My 235 was rebuilt by a race mechanic. It's bored 30 over and has a mild cam in it. The builder told me to use 40W oil, but that's getting harder and harder to find. Have any of you Stovebolters used synthetics in your old engines? Is there any reason not to?

I use Mobil One 10-30. It being available at Costco or Wal Mart is nice.

No problems with leaking or burning oil?

Paul;

Why not just use 10w-40?

SimS

I've been using 40W, but my truck sits for long periods of time. Last year my wife got sick, and the truck didn't even get inspected or licensed. Today was the first time it ran in over 18 months. Natural oils have a tendency to drain off of critical bearing surfaces over time. Synthetics tend to stay on the parts. Thus the question. I know at one time synthetics were not recommended for older engines, because they tended to cause leakage around old seals. The more modern versions don't seem to have that problem, but I'm looking for Stovebolters who have actual experience using it.

Paul, I use VR-1 30 weight. I'm not a fan of using synthetics in engines which were not designed for synthetics for a variety of reasons. The big thing (to me) in oil today is the absence of zinc and VR-1 still has as much as Valvoline can get away with using...along with other higher priced and more hyped and advertised options, of course. You may hear lots of differing opinions regarding synthetic oil. You can find lots of information regarding this online, but there's also a lot of misinformation. I'd suggest researching the effects of the lack of zinc first. Not to say that's a big deal with the 235, but it is nevertheless a consideration.

I don't think synthetics are verboten in older engines. They just weren't readily available when stovebolts were new.
As far as synthetics staying on parts better than dino oil, that's not really a concern. The clearances and actual viscosity will keep oil in the bearings by capillary action. In fact a light viscosity synthetic will drain off quicker than a heavier dino oil. If you're worried about oil draining out of the bearings, throw some STP oil treatment in it. Actually I'm not sure that's even available anymore.
I'd go with 10W40 like SimS suggested. Synthetic is just too expensive to really be worth it.

Straight 40 has the viscosity of asphalt when the engine is dead cold.
I'd use 10W40 to increase cranking speed and get pressure to all the bearings quicker.

BradPenn (now called Penn Grade 1) 10W30 in all of my 235 and 261 rebuilds. Excellent cling, good flow through the bearings (so good for the oil cushion) and a decent zinc package. its a semi synthetic, so dino base and a synthetic additive package. I am pretty aggressive with my 6 motors, nary an problem with the BradPenn.

Thanks, Mike

Not that I know as much as Dragsix, but, ditto on the Brad Penn. That is what the rebuilder used in my 54 3104 Hydra-Matic's 235. I will continue to use it - if I ever get that truck painted, so that I can drive it again (after about 10 years).

However, I will continue to use Rotella T4 (15-40, I think) in the 1960 261 (that I rebuilt back in 1972) that is in my 1954 Suburban.

Paul, FWIW I use 15-40 in my '53 and '38. Available everywhere.

I'm running 5w-30 full synthetic Valvoline in my 283, still has the rope rear main seal with no leaks, no smoke, no lifter noise, 35psi hot wound out. 1957 shop manual calls for 10w-30 for the major temperature range.

Thanks for all the suggestions. The Brad Penn only comes in cases and is pretty pricey. Valvoline VR1 20w-50w Racing Oil is fairly decently priced and seems like a good choice to me.

If VR1 is priced right, use it. Its not priced fair up here in PA. 15w40 diesel oil has a good amout of zinc and is available almost anywhere up here for $12-14 gallon. Thats what i use in my tow truck, etc. So it only makes sense to me. Not to mention, ive asked about oil previously on here and 15w40 was highly recommended by many, to put in about anything.

Wow. Even with shipping, I paid less than $8 a quart for VR1.

Cant be had up here for less than $8 plus tax. And thats if your lucky..$32 compared to $12 a gallon. Big difference..

I am blushing, lol. I don’t know that much but I am happy to spread what I do know around. Nothing better in life then being helpful!

Bradpenn can be purchased in less then case quantities on eBay which is where I get mine from.

Hmmm. Im not really sure what a good price is for Brad Penn?.? But i just took a peek a fleabay and didnt seem to see any good deals.. At least for not much less than $9 a qt. Maybe thats a good price? Im not sure tho...

That price is a lot less than buying it from WalMart?

It ain't cheap (it is not low cost).

Back in 2000 when I bought a new 7.3 diesel, it takes 15 quarts of Rotella 15-40.
So I bought a 55 gallon drum of it.(On the second drum now) Sam's club has them. It is really handy living rural and not have to go to town to get oil.
Extra filters also.
I use it in everything except the two newer rides that require synthetic.
Mobile one is what I use in those.

And get this, The 2018 Tacoma oil change is every 10,000 miles.
Just did the 3rd change and the oil coming out still looked clean and not black.

Don

I generally change the oil about once a year in the old iron. 5 quarts (I do not run an oil filter on my bypass 261 motor), 6 quarts with a filter. So about 45-54 per oil change. Easy money compared to having to change out bearings or rebuild a motor so I can live with 9 per quart. Like I said, I am pretty hard on my motors but in the decade since I have been using the Bradpenn, no issues, and their breakin oil is excellent. I was sold on the stuff when I pulled the valve cover off spring time for the annual valve adjusting and saw that stuff had clinged to the rocker arms all winter during storage. So I stuck with it.

I also like Bradpenn oil, if you ever get around it, put some on your fingers and pull it apart. It' stringing and very hard to get off. It will still be hanging on the crank when you are ready to start it, no matter how long it sets.

As far as the Zinc amounts, your engine has very little valve spring pressure even when wide open, so any oil you choose will be good enough.

That's what STP oil treatment does, it's very stringy, and according to their info, contains ZDDP. I have actually used that at full strength in my Model A tranny. Wasn't very good when temps got down near freezing though. I nearly bent the shifter one morning trying to get it into gear.

Hmmm. I also have a model A. I was actually thinking of filling the trans with Lucas, considering it calls for 600w.

I am currently running during my break-in period Amsoil break-in straight 30W. SAE 30W

I'm going to switch to their Z-Rod 10W-30 after 500 miles. It is made for older, flat tappet cam engines. Z-Rod 10W-30 Synthetic

for you all using VR-1, if it is truly a racing oil, it won't have detergent in it,

I bought five quarts of it the other day. It says (on the bottle) "high performance formula for push-rod and flat tappet engines"
On the back of the bottle it says "High zinc/phosphorous for extreme anti-wear protection, including flat-tappet and performance cam applications"
"For use in classic and modern muscle cars, race cars, and high performance passenger cars"
"Friction modifiers help deliver maximum horsepower"
"Enhanced anti-foaming, even under high stress"
"Exceeds API Service SL"

SL is for automobile engines older than 2004.

The Valvoline FAQ says "....include fewer detergents than regular conventional motor oils"
https://www.valvoline.com/about-us/faq/racing-oil-faq
And "Valvoline VR1 racing oil is conventional, non-synthetic racing oil."