I think this is a time when I'd go for the cubes within the family you have parts for. I think the 55 cubes of the 225 wouldn't hurt the mileage by any means, and the couple extra ponies would be welcome. That's my thought on the subject, at least...

Time to get out the triagular file and groove the flat quench areas on the 302's. Polish the chambers

Gasket match the intakes and leave the intake manifold alone so you have a slant anti-reversion effect.

Gasket match the exhaust on the top and sides of the exhaust ports. Not the floors!

My 302's are almost to that point. Just no money for the valve job, and I need toput a new seat put in. where I got too crazy with the die grinder.

I think the only areas left where we would see gains at this point are expensive. Cheapness is out of the equation. He has hit his 90% and the last 10% are going to be have to be fought for.

The areas I think that could still be improved are

- converter efficiency, high dollar transmission rebuild
- spark control, possibly Jacobs set for economy
- electric fuel pump, cooler fuel at the bowl.
- weight reduction
- build specific headers.
- roller cam

with some yarn,
a hot glue gun,
and a 'chase car' with movie camera
I would bet that
some simple aero 'tweaks' could get the
Highway MPG up at little cost:

http://autospeed.com/cms/A_108656/article.html

the above is the first of a 5 part series from the 'Land of Oz'

This archived website allows you to find out your aero and tire rolling resistance with coast down test on flat pavement:

http://web.archive.org/web/2004080307322...tDownCalcs.html

But I personally like to coast down a 4 to 6 percent grade hill, then use the 'top out' speed on the hill and the equations in this article to find the Cd and rolling resistance:

http://www.etrucker.com/content/downloads/ccj0302.pdf

I have been following this post and I give it a . I was reading somewhere that somebody did a test way back in 1950-1960 can't remember. For every 100 percent of fuel and air that enters a combustion chamber only 28 percent is used for power the rest is out the tail pipe. They retested again in 1990 and found out that it was raised to 30 - 32, WOW Now that's progress They also mentioned that the finer the mist ( more atomization) you can get your fuel mixture the more complete burn. There have been many attempts at this Singh groves, running your fuel through hollow exhaust seats with variable valve timing. Or just heating your fuel. ( I believe Patton had a Mechanic that tried this on his Tank fleet).

I would not try to heat the fuel before it goes in the carb, ever heard of vapor lock?

Mabey if you had EFI you could wrap a heating coil around the fuel rail

The only big gain I think I have left is the OD trans. It should be at laest an easy 2 or 3 mpg.

Other than the trans; things like EFI, custom headers, custom cam, skinneyer wheels, weight reduction... might get me another 2 or 3 all together. Mabey for another $10,000 I could get closer to 40mpg so I can save $2 - 3 grand..

Well it was pouring rain here so i didnt get much done on the slant.

I put in a vacuum gauge and a tech... FYI: Sunpro tach's are CRAP. Says im idling at 250rpm (yes its set for 6cyl).. On the upper RPM's its at least 150rpm off.

Anyways...

Bumped the timing to about 17 at idle and 51 btdc total. All in by 2100ish. Was 7/41BTDC.

Im going on a 260mile each way trip this weekend comming up so i'll see what happens.

Tell you what Dave I'll finish my 302's and get the valves done and mildly shaved. This is after the Duster leaves the driveway with the 4 speed.

I'll give you back your Stromberg that you lent me. Then you can try it.

We can see how my heads with the RUG _ TRUCKER MPG, low to mid torque work. CC them then test them. Then cut them with grooves retest them and see if that treatment will change things.

IIRC I need to finish 2 exhaust ports.

When we going to do a Moparts Nashville time trial night or day?

There is also a Stant 'Standard Grade' 205 degree thermostat that should give about 1% MPG boost if a VERY careful test is done.

Stainless steel wire mesh across the ports between two intake gaskets will 'probably' reduce fuel droplet size and slightly improve fuel economy.

Rigging up an exhaust gas recirculation system feeding into the air inlet might be good for 5% better MPG at highway speed, but the idle quality will suffer unless a way is available to turn it off below 1500 rpm.

I would not personally be afraid to try the new Mobil One Synthetic OW-20 oil, but only if the rings are in good shape.

Heating the fuel was after the carb. I believe they used a heating element underneath it. Anyway the other article that I remember was in Hot Rod. They were talking about this guy who had a 327 Chev with hollowed out exhaust seat. The fuel would flow through there and get super heated. There was small pin holes in the exhaust seat that when the valve open would jet out fuel. To make this work he needed variable valve timing. The longer the valve stayed open the more RPM. At the end he had 450 hp and using 70% of the fuel more efficiently= more MPG. He also had less emmisions

Volcin fuel injection. It was in HotRod in the mid 90's. Excellent article...

another aero drag article just published by AutoSpeed in Oz

http://autospeed.com/cms/A_110351/article.html

From the pages of Design News

http://www.designnews.com/article/CA6551496.html?industryid=43655

Thirty-Year Quest for Lean Burn

Michael A.V. Ward, Ph.D., President & Board Chairman, Combustion Electromagnetics Inc. -- 4/28/2008

Lean-burn technology is alive and well and can help the auto industry — if we let it. With lean burn used to its full extent, today's vehicles can improve fuel economy by 30 percent, identical to that of the direct-injection diesel. It could help us deal with government mandates on fuel economy — well before 2020.

