Fuel Additive for 70 Cuda?

[Alec Taylor]

Hi

I recently purchased by first vintage MOPAR. I will probably be
posting tons of (newbie) questions over the next several weeks so
please be patient with me.

Question:
Should I add any fuel additives to my 70 AAR Cuda? If so, what?

I have heard many conflicting opinions on this issue and I'll let this
group settle it for good.

Thanks for your time!

Alec Taylor

[RedNeck TookOver Hell]

What "fuel additives" are you talking about?
Is this your daily driver?
Nobody on here is a mind reader

>>Question:
>Should I add any fuel additives to my 70 AAR Cuda? If so, what?
>

I'll start watching reality TV shows, when I can vote people off the planet.

[Hemi4268]

>Nobody on here is a mind reader
>
>

This is kinda a funny post. Let me bring out the worst in him by saying the
following. If in fact this person did buy a AAR, I think the last thing he
would be asking is a question about fuel.

Larry

[John Kunkel]

"Alec Taylor" <al...@email.com> wrote in message
news:7167a5ba.03102...@posting.google.com...

You won't get it settled on this group or anywhere else, the debate over the
need for lead to prevent detonation and to lubricate the valve seats goes
on and on.
If you don't have detonation and don't run it hard, you might get by without
the need for additives.
John

[Neil Nelson]

In article <20031028125647...@mb-m28.aol.com>,
hemi...@aol.com (Hemi4268) wrote:

Why?

(had to bite)

[Hemi4268]

>Why?
>
>(had to bite)
>

It's like this..

A guy sees an old car advertised in the paper. Says a nice condition 70 so and
so for $5000. Guy buys car and asks questions later. Sure happens all the
time.

Or Guy sees nice AAR Cuda advertised for $25,000. Guy buys car and ask
questions later. No way.

You drop $25,000 for a car you already know all the answers to any questions on
upkeep.

Larry

[Neil Nelson]

In article <20031028213655...@mb-m06.aol.com>,
hemi...@aol.com (Hemi4268) wrote:

Thanks Larry.

I guess there was a remote possibility that you'd found your mind.

Naaa.... It's still lost.

[Bryan Swadener]

Hi Alec,

 

First, the only bad question is the one not asked -- don't be afraid to ask questions.

The engine in your '70 AAR has concerns similar to any MoPar of that vintage (I own '68 and '69 340-S Barracudas).  These engines were made when there was typically 4 grams/gallon of tetraethyl lead in the fuel. Without that, and with the OEM valve seats in the heads, you can expect the exhaust valves to pound the seats out in short-order.  Tetraethyl lead as an additive, isn't easy to come by and is highly toxic so, the answer is to have the seats in the heads replaced with hardened inserts.  Also, the guides in the OEM heads were cast iron and will quickly be worn, to the point that the valve seals... won't. When you have the heads off for installation of the hard seats, have the guides replaced with silicon-phosphor-manganese-bronze types. They run at a much clearance than cast-iron guides (so close that some people elect to not run teflon seals).  But, teflon seals are better than the OEM rubber "umbrella" seals, and still dirt-cheap.

The other issue is the octane rating of the fuel vs the compression ratio of the engine.  The 340 thru '71 ran an advertised 10.5:1 compression ratio.  In practice, it ain't gonna be that high unless the heads and/or decks have been cut a lot. As long as the CR isn't much over 10:1, you should be able to get away with running a good grade of super for fuel, and limiting the ignition advance to no more than about 34° (total).  If it pings, try backing off the ignition advance (assuming the carburetors aren't jetted too lean).

 

Bryan Swadener

Everett, WA

'68 340-S Barracuda fastback

'69 340-S Barracuda ragged-top

 

"Alec Taylor" <al...@email.com> wrote in message news:7167a5ba.03102...@posting.google.com...

[Alec Taylor]

Bryan

Thanks for the civil response. The car was rotisseried in 2000 by
Reid Stevens in Maine. Can I assume the mods you mentioned were done?
I'm in the process of getting in touch with Reid to ask him some of
this.

