As just about everyone has said you need the zinc to be 1000+ ppm. In the 1000-1500 range. Since your engine is original and not rebuilt you should use conventional oil. Common wisdom is that synthetics will leak so why take a chance? They may or they may not. Today's conventional oils are miles better than the 1960's oil. For weight I would ask the former owner and check the service manual or owners manual for a start. For my rebuilt engines I use what the rebuilders have said. They are pretty consistent in the recommendations: PennGrade 1 (formerly Brad Penn), Joe Gibbs Hot Rod Oil, Valvoline VR1. For original engines I use Rotella T4 conventional in the recommenced weight. Why?For the cleaning power of the diesel motor oil. These cars have had a variety of owners and a variety of service, so I'd like to get them clean and keep them clean.
Best oil for 1968 Z28?
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I had a 69 Z28 back in the early 70s.
It ran fine on Valvoline 20W50.
Sometimes it was a bit hard starting at -20F in Michigan, but never failed me, recall needing a jump a couple times.
It ran fine on Valvoline 20W50.
Sometimes it was a bit hard starting at -20F in Michigan, but never failed me, recall needing a jump a couple times.
The suggestion of. 0w40 is a solid suggestion, but on an engine with an existing oil leak? 0/40 will fly right out of that engine in short order.
The level of ZDDP with a flat tappet cam is dependent upon the spring force (spring peak force x rocker ratio) and lobe intensity. On a factory or very mild cam with mild springs under 300 psi peak, running 800 ppm zinc will be sufficient. I didn't notice a single difference in wear metal switching my '66 Mustang 289 from Valvoline MaxLife to Amsoil Z-Rod. I still kept using the Z-Rod because of peace of mind and because it sat for long periods of time. RPM plays a factor as well as valvetrain jerk and inertia starts pounding the lifters at high rpm.
If the cam is stock or stock replacement, I'd just use something like Pennzoil High Mileage 10w-40 conventional, and not worry about it. In my experience with rear main seal leaks, the only fix is to replace it. I tried HM oil, thicker oil, conventional, synthetic, boutique, additives, etc... and nothing slowed the leak. I finally just pulled the engine and replaced it, along with rebuilding the rest of the engine.
If the cam is stock or stock replacement, I'd just use something like Pennzoil High Mileage 10w-40 conventional, and not worry about it. In my experience with rear main seal leaks, the only fix is to replace it. I tried HM oil, thicker oil, conventional, synthetic, boutique, additives, etc... and nothing slowed the leak. I finally just pulled the engine and replaced it, along with rebuilding the rest of the engine.
That engine was built back in the day when Mult-Grade oils were just being figured out. Any owners manual for that engine will specify straight SAE 30 HD and a few multi's.
The issue with all conventional multi-grades is they start with the W rating oil and add Viscosity Index Improvers (VII's) to get to the higher number (like XW-30), so as they shear down, they become 20's, etc. VII's are not oil. They are form of plastic. They carry oil in the chain structure, but they are not oil. SAE XX HD is all oil and is good for old seals and gaskets, plus it does really well for engines that sit a lot between start-ups.
And any real synthetic will not be terribly friendly to the old dried out and hard cork gaskets used back then. So you MAY get a few more leaks and weeps ...
So, gotta ask the questions. How do you intend to operate this engine. Only mild days and cruising? Or full time all seasons including cold snowy winters? Trips to the drag strip? How many miles on the engine? Any rough running, knocks, ticks, etc?
If it's a mild weather cruiser - SAE 30 HD in your favorite brand. If trips to the drag strip and mild weather SAE 40 HD. If year round including cold weather, prolly a 15W-40 HDEO like Chevron Delo 400 LE.
If it's a true 1968 engine, prolly a 327, I'd be taking it sort of easy on it. You don't know what condition the timing chain is in ... If it's the OEM unit, it's almost guaranteed that it's stretched and crusty, almost running dry and not happy ...
The way to make these engines (all SBC's) really happy is to replace the timing chain and the sprockets with a good solid unit from a reputable source. You can do a timing chain w/o dropping the pan. It does not need to be a roller chain, but that would not hurt. While you are in there, you drill the lifter gallery end plugs 0.030" and let them dribble oil on the cam sprocket continuously. The chain stays wet, and all is good.
