laps. I had the Ivey boys look at it between sessions and it was perfect again. When it dropped again in the next race (and the oil light came on - set to 20#) I pulled off.
i pulled the engine to send it to Ivey for a refresh and found that a baffle in the oil tank came loose and partially blocked the tank pickup. Apparently the baffle was out of the way until I went around a couple corners and would block it again. Engine had enough hours to send it in, so it is there now.
not sure if that is your problem, but it is possible.. also look at the oil filter lines, the “inlet” feeds the “outside” of the filter and the “outlet” comes from the center. I have seen them put on backwards and since most filters now have an anti drain back valve, that would block the flow.
Once again; local FF racer had tube/pipe from dry sump to pump collapsed inside lining (this could cause the problem to be intermittent and could have happened just by removing and replacing the oil pan when the pipe would have been disturbed). Apparently putting a spring inside the tube to prevent it from collapsing is a common fix.Quote:
Originally Posted by Earley Motorsports
Thanks to all for all the advice. I put the oil pump back together and put the motor back in place. I found the fitting which attaches to the frame on the suction side was faulty so replaced it, bleed all the lines, whizzed it over on the starter for a bit, put the plugs back in and fired it up. The gauge climbed to 60lbs and stayed there. Ran it for a bit, turned it off then fired it back up again. Instant 60lbs and stays there. All good. Thanks so much for all the help. On to the paint next.
Nice to hear that you solved the oiling problem. How about some chassis photos of the restoration ?
Here are some photos going through the restoration process. Real original car. Thanks for the interest.
Graham, thanks for doing such a great job on the car I will buy as soon as the lottery numbers hit!
Thanks for the photos, you did a beautiful job on the restoration. I looked at this car a few years ago and quickly realized I didn't have the time, talent or patience to take on the project. It's nice to see the car restored and that it will be back on the track again.
Glad to hear you got the OP issue solved. Sharp looking car!
Care to share what the issue was with the fitting?
Beautiful car!!!
Even in primer. The chassis is a gem!!!
It was a swivel AN fitting for stainless braided line and where the swivel was the seal was leaking.Quote:
Originally Posted by J Leonard