Is there a way by visual inspection that I can tell if they were done?
Also, I am owed pictures of the restoration. I assume I can tell
through them.

Alas, not all of my questions on upkeep were not answered prior to
purchase. The car was a steal and I wanted to snag her before someone
else did.

Thanks again,
Alec Taylor

[Hemi4268]

>Alas, not all of my questions on upkeep were not answered prior to
>purchase. The car was a steal and I wanted to snag her before someone
>else did.

A rotisseried restoration no less. Sure it was a steal at $10,000. Could be a
steal at $20,000 then again it's a steal at $30,000 which is about half of
restoration costs.

If indeed it is a rotisseried restoration AAR you should have way more
questions then fuel additive which is the least of your problems in storage.

Leaded or unleaded fuel is realy not an issue. Some people make it an issue
but for your car it's not. Amoco had been selling hi-test unleaded fuel since
the mid 50's. Lots of people liked it as it kept carbs and sparkplugs clean
and the exhaust system lasted forever.

Lead only comes an issue if your going drag race or pulling a trailer. Your
not as no one drag races a rotisseried restoration.

Besides, with an AAR you would lose as these cars usually ran in the mid 14's
even with 3.91 gears.

Don't get me wrong, they are nice "in your face" cars and the 340 can run. Hot
Rod Magazine had a feature on a 71 Cuda 340 the the big Thermoquad and 3.91
gears. Ran high 13's and was just about as fast as a 71 Challenger 440/6 they
were also testing.

Larry

[dodgeboy]

We'll like the said before, it's a million opinions.
Facts lead help lubricate and cool valve seat.
Facts lead helped reduce detonation as it retards flame travel. (slows
the burn down)
Facts Mopar heads are plenty hard (high nickel content as opposed to GM)
(seats will outlast wimpy bow tie heads)

That said, new high test fuels will work just fine! As stated before if
it detonates you will want to reduce timing and or richen it up a bit.
(rich mixtures burn slower and colder) ( a couple jet sizes from stock
is more than enough). Where you live can be a factor in final jetting!
(altitude)
Adding some 104 and or other lead containing additive will not hurt and
will help slightly. I personally feel the cost is more than the benefit.
Save the money and put it towards a good valve job (maybe install
hardened seats) way off in the future if it needs a valve job
prematurely in the future.

How is the engines and more importantly the heads condition now??
If you only drive it occasionally to shows and the odd cruise, pour on
the additives. The piece of mind will probably be more beneficial than
additives themselves but sleep is important!

Oh!! Ignore Larry, some how a simple question about gas additives gets
him off on his $200,000 restoration rants. Larry's a moron 98% of the
time. harmless if you ignore him and the other 2% of the time he has
some stuff to contribute a couple nice cars and a cool cross ram hot
stand pet!!
Barry A. Lee

[Hemi4268]

>Oh!! Ignore Larry, some how a simple question about gas additives gets
>him off on his $200,000 restoration rants.

Hey, let make that a even million.

Larry

[Hemi4268]

>Facts Mopar heads are plenty hard (high nickel content as opposed to GM)
>(seats will outlast wimpy bow tie heads)

This is very true. And speaking a a million dollars. If someone said that
they would give you a million dollars if you could sink the valves in your AAR
in under 10000 miles using 93 Exxon unleaded, you would loose.

Larry

[RedNeck TookOver Hell]

>Adding some 104 and or other lead containing additive will not hurt

They do not contain lead, they are lead SUBSTITUTES. 104 will turn your spark
plugs orange, no harm, just looks strange
If lead and/or octane is his concern, he'd be way ahead to add 110 racing gas
to his "92" if he's going to drive it
Tetraethyl lead, by itself, is VERY toxic and if you are working with it,
you'd better have one of those "moon man suits"
Now the man has never said what his concerns are nor has he said what his usage
is for the car.
BTW, what kind of gasoline do they use in small planes in Canada?

[Alec Taylor]

> If indeed it is a rotisseried restoration AAR you should have way more
> questions then fuel additive which is the least of your problems in storage.

