Lead additive
-
- Sergeant Major of the Gee
- Posts: 432
- Joined: Sun Sep 28, 2003 8:04 pm
- Location: Tijeras, NM
- Contact:
Lead additive
Probably has been a previous discussion but couldn't find it so I'll ask the question here.
After several decades of self-repair, my M38 had a lack of power I couldn't find the cause but I did attribute it to the time I replaced my oil pump and FUBAR'ed from there. Took it to mechanics that restore old cars, well recommended, and quite pleased with the result. However, they said NOT to put in lead additive as it just junks things up, the engine did not need it. I have a chemistry degree and understand mechanics, so I can follow the logic of an opinion, but do not know if this is accurate. What does the board say, lead or no lead in the gas?
Also, is there a procedure written that I can study to time the engine using vacuum, i.e. what and where to hook up equipment and how to use it, etc?
Scott
After several decades of self-repair, my M38 had a lack of power I couldn't find the cause but I did attribute it to the time I replaced my oil pump and FUBAR'ed from there. Took it to mechanics that restore old cars, well recommended, and quite pleased with the result. However, they said NOT to put in lead additive as it just junks things up, the engine did not need it. I have a chemistry degree and understand mechanics, so I can follow the logic of an opinion, but do not know if this is accurate. What does the board say, lead or no lead in the gas?
Also, is there a procedure written that I can study to time the engine using vacuum, i.e. what and where to hook up equipment and how to use it, etc?
Scott
-
- G-Lieutenant General
- Posts: 3505
- Joined: Sat Aug 16, 2003 7:55 pm
- Location: Texas
Re: Lead additive
The problem today is not the lead but the ethanol added to gas today.Ethenol can be very bad on old engines.
- dpcd67
- G-General
- Posts: 11864
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: Lead additive
Do a search here and you will find lots of info on using vacuum gauges. Most of them have the instructions printed with them. All I use for timing is a vacuum gauge and my ears. Never owned a timing light and don't need one.
U. S. Army 28 years.
Armor Branch
Armor Branch
-
- G-Master Sergeant
- Posts: 114
- Joined: Thu Jan 24, 2008 12:57 pm
- Location: Bloomfield, MI
Re: Lead additive
The M38 was designed to run on very low octane gasoline. Lead would be useful if you don't have hardened valve seats, but that's about all. Ethanol is much worse - not for the motor, but things like fuel pumps and carbs. I have been running plain old regular gas for thirteen years now and no ill effects - except for the carb gasket was turned into mush. Otherwise, all OK.
But - use stabilizer unless you're going to burn it up quickly to avoid phase separation.
My .02.
But - use stabilizer unless you're going to burn it up quickly to avoid phase separation.
My .02.
-
- G-Brigadier General
- Posts: 2473
- Joined: Sun Jun 12, 2016 4:56 am
- Location: Birmingham, England
Re: Lead additive
I use an addative in mine, as recommended, seems to run slightly smoother, although it was O.K. before. I guess i was after peace of mind.
-
- G-Lieutenant General
- Posts: 6906
- Joined: Sat Jan 12, 2008 5:25 am
- Location: Tipton,In.
Re: Lead additive
Gummy hit on the purpose of leaded gas. The valve seats. Or lack of.
Old engines, like an L-134 did not originally have valve seat inserts. The seats were cut in the block itself and were soft, compared to the hardened seats used today.
That is why there was lead in the gas. Tetra-ethyl lead ?? Am I close ?? It cushioned the seat so it did not " Hammer" out. In these engines, no lead and the seats failed pretty quickly, especially under heavy use., and you had to adjust the valves constantly.
Lead also has other bad side effects. Beside being poisonous, it would survive the combustion process and be blow out the exhaust. Was polluting our world. Also because it would survive the combustion process, it left what looked like carbon deposits on valve stems. Valve heads and inside the combustion chamber. When scraped or buffed off, it came off as a white powder. "BAD" in a concentrated form.
If you have hard seats installed, you don't need lead, or " lead additive". As I have said before, anything that gets past the combustion process is going to be banned by the EPA, so, the additive might help the intake valves but won't make it to the exhaust valves. ( If it does, it is probably illegal to use ! )
Ethanol. That is another topic !
Old engines, like an L-134 did not originally have valve seat inserts. The seats were cut in the block itself and were soft, compared to the hardened seats used today.
That is why there was lead in the gas. Tetra-ethyl lead ?? Am I close ?? It cushioned the seat so it did not " Hammer" out. In these engines, no lead and the seats failed pretty quickly, especially under heavy use., and you had to adjust the valves constantly.
