@kevin-ray

Hi Kevin

I think we need some clarification here.

Do both cars continue to show pressures that high after they are warmed up?

Or do they get lower as they warm up?  And if they do, what pressure do they come down to when warm now?

Did you mean you have run the cars for 4 years since you cleaned the engines out and started using the 10W-30 or 40 and that both of them have just recently began showing higher pressures?

And, what is the API rating of the oil you are using?  (for example SN, SP, etc)

My first thought is that this is an oil problem, one of the problems being that your oil (especially 10W-40) is way too thick/heavy for an early Chev engine.

I wouldn't tear into any bearings yet, as excessive bearing clearances LOWER oil pressure, not cause it to go up.

AND, only the main bearings run under pressure anyway.

The connecting rod bearings are NOT pressure fed in a 1932 engine.

PS

If you recently changed from using 10W-30 to using 10W-40, that is probably the cause right there.

I cleaned the sluge out of the motors when i got the cars. After warming up oil pressure is fine . Its when could on start up is when the pressure is to hi. Over time it has gotten worse to where it is now. I have always used 10w30 in winter and10w/40 in the summer so i dont think it’s the oil. Both were heavy on sluge.

@kevin-ray 

When you cleaned the sludge out, did you remove the oil pump intake screen and clean it?

@ole-olson yes. Everything was fine 15,000 miles ago. Slowly got worse on startup to now trying to figure out why. Both cars are doing almost the exact same thing. Might drop pan  to look . It’s been a while

Hello Kevin Ray,

AI thinks you should change oil once a year if not driven and between 500-1000 miles if engine does not have a filter to reduce sludge buildup over time. Also 5w30 or 10w30 oil. AI says you can add to the oil during oil change: Seafoam, Marvel Mystery Oil, Berrymans B-12 Chemtool or ATM Automatic Transmission Fluid to dissolve sludge. If you're 32's are in cold storage and not in warm storage, cold startup high oil pressures would seem logical. If curious, a temporary oil pressure gauge connected to the engine could supply more accurate pressure information.

Edit: AI=ai  

I change oil every 1,000 miles usually add 1 quart of transmission fluid between changes due to oil leaks. Does it just a little less in warmer weather. 

@kevin-ray 

Wait...

Are you saying you add a quart of transmission oil to the ENGINE between oil changes?

Engine oil additive packages are a balancing act.

Some additives compete with others, and adding ANYTHING can and will upset that balance and result in unwanted negative effects.

For that reason, nothing should ever be added to the engine oil, except more of the same engine oil.

Here is a video done by an actual tribologist specifically on the subject of additional off the shelf additives and how they can, and usually do, make things worse:  https://www.youtube.com/watch?v=CAGT5inQScE

In other videos he explains how adding more of one additive (for example ZDDP) can destroy the benefit of some other additive.

With that all said...

Engine oils can not make "sludge" all by themselves by just sitting in an engine for too long.

If they could, you'd find sludge in old unopened jugs of oil, and that never happens (although the additives can separate out and settle to the bottom).

Sludge is a byproduct of the combustion process and only shows up when the amount of that byproduct overwhelms the ability of the oil additives to keep it in suspension and prevent it from accumulating on inner engine surfaces.

This really now only happens when non-detergent or low detergent oil is used, or if a high quality oil hasn't been changed for a LOT of miles.

I have never seen a high quality oil sitting in an engine for 1 or even 2 years EVER accumulate sludge on our farm.

Because the connecting rod oiling system in 1932 engines did NOT run under pressure, and was completely dependent on free flow, lower viscosity oils work best in them.

Doug Bell, one of the original VCCA founders and a mechanic himself, used nothing but straight 10W in his 1931 Chev.

Even though he lived in California and drove the car at higher speeds.

I've done the same with my '29.

My guess is that if you use a 0W-20 API SN or SP oil at your next oil change, your problem will go away.

And remember, 1932 engines require more FLOW for lubrication, not so much pressure.

Anything over a few pounds at hot idle is fine.

