Print Page | Close Window

what type of gas

Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC 6 Cylinder Engine Repair and Modifications
Forum Description: AMC-made I-6 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=89065
Printed Date: Mar/29/2024 at 9:54am
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com


Topic: what type of gas
Posted By: Rogue Rod
Subject: what type of gas
Date Posted: Aug/10/2017 at 3:02pm
Hello:
My 67 Rogue convertible ( big 6 cylinder) restoration is complete and the car drives looks and drives like a dream. My gas is what type of gas is recommended: regular unleaded, unleaded spiked with a lead additive or premium unleaded. I appreciate all responses.

Rogue Rod



Replies:
Posted By: rockAMX
Date Posted: Aug/10/2017 at 3:13pm
91 unleaded is fine if you have hardened valve seats in the head. The bigger concern is ethanol. It will wreck your fuel lines and pump over time. Shell V-power gas is ethanol free in Canada.

-------------
DWR
1968 AMX



Posted By: 6768rogues
Date Posted: Aug/10/2017 at 3:26pm
I replaced the rubber fuel line parts and cleaned the fuel system in my 67 Rogue convertible 232 2-bbl about 13 years ago. I use the cheapest regular I can find, with 10% ethanol. It runs perfect and I have put over 35,000 miles on it since then.
We can get premium non-ethanol gas but it costs a lot more. If my car needed premium, I would consider it. It runs great on regular.
Ethanol can damage rubber parts and it can clean stuff from the system and move it through. If you have a clean system and no old rubber parts, it is good. I have not replaced a fuel filter in 35,000 miles. I never gave a thought to the fuel pump. It was a rebuilt back when I went through the car and I drove it today, still works fine.
If it is tuned properly and in good shape, pull in and buy the cheap stuff. People with those engines in Jeeps have been doing it for decades. People who build Jeep engines by the hundreds have told me that they have never seen valve damage from unleaded gas. Gas costs more in Canada than here, so buy cheap stuff and drive more.


-------------
Content intended for mature audiences. If you experience nausea or diarrhea, stop reading and seek medical attention.

Located usually near Rochester, NY and sometimes central FL.


Posted By: rockAMX
Date Posted: Aug/10/2017 at 5:29pm
Well if it were up to me, I would not go to the time and money to do a complete restoration and then put the cheapest gas I could find in the tank. I would never recommend to that person to use the cheapest thing out there. In Canada, we leave our cars in storage for 6 months in the winter. Leaving ethanol gas in the fuel system is a bad idea.

I would also recommend using a high zinc oil with a flat tappet cam engine. I suppose one could use the cheapest oil one could find as well, but that is bad advice.

But a few bucks more for a fill at the gas pump is worth the peace of mind. Ethanol can also raise the engine temperature, creating manifold problems and so on. It also reduces fuel economy by about 3% - modest to be sure. Ethanol does not clean anything in the fuel system. It is merely a filler so that less gasoline is used. But for some cars, it is never a problem.


-------------
DWR
1968 AMX



Posted By: billd
Date Posted: Aug/10/2017 at 6:32pm
Originally posted by rockAMX rockAMX wrote:

91 unleaded is fine if you have hardened valve seats in the head. The bigger concern is ethanol. It will wreck your fuel lines and pump over time. Shell V-power gas is ethanol free in Canada.


Old myth or problems incorrectly attributed to ethanol. I've run it in almost everything I've owned since about 1980 - no issues. No fuel pump troubles, no fuel line troubles, no carburetor troubles. 
I run it in my JD lawn tractor, my chainsaw, Jeep, pickup, my '36 F20 when I had it, my 70 and 73 Javelins and my SX4 with a 4.0.

I've not had to replace more than 1 fuel line in 10 years and I can't say what the issue was with it other than I sort of wonder if I failed to replace it when I first got that car running. 
Modern fuel hose and pumps handle it fine and carburetors since about 1980 handle it, too, when the companies made changes and carb KITS were changed. 
I was a tech when it first came to Iowa and have been using it since, and worked on hundreds of cars since then as well. 

Unless you use heavier valve springs, higher lift cam, etc. even stock heads should do fine. 
I run stock pump gas - 10%, and in Iowa, it's a whole lot cheaper than non-ethanol fuel (due to the tax breaks it gets)
My 70 actually does best on Walmart premium ethanol. It runs better and pings less when hot. 