Lead also has other bad side effects. Beside being poisonous, it would survive the combustion process and be blow out the exhaust. Was polluting our world. Also because it would survive the combustion process, it left what looked like carbon deposits on valve stems. Valve heads and inside the combustion chamber. When scraped or buffed off, it came off as a white powder. "BAD" in a concentrated form.
If you have hard seats installed, you don't need lead, or " lead additive". As I have said before, anything that gets past the combustion process is going to be banned by the EPA, so, the additive might help the intake valves but won't make it to the exhaust valves. ( If it does, it is probably illegal to use ! )
Ethanol. That is another topic !
Mike Wolford
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB
- YLG80
- G-Lieutenant General
- Posts: 4126
- Joined: Fri Aug 05, 2011 9:45 am
- Location: near Namur, Belgium
- Contact:
Re: Lead additive
In 1975, the US army has made extensive tests on many unmodified vehicles with unleaded fuel.
The conclusion was clear: they could not link any engine problem to unleaded gas even exhaust valves recessions.
The study is available on the Net.
However since that study, it's admitted that if your vintage engine is operated continuously above 3500 rpm or in heavy load conditions, then you will have problems.
For that reason I will never drive my jeep on a highway
In the past, I've seen columns of jeeps going to the Normandy beaches via the highway, with a minimum speed of 70km/h
I'm located in Belgium and Normandy is not close to Belgium
I'm pretty sure it was a disaster for the engines.
Other than that I simply add some lead substitute additive to the gas.
Yves
The conclusion was clear: they could not link any engine problem to unleaded gas even exhaust valves recessions.
The study is available on the Net.
However since that study, it's admitted that if your vintage engine is operated continuously above 3500 rpm or in heavy load conditions, then you will have problems.
For that reason I will never drive my jeep on a highway
In the past, I've seen columns of jeeps going to the Normandy beaches via the highway, with a minimum speed of 70km/h
I'm located in Belgium and Normandy is not close to Belgium
I'm pretty sure it was a disaster for the engines.
Other than that I simply add some lead substitute additive to the gas.
Yves
Ford GPW 1943 - Louisville - DoD 12-7-43
serial 164794
serial 164794
-
- Sergeant Major of the Gee
- Posts: 429
- Joined: Tue Oct 24, 2017 7:19 pm
- Location: Central Arkansas
Re: Lead additive
On the subject of additives, what about isopropyl alcohol added to the ethanol free gas periodically to "clean" the carburetor?
Jay
Jay
43 GPW 110748
52 M38
44 Bantam T3
45 GPW 277391
52 M38
44 Bantam T3
45 GPW 277391
-
- G-Master Sergeant
- Posts: 114
- Joined: Thu Jan 24, 2008 12:57 pm
- Location: Bloomfield, MI
Re: Lead additive
I would prefer to change my fuel filter. Gas has enough alcohol in it already. If you drive THAT many miles, maybe take the carburetor off and clean it on the bench. I know several convoy participants. I'll ask them about 5,000 miles + per year and gasoline/lead/ethanol.
- YLG80
- G-Lieutenant General
- Posts: 4126
- Joined: Fri Aug 05, 2011 9:45 am
- Location: near Namur, Belgium
- Contact:
Re: Lead additive
Jay was talking about ethanol free gas.
Yes the alcohol is good solvent for gums accumulated in the carb.
The cleaning additives have a good percentage of alcohol in their composition.
Yves
Ford GPW 1943 - Louisville - DoD 12-7-43
serial 164794
serial 164794
- Scoutpilot
- G-Lieutenant General
- Posts: 7338
- Joined: Sun May 28, 2006 1:22 pm
- Location: Asheboro, NC
Re: Lead additive
Look here. http://oldjeepcarbs.com/thread/29/time- ... ming-lightThere is a video there as well.Also, is there a procedure written that I can study to time the engine using vacuum, i.e. what and where to hook up equipment and how to use it, etc?
'70-'71 'A' Batt., 377th FA, 101AB
(Slicks and LOH's)(Col's LOH Pilot)
'71-72 CHARLIE TROOP,
16TH AIR CAV, 1ST AVN BDE (AEROSCOUTS)
LOW LEVEL HELL.
'46 CJ2A
'47 CJ2A
'48 CJ2A
'48 B1PW126
'69 CJ5
(Slicks and LOH's)(Col's LOH Pilot)
'71-72 CHARLIE TROOP,
16TH AIR CAV, 1ST AVN BDE (AEROSCOUTS)
LOW LEVEL HELL.
'46 CJ2A
'47 CJ2A
'48 CJ2A
'48 B1PW126
'69 CJ5
Who is online
Users browsing this forum: No registered users and 22 guests