5W-20 in a 5W-30 engine with a flat tappet cam...

[Big O Dave]

Can you run 5W-20 in an older American V8 without damaging the cam and lifters, and non-roller rocker arms?

I read that 5W-20 produces excellent UOA's, but all I can find are UOA's for newer vehicles.

I do a lot of short trip driving, and I purposely have to go out of my way to drive longer routes just to fully warm up the engine. Maybe 5W-20 would do well in such a situation?

The vehicle in question is an '83 Ford F250 with a 460 V8. 103,000 miles.

Thanks, in advance, for your thoughts!

 

[MrClutch]

I don't think that it would be a good idea to run a 5w-20 since your engine doesnt have tight clearences like the newer cars do. It could be an option if you drive in freazing temps. Just my 2 penies

 

[bruce381]

Id stick to a >20wt multi weight like a 15/40 or even a 10/30 oil in that truck using a diesel package like a CF-4/SL. A flat tappet cam needs all the ZDDP and viscosity it can get.
bruce

 

[ford390gashog]

ford has approved the 460 to run the 930a spec oil. not sure if the newer ones had the roller cams and lifters though. i have had some very nice numbers running chevron 5w30 supreme in my 390 which has large clearances.

 

[Big O Dave]

quote:

---

Originally posted by ford390gashog:
ford has approved the 460 to run the 930a spec oil.

---

What is the "930a" spec?

EDIT: I answered my own question with a search... 930a is Ford's current spec for 5W-20 oil. Now I remember seeing that someone (probably TallPaul) posted an official Ford pdf that listed all engines by year that could run on 5W-20 and 5W-30. Mine was listed under 5W-30. I'm just the kind of person to still want to try 5W-20, though.

quote:

---

i have had some very nice numbers running chevron 5w30 supreme in my 390 which has large clearances.

---

That's what I'm running in it right now, as I'm doing an ARX treatment. I did have Rotella 5W-40 in it before that. It was smooth, but more sluggish.

I've done 5W-40 and 5W-30 in this beast, but I'm concerned that if I try 5W-20 I might damage it or cause a lot of unnecessary wear. I'd like to try it just to see how the beast would run on it, but...

BTW, good to see you over here! You are great at FTE.

[ September 21, 2005, 02:12 AM: Message edited by: Big O Dave ]

 

[Jay]

I think that roller cam followers, more than anything else, is what allows the newer engines to perform so well on 20-weight. That said, if you stay off the highway, you may do fine with 20-weight in your older V-8.

 

[Curious Kid]

You're probably right Jay, but having read that Terry and Mola seem to support the lighter 20-weights (of course where applicable with there knowledge in the field and UOA's), there may be additive advancements that just don't show-up in the typical OA. If this is indeed true, I don't foresee any sharing of such info. anythime soon. That leaves taking a chance to some extent and running UOA's.

As far as running a lighter oil for short trips - I'm kind of along the same line as you Dave (though with a different vehicle). One may gain from dealing with a lighter overall weight (mileage, ease of starting, etc.), but since it may not get up to temp, you have the condensation and potential fuel dilution to deal with. I've thought to do an initial fill in the spring with 0w-30 GC and 5w-30 HM GTX, then in the fall for top-up and a filter change, use 5w-20 syntec (would've liked to use M1's 0w-20). A compromise for the 1 yr. OCI. It would seem I don't drive all that much and have mixed duties for the engine (towing,urban/interstate commute, 5 miles to work, and just sitting), hense the idea of weight spread over the likely occurances where I think it practical. And as for why I'm mixing in dino...the rear main seal now seeps.

 

[drums57]

Dave this engine was not designed to run on 5w20 oil , were you live use 10w30 all year long. Some on hear fell that GF-4 API SM will not protect older engines like yours, dont worry it will. My choice would be Havoline high milage or Valvoline Maxlife. But i know Havoline GF-4 WILL protect this engine, on questions about it.

 

[Big O Dave]

Thanks for all of the responses, guys. I've overcome my desire to experiment with this, and the F250 will not get subjected to 5W-20.

 

[Curious Kid]

That's good Dave.

