fuel octane/additives
 

I wanted to post a general question about fuel, oil and additives. I just spoke with a guy who restores these old trucks and he was telling me about ways to prolong the life of the engine:

1. He says to use mid-range octane.
2. Use a fuel additive.
3. Use an engine oil additive. (not stop-leak)

He was saying that the fuel and oil made these days are not easy on these old engines and by adding these additives, it would help keep my truck running longer. I'd like to hear what everyone thinks about this issue.

thanks!!

Re: fuel octane/additives
 

if your engine does not have hardened exhaust seats, then a lead substitute will help, but it'll take many many years to damage them if you skip the lead additive. Plus, in many areas, lead substitutes are very hard to find.
Mid range fuel... throwing money out the tail pipe if the engine doesn't need it.
oil additive... new oils (including diesel oils) don't have the zink needed to keep old engines alive. ZDDP additive IS HIGHLY recomended.

Re: fuel octane/additives
 

x2 on the ZDDP additive

Re: fuel octane/additives
 

Octane booster have been shown to be highly ineffective at boosting octane, also most engines don't need higher octane anyways.

Re: fuel octane/additives
 

About the oil additives...if one were to have his engine rebuilt, shouldn't the new bearings, pistons, lifters, etc. be made to run on today's oils? I'm sure they have some kind of coating on them that the ones from the 60's and 70's didn't right?

Re: fuel octane/additives
 

it's the flat tappet cam that isn't suited for modern oil

Re: fuel octane/additives
 

nope.

Re: fuel octane/additives
 

Darn. I'll just keep running Pennzoil until something goes out.

Re: fuel octane/additives
 

If you convert to a roller cam, then you'll be covered.

Re: fuel octane/additives
 

The only fuel additive I recommend is called Seafoam. I use it on FI engines and it's good for carbs too. I'm not convinced that the lack of ZDDP is harmful to the older engines except maybe the flat tappet cams on breakin. I say that because chevy engines have been flat lobing these cams since the sixties. YMMV.

I don't want to omit using gas line anti-freeze for water in the fuel but that's not really a fuel additive.

Re: fuel octane/additives
 

x2 on the seafoam. Great stuff.

Re: fuel octane/additives
 

x3 on the Seafoam. It also has the lubricity needed to completely eliminate the need for lead additive. It also is guaranteed to stabilize your fuel for two years. It also will do the job of the gas line anti freeze, and if you rub it on your scalp hair grows back! Ok but all the rest is true..

Re: fuel octane/additives
 

Did anyone notice after adding Seafoam a little smoke out of exhaust?

Re: fuel octane/additives
 

the zddp thing is real. Engines have been eating cams for a long time, but now they do it MUCH faster.

Re: fuel octane/additives
 

http://lubriplate.com/webstore/default.aspx

This is the motor oil that I use.

GPO 15W-40

Zinc and Phosphorus Enhanced
ZDDP Formula
Ideal for High-Performance and Classic Car Engines

Re: fuel octane/additives
 

Seafoam does make more smoke because of the crud it cleans out. I had a jeep cherokee with a lot of miles that ran rough when I purchased it. I dumped some in the tank and sprayed the aerosol down the throat and it looked like it was on fire. I've used it on all my vehicles now.

Re: fuel octane/additives
 

Thought I would revive this thread to see if anything has changed in the last few years. Seems like the consensus is that fuel/oil additives are not worth it. My truck has x96K miles on what appears to be the original engine. If it has been rebuilt, then I'm good. If not, a rebuild is in my near future anyway.

Re: fuel octane/additives
 

I've seen a number of flat-tappet engines run many miles (not just toys/cruisers - everyday working rigs) without ZDDP additive with no excessive cam wear or failure - a good oil changed at adequate intervals should protect the stock, low-lift cams in our trucks after break-in, but a ZDDP additive or oil that's already higher in Zinc (some dual-rated gas/diesel oils or special hot rod/classic oils) won't hurt. Seafoam is a good periodic additive, but I don't use any additives full-time and run 89. Our truck's stock engines are nearly all low enough compression that knock resistance isn't much of an issue, but I've just had too many occasions when new and old vehicles ran better on plus than regular it's now habit to punch the middle button on the pump. Burns cleaner, runs cooler, etc.

