They run best on 5W-20 Pennzoil.
Question about Ford Engines and 5W-20
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hominid7, on another thread, suggested a new campain slogan that should/could be put out by Ford: "Don't just change your oil, change your attitude!"
5W-20 is fine in engines spec'd for it. THAT is a FACT. It's probably fine for most any engine spec'd for 30 weights, too....but, that is conjecture, not fact.
5W-20 is fine in engines spec'd for it. THAT is a FACT. It's probably fine for most any engine spec'd for 30 weights, too....but, that is conjecture, not fact.
When I read the owner's book on my new Mustang GT I was surprised that the V6 still specs 5W30. Ford's technical paper from 2001 indicated that some engines would require a redesign of the engine, specifically the oil pump, to maintain proper oil pressure with 5W20. I am curious if that is the issue with the V6 and why it hasn't been redesigned. I am happy with MC 5W20 in my 2 Fords, the 06 GT and an 01 Escape with 75k.
Amen Hirev. I haven't had time to check a bunch of different engines, but my Clyner manual for modulars, and my Seloc manual for Mercruiser GM motors showed virtually the same main and rod bearing clearances. I was really suprised by this as the "common knowledge" and belief on this and other sites is that the newer motors, modulars in particular, have way tighter clearances than the older design motors.
Again, I didn't do a ton of research, but a quick look at the specs for two completely different motor styles proved to me that there must be something else going on.
Again, I didn't do a ton of research, but a quick look at the specs for two completely different motor styles proved to me that there must be something else going on.
It's funny, because everytime someone tells me it's because of tighter tolerances (and then I correct them and say clearances) I always ask them to tell me what the clearances are in a modular motor.
I've been asking that for several years and I still don't know.
The Ford 4.0 SOHC motor is made in Germany. I am wondering if this might have something to do with the 5w30 spec for it. You get a lot of people yaking about same motor here, same motor in Japan, same motor in Europe. They never realize or consider where that motor is manufactured. I guess some people are ignorant on modern manufacturing techniques and supply chains.
Think of it this way most motors in the US are made to two differnt emission standards. California/Green states and federal emission standards. Now imagine some retarded mechanic arguing with you that they are the same motor while you explain to him that the emissions systems are different and all he can tell you is "there the same motor".
Think of it this way most motors in the US are made to two differnt emission standards. California/Green states and federal emission standards. Now imagine some retarded mechanic arguing with you that they are the same motor while you explain to him that the emissions systems are different and all he can tell you is "there the same motor".
Clearances are the same, but I suspect tolearances are much tighter. Statistical process control and CNC machining have redefined what a "good" part is. More uniform parts with tighter tolerances yield more consistant engine assemblies
Perhaps with a more controlled and consistant product coming off an engine assembly line, more focused lubes can be used.
Perhaps with a more controlled and consistant product coming off an engine assembly line, more focused lubes can be used.
Ahh, simple_gifts has the knowledge. It seems you have some exposure to high volume manufacturing.
The problem is to properly explain the whole scenario would take a lot of space, time and effort. Its just a simple fact that a lot of people are always gonna think they are smarter then the people who build and design the engines and specify the lubricants for their creations.
The problem is to properly explain the whole scenario would take a lot of space, time and effort. Its just a simple fact that a lot of people are always gonna think they are smarter then the people who build and design the engines and specify the lubricants for their creations.
Pontiac 326-455 CID from the 1970's.
Main bearings:
Clearance #1,2,3,4 0.0005" - 0.003"
#5 0.002" - 0.0035"
Connecting rod bearings:
Clearance 0.0009" - 0.0029"
1969 Blueprinted 302 SBC
Main bearings:
Clearance .002-.003 (.002 prefered)
Connecting rod bearings:
Clearance .002-.0025 (.002 prefered)
Stock SBC
Main bearings:
Clearance .0007-.003
Connecting rod bearings:
Clearance .0012-.003
1989 Toyota 7M-GTE
Main bearings:
Clearance .0012-.0019
Connecting rod bearings:
Clearance .0008-.0021
1989 Ford 3.0L V6 SHO
Main bearings:
Clearance .0011-.0012
Connecting rod bearings:
Clearance .0009-.0022
1996 Ford V8 SHO
Main bearings:
Clearance .0004-.0012
Connecting rod bearings:
Clearance .0009-.0023
2002 Honda V6
Main bearings:
Clearance .0008-.0017
Connecting rod bearings:
Clearance .0008-.0017
2003 Chevy LSx specs
Main bearings:
Clearance .0008-.0021
Connecting rod bearings:
Clearance .0009-.0025
What is equally important is the finish on the journals. The finish specification for most older cranks is typically 8 to 12 RA. But for newer engines that use 5W-20/30 oil, the spec is 6 RA or less. GM calls for 5 RA on many of its newer engines.
You'll also find a similar trend in piston clearances. Not including skirt coatings, and a change in metallurgy.
Main bearings:
Clearance #1,2,3,4 0.0005" - 0.003"
#5 0.002" - 0.0035"
Connecting rod bearings:
Clearance 0.0009" - 0.0029"
1969 Blueprinted 302 SBC
Main bearings:
Clearance .002-.003 (.002 prefered)
Connecting rod bearings:
Clearance .002-.0025 (.002 prefered)
Stock SBC
Main bearings:
Clearance .0007-.003
Connecting rod bearings:
Clearance .0012-.003
1989 Toyota 7M-GTE
Main bearings:
Clearance .0012-.0019
Connecting rod bearings:
Clearance .0008-.0021
1989 Ford 3.0L V6 SHO
Main bearings:
Clearance .0011-.0012
Connecting rod bearings:
Clearance .0009-.0022
1996 Ford V8 SHO
Main bearings:
Clearance .0004-.0012
Connecting rod bearings:
Clearance .0009-.0023
2002 Honda V6
Main bearings:
Clearance .0008-.0017
Connecting rod bearings:
Clearance .0008-.0017
2003 Chevy LSx specs
Main bearings:
Clearance .0008-.0021
Connecting rod bearings:
Clearance .0009-.0025
What is equally important is the finish on the journals. The finish specification for most older cranks is typically 8 to 12 RA. But for newer engines that use 5W-20/30 oil, the spec is 6 RA or less. GM calls for 5 RA on many of its newer engines.