@ole-olson I personally would not use 0w oil in any older engine. Older engines I believe have bigger tolerances a need the heavier oils were new engines run tighter tolerances. The cars were built to run strait 30 non detergent. Not only does today oil have detergents it’s a lot more consistent in quality as is the gas we use. I add ATF usually old type f as it has less tec additives but is also a good detergent to help hopefully break the sludge down slowly so it can be removed over time with oil changes. Looking to maybe put a filter on it but from what I read would only filter about 80% at a time. But that would be better than 0 % now. But good hot on time oil changes are important. Again when first got the cars at cold start it would hold 17 to 20 on gauge and not rise maybe 2 psi if you drove before warming up with about 12 psi at 45 mph and 3 to 5 at idle. The warm engine numbers are good only at cold start up do i feel I’m got a problem.Something has change in the engine somewhere as I’m doing the same as I always have. Thanks for suggestions and opinion. If I do figure it out I will let all know.

@kevin-ray 

Your cars, your call.

But you should be aware of a few things.

First, clearance and tolerance are 2 very different things... and in old Chevs clearances were SMALLER than new engines, especially main and connecting rod clearances.

Rods were fit so tight that it took a light tap with a small hammer to move the rod side to side on the journal, that giving .001" as being the maximum acceptable clearance.

Main bearings were fit only slightly looser, adding 1 shim on 1 side at a time until any drag was just eliminated, giving about .001" to .0015'' clearance.

I don't think many new engines are being manufactured any tighter than that.

Second, 0W only means an oil doesn't thicken as much when cold, which is a very good thing for start up lubrication, it says nothing about the viscosity when hot.

Also, the oil filters added to old Chevs filter a LOT less than 80% of the oil per pass.  It's more in the order of 10% or less. But of course eventually almost all of the oil will be part of that 10%.

Type F oil will be considerably lower in viscosity than a 10W-40.  Closer to a 5W-20 actually.

And it contains lots of additives, including friction modifiers to increase the friction between the clutch plates in old Ford automatics so they wouldn't slip.

I suspect that the reason ATF gained it's heroic reputation in the first place was because it contained additives such as esters that slightly swell neoprene seals and maintain their pliability, keeping them from leaking, which is of course very necessary in automatic transmissions.

However, modern synthetic engine oils already have that covered.

Anyway, I wish you good luck.

Old Chevs are a joy to own and drive.  🙂

Posted by: @kevin-ray

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@ole-olson I personally would not use 0w oil in any older engine. Older engines I believe have bigger tolerances a need the heavier oils were new engines run tighter tolerances. The cars were built to run strait 30 non detergent.

You have been given bad information. I don't have access to the '32 manual but I'm linking the '34 which will be the same. You should read the linked page and the next. You can go UP TO 30 weight if the air temperature is 90F or higher. Summer weight has a recommended max of 20 weight and that needs to be thinned when the temperature starts to lower. My 38 had the same spec. I ran full synthetic 10w30 in my 38 without issue. I've not tried 0 weight oil personally but I trust Ole's knowledge. These old low pressure splash & squirt engines depended on flow over pressure. Thick oil does that poorly.

<READ ME PLEASE>

@ole-olson Ole and others, In my years in the Old Chevy hobby, I have run into 3 people who were proponents of 10w oil. One was my uncle Will. He was born around 1917. The other two guys would have been of a similar age. All of them lived in Missouri and Illinois, where winters are cold a summers are hot.

These guys grew up using Chevys to make a living and all of them sang the praises of 10w oil for year round use in Chevrolets.

As a side note, I have a 1926 T Model Ford which, to my knowledge, has had only 10w oil used in it since new. It is one of the quietest and smooth running engines you can find.

I would be using more 10w if it was easier to get and if I could find a detergent version.

Mike

Good reading of the 1934 Chevy manual Tiny. Thanks. Pertains to all universally.

ok I went back and reread my manual and notes. 4 years ago on the old board some had said after cleaning out engine 10w- 30 would be fine. I guess because I have drove  it more in the winter then before even in temps of low 20s I guess that’s been my issue. Went and put 5w-20 on both cars. On start up around 15 psi. After warm up take off around 18 . When motor u p to temp10 psi at 30 mph and 12 at 45mph about same on both cars. I’m happy And can live the these numbers. I plan on running the 5w-20 conventional oil , unless unavailable the I will run 5w-20 semi-synthetic. Thanks for all the advice and patience. If anyone ever near Evansville, Indiana, I’ll buy lunch. Also check out this car show in my town Evansville Indiana. Thanks again to all.

@kevin-ray 

Very glad to hear your cars are fine.  👍  🙂

And thanks very much for coming back and giving us an update!

We are sometimes left to wonder how things work out for people, so it's nice to hear that 2 beautiful old Chevrolets are running strong.