If you are struggling with oil pressure, only drill one side. New timing cover gaskets, new front seal, and it's all good. Once you have a new chain, the timing will be much better, so the engine will act more like the original. Then you can decide if you want to start chasing other leaks, weeps, the RMS, etc.
The issue with all conventional multi-grades is they start with the W rating oil and add Viscosity Index Improvers (VII's) to get to the higher number (like XW-30), so as they shear down, they become 20's, etc. VII's are not oil. They are form of plastic. They carry oil in the chain structure, but they are not oil. SAE XX HD is all oil and is good for old seals and gaskets, plus it does really well for engines that sit a lot between start-ups.
And any real synthetic will not be terribly friendly to the old dried out and hard cork gaskets used back then. So you MAY get a few more leaks and weeps ...
So, gotta ask the questions. How do you intend to operate this engine. Only mild days and cruising? Or full time all seasons including cold snowy winters? Trips to the drag strip? How many miles on the engine? Any rough running, knocks, ticks, etc?
If it's a mild weather cruiser - SAE 30 HD in your favorite brand. If trips to the drag strip and mild weather SAE 40 HD. If year round including cold weather, prolly a 15W-40 HDEO like Chevron Delo 400 LE.
If it's a true 1968 engine, prolly a 327, I'd be taking it sort of easy on it. You don't know what condition the timing chain is in ... If it's the OEM unit, it's almost guaranteed that it's stretched and crusty, almost running dry and not happy ...
The way to make these engines (all SBC's) really happy is to replace the timing chain and the sprockets with a good solid unit from a reputable source. You can do a timing chain w/o dropping the pan. It does not need to be a roller chain, but that would not hurt. While you are in there, you drill the lifter gallery end plugs 0.030" and let them dribble oil on the cam sprocket continuously. The chain stays wet, and all is good.
If you are struggling with oil pressure, only drill one side. New timing cover gaskets, new front seal, and it's all good. Once you have a new chain, the timing will be much better, so the engine will act more like the original. Then you can decide if you want to start chasing other leaks, weeps, the RMS, etc.
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My dad runs 10w-30 conventional in his 60's 327. He probably puts 1-2k per summer on it. Changes oil once a year. In storage all winter (not sure if he changes oil before or after storage). He's been doing this for 20 years, no issues so far...
I'd run a high ZDDP HDEO 5W40 and tweak it if needed with RL break in oil additive, or Rislone's ZDDP additive, to get the ZDDP in the 1,400 ppm range,
Originally Posted by Sunnyinhollister
Originally Posted by 69Torino
Originally Posted by elpcmaster
You are gonna want to use an oil with zinc to protect that cam. I suggest either Valvoline VR1, Amsoil Z-Rod, Royal Purple HPS,or Redline. All in 10w30.
Change your oil every 3K or once a year, whichever comes first. BTW 10w50 is too heavy. Don't buy into that thick oil stuff. 50w oil is okay for a 454. And stay away from Lucas HotRod. It contains way too much zinc and that can do more damage than good.
Good advice. I second this. And other posters are correct, HM oil will not help a two piece rope rear main seal.
There's also Brad Penn oil and Joe Gibbs Driven oil.
My machinist and cam maker (Lunati) both recommended Driven to me. The local sunoco race fuel dealer has it on the shelf.
Originally Posted by 69Torino
Originally Posted by elpcmaster
You are gonna want to use an oil with zinc to protect that cam. I suggest either Valvoline VR1, Amsoil Z-Rod, Royal Purple HPS,or Redline. All in 10w30.
Change your oil every 3K or once a year, whichever comes first. BTW 10w50 is too heavy. Don't buy into that thick oil stuff. 50w oil is okay for a 454. And stay away from Lucas HotRod. It contains way too much zinc and that can do more damage than good.
Good advice. I second this. And other posters are correct, HM oil will not help a two piece rope rear main seal.
There's also Brad Penn oil and Joe Gibbs Driven oil.
My machinist and cam maker (Lunati) both recommended Driven to me. The local sunoco race fuel dealer has it on the shelf.
