Topic: Oil pressure


gobbie    -- 09-07-2011 @ 11:02 AM
  What should the oil pressure be on a
1936 Ford pick-up V/8 221 / 85 H.P.
Flathead? The engine was supposed to
have been rebuilt. I was told by the
seller there is very little oil pressure
in older flatheads when I purchased 3 weeks ago.
I pulled the sending unit this am and put a pressure gauge on it. At warm oil it idled at 6 lb and
at about 2,000 rpm -about 10/12 lb.
HELP PLEASE
gobbie


nelsb01    -- 09-07-2011 @ 11:07 AM
  Does seem a little low for a re-built. My rebuilt 1949 runs at 80 lbs (at the factory gauge) while driving and about 20 lbs (at the factory gauge) at idle when warm.
I have never connected a modern gauge to it, so I am believing what I see to be somewhat correct.
First question to ask is: Do you have at least 4 quarts of oil in it? Five if running some sort of oil filter.
I am sure others will soon respond.


supereal    -- 09-07-2011 @ 11:45 AM
  What weight oil are you using? Many of us use 20W-50 in the warmer months to compensate for thinning at operating temperature. The bearing type was changed in mid 1936 from babbit to inserts, so you may have the earlier kind. Sometimes those unfamiliar with the old style bearings attempt to adjust clearances by filing down the caps. This can result in out of round problems that allow enough oil to escape that it affects pressure. I will agree that the indicated pressure is on the low side, but if the engine isn't noisy, I'd just drive it. Your comments make me wonder if the "rebuild" was done because of the low pressure, or it happened after. It isn't reasonable to compare the early engine with the later type because the oil pumps were changed to 80 pounds from the 40 pound early kind. I'm always skeptical of "rebuilt" claims unless they are accompanied by documents showing who, when, and what work was done, including a list of parts. At our shop, we have seen lots of poorly done "rebuilds", and many of them that were not more than a coat of paint designed to hype the sale.


gobbie    -- 09-07-2011 @ 12:54 PM
  OK Just took it out for a drive with the modern
pressure gauge installed. 1st gear went up to 20 lb
2nd gear 20 lb and ran at 10/12 lb at 45 MPH.
I got no documants on rebuilding. The dipstick
says full but not sure what kind oil is in it.
I did not ask what type of oil to run.I think it should be an SAE and not a HD? ALSO add .04 OZ.of
marvel mystery oil to each gal.of gas. After just buying 3 wks. ago I did want to enjoy.Also found there is an oil sending unit for light and one for gauge!
All Info. Appriciated


ole_Bill    -- 09-07-2011 @ 1:06 PM
  My '36 runs about 20lbs at idle, but it has just been rebuilt and is not broken in. My rebuilder also races flatheads and builds those engines very loose. His theory on race engines is if the oil pressure moves the gauge needle it's good to go.


supereal    -- 09-07-2011 @ 3:14 PM
  Any good brand of detergent oil is OK. Many of us run Castrol 20W-50 because it is readily available. Sh*ll Rotella 15W40 is also good. If you don't have an oil filter, install four quarts. Five if you have a filter. Then check the dipstick marking to know when the oil level is correct. If it doesn't match the marks, make a new mark. Avoid synthetic oils, as they tend to leak past the seals. Try to change your oil at least twice a driving season to keep the engine clean. As for MMO, don't overdo it or you may have spark plug fouling. Just a few ounces to a full tank of gas occasionally is best. Have fun with your "new" truck!

This message was edited by supereal on 9-7-11 @ 3:17 PM


gobbie    -- 09-07-2011 @ 5:29 PM
  OK I bought 5 qts. of SAE 30 . I am told to
add 4 oz. of zink phosfate? per qt.of oil so
tomorrow I will change oil which calls for
5 qts. NO HD. oil. I will leave modern oil
preassure gauge attached and see what happens.


supereal    -- 09-07-2011 @ 9:06 PM
  Adding zinc to oil for flatheads is overkill. ZDDP is essential for high revving engines with high valve tension, but our old engines will be fine. If your '36 engine doesn't have an oil filter, put in four quarts only, or you will lose the excess, mostly at the rear main. Many reprint owners manuals call for five quarts, but that is incorrect.


gobbie    -- 09-08-2011 @ 12:24 PM
  OK Thanks To all.
Changed oil this am.,put in 4 qts. of 30 wt.SAE
After warm idles at 12 lb. pressure up to 20 lb
1 st & 2nd gear. Orderd a gage type sending unit
switch and will run it.


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