Club Cobra - Pre-oiler question

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Quote:

Originally Posted by kevins2 (Post 1251028)

After reading through this thread, for a street driven car, if you put all the opinions in a blender you come out with the Accusump probably not necessary but certainly can't hurt and may provide some marginal benefit.

Rather than pre-oiling, what do you think of pre-heating the oil? My engine builder has recommended an oil pan heater - not the cheesy stick on kind - but one that installs inside the oil pan through a welded-on bung. Assuming I don't mind plugging the thing in 20 - 30 minutes before driving, and plug it into a cord with a timer in case my CRS kicks in and I plug it in and forget...it seems to me that having warm oil at start, although not pre-oiling, would provide good benefit. Also, since I plan to drive the car in cooler weather it seems this would be a good investment for about $225.

An oil heater would be a good idea for your area, warm/warmed up oil is a lot thinner than cold oil and will flow so much better at start up......also, a good oil pump will not hurt....
case in point:I rebuilt a 351-W for a daily driver truck, standard rebuild, the owner brought me the parts and I did the work for him, the oil pump was a stock replacement parts store oil pump........on start up,the oil pressure gauge would sit still for at least 3 seconds, then slowly go up to 50 psi, and I mean slowly, but acceptable......

On my 331 stroker,I'm using a Melling High Performance oil pump, standard pressure/volume, on start up, the oil pressure instantly goes up to 60 psi, and I mean instantly......
BTW: both engines use the same oil, 15/40 Shell Rotella T...so that takes the oil itself out of the equation....

David

Quote:

Originally Posted by DAVID GAGNARD (Post 1251040)

the oil pump was a stock replacement parts store oil pump........on start up,the oil pressure gauge would sit still for at least 3 seconds, then slowly go up to 50 psi, and I mean slowly, but acceptable......

On my Melling High Performance oil pump, standard pressure/volume, on start up, the oil pressure instantly goes up to 60 psi, and I mean instantly......
David

To be scientific, I would have to consider that the sender/gauge combination in the two different vehicles could be different. Capacitors make great filters, but they add lag time. You would have to test both engines with the same mechanical gauge to be certain.

Honestly gear pumps can have poor efficiency if they have too much clearances, which causes low flow at high pressure. I cannot see a mechanical reason that could cause one to build pressure slowly.

PS
It occurred to me that if all the oil drains back to the pan on an engine, the pump is going to take time to fill the passages and it will be compressing air as it pushes it out. On the other hand, if the passages do not drain back, oil is not compressible and the pressure would be instant. Perhaps a loose pump would allow drain back where a tight pump would slow that process down. That said I could be wrong.

Quote:

Originally Posted by olddog (Post 1251130)

I agree a pump with a lot of clearance will build pressure slower, that's why I think the precision made Melling pump was better than the generic parts store pump....I didn't use the same gauge, but do/did check the gauges for accuracy as I do all my gauges before I install them....
I think the High Performance line of pumps are made to tighter tolerances than the generic pumps, that's why they get the pressure up quicker, they are more efficient to begin with...

David

Quote:

Originally Posted by DAVID GAGNARD (Post 1251040)

An oil heater would be a good idea for your area, warm/warmed up oil is a lot thinner than cold oil and will flow so much better at start up......
David

True, and the engine builder pointed out that even in warmer weather there is good benefit to using the pre-heater to get the oil closer to operating temp. I'm still reading about these but one claims to add 50 - 60 degrees in 15 min. and 175 degrees in 45 minutes. If true, that would absolutely be beneficial...not the same as pre-oiling, but the next best thing and a lot easier to install.

Regards,

Kevin