Re: fuel octane/additives
 

What is ZDDP?

Zinc dialkyldithiophosphate (ZDDP) is the most commonly used anti-wear additive in motor oils. It contains both zinc and phosphorus components that work together to provide anti-wear protection and minimize lubricant breakdown. ZDDP also exhibits mild extreme-pressure protection. Some motorists think that increased zinc content equals increased wear protection. Although somewhat true, the statement can be misleading. First, the mere presence of zinc doesn’t mean it is in the form of ZDDP. In other forms, zinc offers additional oxidation protection but little wear protection. Second, other factors influence the oil’s ability to control wear, such as its viscometrics and base stocks. While zinc is important in protecting against wear, the greatest concern should be in using a well-balanced oil that is designed for its intended application.

How ZDDP Works

As temperatures rise and surfaces come closer together, ZDDP decomposes, and the resulting chemistry protects critical metal surfaces. When parts move during operation, any sliding or rolling motion takes place on top of or within the ZDDP anti-wear film, which reduces metal-to-metal contact. This is especially important in modified engines with flat-tappet camshafts because the engine is creating more horsepower than it was designed for, which puts more stress on the engine. High-tension valve springs, often used in racing applications, also increase the potential for cam wear and require additional ZDDP.

Negative Effects of ZDDP

ZDDPSince all engines benefit from oils with superior anti-wear properties, it seems obvious to formulate all motor oils with high levels of ZDDP. Generally, high levels of ZDDP result in volatile phosphorus being transferred from the combustion chamber to the catalytic converter. Phosphorus can blind over the catalytic reaction sites in the converter, making it less efficient in turning carbon monoxide (CO) into carbon dioxide (CO2). The EPA mandates that catalytic converters operate as designed for more than 100,000 miles. As a result, phosphorus is limited for newer motor oil specifications.
When the American Petroleum Institute (API) and the International Lubricants Standardization and Approval Committee (ILSAC) established phosphorus limits at 0.10 percent weight in 1996, motorists and enthusiasts wondered if it would negatively affect wear protection. The move to reduce phosphorus may not have taken into consideration high-performance and modified engines or engines that had yet to be broken in. The debate intensified in 2004 when the API and ILSAC further limited phosphorus to 0.08 percent, where it remains today.


When it comes to older engines – particularly those equipped with flat-tappet cams – and engines modified for increased performance, the challenges to delivering adequate wear protection become more pronounced.
Flat-Tappet Cams

The design of flat-tappet cams makes them especially vulnerable to wear. As the name indicates, the tappet – or lifter – is flat. During operation the surface of the cam lobe slides rapidly over the surface of the tappet, producing high friction and temperatures. The camshaft and lifters are responsible for triggering the precisely tuned movements of the valvetrain

Without the protective film barrier provided by ZDDP, the cams and lifters wear from the force of operation, negatively affecting cam and valve operation. Because most V-8 engines of the muscle car era came standard with flat-tappet cams, the problem is especially prevalent to classic-car and hot-rod owners.

Re: fuel octane/additives
 

there's an EXXON station nearby that sells non-ethanol 90 octane and both of my old trucks seem to start/idle/run good on it. About $3 a Gal.. WaWa sells 89 octane a little cheaper and neither truck likes it as well. I loose about 100 rpm off the idle speed. Both trucks are low compression and I can advance the timing til they run crappy and won't turn on the starter and they still won't spark knock.

Re: fuel octane/additives
 

For the tech savvy: Gas treatment

Aqueous monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) are widely used industrially for removing carbon dioxide (CO2) and hydrogen sulfide (H2S) from natural gas and refinery process streams. They may also be used to remove CO2 from combustion gases and flue gases and may have potential for abatement of greenhouse gases. Related processes are known as sweetening.[15]

Re: fuel octane/additives
 

gas treatment for the non-tech savy.... Related processes are known as sweetening ;)