1970 Monte Carlo oil recommendation

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wtd

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I have a 70 Monte Carlo with a 396 big block in it. I've been reading about how the newer SM and SN oils don't have enough Zinc in them to protect the cam on a flat tappet engine. This engine is pretty much stock except for it being bored out .60 Cam is stock.

I'm currently running 10W-40 Havoline conventional in it. I've tried a 10W-30 in it but the engine doesn't seem to like it and oil pressure is not where I want it. Engine probably only has 15,000 miles on the rebuild.

So what oil should I run in this engine? No synthetic recommendations please. I also want to stick to a 40 weight.

Are there any additives that you would recommend instead that can be added to the oil to add some Zinc back into it.? Thanks for any information.

Wayne
 
Rotella T6 or T5. Also MTD or John Deere lawn tractor oil is formulated with high addp. Also 4T Conventional Motorcycle oil is high zddp and is probably the most cost effective. The Motorcycle picture on the bottle doesnt mean anythig the oil typ meets API-SH/SJ automotive standards. You cam is broken in and doesnt need killer amts of zddp - a moly additive migh be beneficial.
 
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Run any of the big three diesel oils (Chevron Delo, Rotella T, or Mobil Delvac). You can always buy some break in additive as offered by Redline, Comp Cams, or Lucas as well.

If you want another route, you can use Brad Penn Oil or Valvoline VR1 oils. Kendall GT1 in 20w50 is the only Kendall GT1 with boosted levels of zinc so you can use that one as well. Kendall GT1 locally here is about 3 bucks to 3.50 a quart. Between Kendall and Valvoline VR1 you should be able to get one or both at most parts stores easily.
 
And honestly, I would dump that current fill ASAP. Big Block Chevy motors have a 1:7 ratio and I would not trust an oil with low levels of ZDDP in them in any BBC engine, let alone a pre smogger era one. It would have to be loaded with moly or titanium, and even then I would be leery. My cousin has a 427 powered 67 Chevelle and his has a stock cam. No problems and he beats the tar out of that thing.
 
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Buy some oil meant for diesel engines - Rotella, Delvac, Delo, etc. They'll all do you well. 15w-40 would probably be fine as a summer fill for you; many of those same oils come in 10w-30 as well.

Or you could just use Rotella T6 year round if you're willing to spend a little more.
 
For your car I'd say that you should at least go with a 15-40 diesel oil. I've got a '73 Caddy and after ten years of running nothing but Mobil 1 15-50 I played around the Valvoline VR-1 and Pennzoil but I'm now running Rotella T6 5-40.

I know you said you didn't want to run a synthetic but have to say. There is absolutely NOTHING as good as Mobil 1 15-50 for an old V-8 short of the "boutique" oils if you live in the right climate and you do. It's got plenty of ZDDP. The only reason I don't use it anymore is because of the frigid temps where I live.

If you really want to stick with dino then the diesel oils or a boutique oil are your only option. You could get away with a 15-40 year around where you live as long as you don't drive the car all the time when it gets down below 30 and/or make sure you warm it up before you drive off.

Even at that, I know a guy that lives in Canada of all places and uses nothing but 15-40 diesel oil in ALL of his cars and they are NOT garaged. He's a mechanic and has never had a problem.
 
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Originally Posted By: Robenstein
And honestly, I would dump that current fill ASAP. Big Block Chevy motors have a 1:7 ratio and I would not trust an oil with low levels of ZDDP in them in any BBC engine, let alone a pre smogger era one. It would have to be loaded with moly or titanium, and even then I would be leery. My cousin has a 427 powered 67 Chevelle and his has a stock cam. No problems and he beats the tar out of that thing.



+1 on getting that garbage out of the engine ASAP.
 
Well, luckily I've only driven the car about 500 miles in the last 2 1/2 years so not much damage should have been done. I will probably try a 15W-40 diesel oil because I don't drive it all of the time but want to start driving it more than I do. What about a 5W-40 diesel oil?

Thanks for the ideas. I plan on changing it tomorrow.

Wayne
 
Like others have said, any 15W-40 HDEO you can get easily, and at a good price, will be perfect.

Nice car!
 
You can get a really good deal on diesel if you buy it in the 5 gallon buckets. Look up a Chevron, Shell, or Mobil oil distributor in your area. Sometimes you can get a good deal from them. Or any of your farm stores will usually have a good selection.

I know I can buy Mobil Delvac 1300 for 52 bucks for a 5 gallon jug at my local farm store, or 2 gallon jugs of Mystik Syn Blend in 10w30, 10w40, 15w40, or 15w50 for 21 bucks.
 
You'll loose power with the cheap 15w-40 diesel oil and you dont want or need the soot dispersant. The Havoline was fine if not ultimate - good moly content. I would still highly recommend 4T motorcycle oil. If you are afraid of buying buike oil then you bettrer leave BITOG and go back to Lubricant's 101 to revisit the motor oil primer. You guys are off base recommending diesel oil over superbike motorcycle oil or Lawen tractor oil. Very silly boys. Ive built a few nice torquey 402 and 427 in the '70's - not that 454 externally balanced junk
smile.gif
 
From every thing I've been reading, the diesel oils have had the zinc lowered in them as well. What I've decided to do in the meantime since I can't seem to find any of the specialty oils locally, is go with Valvoline 10W-40 and add Lucas Zinc-Plus to the oil. That should be good in the meantime.

Wayne
 
I didnt know lucas was selling that stuff OTC. Not that I would want to support Lucas ... Whats the PPM ZDDP in the stuff any VOA here? I recommend you stay under 1200-1500ppm phos to prevent chunking.
 
I read that the zinc content in one bottle is 5400ppm but I don't know for sure. I plan on checking at the John Deere dealership and see if they have anything in 10W-40.

If the 4T motorcycle oil you are referring to is made by Mobil, than thats a no go for me. I won't run Mobil anything in my vehicles anymore. Thanks for the input.

Wayne
 
Originally Posted By: ARCOgraphite
I didnt know lucas was selling that stuff OTC. Not that I would want to support Lucas ... Whats the PPM ZDDP in the stuff any VOA here? I recommend you stay under 1200-1500ppm phos to prevent chunking.

About 38,000 ppm according to an email from their tech department. I only use an ounce per oil change.
 
All you need to know, in my opinion:

Conventional- Rotella 15w40

Synthetic- Rotella T6 5w40

Blend - Rotella T5 10w30

All have strong anti-wear additive levels like oils did back when your car was new, but in much better and longer lasting base oils. That is hard to find in modern passenger car oils.... the diesel rated oils are still allowed to have the additives that were taken out of most gasoline rated oils some years ago over minor environmental issues.

I'd try the T5 10w30 first and see how it goes. That weight is probably what was run in most of those engines in the 1970s. If leaks are a problem, you could always try the 15w40. 40 weight oils were common in passenger cars back then, too. If cold weather starting is an issue, there's the T6 5w40. All can be picked up in jugs at decent prices from Walmart shelves everywhere I've ever looked for them.
 
Amsoil has products for your car that are better than the 'good ole daze'!!

AMSOIL Z-ROD™ Synthetic Motor Oil is specially engineered for classic and high-performance vehicles. It features a high-zinc formulation to prevent wear on flat-tappet camshafts and other critical engine components, along with a proprietary blend of rust and corrosion inhibitors for added protection during long-term storage. Z-ROD Synthetic Motor Oil is designed to perform on the street and protect during storage.
 
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