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Discussion Starter #1
I have been considering picking up a spare cylinder head this summer, but I'm not quite sure what I want to do with it yet.

Does anybody know if work could be done to the head to increase MPG?

I know that port-and-polish jobs allow for more airflow, but I was thinking this will hurt MPG since the engine will in turn use more fuel to compensate for the extra air.

I will be able to use this in conjunction with a dual-potentiometer setup that I have not yet installed... if that makes a difference at all. I already hope to install that in order to (slightly) lean the mixture out while cruising so I get better mileage.

Or maybe even if there is no MPG increase, I was wondering if any work could be done to simply increase the efficiency of the combustion chamber so that there's a more even and complete burn (as long as it doesn't HURT mileage).

I couldn't see where this had been discussed before, since most people who PnP heads do it for the power increase. My ultimate goal with this car is to keep improving MPG and efficiency as I go.

Please discuss.
 

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nezwick said:
I have been considering picking up a spare cylinder head this summer, but I'm not quite sure what I want to do with it yet.

Does anybody know if work could be done to the head to increase MPG?

I know that port-and-polish jobs allow for more airflow, but I was thinking this will hurt MPG since the engine will in turn use more fuel to compensate for the extra air.

Please discuss.
i don't think it would compensate all that much extra fuel. our cars use a maf not a map sensor. IIRC almost all our metered air passes by the maf and then the only other sensor that would detect a change in the amount of air would be the o2 sensor... a very mild pNp shouldn't hurt... i don't think. if anything i said is wrong, please correct me.my bad.

-Nick
 

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so you've got an escort and want better fuel economy?
 

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Discussion Starter #5
Haha CHEAP? $300-400 is not what I had in mind, although I'm sure it would do the trick.

racetracer, I wouldn't be doing the head work myself, in fact, I had you in mind as one of my options for the work should I want to have it done.

If proper head work was done (PnP, valve job, possibly a reground cam, etc) would better gas mileage be feasible?

Or would I be better off just shaving .030 off the head to raise compression?
 

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Discussion Starter #6
alxdgr8 said:
so you've got an escort and want better fuel economy?
Yes. For now, 40 highway mpg is good, but I'd like to hit mid-40's eventually.

My next project car is going to be like, a Festiva or a Yugo or something.
 

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Here's my thoughts.
If you use a header that isn't hugh sized, a nice port & polish, a real Cold Air Induction
system and a cam ground for more low end it should give you a little better mileage.
The reasoning: The more low RPM power the less you have to work to get up through
the gears. The right cam and timing helps you to maintain speed with less throttle. The freer
flowing exhaust means the motor doesn't have to 'push' so much to get the spent gases out.
I'd also be experimenting with how many and how much of the front grill(s) I could block off so
as to reduce drag. Get it so the engine doesn't overheat on the really hot days or else make the
block off plates removable in sections.
But I diverge. Most of the milder "Hot Rod" techniques work if you just drive like you want to save gas.
If the engine makes power easy it doesn't work as hard to make 'Normal' power.
 

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Strip the interior, get skinny tires, improve aero (remove side mirrors/windshield wipers, tape body lines)

:D
 

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If you have a lawn mower sitting around, take the good ol' Briggs and Stratton off it and swap it into your Escort. :p
 

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Discussion Starter #11
Alright, so the consensus is, just get all the PnP and cam work done anyway and that will work out to better mileage (as long as I drive the car with fuel economy in mind).

Sounds good to me.
 

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Discussion Starter #15
Alright. So I should probably buy a reman head instead of a junkyard head. Trying to run the used head with high compression, I'd be afraid of making old valve seals fail and all that.

I don't mind running 93 octane fuel... it's not so much the cost of fuel that I'm worried about, it's how much of it that I'm wasting.
 

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I'll let you know what I get out of my car with my racetracer head with only sr muffler and k&n drop in

its shaved .035 and pnp tb is a little cleaned up and the secondaries are hoged out
 

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Discussion Starter #18
Wow, yeah I have always wanted to do MS but I don't understand enough about it to do any of that lol
 

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I've routinely recorded 42 mpg @ 70 mph on my car. That's with a CFI, cracked bumpers, riding high, and the low-geared GT transaxle. My recent project is to re-do all of this. I'm swapping in a Tempo transaxle that'll take off ~250 revs in top gear (75 mph by 2750 rpm instead of 3000), along with replacing the bumpers, and hopefully lowering back to stock height, or adding some underbody stuff to reduce air drag. If you can snag one, go for an HO header...seems to help me anyway. I also cleaned up casting flash from my intake and ports when I put the engine together. I left the exhaust side mostly alone since it had been repaired. My head was heavily milled (never got a figure). The block was bored over 1mm as well, and this definitely made an increase in compression. The engine runs strongly enough, but requires premium, otherwise it has little power, and horrid mileage. I increased base ignition timing to 12 degrees BTDC, and have no detonation problems with premium. My goal is to hit 50 mpg, and I'm pretty sure I can do it. Any more things I can think of, I'll try to let you know. This is from a 1st gen perspective, although I imagine you can find higher ratio transaxles, and such. Your car will become dog slow, though.
 
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