flathead oil pressure

my 53 merc flatmotor has great oil pressure (around 55 lbs when driving)
running strait 50 weight oil. problems come in at idle, dropping to
around 5 lbs. when good and hot. any input? engine has around 800 mi.
thanks for your input showkar

 

Your good. As long as it has pressure.
BTW, Where ya from in our crappy snow filled state? Any pics of your car?

 

Sounds a bit low for a fresh motor but flatheads are kinda known for low presser at idle….if there's no metal in the oil and no bad noises I wouldn’t worry.

 

Have you changed the oil yet? If not, DO IT! And again in about 5-700 miles. Hopefully it's clean and not metallic.

 

Sounds about right. I personally wouldn't be too concerned. My rebuilt Lincoln flathead ran identical to what you described, and is still running fine, twenty years later....

 

Why would you run straight 50W in Michigan?

 

Try using Castrol 20W50. It may not be a good idea to use straight weight oil in cold temperatures according to this ; http://www.upmpg.com/tech_articles/motoroil_viscosity/ Also, did you change the cam bearings?

 

i have a 1937 ford phaeton with stock motor oil pressure is about the same and i run straight 30w change every 500 miles. also have a filter that filters some of the oil.

 

I would run 20 w 50 Castrol as mentioned above and add a small amount of Marvel Mystry oil to it.

Frenchy

 

hey, thanks for all the input, new address is florida, michigan winters suck.
i run strait 50# valvoline racing oil, was thinking of streching oil pump spring
guess i will leave it alone, dont need anymore oil pressure at driving speed.
thanks again

 

well im glad you posted this question up here. now i wont have to ask. ive got 8ba that i got running awhile back. first crank up it runs about 40 or more then after it gets warm it drops to around 5. so nowi feel alot better. i cant afford to rebuild one of these right now.a sbc they aint.damn near build 2 sbc for one flatheaD, but god they sound good dont they!!!

 

Long as you show some oil pressure at idle you are good. I'd try 15w/40 Diesel oil, like Rotella, this stuff is liquid Ball bearings...saved an old 305 chevy I had, doubled the op by changing to this...good luck!!

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Hey,update your location in your member profile.Florida a good place to live this time of year.Im jealous