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So starter is back in and now the engine turns overs! I don't have the spark plugs in to reduce resistance and to enable it to spin faster (at least that was the plan but I guess the starter motor speed will just mean it draws less current) to build up oil pressure but I'm not reading any pressure on the gauge. It is a mechanical guage with a pipe to the back of the meter.

How long should I crank the engine in order to see oil pressure? If there is none then, with a mechanical gauge what could be wrong?

 

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Hi Mike,  I have a mechanical gauge on my other car, only takes a few seconds of cranking to show pressure.  Was the gauge working ok before?

The gauge has a flexible coiled tube called a bulb the open end of which is rigidly mounted to the outer casing. the other end of the bulb is closed and connected to a lightweight linkage at the bottom end of the needle.  The oil is fed up the supply pipe and tries to straighten out the bulb under the pressure and moves the needle in the process.

 I am assuming that you used a new feed pipe, so that should not have any blockages, might be worth cecking the run for kinks though.  The oil should move freely through the union at the engine, so check that out as well.  It would also be worth checking the union at the gauge end for leaks, should be easy to feel for.  Could also be some dirt in the gauge stopping it from moving.

Work methodically from the engine to the gauge, I'm sure you will find the problem. 

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Unused the old supply pipe... I will renew throughout since if it only takes a few seconds to show then I don't want to run the white without knowing if it has lubrication or not. The gauge was working fine when it came out but that was a few years ago now.

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So I removed the gauge supply pipe from the block and no oil there. Cranking the engine with this removed for a minute or more does not reveal any sporting oil also. No oil in the filter yet either! Can you prime the oil system on these engines?

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If there is no oil in the filter it sounds like the pump may not be producing enough suck to get the oil round the engine, it needs a thin film of oil between the moving surfaces.  If the engine was rebuilt and/or has stood for a while that may acount for it

Found this  http://www.lotuselan.net/forums/lotus-twincam-f39/how-prime-the-oil-pump-t32653.html

 

 

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4 minutes ago, Trunnion 74 said:

If there is no oil in the filter it sounds like the pump may not be producing enough suck to get the oil round the engine, it needs a thin film of oil between the moving surfaces.  If the engine was rebuilt and/or has stood for a while that may acount for it

Found this  http://www.lotuselan.net/forums/lotus-twincam-f39/how-prime-the-oil-pump-t32653.html

 

Thanks for that. Maybe that's the problem since the engine has been standing a while but to get to the pump and fill with oil the cam belt has to come off. The high pressure spray into the gauge take of seems like an easier way. Any other tips?

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I have seen something done on Car SOS, where Fuzz Townshend uses cable ties wrapped round the cam belt to relieve pressure on an idler pulley so he could get it off without removing the belt, not sure if that's possible on a 907.

I see form your resto page you had the engine rebuilt, erm, I assume they put the oil pick up pipe back in?  That's if it's got one, as I can't see it listed on the RD Manuals page  Could also check to see if screen is blocked.

Sorry can't be of more help. :(

 

 

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After reading some more on the Jensen Healy forums, it is self priming, but the esprit forums it needs priming... I think the cam belt will come off so I can at least spin up the oil pump without turning the engine.

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12 minutes ago, Trunnion 74 said:

I assume they put the oil pick up pipe back in?  That's if it's got one, as I can't see it listed on the RD Manuals page 

10 minutes ago, Trunnion 74 said:

 

Doh!! Silly me, of course it has one, was looking at the wrong pic :getmecoat:

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Mike, about the only thing I had with my engine was oil pressure, definitely self priming and why would you ever build an oil pump that did not. If the engine is not firing I woud not worry too much abou damage, perhaps pull off the pipe from the block to the pressure guage and make sure there is oil comimg out of the block. If no oil there and you have oil in the sump then perhaps the pump is not working? 

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I also read that a bad seal around the dizzy will stop the pump from pulling

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Mike, Do you have an oil cooler? If so can you disconnect it and prime the oil pump by pouring oil in through one of the hoses

Hope the picture helps

regards Dan

image.jpg

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Definitely need to prime the oil system in a 907 after a rebuild, it is self priming but takes a long time.

Take the cam belt off the oil pump drive wheel and then put an allen key bit in a battery drill and run it until you show oil pressure on the gauge, you should feel the drill slow slightly as the pressure builds up.

Still takes a few minutes to achive pressure!

  • Thanks 1

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