GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.
Home » Public Forums » GMCnet » Blackstone Labs and ZDDP oils
Re: [GMCnet] Blackstone Labs and ZDDP oils [message #109438 is a reply to message #109432] Wed, 22 December 2010 13:34 Go to previous messageGo to previous message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma:
Senior Member
Steve Stolley wrote on Wed, 22 December 2010 13:09

Thanks Steve! I was hoping either you or someone who was at the GMCWS tech presentation would eventually comment on my original question. After seeing the thread heading in an opposite, although parallel direction, I called Blackstone and spoke with Ryan Stark. He now runs things as Jim is "retired". He told me that the no-ash aircraft oil (e.g. no additives what-so-ever) testing continues in his flat tappet engined truck without incident or damage. He also said that everyone who works there buys and uses the cheapest non-synthetic oil they can find on sale no matter what the vehicle and have no brand preference other then the appropriate grade per the manufacturer. The frequency of their oil changes is entirely usage specific.

Based on your comment and my discussion with Ryan, I'll be using the Delo 15W-40 dino oil.

Steve,

It is your engine to do as you wish.

There is a lot of known truth in your and the previous Steve. But, there are other facts not addressed at all.

Passcar service is very much different than motorhome, real truck or marine. The last three invite being run at very high MAP (load) for extended periods. This is not particularly tough on the lube oil as a lubricant per se.

The problem is two fold in our coaches.
First is use. Most of these coaches get run hard (compared to a passcar) and this can cause the lubricating oil to get broken down if it is EVER exposed a temperature in excess of 305*F. This is not a time/temperature problem. If the oil molecule gets to 305, it comes apart into pieces that have no lubrication properties.
Second is disuse. The combustion by-products (blow-by that every engine has and is worse with increasing MAP) are collected in the crankcase and necessarily accumulated in the lubricating oil. Many of the constituents of the combustion blow-by are corrosive and very chemically active and attack both the additive package and the oil itself.

The time that this contamination seems to become most serious in a dino oil is in the region of six months - running or not .

Synthetic lubricants are less susceptible to this damage. I never got a read on how much less as the longest test I could run was one year, but that was still good.

So, if you are going to run a dino oil, just be ready to change it out every six months. Also be certain that it does not get overheated. This is not all bad. Remember though, this is not an average temperature that an instrument will read. If the oil cooling the piston crowns gets too hot - ever - it will be damaged and then contribute to the contamination.

As to ZDDP and cam wear, this is known to be primarily a break-in issue that can be largely eliminated by the use of a good application of the right coating at build.

Me, I've been using MoS2 for forty years and have only lost one engine in that time and that was not to lubrication. I am currently replacing the trans in a vehicle universally know to be and 80K engine, but this one is at 165 and has just begun to need an oil addition and that is due to a rear main seal that I will replace while the trans is down.

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

Report message to a moderator

[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: OKC Lunch Bunch - January
Next Topic: Re: [GMCnet] Idiots Guide to Finding 1973-1978 GMC MotorhomeInformation on the Internet
Goto Forum:
  


Current Time: Mon Jul 01 06:05:24 CDT 2024

Total time taken to generate the page: 0.00934 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.1.1.
Copyright ©2001-2021 FUDforum Bulletin Board Software