I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
5w-20 Synthetic Oil In Flat Tappet Engine
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Originally Posted By: qdeezie
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
I do hope the experts come and give us other examples and years of a "Flat Tappet Engine" because I have heard this term before, and I always thought "2000ppm of ZDDP" and 20W-50 were what "Flat Tappet Engines" needed.
Then they have "Roller Tappet" engines and what also is a "Yank tank?"
Its hard to elaborate on how thin or thick an engine needs if one does not know what a "Flat Tappet Engine" needs.
Some of those older engines needed thicker oil BY DESIGN and were Specd for thicker stuff, if not from the manufacturer, than a performance builder company, like Foose or Roush or AC Schnitzer.. Were those Flat Tappet engines?
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
I do hope the experts come and give us other examples and years of a "Flat Tappet Engine" because I have heard this term before, and I always thought "2000ppm of ZDDP" and 20W-50 were what "Flat Tappet Engines" needed.
Then they have "Roller Tappet" engines and what also is a "Yank tank?"
Its hard to elaborate on how thin or thick an engine needs if one does not know what a "Flat Tappet Engine" needs.
Some of those older engines needed thicker oil BY DESIGN and were Specd for thicker stuff, if not from the manufacturer, than a performance builder company, like Foose or Roush or AC Schnitzer.. Were those Flat Tappet engines?
Originally Posted By: HangerHarley
Originally Posted By: qdeezie
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
I do hope the experts come and give us other examples and years of a "Flat Tappet Engine" because I have heard this term before, and I always thought "2000ppm of ZDDP" and 20W-50 were what "Flat Tappet Engines" needed.
Then they have "Roller Tappet" engines and what also is a "Yank tank?"
Its hard to elaborate on how thin or thick an engine needs if one does not know what a "Flat Tappet Engine" needs.
Some of those older engines needed thicker oil BY DESIGN and were Specd for thicker stuff, if not from the manufacturer, than a performance builder company, like Foose or Roush or AC Schnitzer.. Were those Flat Tappet engines?
Nope. The Jeep 2.5L/4.0L Inline engines were flat tappets, and they would run just fine on any SM Rated 10w30, I think one of our members (Amsoil guy I think) did a run on a special blended 0W-10 and it came out looking fine.
Originally Posted By: qdeezie
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
I do hope the experts come and give us other examples and years of a "Flat Tappet Engine" because I have heard this term before, and I always thought "2000ppm of ZDDP" and 20W-50 were what "Flat Tappet Engines" needed.
Then they have "Roller Tappet" engines and what also is a "Yank tank?"
Its hard to elaborate on how thin or thick an engine needs if one does not know what a "Flat Tappet Engine" needs.
Some of those older engines needed thicker oil BY DESIGN and were Specd for thicker stuff, if not from the manufacturer, than a performance builder company, like Foose or Roush or AC Schnitzer.. Were those Flat Tappet engines?
Nope. The Jeep 2.5L/4.0L Inline engines were flat tappets, and they would run just fine on any SM Rated 10w30, I think one of our members (Amsoil guy I think) did a run on a special blended 0W-10 and it came out looking fine.
The engine is spec'ed for 5w30 and it works well. The whole 20w-50 thing in my opinion is for heavy oil burners or extremely hot climates.
What year is the engine? Ford back spec'd certain engines for 5W20 oil, others weren't. If the engine calls for 5W30 and wasn't back spec'd to 5W20 then stick with the 5W30. IIRC the flat tappet engines were not back spec'd.
Originally Posted By: qdeezie
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
Not likely a good idea unless you bump up the phos level to something closer to 1,200 ppm with a ZDDP additive.
Also while I'm generally in favor of running light oils I wouldn't likely run a light 20wt like QS in your 302 without an oil pressure gauge, just to be on the safe side.
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
Not likely a good idea unless you bump up the phos level to something closer to 1,200 ppm with a ZDDP additive.
Also while I'm generally in favor of running light oils I wouldn't likely run a light 20wt like QS in your 302 without an oil pressure gauge, just to be on the safe side.
FWIW my cavalier didn't do so well on 5W-20. Then again, it seems the oil pump was going because then the oil light started coming on with 5w30 as well, so...
What year and specifics of that engine?