It hasn't been that way for 25 years, since Chrysler and Honda first attempted lean burn in 1975. They achieved a lean air-fuel ratio (AFR) of 20:1 for better fuel economy, versus the normal 14.7:1 AFR. But, they were unable to burn lean enough to meet the EPA's standards for NOx.

Two other companies, Nissan and Ford, introduced the NAPS-Z and the PROCO around 1980, with two spark plugs per cylinder. They performed even better under dilute AFR conditions. They used exhaust gas recirculation (EGR) for very low NOx and obtained 60 percent of the gain in efficiency available with lean burn. Lean burn at light loads reduces pumping losses, heat transfer losses and increases Otto cycle efficiency. Despite their good results, both approaches were abandoned.

The three-way catalyst operates in a narrow range of 14.7:1 AFR, with oxidation of HC occurring above 15:1 and reduction of NOx occurring below 14.5:1. Under lean conditions, the catalyst cannot reduce NOx emissions. NOx peaks at 17:1 and falls off with leanness. An AFR of 25:1 is needed to satisfy EPA emission standards.

In 1977, CEI was formed to pursue lean burn. Initially, it pursued ignition aspects of lean burn and had its first success in 1986 on a Ford Escort at Lucas, England. Under conditions of 20, 35 and 50 percent load, it obtained 25, 17 and 10 percent gain in fuel efficiency at 24:1, 24:1 and 28:1 AFR, with negligible NOx — never seen before in a homogeneous charge engine, reported in the “Economist,” July 5,1986.

In 1987, CEI was invited to GM where it ignited mixtures five AFRs leaner. In 1989, flow tunnel tests were conducted, but CEI was not shown the results. GM went no further despite the positive results.

Successful lean burn tests were also conducted at Mazda, but further ignition development was needed, especially in the one-coil-per-plug format.

Between 1990 and 1995, carmakers gave up on lean burn. California dictated the super-ultra-low emission standards to, in effect, kill lean burn and increase our dependence on imported oil.

Five years later, CEI finally received the flow-tunnel from GM. The results were astonishing. GM's HEI had a lean limit of 23:1 to 26:1 AFR. The CEI ignition gave, by comparison, 33:1 to 34:1 AFR, or a hard-to-believe eight AFRs gain. Flow enhanced lean burn, contradicting Exxon's claim. Flow-coupling was seen to be the missing link in lean-burn technology.

Chrysler tested the CEI ignition on a four-cylinder engine and found it to be “an enabling technology for the lean-burn engines of the future.” Three years later, CEI built a single-cylinder engine with two plugs and strong flow-coupling. The ignition was developed to deliver five times the energy with small coils. The engine results were, again, hard to believe. An air-fuel ratio was achieved above 30:1, never seen before, with an efficiency of the direct-injection diesel. Lean burn had been solved. See “Lean Burn Lives.”

This year, a low-cost, high-efficiency, high-compression ratio lean-burn engine, similar to the May Fireball, was designed with a more than 40 percent gain in efficiency, with the promise of being the “Engine of the Future.”

Author Information
Michael A.V. Ward is the founder of CEI in Arlington, MA. He can be reached at ignition@rcn.com

© 2008, Reed Business Information, a division of Reed Elsevier Inc. All Rights Reserved.

Interesting stuff 360 veiw.

It seems as though I could run a lot leaner with a super high out put ign(and asumeing a real thorough mixture). I picked up a MSD 5200 box at bowling green, are they any good? Can I open the plug gap more with that than the mopar electronic ign I have on it? How big of a gap have you guys gone before problems?

I am not a fan of the MSD ignition muliti-spark system.

I did install one on a Subaru boxer 4 cylinder years and found no difference except much more radio interference.

I do still have a MSD ignition delay 'add-on' box that allows continued use of the oem ignition but allows up to 20 degrees of ignition retard. I bought this MSD single spark 'black box' after finding that the Mopar Performance PCM computer for a 1995 Magnum 5.9V8 advanced the ignition timing so much that it would ping when at full throttle starting at 3200 rpm in 95 degree summer air temperatures even if Sunoco 95 octane gasoline were used.

If you want to try lean burn carb jetting,
I would suggest using Iridium alloy 'tiny tip' sparkplugs with wide gaps.

The Pertronix 'Second Strike' aftermarket ignition would be a better choice than the MSD, because the first strike is still the long burn time from the inductive coil.

Tiny 'vortex generators' in the intake manifold port ends might be a low cost mod that would help during lean afr





note that these vortex generators,
called 'Wheeler VG design'
are actually two airplane wings side by side
with each wing at the angle
that causes a vortex
similar to what you see on the Space Shuttle



Mitsubishi has this paper in pdf file form that shows two other shapes that can be used as vortex generators
that I call 'shark fin and 'Kamm-back' shapes:

http://www.mitsubishi-motors.com/corporate/about_us/technology/review/e/pdf/2004/16E_03.pdf

Mitsu research resulted in single wing vortex generators on the Lancer:

http://www.seriouswheels.com/2005/2005-M...ar-1280x960.htm

You can see similar single wing vortex generators on the top of some BMW outside rear view mirrors, and on the bottom of the Mercedes ML500 SUV outside mirrors

Why would that do anything in a carbed car?