350 dauntless M.P.G. ????

[kuzzzer61]

ive got the 350 buick dauntless in my J-4000, with hei,2gv carb, Will i get better mpg with fuel injection ???i get 10 mpg all the time empty or loaded.looking for a way to increase my mpg for the future, but dont wanna get into an overdrive.
Thanx in advance

[BobBarry]

<BLOCKQUOTE>quote:</font><HR>Originally posted by kuzzzer61:
ive got the 350 buick dauntless in my J-4000, with hei,2gv carb, Will i get better mpg with fuel injection ???i get 10 mpg all the time empty or loaded.looking for a way to increase my mpg for the future, but dont wanna get into an overdrive.
Thanx in advance<HR></BLOCKQUOTE>

Well, it won't be WORSE! http://www.ifsja.org/ubb/wink.gif

It's an open question whether the increase will be dramatic or not. How well is your engine running? If it's in top-shape, then a FI system may only net you another MPG or two. OTOH, if it's worn out, then the FI won't help much either. In either case, it wouldn't be worth the $1000+ cost.

Then again, if you drive it daily, and your engine is in solid shape, then it might be worth your while. I imagine you'd see the biggest improvements in cold-weather driving and around-town travel.

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Bob Barry<UL TYPE=SQUARE>* '78 Cherokee 4-door
* '88 Grand Wagoneer[/list]http://studentweb.providence.edu/~rbarry/wheels/

[joe]

I agree with Bob B. that if your motor is getting tired FI would be a waste of money. Even on fresh motors I'm not real convineced it's worth the cost. Brand new full size pickups are only getting around 13 mpg's and they're all FI and all the running gear is new too.
If your motor is weak you'd be better off putting the $1000+ or so into rebuilding it.
Another option in the $1000-$1200 range is swapping ring and pinions. Stock yours will be running either 4.09's or 4.27's. If you use it as a daily driver with just the occasional dump or firewood run you'd probably be happy with 3.54's or so. They'd even be ok for minor towing.
I wouldn't rule out an OD unit if you could find one. Warn/AA's Saturn OD I don't think will run behind a D20 though just the D18 but may be wrong there. I suppose another option would be to get a later 350 Buick with FI and swap it in along with the computer etc but then again you've still got an old used motor so you may not gain much there unless of course money is no object but I'm guessing it is if mpg's are a concern.
I don't think is there is a "bolt-on instant MPG increaser" or everyone would already have one http://www.ifsja.org/ubb/frown.gif
FWIW both my J-4000's/360's get 10 mpg and both run 4.09's one with 175,000 and one with 58,000 on the clock.
Depending I guess what you do with the truck and what shape the motor and the rest of the running gear is in I would rate bang for the buck in order of: 1. engine rebuild, 2. axle gear swap, 3. OD or late model motor swap. None will give you a dramatic mpg increase though. These are full size trucks that are reasonably heavy and it takes power and gearing to make'm usable. Don't matter if it's a 1970 or a 2001.

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Regards,
-joe
63 2-dr Wag, 72 J-4000, 73 J-4000, 82 CJ-8

[miked]

i'm at 11 pulling a pickup truck bed trailer up into the sierra's, and 13 coming back down

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Mike D'Ambrogia - San Ramon, CA
69 Custom Wagoneer - The Firetruck (http://www.tworock.com/mjd/firetruck.html)

New and improved - now with 3" lift!

[joe]

<BLOCKQUOTE>quote:</font><HR>Originally posted by miked:
i'm at 11 pulling a pickup truck bed trailer up into the sierra's, and 13 coming back down

<HR></BLOCKQUOTE>

That's not bad towing Mike. I would contribute some of that to a bit higher gearing since the 69 Wags w/Buick motor came with either 3.31 or 3.73 gearing. Any idea which gears you have?
I cruised through your pic file too. You've done a fine job. Very nice Wag!

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Regards,
-joe
63 2-dr Wag, 72 J-4000, 73 J-4000, 82 CJ-8

[miked]

using the 3.31's, thanks for the compliment - the firetruck took its maiden voyage this weekend (even towing the trailer on the outbound leg!), I had a great time riding around in the rig and was suprised how well it ran at freeway speeds. Its nice to see it out on the road after 3 years in the garage, now onto the next big project!



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Mike D'Ambrogia - San Ramon, CA
69 Custom Wagoneer - The Firetruck (http://www.tworock.com/mjd/firetruck.html)

New and improved - now with 3" lift!

