Recommended engine oil 1935 Straight 8

TerriblePain

Hello,
I know guys are recommending diesel engine oil in some old cars since it supposed still retains some of the good additives.
What is recommended for a 1935 straight 8?
Thanks

D7fever

Guess it is what you decide.  I put Mobil Delvac 1300 in my '36 straight 8, AFTER I cleaned out the oil pan. There was about 2 inches of sludge in the bottom.  I would clean the oil pan before I out any detergent oil in it.

tigermoth

Good idea to pull the pan periodically in any case. 

You may know this, but if not, there are no “detergents” or cleaning agents of ANY type in detergent oils. Detergent oils have additives that help keep by-products of combustion in suspension to be carried with the oil to be removed by your oil filter. There is no scrubbing action or anything that will loosen sludge build up in an engine.

do use a multi viscosity oil.

regards, Tom

TerriblePain

Great thanks.  I will use some of my diesel oil.
I suppose cleaning the pan would help cool the oil a little bit too.
What is the capacity of the straight 8?

37 CTS

The Zinc has been removed from Diesel oil, the additive package is not suitable for gasolene engines.   Use either classic car oil with ZDDP or modern oils and add a bottle of ZDDP to it. Rislone also makes ZDDP additive.  If the pan has not been down, clean it out first.  10 W 30 weight.   I have good results in many years.

Geoff

If you get 100 replies to this, you will get 100 different opinions!  I have used multigrade oil for at least 60 years in my 1928 Essex, which has exactly the same lubrication system as your Hudson 8.  You will benefit from a zinc-added oil, as the most prone-to-wear components in your engine are the cams and lifters. 

lostmind

If you drop the pan , be sure to fill the dipper tray BEFORE you reinstall the pan.

tigermoth

you can also fill the dippers buy pouring oil in area of the tappers with the side covers removed. 

Regards, Tom

tigermoth

Regarding ZDDP, oils did not contain ZDDP when these engines were developed and in service in the 1930’s. all modern gasoline oils have it. The level was just reduced a few years ago to make the oil more compatible with catalytic converters. 

 I am not sure how ZDDP is added into the oils when they are formulated so I am not sure of the efficacy of a bottle poured in by a consumer. The only readily available information is provided by manufacturer of the after market product. Which makes me a bit suspicious. 

 In period literature there is no discussion of excessive premature valve train failures with our engines and this was during a time when ZDDP had not even been invented. 

 To me it has a little bit of  “snake oil” aura surrounding it. The proof that it works is a bit like an elephant repellent in Illinois.. “since I started using it I have not had one elephant in my yard.”

I’ve only been a licensed mechanic for 48 yrs. I will probably get smarter in the next 48. 

 It is your car and your engine. Mostly just drive them and enjoy them. 

Regards, Tom

Geoff

I have seen extreme cam and lifter wear in these engines, probably due to the inferior oils they had back in the day.   Don't skimp on cheap oil. 

terraplane8

tigermoth said:

Regarding ZDDP, oils did not contain ZDDP when these engines were developed and in service in the 1930’s. all modern gasoline oils have it. The level was just reduced a few years ago to make the oil more compatible with catalytic converters. 

 I am not sure how ZDDP is added into the oils when they are formulated so I am not sure of the efficacy of a bottle poured in by a consumer. The only readily available information is provided by manufacturer of the after market product. Which makes me a bit suspicious. 

 In period literature there is no discussion of excessive premature valve train failures with our engines and this was during a time when ZDDP had not even been invented. 

 To me it has a little bit of  “snake oil” aura surrounding it. The proof that it works is a bit like an elephant repellent in Illinois.. “since I started using it I have not had one elephant in my yard.”

I’ve only been a licensed mechanic for 48 yrs. I will probably get smarter in the next 48. 

 It is your car and your engine. Mostly just drive them and enjoy them. 

Regards, Tom

Interesting question, but I know my own 212 had very extreme cam and follower wear with deep troughs cut in the followers by the cam! This car had done some 138,000 miles very likely on the original cam train. It may have been that when the cars were new the service life wasn't very long so that the cars after say five years and 50,000 miles their value had dropped so low that they weren't worth a major repair to the engine if they still went ok. I remember reading that a reason why the Terraplane had such a skimpy gearbox was that the design life of the cars was only a few years (4?) so that there was no reason to over-design it for a long life that wasn't required.

The mists of time have closed in, we may never know what they were thinking back in the '30's with this awful cam-train wear. Notwithstanding that, using ZDDP seems like a very good idea, although the counterpoint is that probably most owners do low mileages these days so they will expire long before their car's cam-train does!

BigSky

Some good information at this link, especially post #11…

https://www.corvetteforum.com/forums/c3-tech-performance/3402561-vette-magazine-all-about-oil-article-march-2014-a.html

tigermoth

From the above article regarding their test results:

  “Most major Oil Companies say to NEVER add anything to their oils, because adding anything will upset the carefully balanced additive package, and ruin the oil’s chemical composition. And that is precisely what we see here. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. ”

Regards, Tom

terraplane8

BigSky said:

Some good information at this link, especially post #11…

https://www.corvetteforum.com/forums/c3-tech-performance/3402561-vette-magazine-all-about-oil-article-march-2014-a.html

If you go to this guy's blog linked from there, he has tested hundreds of oils and says the whole anti-wear zinc thing is overstated, as some oils with low zinc offer far better wear protection than high zinc oils. He seems to focus on tappet wear which of course is what also concerns us. I had a look for what I use which is basic Castrol GTX 20W50 and that seems ok, ie a mid-field result with plenty far worse. I'll be having a closer look at this for my modern cars too and look for the best which is either a particular Quaker State or Amsoil one according to his test results.

tigermoth

same conclusion reached by a well footnoted article in “Skinned Knuckles” mechanical journal several years ago…ZDDP additives essentially snake oil. 

Regards, Tom

Hans

1928 Essex had roller lifters.  Aprox. 1 inch diameter.

1935 Hud and Terr had aprox 3 inch radius shoe lifters

Much different contact surfaces, roller vs sliding.

My observations of cam lifter wear is from1927 to 1937 and somewhat limited but, I am left with the general impression that more wear was seen on the later lifter faces. The change from aprox 3 in. radius to aprox. 5 in. radius shoe faces.  Of course, miles of use may have contributed to more wear when road conditions improved.

/////////////////////

Roller surfaces on several high mileage engines seemed to be corrosion/erosion from acidic residue on long term storage. My observations.

Of course early engine ( chain driven cams ) rotated in oppositt direction than later Gear driven cams.  Not implying direction of rotation affected wear.

Geoff

Wear on early cam  roller followers was mainly on the roller pins.  Also the pins tended to come loose on the lifter body , causing it to rotate therein, and rattle in the process. If you have adjusted the  tappet and the pin starts to move around in the lifter, it is of course eccentric because it is worn on  the  bottom only, hence the  tappet will close up as the pin moves around.   The pins can only be replaced  by hardened stock, anything else, (like a sawn off valve stem)", will rapidly wear.   The solid lifters were quiet until they started to wear, and then  got progressively worse as the cam wore as well.   Just a few observations of my own experience over 66 years of driving these cars.