Topic: oil in flat head ??


4ford    -- 11-12-2017 @ 6:39 PM
  Hello all,
just returned from SEMA last week and have a question to ask because I don't think I was given the right on at the Sh*ll both, I asked the question of what kind of oil to use in my rebult 1941 flathead with up graded rod bearings and adjustable lifters and a small step up on a cam and two 97s well I didn't get in to all that with them, the gentleman that I talked with was there oil (Expert) I said I was using their 15/40 0il rolella T the guy there told me that a better one would be 5/40 better start ups because of the thinness of the oil.....But we would like a thicker oil ?? right? Then found a Lucas oil guy there and he suggested Hot Rod oil 20W-50 I think this would be a better choice .. but is there any truth in the sh*ll oil?? on what the guy was telling me??


deluxe40    -- 11-12-2017 @ 6:59 PM
  Somewhere I have a 100-page treatise on the subject of oil that was originally published by the Ferrari club. Bottom line was that most of the wear in an engine occurs at start-up and, consequently, the thinner multi-grade oils are better. I don't remember the other 99 pages, but I have been using 10-30 ever since.


carcrazy    -- 11-12-2017 @ 9:56 PM
  A straight SAE 30 Detergent motor oil with an additive package like Red Line Engine Oil Break-In Additive works well in Flathead Engines. This additive contains the zinc, phosphorus (ZDDP), and anti-wear ingredients necessary to minimize camshaft and valvetrain wear.


TomO    -- 11-13-2017 @ 3:02 PM
  Talk to the builder of the camshaft and the engine.

Most stock flatheads do not put enough stress on the camshaft to need the addition of ZDDP. The anti-wear additives in good oils are enough. If you are using extra heavy duty valve springs, you may need ZDDP added to your oil, like the 2 "experts" told you.

When the engines were new Ford recommended 30w oil in the summer and 10w in the winter. Both oils that you mentioned have higher viscosity when warm than 30w oil.

The 5w-40 oil would give better lube at startup and work OK at operating temperatures. It would have the film of a 40weight oil and the cold viscosity of a 5 weight oil.

The 20W-50 oil would have the film of 50 weight oil and the cold viscosity of 20 weight.

Either oil will work fine in your engine as long as they have the other detergents and anti-wear additives.

I use 10W30 oil from Castrol in both of my cars. My Merc runs cooler since I switched back from 20W50 oil.

Tom


4ford    -- 11-15-2017 @ 7:30 AM
  so the gentleman from sh*ll was right the viscosity is the same when it gets hot. hence the idea of 20w40 vers 10w40.. 20w40 would be thicker all the time and give better oil pressure. OK what about the synthetic of the same consistory? is this a consideration?

thanks everyone


Yokomo99    -- 11-15-2017 @ 8:30 AM
  Tom has got it right. If the engine bearing clearances are within spec and the oil pump is in good shape you will be just fine with any quality 10W/30 oil. They push lighter oils for overhead cam engines as the thicker oil takes a long time to get to the cam bearings on cold mornings. I would also look at using a synthetic based oil as it will reduce friction and lower engine operating temperature as well. When we switched to synthetic oil in the 10000 Hp MG set babbitt bearings where I work our operating temps dropped 30 degrees C. Made me a believer.

Matt

Be sure to check out my YouTube pages at:

https://www.youtube.com/user/MatthewBergin1

https://www.youtube.com/channel/UCJCdOfmXtM8xO9nXeQ-iSQQ

This message was edited by Yokomo99 on 11-15-17 @ 8:39 AM


4ford    -- 11-16-2017 @ 6:52 AM
  so a 5w40 oil would be good to use and even the synthetic oil? I always thought it was for new motors but it looks like that has changed?

thanks


carcrazy    -- 11-16-2017 @ 8:55 AM
  From my experience with newly overhauled Flatheads, if you use oils of less than 30 weight you will have leaks.


sarahcecelia    -- 11-16-2017 @ 8:20 PM
  Valvoline 30-50 Racing oil with zinc to protect that flat tappet cam!


TomO    -- 11-17-2017 @ 7:13 AM
  I would not use a 5W40 oil, just because I believe in keeping the cold viscosity close to the hot viscosity. My preference for oil is still 10W30. If I needed a thinner oil I would go with a 5W20. I would also worry about 5w oil seeping past the bronze bushings in the water pumps and distributor.

I see no reason not to try the synthetic oil except that you will hurt your wallet. Synthetic oils work best with fuel injection systems, because there are fewer unburned hydrocarbons to dirty up the oil. Carburetors do not run as efficient and can leak unburned fuel into the oil. Your oil should be changed at least every 1,000 miles and sooner if driven on short trips. Synthetic oil typically costs about 1.75-2x conventional oil and you cannot take advantage of the longer oil change interval of the synthetic oil.

The newer blends of synthetic oil are not supposed to hurt the seals on older engines

Tom


Yokomo99    -- 11-17-2017 @ 9:48 AM
  Tom the only way I would spend the money on synthetic is if I had converted the engine to a full flow oil filter system. With 1000 mile oil change periods synthetic is a waste of money. On the other hand almost any 10W- 30 oil even the really cheap ones will last 1000 miles without any engine worries. I would use the zinc additive though.

Be sure to check out my YouTube pages at:

https://www.youtube.com/user/MatthewBergin1

https://www.youtube.com/channel/UCJCdOfmXtM8xO9nXeQ-iSQQ


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