-------------


http://theamcpages.com" rel="nofollow - http://theamcpages.com

http://antique-engines.com" rel="nofollow - http://antique-engines.com


Posted By: billd
Date Posted: Aug/10/2017 at 6:39pm
PS - the high zinc part has been debunked by engineers and load testing as well.
There is oil out there with less zinc than others that actually protects better than higher zinc oil. Zinc is only part of the equation.
I run synthetic oil in my 4.0 - no additives, and have a Comp XE cam in it. 
I run standard quality oil in both Javelins, zero cam issues and have a Comp XE in the 70 and a fairly strong cam in the 73

I need to find my notes on the zinc oil tests and try to put that to rest. When tests are done in the lab showing the differences it's pretty telling. The reports also showed that some of the additives caused the oil to protect LESS than if one had not added the additives with zinc. 
But some would rather not believe scientific tests so I'm not sure it's worth my time and effort to present facts and science. 

The issue with cams is when they are new - and a respected engine guy, who worked with Isky and others in the 60s, explained it well in a book I have. I'm sure some would argue with him as well. 
My 70 has 12 years on the build and the cam and lifters look like brand new - even the XE cam with the more radical ramps (I swapped intakes a couple of times and checked the cam and lifters both times just to satisfy myself, paranoia and all)
Not sure about the 73 - it's a 360 that was built to 400 hp by the previous owner and I put in decent 10w40 and it's been fine.
My 4.0 has 30,000 miles on the rebuild, strong as ever.

-------------


http://theamcpages.com" rel="nofollow - http://theamcpages.com

http://antique-engines.com" rel="nofollow - http://antique-engines.com


Posted By: FSJunkie
Date Posted: Aug/11/2017 at 2:25am
87 AKI (91 RON) regular unleaded, up to 10% ethanol. Drive it at least once every two weeks and enough miles that you go through a full tank of gas at least every two months.

Where people get in trouble with ethanol is if their fuel system I already in bad shape (old rubber that should have been replaced decades ago), if they don't drive their car enough so the fuel absorbs moisture, or if they don't drive it enough so that the fuel dries out in the carb/lines. If you drive your cars like they were meant to they do fine on ethanol. 

10% ethanol fuel runs 3% leaner, which is significant. Some cars run too lean and need larger jets in the carburetor. Most engines, however, are fine with their factory jetting. 

Forget the myth about ethanol fuel causing vapor lock. Look up the Reid Vapor Pressure or RVP of fuel over the last five decades. This is a measurement of the fuel's tendency to vaporize. In other words: it's tendency to vapor lock. RVP has actually been REDUCED in the past few decades to reduce evaporative emissions. Fuel has never been better at resisting vapor lock. Both ethanol and non-ethanol fuel has to meet the same RVP. The problem is with us: the drivers. We've been spoiled by cars with fuel injection that never ever vapor lock and most drivers don't know what to do when vapor lock happens. Most push the throttle pedal MORE when they feel vapor lock, which is the opposite of what you need to do. People used to know that back then. It was part of knowing how to drive. That was also back when people knew how to operate manual chokes and double clutch...

Unleaded will reduce the life of your valve seats. How much is uncertain; there are a lot of factors affecting seat life, but it's all a matter of time. By the time they fail, the engine will likely be due for a top-end rebuild anyway. At that time you can take the head to a machine shop where they will install hardened valve seats for unleaded gas that will last MUCH longer this time. Now with a reconditioned head (valve job), new timing chain, and new cam/lifters if needed, your engine will breathe new life for a long time. 




-------------
1955 Packard
1966 Marlin
1972 Wagoneer
1973 Ambassador
1977 Hornet
1982 Concord D/L
1984 Eagle Limited


Posted By: electricbluesc/360
Date Posted: Aug/11/2017 at 2:53am
Originally posted by rockAMX rockAMX wrote:

Well if it were up to me, I would not go to the time and money to do a complete restoration and then put the cheapest gas I could find in the tank. I would never recommend to that person to use the cheapest thing out there. In Canada, we leave our cars in storage for 6 months in the winter. Leaving ethanol gas in the fuel system is a bad idea.

I would also recommend using a high zinc oil with a flat tappet cam engine. I suppose one could use the cheapest oil one could find as well, but that is bad advice.

But a few bucks more for a fill at the gas pump is worth the peace of mind. Ethanol can also raise the engine temperature, creating manifold problems and so on. It also reduces fuel economy by about 3% - modest to be sure. Ethanol does not clean anything in the fuel system. It is merely a filler so that less gasoline is used. But for some cars, it is never a problem.



Agree 100% with all of this. Most factual post on this thread.