You'll also find a similar trend in piston clearances. Not including skirt coatings, and a change in metallurgy.
Tolerance would be nothing more than the allowable range of clearance, right? In looking at the main and rod specs for older and more modern engines that has been posted elsewhere, I'd say neither tolerances or clearances have gotten any tighter.
Edit: Someone was nice enough to post those specs here.
Edit: Someone was nice enough to post those specs here.
"The problem is to properly explain the whole scenario would take a lot of space, time and effort. Its just a simple fact that a lot of people are always gonna think they are smarter then the people who build and design the engines and specify the lubricants for their creations."
It's pretty easy to explain why a 5W20 oil is recommended by Ford or Honda as they said so; to improve fuel economy. Ford did recommended it retroactively, suggesting that it's just fine to dump in a specified number of older vehicles, with no qualifier for vehicle age or mileage.
It's pretty easy to explain why a 5W20 oil is recommended by Ford or Honda as they said so; to improve fuel economy. Ford did recommended it retroactively, suggesting that it's just fine to dump in a specified number of older vehicles, with no qualifier for vehicle age or mileage.
So what your saying is 1struck is that the Ford engineers did an awesome job at developing and writing specs for 5w20 weight oil that do the following: protects the engine better then older technology 5w30 10w30 and 10w40 oil, provides better fuel economy, and makes the conspiracy theorists go bonkers.
If you trying to engineer for better fuel economy and you develop a superior oil in the process then where is the problem at?
If you trying to engineer for better fuel economy and you develop a superior oil in the process then where is the problem at?
Taking a look at a real GM repair manual for a 1969 300 HP 350 CI cast piston Chevy motor I got what is below.
I got a 1969 300hp 350 in my shop that made it to 147,000 miles before I pulled the motor in 1981 and junked the car. I got the original maintenance log with the car. It ran straight 30 wt about the 1st 5 years and 10w 40 the rest of its life. The motor was still running but smoking some using a qt about every 700 miles.
Piston clearance.
.0005- .0011
Rod bearing journal diamter... 2.099 - 2.100
Rod bearing clearace........ .0007 - .0028
Main bearing journal diamter... 2.4479 - 2.4488
Main bearing clearance......... #1 Thru #4 .0008 - .0002, #5 the (thrust) main bearing .0018 - .0034.
I got a 1969 300hp 350 in my shop that made it to 147,000 miles before I pulled the motor in 1981 and junked the car. I got the original maintenance log with the car. It ran straight 30 wt about the 1st 5 years and 10w 40 the rest of its life. The motor was still running but smoking some using a qt about every 700 miles.
Piston clearance.
.0005- .0011
Rod bearing journal diamter... 2.099 - 2.100
Rod bearing clearace........ .0007 - .0028
Main bearing journal diamter... 2.4479 - 2.4488
Main bearing clearance......... #1 Thru #4 .0008 - .0002, #5 the (thrust) main bearing .0018 - .0034.
I had the '70 version of that engine, L-48 I believe. It was still running strong with over 120K miles on it before I got rid of it. Burned very little oil, and you could still run it to 6K rpms without a wimper.
That is obviously wrong.
1969 Stock 302 SBC
Main bearings:
Clearance #1(.0008-.0020) #2,3, 4 (.0008-.0024) #5-(.0015-.0031)
Connecting rod bearings:
Clearance .0007-.0027
Pistons: .0024-.0030
http://www.67camaros.com/models/z28/engine_piston.htm
http://www.67camaros.com/models/z28/crankshaft.htm
This is how we would blueprint them to race:
http://www.yearone.com/enthusiast/restoarchives/spring98/sp98engineassembly/engass2.htm
Also, HiRev, tell me about that parting line slot in older SBC connecting rods. Never did see any of those in the half a dozen SBCs I built over the years.
I agree. But the bias seems to be to tell people that happen along here to ignore the factory recommendations and use thicker oil to "save their engine from wearing out", like there was some grand conspiracy.
What if it was the other way around and everyone was told to use a thinner oil than what the factory recommends? Heads would explode, pigs would fly, and all used car salesmen would become honest, I tell ya'.
The oil slot is found in SBC small journal rods only and only on the rod cap on one side. It is why most all small journal rod bearings have a oil hole at the parting line. The oil slot goes thru the rod bolt hole area from the inside out and is directed at an angle to the bottom of the cam lobes as the crank spins around. Its was designed to squirt pressurized oil on the bottom of the cam lobes at low RPM. But also puts more oil on the cylinder wall.
The link from year one has incorrect information.
The MO 302s used in the 1967 AND 1968 Z/28 302 motors were small journal blocks and rods. Both of my 1968s Z/28s came with 2 bolt main, small journal 302s MOs. Only in the 69 DZ motor will you find large journals and 4 bolt mains. The 68 327s could be small journal or large journal depending on how early or late in 68 they where made. All the Camaro SS 350s from 67 on up were large journal.
As far as running greater than .0018 rod bearing clearance for blueprinting a Small block that is old school stuff unless you are running aluminum rods. It just not necessary with todays oils and the oil pressure will run very low near idle unless you go to a BBC style oil pump. Even the big boys in NASCAR find .0018 rod bearing clearance works fine.
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