Mild flat tappet cams are just fine with modern oils. Most cars have mild valvetrains.
My OHC cars have flat tappets, BTW.
Mild flat tappet cams are just fine with modern oils. Most cars have mild valvetrains.
My OHC cars have flat tappets, BTW.
Originally Posted By: mechtech2
What year and specifics of that engine?
Mild flat tappet cams are just fine with modern oils. Most cars have mild valvetrains.
My OHC cars have flat tappets, BTW.
The issue doesn't apply to OHC engines but pushrod engines of a certain vintage.
What year and specifics of that engine?
Mild flat tappet cams are just fine with modern oils. Most cars have mild valvetrains.
My OHC cars have flat tappets, BTW.
The issue doesn't apply to OHC engines but pushrod engines of a certain vintage.
5-20 in a Ford 302??? My god this thin stuff is doing what it was probably designed to do. Blow up all the older engines so people have to buy new go-karts with sewing machine motors so they can run 3in1 oil in them.
If it's one of the old 302's like back in the 80's or 90's I think 10-30 would be a more intelligent choice. 20-50, 15-50,10-40, 15-40 would work just fine as well in North Carolina. One with enough ZDDP for that engine would help also.
800ppm of Phosphorus is about minimum for an old flat tappet engine. My personal opinion is 1000ppm minimum. For MY old V-8. ZDDP does more than just protect the cam and lifters. It also helps with upper cylinder wear. I like to see 1200ppm in mine.
If it's one of the old 302's like back in the 80's or 90's I think 10-30 would be a more intelligent choice. 20-50, 15-50,10-40, 15-40 would work just fine as well in North Carolina. One with enough ZDDP for that engine would help also.
800ppm of Phosphorus is about minimum for an old flat tappet engine. My personal opinion is 1000ppm minimum. For MY old V-8. ZDDP does more than just protect the cam and lifters. It also helps with upper cylinder wear. I like to see 1200ppm in mine.
Last edited:
Originally Posted By: HangerHarley
Originally Posted By: qdeezie
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
I do hope the experts come and give us other examples and years of a "Flat Tappet Engine" because I have heard this term before, and I always thought "2000ppm of ZDDP" and 20W-50 were what "Flat Tappet Engines" needed.
Then they have "Roller Tappet" engines and what also is a "Yank tank?"
Its hard to elaborate on how thin or thick an engine needs if one does not know what a "Flat Tappet Engine" needs.
Some of those older engines needed thicker oil BY DESIGN and were Specd for thicker stuff, if not from the manufacturer, than a performance builder company, like Foose or Roush or AC Schnitzer.. Were those Flat Tappet engines?
I don't know how much difference this would make when you compare these newer, much smaller higher revving engines to the older far bigger, slower revving engines but it seems to me that the old V-8's such as the 480 ci engine in my car have much larger, heavier components in them. Compare a 302 Ford to a Yaris engine. It's HUGE in comparison.
Maybe those bigger parts need a thicker oil film due to the fact that the pistons and everything else just weigh so much more when they are flying around in there. Then there are the tolerances and the far more precise machining of the parts in this day and age. Different metallurgy which dissapates heat better than solid cast iron and far more aluminum and plastic composites with better cooling systems.
I would NEVER enertain the thought of putting a 5-20 weight in my engine unless I was living up in Alaska and even then I wouldn't. I'd just plug it in somewhere. I live where it gets down to 10 degrees in the winter and the thought of a 5-20 has never crossed my mind. A STRAIGHT 20 maybe but not a 5-20. What happens when it starts shearing? Then you don't even have your 20 wt.
The problem with the real thin stuff to me is that it's great when you just starting it up but once the engine gets to 190-200 degrees you have nothing in there but water. On a new, modern engine designed for clipper oil yes. On an old V-8? I don't think so.
Originally Posted By: qdeezie
I saw an absolute steal of a deal today on Quaker State 5w-20 Synthetic Motor Oil and I thought about maybe stocking up on it and using it during the winter. My thought is that because the engine is a flat tappet stock 302 engine, that might not be a good idea. What are your thoughts?
I do hope the experts come and give us other examples and years of a "Flat Tappet Engine" because I have heard this term before, and I always thought "2000ppm of ZDDP" and 20W-50 were what "Flat Tappet Engines" needed.