-------------
sc/360 hornet


Posted By: billd
Date Posted: Aug/11/2017 at 7:06am
You have to be kidding me!? Factual?
Ethanol sure does clean - if you ever worked as a tech when it first came out you'd know that. In fact most cleaners and gas line antifreeze contains alcohol. You can watch it work in a small tank with little water droplets in the bottom. It has an affinity for water and absorbs all it can, what it can't, is left - unless you add the gas line treatment to absorb the rest. 
Where does it ever create manifold problems?
This is crazy, more old myth and old wives' tails that fact - pure and simple. I have a degree in this sort of thing, training by SUN with a certificate on fuel systems and you believe the BS on the anti-ethanol sites and "my friend's brother in law had a cousin" instead of fact.  What a joke. Remind me to never let either of you touch any of my stuff. 

People come here for facts, not BS like this. Of all the people who have run it in everything for decades, a couple of you come here not with real fact, but with stuff found on anti-ethanol sites. Not with real experiences, but with this sort of stuff. 

When you study this in college and have over 40 years experience with ethanol in hundreds, not 3 or 4, but hundreds of cars, come back with FACT.

For truth about ethanol fuels, go to ISU's site - the place where the computer and fax machine technology were invented, much space exploration technology came from, etc. They have dealt with the study of fuels for many years and they tell the good and the bad (fact is there's not as much bad as some would have you believe).

You can believe fact, science and REAL EXPERIENCE, or stuff repeated over the years and like many things, keeps getting bigger and badder............



-------------


http://theamcpages.com" rel="nofollow - http://theamcpages.com

http://antique-engines.com" rel="nofollow - http://antique-engines.com


Posted By: 6768rogues
Date Posted: Aug/11/2017 at 7:57am
Again, I use the gas that is the cheapest. None of them are inferior, buying a specific brand when it costs more is a waste of money. Gas formulations are closely regulated in the US, no idea what our friends north of the border get.
I store my vehicles for extended time by simply putting cheap 10% ethanol and StaBil in them and running them until it is through the system. I recently got my Jeep out from a 4 year slumber and took it to Kenosha. It started right up, I drove it all around Kenosha, and then came home to put it back to sleep. I keep my cars in a climate controlled building and that is more important than what gas is in them. No condensation and no temperature fluctuations. Unhook the battery, put a maintainer on it, and it is good for long periods coming out just like it went in.
The days of extreme gas formulation variances are long gone. It is not all the same, but there are no appreciable differences.  If it makes you feel good to waste money buying something that exceeds the needs of your car, go ahead. I have a lot more money in my new pickup truck than I have in any of my AMCs and I just pull in and fill it up at any reasonably priced station. If the manufacturer said to avoid a brand I would, but they never do because they know it all acts the same. New vehicles have more sophisticated systems than old ones and all gas works. Old cars will let all kinds of garbage go through the system compared to new ones. When was the last time you saw a new car broken down because of bad gas? I remember it years ago when gas was unpredictable, but not any more.
I use Walmart oil, too. It is about 10 generations improved over what old cars were designed for, so I am automatically far exceeding their needs simply by using modern oil.
The bottom line is that it is your money. If I had to pay the prices that you pay in Canada for gas, there is no way I would look around for a higher price.
Some people think their cars care. The car doesn't care. If gas and oil meet the octane and lubrication needs of the car, anything else is wasted. I don't race or run them hot, so meeting their needs is sufficient.
One of the gas companies advertised that they added nitrogen to their gas. Catalytic converters remove oxides of nitrogen. Nitrogen is inert and does not contribute to combustion, while its volume displaces other things you want in the combustion chamber. I have no idea why I would want nitrogen added to my fuel. Some people thought it was better.


-------------
Content intended for mature audiences. If you experience nausea or diarrhea, stop reading and seek medical attention.

Located usually near Rochester, NY and sometimes central FL.


Posted By: nickleone
Date Posted: Aug/11/2017 at 4:03pm
High ZINC oil for break in of FLAT TAPPET camshafts.
Recommended by most cam makers.

Nick


-------------
nick
401 71 Gremlin pro rally car sold
390 V8 SX/4 pro rally car sold
1962 Classic SW T5 4 wheel disc brakes


Posted By: Rogue Rod
Date Posted: Aug/12/2017 at 6:55am
Thanks to all for their detailed responses. Lots of detail to digest, I appreciate it.  


