I pulled my intake off this weekend to change to a Holley ProJection and I was shocked. My engine has 80-90k on it and there was no gunk whatsoever in the top of the engine. It was very clean and looked like a new engine!

In my original motor, I used Castrol all 128k miles and it was gunked up pretty good all over the top of the engine.

I'm definetly impressed with how clean Penzoil keeps the engine!

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1988 TA 300+hp 350 w/ TBI and Holley TB unit,
WC T-5, 3.42 gears w/ Auburn posi. MSD 6A, edelbrock TES headers, dynomax 3" cat and cat-back system, ACCEL coil, polyurethane bushings all around, aluminum driveshaft, Mr. Gasket open air cleaner.

1993 S-10 w/ 4.3L V6 TBI, slightly bigger cam, Mild polish job and 3 angle valve job on heads, Edlebrock TES headers, Dynomax cat back, MSD 6A, ADS chip
(bought from my dad)

2000 GMC Sierra Regular Cab Stepside
285hp 5.3L w/ 3.42 gears and locking diff. (sold to my dad..no!!)

 

i have used castrol in all my cars and trucks i just recently rebuilt my truck engine which had 170,00 miles on it and when i took it apart it still looked new..

 

interesting, wonder why mine was.

 

Yeah, I had a similar experience with Pennzoil. I recently pulled my 210k mile engine and it was spotless! No sludge anywhere. There wasn't even a speck in the oil pan! I couldn't freakin' believe it.

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'87 IROC 5.7l TPI - original owner!

 

With the SF rating, Penzoil and most of the majors skimped on the receipe and made some stuff that really gunked up engines. With the SG rating, sludge formation became part of the standards that had to be met. Your previous experience was probably with SF rated oil. I bought a car that had Castrol GT 10W40 oil changes at 3k intervals for 70k miles in the 80's (when SF was out there), and it was a mess inside.

The other part of the equation is the viscosity. GM wouldn't allow 10W40's in their roller-cam diesels because the viscosity index improvers required for that range would gunk up the lifter rollers and tear up the cam. 10W30 was all they would allow.

API is up to SJ now for spark ignition engines. Sludge and varnish are still requirements that have to be met.

You might find a different story if you pull the pan. There's always 1/4-1/2 inch of oil that doesn't get drained when you change the oil, and that's where stuff typically collects. You say your engines are clean, and I'm not saying that isn't true by 70's and 80's standards, but I'll bet they aren't as clean as they would have been if you'd been using synthetic all that time. I've seen the inside of a 150k engine that had AMSOIL from its 1st oil change that didn't even have a brown film on the internals.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open, cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, ported heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

it's funny how everyone has a good/bad story about oil. i ithnk it's more important to change the oil and filter regularly than what kind of oil you run. all the engines i've taken apart today are much cleaner than engines i worked on 20-25 years ago.

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ICON MOTORSPORTS

 

If you change the oil and filter every 2000-3000 miles, it doesn't matter what kind of oil you use. You would have the same results with Wal-Mart (super-tech) oil, or Farmland, or TropArtic, Napa, and any other oil that meets the same specs.

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82 camaro--original steering wheel, brake/gas pedals, seats--everything else modified
82camaro

 

All my cars except the IROC get Wall Mart oil every 10k miles whether they need it or not

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The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

57,
Thanks for the info on SF, SG, etc. ratings.

I too, am a real believer in synthetic oils, and like them for their properties of heat toleration and lubricity.

Dino oils are universally based on paraffin, which is a major factor in oil breakdowns under heat stress. Also, the individual particles offer less than 1/2 the lubricity of a high-grade synthetic.(Mobile 1 and Amsoil come to mind)

Just remember guys, DO NOT use synthetic oil to break-in a new motor. The rings will not seat.

BOR

[This message has been edited by Box of Rocks (edited September 26, 2000).]

 

How many miles should I use conventional oil? My car has ~4000 miles on the new motor, which has Moly rings. Time for synthetic?

------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

Yep. A couple thousand is all that's usually required.

Can't say I agree with you, 82. I didn't say it, but that 150k engine had the oil changed once a year, averaged 20k per year. When the car was totalled at 170k, it was using about 1 qt per 10k miles. Synthetic doesn't have to be changed as often, and will lubricate better at those long intervals than petroleum will at 2-3k intervals.

Also, I have some torn up big block bearings that tell me Pep Boys oil doesn't cut it with only 300 miles on it.

[This message has been edited by five7kid (edited September 26, 2000).]

 

Thanks for the info Kid, It's been about 6-7 years ago whe nI was using Castrol so that is probably the reason was the SF and SG rating you were talking about.

 

I think the verdict is still out or has come in "not guilty" as to any ills of using synthetic from the beginning or at least very early on. Factory fill on some high end engines. Not sure if they run them in on conventional before leaving the factory?

 

DO NOT TRY THIS AT HOME!

One thing I do that really seems to help no matter what the oil is to change it when the car has been driven at operating temp for at least 20-30 minutes. The oil is VERY hot but I use gloves, anyway. It flows out much easier and I don't have to worry about the suspended particles... They are surely suspended... Makes it tricky to do the filter so, DO NOT TRY THIS at home...

 

Factory fill, true. If it was filled with petroleum from the factory, go ahead and change to synthetic when you get home.

The question was about rebuilt engines. If you go to the GM Performance Parts web site, you'll find their recommendations for break-in of a crate motor. If you follow that, you can fill with synthetic the last time they say to change the oil.