Then they have "Roller Tappet" engines and what also is a "Yank tank?"
Its hard to elaborate on how thin or thick an engine needs if one does not know what a "Flat Tappet Engine" needs.
Some of those older engines needed thicker oil BY DESIGN and were Specd for thicker stuff, if not from the manufacturer, than a performance builder company, like Foose or Roush or AC Schnitzer.. Were those Flat Tappet engines?
I don't know how much difference this would make when you compare these newer, much smaller higher revving engines to the older far bigger, slower revving engines but it seems to me that the old V-8's such as the 480 ci engine in my car have much larger, heavier components in them. Compare a 302 Ford to a Yaris engine. It's HUGE in comparison.
Maybe those bigger parts need a thicker oil film due to the fact that the pistons and everything else just weigh so much more when they are flying around in there. Then there are the tolerances and the far more precise machining of the parts in this day and age. Different metallurgy which dissapates heat better than solid cast iron and far more aluminum and plastic composites with better cooling systems.
I would NEVER enertain the thought of putting a 5-20 weight in my engine unless I was living up in Alaska and even then I wouldn't. I'd just plug it in somewhere. I live where it gets down to 10 degrees in the winter and the thought of a 5-20 has never crossed my mind. A STRAIGHT 20 maybe but not a 5-20. What happens when it starts shearing? Then you don't even have your 20 wt.
The problem with the real thin stuff to me is that it's great when you just starting it up but once the engine gets to 190-200 degrees you have nothing in there but water. On a new, modern engine designed for clipper oil yes. On an old V-8? I don't think so.
Thank you for all the replies. It is a 1990 F150 302. Maybe once or twice a year I may tow something with a tow dolly. I thought it was a roller engine, but I found out that the truck engines were not rollers until about 93-94 and also I saw it for myself that it was a flat tappet when I took the upper intake off to fix a leak. It is an OHV pushrod engine. I've used 5w30 the whole time I've owned it and I am very satisfied with the performance and longevity of it and I have no complaints about 5w30, but I was thinking perhaps using this 5w-20 during the winter this year since it's so cheap. I wouldn't dare use it during the summer months.
Originally Posted By: Trvlr500
If it's one of the old 302's like back in the 80's or 90's I think 10-30 would be a more intelligent choice. 20-50, 15-50,10-40, 15-40 would work just fine as well in North Carolina. One with enough ZDDP for that engine would help also.
800ppm of Phosphorus is about minimum for an old flat tappet engine. My personal opinion is 1000ppm minimum. For MY old V-8. ZDDP does more than just protect the cam and lifters. It also helps with upper cylinder wear. I like to see 1200ppm in mine.
Many of the SM/GF-4 oils do have around the 800 ppm limit. I agree that 1000 ppm to 1200 ppm are more optimal. I doubt there are huge valve spring pressures, though.
Aside from those concerns, 5w-20 wouldn't be the end of the world, and might be fine for extreme cold combined with short trips. Personally, there are plenty of good 5w30 oils that would do the job. I wouldn't say that 5w-20 is a death sentence for the engine, but it just may not be optimal. If Ford back speced the engine to 5w-20, fine. Otherwise, the recommended 5w30 is probably the best choice.
As an aside, my Audi allows 20w-50 in the summer and 5w-20 in the winter. The average, non-performance engine isn't as married to one viscosity as the EPA would have us believe.
If it's one of the old 302's like back in the 80's or 90's I think 10-30 would be a more intelligent choice. 20-50, 15-50,10-40, 15-40 would work just fine as well in North Carolina. One with enough ZDDP for that engine would help also.
800ppm of Phosphorus is about minimum for an old flat tappet engine. My personal opinion is 1000ppm minimum. For MY old V-8. ZDDP does more than just protect the cam and lifters. It also helps with upper cylinder wear. I like to see 1200ppm in mine.
Many of the SM/GF-4 oils do have around the 800 ppm limit. I agree that 1000 ppm to 1200 ppm are more optimal. I doubt there are huge valve spring pressures, though.
Aside from those concerns, 5w-20 wouldn't be the end of the world, and might be fine for extreme cold combined with short trips. Personally, there are plenty of good 5w30 oils that would do the job. I wouldn't say that 5w-20 is a death sentence for the engine, but it just may not be optimal. If Ford back speced the engine to 5w-20, fine. Otherwise, the recommended 5w30 is probably the best choice.