Posted By: Ollie
Date Posted: Aug/12/2017 at 7:32am
Originally posted by FSJunkie FSJunkie wrote:


...........10% ethanol fuel runs 3% leaner, which is significant. Some cars run too lean and need larger jets in the carburetor..........



I agree with this statement. I put a Carter YF on the 199 that was in The Rambler. It was a factory size jet. It was getting 18-20 MPG. I went up one size jet and my mpg jumped to 20-22. (That is the motor and transmission that is now in Rapid Delivery)

Having AMC Fun,
Ollie

-------------
1966 American Convertible -- "The Rambler"..SOLD
1974 Postal Jeep -- "Rapid Delivery"...SOLD
1969 Rambler 220 post car--"Road Warrior"
1989 Jeep Comanche Pioneer, 4.0L, auto, 2wd


Posted By: 6768rogues
Date Posted: Aug/12/2017 at 7:51am
Any modern gas formulation is very different from gas 40 or 50 years ago and an old car needs to be tuned to run on modern gas. When they are, they run great.

-------------
Content intended for mature audiences. If you experience nausea or diarrhea, stop reading and seek medical attention.

Located usually near Rochester, NY and sometimes central FL.


Posted By: farna
Date Posted: Aug/12/2017 at 10:53am
Now that last statement is a fact! Modern gas will generally take more timing too, so set timing by the book to start with, then go out and find a hill to pull and bump it up until you get ping, then lower a bit. Might want to put a light on it to see where it is, record for future use. Setting it "by ear" like that on a cool day will likely require a slight adjustment on a hot day (more likely o get ping on a hot day), but it's the only way I know of to get the most timing on the gasoline you are running.

You need a "break-in additive" to break a new flat tappet cam in regardless of type of build -- stock to full race. After that regular "cheap" oil will be fine for stock valve springs as long as the oil has an API rating. Non-rated oils (some race oils) could be suspect, as they can be formulated however the company wants. Current oil is SN, but SF or more (F-N in the alphabet) is suitable. Actually, SD started in 1967 and would technically be fine for most of our cars. but the SAE only recommends SF or newer in all vehicles.

I got to have a discussion with an oil company engineer a few years ago regarding the removal of zinc. He stated that it was safe for all stock motors with the exception of some of the 1960s "hi-po" models. The general rule is anything with valve springs under around 300# of pressure open needs more high pressure lubricant than current oil standards have.  Crane sells a 330# spring for AMC six cylinders that should still be fine, but that's on the edge. So if you're building a race engine with a high lift/long duration cam and stiff springs you need to run an off-road racing oil or use an additive. I use the break-in additive to break a flat tappet motor in, then use it in the first oil change just to be safe, but none after that. There are other additives in modern oil that make if safer than older oil formulations. The engineer stated he'd not run older oil in anything. From the SAE specs page, SM oil was "Introduced in October 2010 for 2011 and older vehicles, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility (than older spec oil)."

All the stuff about ethanol fuels is a joke, just like taking the lead out of gasoline ages ago. There is a little increase in wear with unleaded gas in an engine designed for leaded gas, but for 90% of engines it's very little. There is a noticeable increase on hard worked engines, such as heavy trucks (towing) and race engines. Even then it's in the 20-25% range -- for most it's 10% or less extra wear. So if you would rebuild a head at 100K miles, you do it at 90K or so instead. Even then valve seat inserts aren't really necessary -- the valves can generally be ground twice before the seats start to wear down into the head to the point inserts are required. Inserts are common enough now that they are relatively inexpensive to have installed, so you may as well if the engine is being rebuilt. Generally $15-25 a seat (if doing more than one), and you really only need to do the exhaust seats -- no extra wear on intake seats.


-------------
Frank Swygert


Posted By: Ollie
Date Posted: Aug/12/2017 at 1:19pm
I don't own a timing light.
I set everything with my vacuum gauge.
Every engine has a sweet spot.



Having AMC Fun,
Ollie

-------------
1966 American Convertible -- "The Rambler"..SOLD
1974 Postal Jeep -- "Rapid Delivery"...SOLD
1969 Rambler 220 post car--"Road Warrior"
1989 Jeep Comanche Pioneer, 4.0L, auto, 2wd


Posted By: electricbluesc/360
Date Posted: Aug/13/2017 at 12:33am
Originally posted by billd billd wrote:


You have to be kidding me!? Factual?
Ethanol sure does clean - if you ever worked as a tech when it first came out you'd know that. In fact most cleaners and gas line antifreeze contains alcohol. You can watch it work in a small tank with little water droplets in the bottom. It has an affinity for water and absorbs all it can, what it can't, is left - unless you add the gas line treatment to absorb the rest. 
Where does it ever create manifold problems?
This is crazy, more old myth and old wives' tails that fact - pure and simple. I have a degree in this sort of thing, training by SUN with a certificate on fuel systems and you believe the BS on the anti-ethanol sites and "my friend's brother in law had a cousin" instead of fact.  What a joke. Remind me to never let either of you touch any of my stuff. 