I'm still curious though...say that the ambient air temperature was cool enough to maintain an oil temperature that would yield similar "at temp" oil pressures (oil here would be cooler than the heavier weight). Aside from gaining fuel economy over the heavier weight oil in like temperature conditions, you have a more robust additive package as far as boundry lubrication may go as I'm being lead to believe...thought the oil would have a lower HTHS - not that it would reach such temps during this situation for daily transportation. Am I understaind this potential correctly?

Thanks in advance.

 

[MIAMI-DADE]

quote:

---

Originally posted by Big O Dave:
Thanks for all of the responses, guys. I've overcome my desire to experiment with this, and the F250 will not get subjected to 5W-20.

---

Best news i heard today

.

Oh yeah i thought i was the only one taking the long way instead of the quickest way so the engine gets fully warmed up.

Will be looking for a better job soon i will take one further away this time.

 

[unDummy]

I don't see why you couldn't run a 5w20. The oil has proven to be stout 'cause of the test requirements by Ford/Honda/Mazda/Chrysler......
If oil PSI is good, I can't see how any damage can occur.

Another thing to consider is that this engine shouldn't really stress any oil too much. How much HP did this motor make when new in '83? as much as most import 4cyl engines today?

But, 5w20 is thin and the temp/PSI should be controlled. I'd only use it if the oil pressure and temp were checked for reference with acceptable specs for the engine.

Another option, if room is available, is to use the larger filter(FL299 instead of FL1a) to provide additional oil capacity and cooling(regardless of weight chosen but seriously recommended is you want to test 5w20).

And, if this is a carb'd engine(I assume 4bbl), fuel control s@cks. Fuel dilution.......might be excessive and you might just be better off with any ol' 15w40 or 10w30 HDEO with more frequent OCI's. The HDEO's, usually with better TBN, will be suberb with all those short trips.

To use 5w20 where not called for:
Increase oil capacity with bigger filter or pan.
Increase oil flow via higher volume/PSI pump.
Increase oil cooling with aftermarket airil cooler or oil:water cooler.
Toyota oil:water coolers off the SUV/truck might be available at the boneyard.
Monitor wear with a couple UOAs comparing thick with thin.

I'm surprised that there is such a big anti-thin crowd. And, IMO, ZDDP and thick oil is obsolete. Its time for better flowing oils with newer AW/EP additives. 5w20 and SM/GF4 are slowly bringing about the change.

 

[ford390gashog]

quote:

---

Originally posted by Big O Dave:

quote:

---

Originally posted by ford390gashog:
ford has approved the 460 to run the 930a spec oil.

---

What is the "930a" spec?

EDIT: I answered my own question with a search... 930a is Ford's current spec for 5W-20 oil. Now I remember seeing that someone (probably TallPaul) posted an official Ford pdf that listed all engines by year that could run on 5W-20 and 5W-30. Mine was listed under 5W-30. I'm just the kind of person to still want to try 5W-20, though.

quote:

---

i have had some very nice numbers running chevron 5w30 supreme in my 390 which has large clearances.

---

That's what I'm running in it right now, as I'm doing an ARX treatment. I did have Rotella 5W-40 in it before that. It was smooth, but more sluggish.

I've done 5W-40 and 5W-30 in this beast, but I'm concerned that if I try 5W-20 I might damage it or cause a lot of unnecessary wear. I'd like to try it just to see how the beast would run on it, but...

BTW, good to see you over here! You are great at FTE.

---

when i rebuilt my 390 i ran 5w20 for break in and for the first 11,000 miles with no issues. i may even consider using it again. but i picked up a lot of 5w30 chevron for .49 a quart. my 390 takes 14 quarts plus 1 for the filter so i will be going through this current stash very soon. the pressure running 5w20 pennzoil was 75 psi cold 18 psi hot(a fe only needs 8 psi at hot idle to live) with 5w30 it is 20 hot and about the same cold. i had no noise running the 5w20 no lifter noise or valves. i did have to pull the pan at 9,000 miles for a pan leak and i took the chance to inspect the rod and main bearings. nothing unusual looked brand new so i believe the 5w20 did a good job.