[RudyC]

You could upgrade the 2bbl to a Q jet. They are an improvement over the stock 2v.
The Buick motor is good. That's what I'm holding out for on my next FSJ.

[lrrh]

well i get about 12pmg in mine...and its a 350 w/ TA Performane 4bbl, and a Jocabs electronic ignition. no clue what gearing it is though.....

[jm072378]

I have a 69' Gladiator with the 350. Right now I get around 11mpg. The motor only has 30k mi on it and is stock with a 2bbl. I just spoke with TA Performance today and was told I would get better performance and maybe (that's a big maybe) better gas mileage if I went with a Stage I Dual Plane manifold and a 4bbl Edelbrock 650 or 750 (about $210 from Summit).

[miked]

I bought a 4bbl manifold for the 69 350 that came in the skylark (used the same engine) and the qjet for the same, once this current round of fixes goes in I'll probably install it, but as of right now its sitting on the garage floor. "They" say that the 4bbl carb gets better milage, probably due the fact that the 2bbl is trying to be all things to all motors whereas the 4bbl handles lightfoot and heavyfoot with separate sections that are better designed towards each purpose

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Mike D'Ambrogia - San Ramon, CA
69 Custom Wagoneer - The Firetruck (http://www.tworock.com/mjd/firetruck.html)

New and improved - now with 3" lift!

[kuzzzer61]

well first thing is that the motor only has about 6000 miles on a new rebuild , im running amsoil syth. in it and in all the oil needing devices , my buddy has a 71 j-3000 and the only difference is he has a 360 and basic set up is the same ,however hes getting 18 mpg with his ,and his motor has over 47,000 on it. same t-18a and dana 20 transfer case , wheels same size. now granted mine is the j-4000 ( and heavier, I think)and i do have HEI ignition , but it got the same before i rebuilt the motor or added the HEI. also is the dauntless a high performance motor???, was told because it has the angled plug heads that this was consider an HP motor in its time, similar to the 327 with the angled plug heads. My buddy also has the 2gv on his 360, but i cant for the life of me figure out why he gets such good mileage. We both went to amsoil synth at about the same time and his mpg went up while mine stayed the same.his went from 11 constantly to 18 highway 16 city, even he was surprised at the difference.And with gas ging up, i need all the help i can get to help save money before my beloved jeep has to stay parked cause of the gas prices.

[RudyC]

Wow 18 mpg. On a 360,J-4000! Holy cow.
Well I'm stumped.
On the other hand if the carb has smaller bores like the ones on the 302 Fords and is set up very lean. And yes the Syth. oils are a help.
Are you sure he didn't have two tanks and was pulling your chain?
WOW 18...
When My wagoneer blew the transfer case it still got 8 mpg on the flat bed tow truck http://www.ifsja.org/ubb/biggrin.gif just to piss me off http://www.ifsja.org/ubb/biggrin.gif

[kuzzzer61]

yep he has syth in everything and did it about a week after i finally went to syth.his mpg went up mine stayed the same,i have taken mine to a carburater mechanic i know and he says everything is fine in mine ,He also worked on my buddies rig.He told me something that i dont know if i can believe though.He said that you must run a motor at least 10000 mile before using syth oil ,so it can wear in proper. Now hes telling me that he thinks the reason the other j-3000 gets better milage is because the motor was worn to 41,000 before using the syth oil..Come on now ,is he pulling my leg or can that happen. I still dont think it can.

[krek]

Bringing this back from the dead...

What would be a good aftermarket EFI kit for the Dauntless 350?

[Wagonforever]

Just think EFI may only net you 1-2 MPG, but on 10MPG that's 10-20%!!:eek: That's pretty **** good.

You can mod a GM TBI pretty easily onto your buick motor, I've got a buddy that just did it on an Olds motor in a 72 Cutlass. The Early GM TBI's are probably one of the most adaptable EFI systems ever built!

[krek]

I was looking at the Holley Commander 950 kit but at $1,600 that's a load...

[Wagonforever]

You can build your own MUCH cheaper than that. I got mine off a 90 GMC Suburban. I bought the Suburban for $300, stripped all the parts I need, sold the motor for $100, sold some other misc parts for $50, scrapped the rest for $80. So in the end I paid $70 for a complete running system!:eek: Of coarse I still have to buy a couple things to adapt it to my Jeep, but I don't see me needing more than $2-300. You can do the same for the Buick motor, you would just need a different carb to TBI adapter, actually it would be alittle easier since your already running a GM distributor. There's a member on here that just did a write up on DIY EFI.