People come here for facts, not BS like this. Of all the people who have run it in everything for decades, a couple of you come here not with real fact, but with stuff found on anti-ethanol sites. Not with real experiences, but with this sort of stuff. 

When you study this in college and have over 40 years experience with ethanol in hundreds, not 3 or 4, but hundreds of cars, come back with FACT.


For truth about ethanol fuels, go to ISU's site - the place where the computer and fax machine technology were invented, much space exploration technology came from, etc. They have dealt with the study of fuels for many years and they tell the good and the bad (fact is there's not as much bad as some would have you believe).

You can believe fact, science and REAL EXPERIENCE, or stuff repeated over the years and like many things, keeps getting bigger and badder...........


"Remind me to never let either of you two to touch my stuff".....likewise Billy
Please stop on spreading your misinformation bill! Your perception of zinc in a flat tappet
engine is completely wrong.. How many have you built? Are you 60 or 160
years old? I'm guessing 160, due to your VAST knowledge on everything you post on.
SUN CERTIFICATE- lmao!!!!!


-------------
sc/360 hornet


Posted By: vinny
Date Posted: Aug/13/2017 at 9:25am
I also read that article by the engineer that did oil testing which basically stated that with the addition of additives most oils performed worse than without them. I believe that.

I had a problem with cheap gas bought at a place called Discount gas in Edmonton back in the winter of 77-78. It was around minus 40 and it took me a couple of days to get my car started. After that when cold I would buy the premium at a big name station and car started much better. I don't think they put ethanol in it back then.

My Rambler has 155,000 miles on it now and onto its second engine but still AFAIK both engines with original fuel pumps and carburetors. I buy the regular with up to 10 % ethanol without problems. One thing when using ethanol you don;t need to worry about gas lines freezing up.


Posted By: 6PakBee
Date Posted: Aug/13/2017 at 9:27am
I have no dog in this fight.  I buy the cheapest gas that will work acceptably.  But I do note this post is going the same path as the synthetic oil one.
  :popcorn:

-------------
Roger Gazur
1969 'B' Scheme SC/Rambler
1970 RWB 4-spd Machine
1970 Sonic Silver auto AMX

All project cars.

Forum Cockroach


Posted By: MaxiBlue
Date Posted: Aug/18/2017 at 12:40am
I personally don't mind what others do, it's their car.  But I noticed with my gremlin (232, Carter YF) that the needle and seat in the carb stick when I use ethanol fuel.  The car would run out of fuel with a full tank, and I'll pull the top of the carb, and the bowl is empty.  I put it together, and it overflows through the vent.  Next time, it will run fine for a little while and then run out of fuel again.  That float/ needle and seat were driving me nuts for about a day and a half.  Through trying different needles and seats and then trying different fuels, I found that the ethanol added fuel was the culprit.  I can get fuel without ethanol, but it's only the premium around here.  I use premium to avoid ethanol, and the needle and seat have stopped sticking.  I've even tested it with two gas cans, swapping a hose from the pump from can to can.  It makes a difference in my car almost immediately.  I've heard (only rumor) that the old rubber tipped needles aren't compatible with ethanol and swell with the fuel and that causes them to stick.  From my own personal experience, I buy this.  The gremlin gets shell premium.  I've also noticed that it idles better (especially when cold) on the non ethanol fuel.

These are my observations on my car.  If you have differing results with your car, just keep doing what works for you.  I will likewise.

Scott


Posted By: farna
Date Posted: Aug/18/2017 at 6:50am
Well, a new carb kit should have a solid brass or Delrin tipped needle that is compatible with ethanol. I can understand the bit better idle when cold with non-ethanol though. One reason more than 10% ethanol doesn't work well in cars made for normal driving is cold weather performance. E-85 is blended with less alcohol for winter as well -- it's not really E-85 in winter. 

-------------
Frank Swygert



Print Page | Close Window

Forum Software by Web Wiz Forums® version 12.03 - http://www.webwizforums.com
Copyright ©2001-2019 Web Wiz Ltd. - https://www.webwiz.net