I have a Gen I Chevy Small Block 350 in my car and the previous owner was using NAPA NON-DETERGENT SAE 30 motor oil in the car. I have continued to use this oil since that is what has been in the engine prior to my ownership but I am curious what others use in this vintage motor?
Old Engine Motor Oil
- Thread starter VintageMonte
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If memory serves me correctly, General Motors started making the 350 V-8 in 1967 when detergent motor oil was already well known and well used. However, if the engine has been run with non-detergent motor oil for a long period of time, do not put detergent motor oil in it. (Seems to me we had this discussion not long ago here in Bitog land). A detergent oil will go to work cleaning the motor, (which is a good thing), but having used a non-detergent motor oil for so long, you will have quite a bit of gunk in your motor, (which is a bad thing). If that gunk starts breaking up, it can clog oil passages stopping oil flow to vital parts, (a really bad thing). If I were you, I would keep using the non-detergent motor oil till a rebuild is in order.
I'd definitely be using a detergent motor oil.
Quaker State Defy 5W-30 would be one choice.
Quaker State Defy 5W-30 would be one choice.
What year is your 350 and how long has it run non-detergent?
Originally Posted By: CATERHAM
I'd definitely be using a detergent motor oil.
Quaker State Defy 5W-30 would be one choice.
And you would definitely have a major problem.
I'd definitely be using a detergent motor oil.
Quaker State Defy 5W-30 would be one choice.
And you would definitely have a major problem.
The engine is a 1969. The car was used for drag racing for the last 15 years and I suspect that is how long the non-detergent oil has been used. That said it was trailered to the track and has had minimal miles put on it in that time.
I have been using non-detergent oil for the last three years. During my use I put 500 - 800 miles on the car per year between May and October. I always change the oil in October before I put the car in heated storage for the winter (I live in western PA). The oil pressure has always been at 40 psi. Thoughts?
I have been using non-detergent oil for the last three years. During my use I put 500 - 800 miles on the car per year between May and October. I always change the oil in October before I put the car in heated storage for the winter (I live in western PA). The oil pressure has always been at 40 psi. Thoughts?
I'd be more concerned about the entire additive package of this oil, not just the detergent. Most ND-30 oils are SA or SB rated which IMO don't have enough anti-wear additives.
I also agree that Defy would be a good choice, but maybe you could add it in increments per OCI. For example, next oil change use one qt. Defy with 4 qts ND30, for a 20% mixture. Next time go 2 qts Defy...etc.
I also agree that Defy would be a good choice, but maybe you could add it in increments per OCI. For example, next oil change use one qt. Defy with 4 qts ND30, for a 20% mixture. Next time go 2 qts Defy...etc.
Originally Posted By: GreeCguy
If that gunk starts breaking up, it can clog oil passages stopping oil flow to vital parts, (a really bad thing).
IMO I think there is little chance of that.
If there was a thread on this subject I'd like to see it.
If the OP is concerned he could pull a rocker cover to see what what build-up of sludge there is and go from there.
As a kid I new of many badly sludged up motors. The rocker covers and sump were removed in the worst cases and all visible sludge was removed. Engine was filled with oil and some kerosene. Run for a while then drained. Re-filled with fresh detergent oil and driven normally for a short OCI based on how quickly the oil got black then drained again.
If that gunk starts breaking up, it can clog oil passages stopping oil flow to vital parts, (a really bad thing).
IMO I think there is little chance of that.
If there was a thread on this subject I'd like to see it.
If the OP is concerned he could pull a rocker cover to see what what build-up of sludge there is and go from there.
As a kid I new of many badly sludged up motors. The rocker covers and sump were removed in the worst cases and all visible sludge was removed. Engine was filled with oil and some kerosene. Run for a while then drained. Re-filled with fresh detergent oil and driven normally for a short OCI based on how quickly the oil got black then drained again.
Pull the valve covers and have a look inside - I've seen 'em to where they looked like they were packed with black grease. If you're is clean, chances are the oil pan is clean as well and you can risk some regular detergent motor oil. If it's gunky, you can clean it out, but keep in mind there will be gunk throughout your motor. I had an old '58 235 straight six that ran 35-40 psi till the day it broke the timing gears. When we took the valve covers off, it looked like it had been pumped full of grease.
I'm not trying to sound arrogant here, but I too have seen some seriously sludged motors. Back it the day, a buddy of mine had a neglected 302 he thought he would "clean out" with an oil change and some diesel fuel. Drained the old oil, put in four quarts of new oil with a quart of diesel and ran it at idle for five minutes. Drained, replaced with new oil and new filter. Car ran literally for one week and threw a rod.
Originally Posted By: GreeCguy
Originally Posted By: CATERHAM
I'd definitely be using a detergent motor oil.
Quaker State Defy 5W-30 would be one choice.
And you would definitely have a major problem.
I really doubt that this engine has been run on ND 30 since new.
It would not likely still be running.
The OP should use any 10W-30 in it, maybe with a few short OCIs.