Originally Posted by CrAlt
Originally Posted by Sunnyinhollister
Originally Posted by 69Torino
Originally Posted by elpcmaster
You are gonna want to use an oil with zinc to protect that cam. I suggest either Valvoline VR1, Amsoil Z-Rod, Royal Purple HPS,or Redline. All in 10w30.
Change your oil every 3K or once a year, whichever comes first. BTW 10w50 is too heavy. Don't buy into that thick oil stuff. 50w oil is okay for a 454. And stay away from Lucas HotRod. It contains way too much zinc and that can do more damage than good.
Good advice. I second this. And other posters are correct, HM oil will not help a two piece rope rear main seal.
There's also Brad Penn oil and Joe Gibbs Driven oil.
My machinist and cam maker (Lunati) both recommended Driven to me. The local sunoco race fuel dealer has it on the shelf.
I really like Driven oil. It's a stouter version of Red Line at a cheaper price.
Originally Posted by Sunnyinhollister
Originally Posted by 69Torino
Originally Posted by elpcmaster
You are gonna want to use an oil with zinc to protect that cam. I suggest either Valvoline VR1, Amsoil Z-Rod, Royal Purple HPS,or Redline. All in 10w30.
Change your oil every 3K or once a year, whichever comes first. BTW 10w50 is too heavy. Don't buy into that thick oil stuff. 50w oil is okay for a 454. And stay away from Lucas HotRod. It contains way too much zinc and that can do more damage than good.
Good advice. I second this. And other posters are correct, HM oil will not help a two piece rope rear main seal.
There's also Brad Penn oil and Joe Gibbs Driven oil.
My machinist and cam maker (Lunati) both recommended Driven to me. The local sunoco race fuel dealer has it on the shelf.
I really like Driven oil. It's a stouter version of Red Line at a cheaper price.
Just picked up some Valvoline VR1 10w30 for my 355. It has a big cam and head work. The 10w30 version is hard to find. So I ended up only being able to find 4 qts. So I bought 20w50 for the last qt, figured it wouldn't hurt anything.
Originally Posted by WiskyBadger
Just picked up some Valvoline VR1 10w30 for my 355. It has a big cam and head work. The 10w30 version is hard to find. So I ended up only being able to find 4 qts. So I bought 20w50 for the last qt, figured it wouldn't hurt anything.
I've noticed the 10w-30 version is tougher to find too. You can get the 20w-50 almost anywhere. Wonder why that is. 10w-30 is my choice for hot street and bracket race engines, oil pressure permitting. Mostly Fords for the last 20 or so years.
Just picked up some Valvoline VR1 10w30 for my 355. It has a big cam and head work. The 10w30 version is hard to find. So I ended up only being able to find 4 qts. So I bought 20w50 for the last qt, figured it wouldn't hurt anything.
I've noticed the 10w-30 version is tougher to find too. You can get the 20w-50 almost anywhere. Wonder why that is. 10w-30 is my choice for hot street and bracket race engines, oil pressure permitting. Mostly Fords for the last 20 or so years.
Originally Posted by 69Torino
Originally Posted by WiskyBadger
Just picked up some Valvoline VR1 10w30 for my 355. It has a big cam and head work. The 10w30 version is hard to find. So I ended up only being able to find 4 qts. So I bought 20w50 for the last qt, figured it wouldn't hurt anything.
I've noticed the 10w-30 version is tougher to find too. You can get the 20w-50 almost anywhere. Wonder why that is. 10w-30 is my choice for hot street and bracket race engines, oil pressure permitting. Mostly Fords for the last 20 or so years.
Yea, I found endless amounts of 20w50 and a bunch of straight 50.
Originally Posted by WiskyBadger
Just picked up some Valvoline VR1 10w30 for my 355. It has a big cam and head work. The 10w30 version is hard to find. So I ended up only being able to find 4 qts. So I bought 20w50 for the last qt, figured it wouldn't hurt anything.
I've noticed the 10w-30 version is tougher to find too. You can get the 20w-50 almost anywhere. Wonder why that is. 10w-30 is my choice for hot street and bracket race engines, oil pressure permitting. Mostly Fords for the last 20 or so years.
Yea, I found endless amounts of 20w50 and a bunch of straight 50.
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