Larry

Like I said, I'm completely new to this. I'm starting from ground
zero and working my way up. She arrived with just a couple of gallons
of gas in her. I didn't want to start off by (potentially) wrecking
the engine. Given that she'll be sitting in my garage during this
upcoming Maryland winter, what types of maintenance/upkeep things
should I be thinking about?

BTW, here she is: http://www.taylor5.net/cudaside.jpg

Thanks for your time,
Alec Taylor

[dodgeboy]

AV 100 low lead (its 104 to 110 test octane) the government has got
sticky and many won't sell it to you unless you have a plane!!
Course it's driven by the road tax issue as well as the lead!!
Barry A. Lee

[RedNeck TookOver Hell]

> Given that she'll be sitting in my garage during this upcoming Maryland
winter, what types of maintenance/upkeep things
should I be thinking about?

NOW we are starting to get somewhere

[dodgeboy]

Fist off a good antifreeze!! Oil change and filter before sitting. Full
tank of gas with gas line antifreeze or other moisture absorbing
alcohol. Some gas stabilizer too for sure. Off tires if possible or move
it back and forth through winter.
Start it up and let it worm up every two to 4 weeks if possible.
Unhook positive battery cable while stored.
Barry A. Lee

[dodgeboy]

After reading it below!! fist off is not a good antifreeze. But I
recommend good antifreeze for your storage.
Barry A. Lee

[Bryan Swadener]

Alec,

 

I agree with everything Barry says except that MoPar heads will (significantly) outlast anything else because of metallurgy...

 

The heads on the '70 340 I had rebuilt were leaking past the exhaust valves very badly in about 50K miles, and power wasn't what it was when they were new.  My machinist confirmed what my leak check indicated... the seats were being pounded into the heads. After installing hard seats, the heads now have more miles than that on them, and it pulls as hard as it did when I put the heads (back) on the engine.  Because I run straight race gas (4g/gallon of lead) in the hotrod, I have no need to run hard exhaust seats.

 

Chrysler started using hard seats sometime in the late 70s... I dunno when. It can't be a bad thing to make sure you have 'em -- but if it doesn't have 'em now, you could just as well wait 'til the exhaust seats go away. Using a lead-substitute will only delay how soon the seats sink into the heads... it's your call as to whether or not it's worth the expense.

 

Bryan Swadener

 

"dodgeboy" <68gtx...@rogers.com> wrote in message news:lrRnb.101203$3f.2...@twister01.bloor.is.net.cable.rogers.com...

[RedNeck TookOver Hell]

>AV 100 low lead (its 104 to 110 test octane) the government has got
>sticky and many won't sell it to you unless you have a plane!!

Exactly what I figured. You know small airplane engines were never redesigned
for unleaded fuel.
I guarantee that "low lead" stuff has got enough lead to keep the valves from
receding.in that airplane engine
As far as owning a plane and road taxes go, if Canadians are half as ingenious
as Americans, it ain't a problem.
I'm not saying to use AvGas in your car, because that is another whole debate
Some say it's fine, some say no way
Personally I've tried it, never had a problem

[dodgeboy]

I really liked it too!
Barry A. Lee

[Bscuda]

Worked great in my dad's 340 mixed 50/50!!

Bob

"dodgeboy" <68gtx...@rogers.com> wrote in message

news:rqgob.127726$h61....@news01.bloor.is.net.cable.rogers.com...

[michael]

Bscuda wrote:

7 or 8 years ago our daily driver was a 64 Belvedere with a poly. I would add
3-4 gallons of 100LL to a tank and got a noticable increase in power and ended
pinging when pulling the steeper hills. One thing to keep in mind is that avgas
is formulated to atomize in colder atmospheric conditions. Just a semieducated
guess on my part is that adding too much may result in a case of diminishing
returns. The fuel not atomizing at proper levels would likely net less power.
Certainly an optimum ratio exists. Maybe someone has that info to share.
No time comparisons were done when I was mixing, but one day the wife came back
from running errands and asked if I did something to the car. I asked what was
wrong, not letting on, and she said nothing, just that she dusted everybody
coming back up the hill and had to watch her speed cause the car was running so
well. That's when I told her about the avgas. She said it was okay to put it in
*her car* anytime.

michael

[Bscuda]

Only problem I have with that theory is: An airplane needs more power at
takeoff and go around than any other time. The engines are setup to develop
full power on take off. If they can't do that, they are grounded.