Originally Posted By: CATERHAM
I'd definitely be using a detergent motor oil.
Quaker State Defy 5W-30 would be one choice.
And you would definitely have a major problem.
I really doubt that this engine has been run on ND 30 since new.
It would not likely still be running.
The OP should use any 10W-30 in it, maybe with a few short OCIs.
I agree. Pull a cover (and post pics!). If it's clean, run a stout oil like Rotella T6 or T5.
If it's sludged, run incrementally larger concentrations of detergent oil mixed with the ND you've been using.
If it's sludged, run incrementally larger concentrations of detergent oil mixed with the ND you've been using.
I have personal experience here. I bought a 1965 Mustang w/289 around 1970 I would guess. I was 17. Immediately changed the oil and started the engine. The new detergent oil caused the sludge to loosen and jam the oil pump. The oil pump was driven by a steel shaft shaped like an unsharpened pencil going up the the dist. which was cam driven. This steel shaft sheared in half.
I would suggest dropping the pan and pulling a valve cover. I believe the solution is to use non-detergent oil but adding a cup of oil, then wait, then a 2nd cup. Pull the filter and cut it open. Maybe 100 miles between adding more detergent oil.
I believe we found sludge inside the oil pump.
This was 43 years ago, so its from memory.
On the plus side I pulled the engine and rebuilt the engine myself (machine shop did boring and crankshaft) and learned a lot.
I would suggest dropping the pan and pulling a valve cover. I believe the solution is to use non-detergent oil but adding a cup of oil, then wait, then a 2nd cup. Pull the filter and cut it open. Maybe 100 miles between adding more detergent oil.
I believe we found sludge inside the oil pump.
This was 43 years ago, so its from memory.
On the plus side I pulled the engine and rebuilt the engine myself (machine shop did boring and crankshaft) and learned a lot.
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As I said, pulling a rocker cover will tell what needs to be done.
If it's just a film of black liquid sludge he'll be fine.
I very much doubt it's a bad case of thick solid sludge since the OP appears to be able to drain the oil normally.
I'm old enough to remember cases so bad that the oil wouldn't drain out of the sump.
If it's just a film of black liquid sludge he'll be fine.
I very much doubt it's a bad case of thick solid sludge since the OP appears to be able to drain the oil normally.
I'm old enough to remember cases so bad that the oil wouldn't drain out of the sump.
Originally Posted By: VintageMonte
The engine is a 1969. The car was used for drag racing for the last 15 years and I suspect that is how long the non-detergent oil has been used. That said it was trailered to the track and has had minimal miles put on it in that time.
I have been using non-detergent oil for the last three years. During my use I put 500 - 800 miles on the car per year between May and October. I always change the oil in October before I put the car in heated storage for the winter (I live in western PA). The oil pressure has always been at 40 psi. Thoughts?
By the owners estimation that car has 1500-2400 miles plus 15 years of drag racing only (couple thousand miles maybe?) on it with non detergent oil. You guys really think the engine would get sludged up that quickly? My guess is the oil was changed enough times in the past 18 years that it is spotless inside.
The engine is a 1969. The car was used for drag racing for the last 15 years and I suspect that is how long the non-detergent oil has been used. That said it was trailered to the track and has had minimal miles put on it in that time.
I have been using non-detergent oil for the last three years. During my use I put 500 - 800 miles on the car per year between May and October. I always change the oil in October before I put the car in heated storage for the winter (I live in western PA). The oil pressure has always been at 40 psi. Thoughts?
By the owners estimation that car has 1500-2400 miles plus 15 years of drag racing only (couple thousand miles maybe?) on it with non detergent oil. You guys really think the engine would get sludged up that quickly? My guess is the oil was changed enough times in the past 18 years that it is spotless inside.
I would introduce one bottle detergent oil to the brew, preferably PYB on the next oil change. Then 2 bottles PYB after that. Three on the next oil change and so on. That would wean the engine off the non-detergent and slowly get rid of the sludge if any.
If the oil pan was pulled you never know what you may find.
It might be clean.
If the oil pan was pulled you never know what you may find.
It might be clean.
Unfortunately I do not know why the ND oil was used. The guy who built the engine was my buddy's dad. He knew what he was doing when he did it but rarely remembers why now. He gave the car to my buddy (his son) and told him that is what he used. I got the car from my buddy three years ago and received the same recommendation. I have been on this site doing some research about gear oil and I decided to start up the engine oil chat because I never knew why the engine had ND oil in it. I assumed it was to preserve the seals but since I did not know that is why I am asking. I will pull a valve cover and see what I find. Don't know if I will get to it this weekend but I will let you know what I find. What would others recommend for the engine as I break in the detergent oil? What should I use long term?
We're talking about using detergent oil, not some shock cleaning method. I would suspect the detergent oil would slowly dissolve build up and put it into suspension in the oil. I don't believe it would knock chunks of gunk off. Frequent oil and filter changes at first should rid the engine the dissolved carbon gunk. Looking under the valve cover is a good idea to see how bad the build up is, if any.
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