As an aside, my Audi allows 20w-50 in the summer and 5w-20 in the winter. The average, non-performance engine isn't as married to one viscosity as the EPA would have us believe.
1990 Ford 302 truck in NC?
Stick with 5-30 for the winter also.
Stick with 5-30 for the winter also.
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I've run 5w20 in a 302. My cam grinder has run 5w20 in a 302.
But these were both late 80's (87 and 89 respectively) ROLLER engines. Both had no issue with it. And he raced his.... A LOT.
That being said, that doesn't mean you should do it. In fact, with the old flat tappet engine, I'd advise against it.
However, 302's are not picky on oil choice. I personally love running an HDEO on them. If you can get a good deal on Rotella or Delvac 1 5w40, I'd use that.
But these were both late 80's (87 and 89 respectively) ROLLER engines. Both had no issue with it. And he raced his.... A LOT.
That being said, that doesn't mean you should do it. In fact, with the old flat tappet engine, I'd advise against it.
However, 302's are not picky on oil choice. I personally love running an HDEO on them. If you can get a good deal on Rotella or Delvac 1 5w40, I'd use that.
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How long is the typical trip in this truck? Being 20 years old I can't see this being a long distance daily driver. If your events are 15minutes or less, you would probably be turning off the key to a 40 weight with a 5w-20 in the sump.
Your cooling system will limit your oil temp, which will limit it's low end viscosity.
Your cooling system will limit your oil temp, which will limit it's low end viscosity.
As has been hinted, the issue isn't so much the viscosity. In the right climate and situation, in good condition, your engine could do 5W20. Probably not optimal, though, and the best idea is to stick with a 5W30.
The larger potential issue for a flat tappet engine is really SM oils (few 5W20s are anything but SM) but for all we know, you are already running a modern SM oil and have been for years. SM oils are a bit light on ZDDP compared to what your engine was designed to use. "They" say it's enough. In most cases "they" seem to be correct. A broken-in low performance engine (sorry, "standard performance" sounds better, huh? ( : < ) with light valve springs doesn't usually have issues. In your shoes, ZDDP is the only issue worth much consideration. And then, probably not all that much.
The larger potential issue for a flat tappet engine is really SM oils (few 5W20s are anything but SM) but for all we know, you are already running a modern SM oil and have been for years. SM oils are a bit light on ZDDP compared to what your engine was designed to use. "They" say it's enough. In most cases "they" seem to be correct. A broken-in low performance engine (sorry, "standard performance" sounds better, huh? ( : < ) with light valve springs doesn't usually have issues. In your shoes, ZDDP is the only issue worth much consideration. And then, probably not all that much.
Originally Posted By: Jim Allen
As has been hinted, the issue isn't so much the viscosity. In the right climate and situation, in good condition, your engine could do 5W20. Probably not optimal, though, and the best idea is to stick with a 5W30.
I agree. If we're taking about driving it in the winter for, say, ten blocks to work, then ten blocks home at the end of the day, I can't see 5w-20 being a problem. It might even be a good choice, then. If the oil is being brought up to temperature, stick with the 5w30. It's hard to go wrong with the manufacturer recommendation, all things being equal.
As has been hinted, the issue isn't so much the viscosity. In the right climate and situation, in good condition, your engine could do 5W20. Probably not optimal, though, and the best idea is to stick with a 5W30.
I agree. If we're taking about driving it in the winter for, say, ten blocks to work, then ten blocks home at the end of the day, I can't see 5w-20 being a problem. It might even be a good choice, then. If the oil is being brought up to temperature, stick with the 5w30. It's hard to go wrong with the manufacturer recommendation, all things being equal.
The driving conditions for this engine will be city driving most of the time about 15 to 20 mins at a time, but I do make 3 hour (one way) highway road trips at least once every 4 to 6 weeks. From what I'm grasping, I guess if it ain't broke don't fix it. If it was a roller engine, I would have picked that 5w-20 up on the spot, but I think I'll be sticking with the 5w30 since it's flat tappet. I just hate to see really cheap synthetic oil and pass on it, but sometimes you have to if it's not right for your application.
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