Bob

"michael" <tail...@hitechnetworks.net> wrote in message
news:3FA36738...@hitechnetworks.net...

[michael]

Bscuda wrote:

> Only problem I have with that theory is: An airplane needs more power at
> takeoff and go around than any other time. The engines are setup to develop
> full power on take off. If they can't do that, they are grounded.
>
> Bob
>

That's a good point. I'm thinking that, as in most things, there would be
something of a trade-off. Aircraft do spend the highest portion of engine on
time in flight, rather than in ground ops. I'll try to pursue this with someone
I know that flies regularly, as this is not my field of expertice.

michael

[Joshua Skinner]

Plenty of road racers here in the Pacific NW run 100LL in their race cars. I run it
in my '66 Dart. I used to be able to buy the stuff about 5 miles from the house,
but the little oil company that carried it was either bought out or sold out to a
larger regional company. I have to check with the new company to see if they will
be selling the AvGas again. They have it in Salem, but I'm not driving 40 miles for
fuel.

The only thing to worry about with the 100LL is that the specific gravity is
slightly lower (less dense) than most pump gas and most all racing gasolines. This
means that if your jetting is absolutely spot on with say 76 racing 100 octane
unleaded you will probably need to go up one or two jet sizes if you run 100LL
AvGas. Most street cars are too rich to begin with so not much to worry about on
the street.

Joshua Skinner

[Hemi4268]

>Only problem I have with that theory is: An airplane needs more power at
>> takeoff and go around than any other time. The engines are setup to develop
>> full power on take off.

I think the fuel mixture is adjustable in the cockpit. In fact that's why a
cockpit is named a cockpit. It's the pit in the airplane where all the fuel
cocks are located. Someone got the idea that would also be a good location for
a seat.

Larry

[John Kunkel]

"michael" <tail...@hitechnetworks.net> wrote in message
news:3FA36738...@hitechnetworks.net...
>

> 7 or 8 years ago our daily driver was a 64 Belvedere with a poly. I would
add
> 3-4 gallons of 100LL to a tank and got a noticable increase in power and
ended
> pinging when pulling the steeper hills. One thing to keep in mind is that
avgas
> is formulated to atomize in colder atmospheric conditions. Just a
semieducated
> guess on my part is that adding too much may result in a case of
diminishing
> returns. The fuel not atomizing at proper levels would likely net less
power.
> Certainly an optimum ratio exists. Maybe someone has that info to share.
> No time comparisons were done when I was mixing, but one day the wife came
back
> from running errands and asked if I did something to the car. I asked what
was
> wrong, not letting on, and she said nothing, just that she dusted
everybody
> coming back up the hill and had to watch her speed cause the car was
running so
> well. That's when I told her about the avgas. She said it was okay to put
it in
> *her car* anytime.

Every time the subject of avgas in cars comes up the myths emerge again.
Airplanes take off at full power at sea level and routinely cruise at a
couple of thousand feet; I rarely see 3000 feet in my Cherokee. The point
being that avgas must operate in a variety of altitudes and temperatures,
just like a car. All the myths about avgas being formulated for high
altitudes and cold temps are just that, myths. There are no anti-icing
additives in avgas that aren't in mogas.
The main difference between avgas and mogas is the Reid Vapor Pressure (RVP)
rating, this is a measure of the fuel's tendency to evaporate. The
difference in RVP has to do with preventing vapor lock at altitude where the
air pressure is lower.
No one should claim that 100LL is a straight across substitute for racing
gas but at the compression ratios and operating conditions seen in most
muscle cars it works just fine. My 11-1 Max Wedge runs just as good on $2.40
a gallon avgas as it does on $5.50 a gallon VP red.
John