[LandYacht]

I think your buddy's math is off...

Regarding modificaton for improved mpg to pay less at the pump:

How many miles would you have to put on to break even at the cost of improving your MPG?

About the best way that I can think of is to switch over to diesel. Using an IDI diesel like the GM 6.2 or Ford 6.9 or '93 and older 7.3(pre-powerstroke) (non turbo) which can run on ultra-filtered waste oil quite nicely, converting to a 2 tank setup greaser would cost about $2,000-$3,000 typically. Incuding filtration equipment and bulk tanks for your garage.

Now your fuel costs you about 9-13 CENTS a gallon depending on things.

Worst case...At a savings of $3.00, it takes you 1000 gallons of fuel to recoup that.

At 22mpg, that happens at 22,000 miles. How long would it take you to run those miles?

Keep in mind you have to obtain and process your waste oil... used food oils, engine oils, transmission fluid can all be used.

Is it worth it?

[drlocke]

I think your friend may be slightly stretching it here with this 18MPG talk. If he drives it like a model T Ford (10mph uphill and 50mph downhill) then I guess it's conceivable. But it's also conceivable I could win the lottery. I have heard of some of the 258 I6s getting that kind of economy, but.... :confused:

As for your engine you may want to retime the ignition for optimum manifold vacuum. That's what I did to my 327, and it is doing a little better on the fuel than before. Make sure your advance diaphragm on the dizzy is working, and not perforated, and is connected to the appropriate port on the carb.

But with these boxy bad boys the key is slow speed and a very light foot on the skinny pedal.

[Wagabond]

Edelbrock 4 bbl intake and a a well tuned Q-jet will get you within a few percentage points of EFI MPG.

[krek]

Edelbrock 4 bbl intake and a a well tuned Q-jet will get you within a few percentage points of EFI MPG.
True. But won't EFI be more forgiving in regards to temperature and altitude changes?

[GWChris]

Weight, driveline losses, and poor aerodynamics - these are the fundamental fuel economy problems, and no fuel system will address them. If you DID fix all these it would not be a FSJ anymore.

Why does it seem surprising that you can only move a beast like an FSJ 10-13 miles with 1 gallon of fuel (at 60mph no less)? Heck, I'm amazed that it only takes that much.

[Wagabond]

True. But won't EFI be more forgiving in regards to temperature and altitude changes?

Yeah. If you deal with a lot of that, go EFI. If you can get it at a good price.

[PlumCrazy]

Not too long after the new motor install and an upgrade to a 4bbl (with Holley) and a Pertronix unit, I took a road trip down to Memphis, TN and back.
With mixed driving and averaging about 45 mph I got around 17 mpg...I've not been able to duplicate that trip, but I was holding around 14 mpg the last long trip I made over to the OK line and back.
Running around town and up to the MO state line, I see around 12ish with some steep hills.

I have new 4.10 gears in the rear and my weakest link now is the Th400, but that is from age more than mileage (21000 on the truck and 4000 on the motor).

Wayne S

[Herk]

I have been running a 350 Buick in my 71 J-4000 as a dialy driver for about 10 years now and my average has been about 12 mpg. With the 2v carb, point ignition and 31" tires it got 12. Swapped to a Q-Jet and HEI I got 14 for a while. Put on 33" tires and Comp 268H cam, went back to 12.

I broke the 350 a few weeks back and now it is at the machine shop. I will be getting better than 12 when it goes back in. I plan to come up with a more detailed post in the future, but heres why. I was running a whopping 7.2:1 compression. Beware of most 350 replacement pistons, as they are actually 231 smogger pistons with a 1.805 compression height. The original Jeep/Buick low compression piston had a 1.835 comp height. My pistons were 0.100 in the hole!!! figure in the 24cc dish, a 50cc chamber and a .043 composition headgasket and compression was basically none! T/A performance will be source for higher compression pistons and their TA112 cam. Going from 7.2 to 9.5 should help thermal efficiency a bit.

The other upgrade planned this time around is a 700R4 transmission swap. My 400 is about shot anyhow. And the TH400 was the most power sucking auto ever made, thats why Jeep went over to the TF727. TBI is in the cards later on as well, but that may be a while.