Most fuel efficient drivetrain for an A roadster build?

see you should have Read This First!

then spent some time reading on here. For the most part if you didn't see it in the early to mid 60's or before it's a no go. That's what is meant by Traditional Hot Rods and Customs. So all that EFI crap needs to be under wraps, a hood and sides would be good if you go that route.

 

I read that this morning, not before I posted, sorry.

I am reading as much as I can (fast) but I wouldn't/couldn't have waited to post my basic question for long after finding this place.

i'm definitely a fan of mid-sixties and earlier, don't really want to do EFI unless it's relatively simple, accomplishes my ultimate goal, and can pull off the look of non-EFI (maybe TBI would work since it resembles a carb and hides well under a breather?)

Thanks for your patience with me, but I'm fairly thick-skinned as well. i'll be OK.

 

In all actuality EFI does not give you any great leaps in MPG over a carb. Mostly cold start advantages and maybe 1 or 2 MPG over a properly tuned carb'd engine.

 

I suspected that but wasn't sure. i figure for my goal, the right 4 barrel or 2 barrel will be a great choice.

 

contact paulweldit - buy his mercruiser 4 banger

 

from where I sit the best bang for the buck would as mentioned above is a 305sbc quadrajet (4 brl) 700r4 and 3.55 gears it's what I had in my station wagon got 30mpg highway at 65mph and 24mph towing an open trailer with a mini sprint/midget plus spares and tools it was the best and cheapest tow car I ever had. but for looks I would go with the 215/rover v8 stay away from the 4.6 Fords big pieces of garbage too many variations

 

For my money I run a 350/350 combo with Tri-Power. I run a later engine ( 1992 ) with factory roller cam, early Offy intake and 3 Rochester 2GCs. It has the early traditional look but the advantage of the roller motor. Some guys here don't like the SBC but they have been in hot rods since the first 55 Chevy got wrecked and went to the bone yard. I've got 3:91 gears so I'm not getting the mpg I could but I really like the performance up to about 60 mph, It'll pull the fillings out of your teeth through the 1-2 shift, lot of fun. Long story short SBC w/ tri-power, decent gears.

 

Glad you're back-wondered about you.

 

Actually efficiency and hot rods do go well together. The most efficient motor will burn the highest percentage of fuel pumped into it. That doesn't necessarily mean good mileage. If your engine will burn copious quantities of fuel well and does it probably won't be getting good mileage.

About any of the smaller valve in head V-8s can be made to get good mileage. I've had good luck with Chebbies for a long time, they are good driver engines. But you can do the same with a Plymouth or a Ford or whatever you have.

Overdrive doesn't always mean better mileage. It depends on your final gear and how your engine is built. You have to keep your engine running in the power band if you are going to expect good mileage.

For example, one of the fellas here has an OD in his pickup but his rear gear is too high for the small block he is running. His engine doesn't start pulling until about 3K. So at normal highway speeds he actually gets better mileage in 4th gear. Now if he were cruising above about 85 MPH (which he does on occasion) he has use for 5th. But much below that he just leaves it in 4th.

There is no definitive answer to your question. A lot of opinions but no answer. Build yourself a small block of some sort. Make sure all the parts go together IE 12 carbs and no cam or head flow don't match. I would stay with a smaller 4 bbl carb like say a Vac secondary 600 CFM Holley or the equivalent in whatever carb you like milder cam like say a 300 to 350 hp cam. Good heads if you can find them. Figure what your power band is going to be, and gear accordingly. Always tune to the max.

 

Okay... I'll bite.
What about a modded banger? Intake, exhaust, carbs, oil system upgrade, pistons, etc. About 5 grand probably?

How would dependability be?

Who's got this and what say you?

 

I would run hood sides and a dreaded LS1. You will have tons power and get great mileage. I wouldnt be surprised to see it run 12's on a stock motor! I know its not trad, but a flathead a car that sits in a garage 99% of the time isnt half as cool as a EFI car that gets driven daily!

 

Use a Audi/VW turbo diesel with manual stick they have made inline 4,5,6 and V6 and V8

 

I'd find a '96-'99 vortec 305. They are roller cam from the factory and have really good heads on them. Top it off with a 750 quadrajet. They have a small primary which is great for economy plus the very large secondary for having a little fun. Dress it nostalgic and tell everyone it's a powerpac 283.

http://image.superchevy.com/f/9083524/sucp_0701w_13_z+57_chevrolet+power_pack_283.jpg

Then I'd mate it with a T5. Find someone with a Innovate to tune it and you'd have a well running and efficient combination.

 

Now there's a plan.

I used to run an Iron Duke in a light vehicle with a 5 gear. A 4 gear would have worked as well I believe. With it dialed in and the tri-y open it sounded like a swarm of bees when it was spun tight. Normally got about 30-32 on the highway with a 4.10:1 gear through the muffler. Fun little bugger.

No it didn't snap your neck like one of Zs big nailheads but it was a fun little ride.

 

if you guys ^^^^^ are worried about mpg's and considering putting modern efi shit in your rides is up to you but, you might as well head over to a street rod website, with all there glorious pastel paints, mustang two ifs , and their ls1 conversions . fuck me isn't this site about traditional hot rods. sorry for the rant

to the op worried about mpgs get a good carb set up, overdrive trans and a low rear gears

 

Not Familiar with "Hemi, 6-97's" - you need to do a lot of studying on here before you start talking about traditional if you don't understand those terms

Inlines don't work in A's - way too long to not lose tons of interior (firewall) space

had one in a very light car - Triumph Spitfire, and grandma had a stocker Buick Special. Both got terrible mileage, a really inefficient motor.

Dual Weber's will KILL the mileage. My L18 Datsun motor with dual DCOE's and a 5 speed got around 16 MPG!

I really like this idea, a lot. Mod motors are small displacement, make toms of power, are lightweight and have a great aftermarket support. Only down side is they are a bit wide.

Killer motors, but again won't fit a n A very well and parts are ungodly expensive

 

In my A coupe I run a 5.0 liter Ford EFI (302) backed with an AOD trans. Ford 8" rear with 3:80 gears. 235/75 r 15 tires.

24mpg
2100 rpm @ 70 mph

 

First make sure you have an overdrive trans and a rear gear of around 3.25 . Engine wise PLEASE don't do the same Ole SBC crate crap . Think outside the box some . A turbo-V6 will be nice with plenty of torque and HP and still get good gas mileage . Straight 6 will be harder on gas than a V6 .
V8's , look for a smaller lighter one . The older engines are very heavy.
Now how about a good Ford 4 cylinder ? They are some real power house engines . They use them to race all the time ! They are very light , sound good and can get any "goo fast" parts you want for them ! I have seen one and it really looked good ! Then it will pretty much drop in with no heavy mods to the frame .
Clark on the HAMB was building one with a Ford 4 cyl and it really looks good ! It just fit the look of the car better than you can think it would . He might have a picture of it . It's a customers car and that thing just looks Great ! I wish it was mine ! It's white with red & white tuck and roll . Beautiful Car !
OK , it's just my opinion but the 4 banger would be a great choice !

Retro Jim

 

I appreciate the sentiment, as I love old and esoteric engines as much, or more that anyone else on this list.

However, once the overall cost-benefit-ratio is analyzed, old, or more off-beat engines don't always pan out.

While the SBC might be boring and passe to some, they have a huge advantage on cost. If purpose of the exercise is to save money, ostensibly on fuel, the savings has to be reflected on the build side too. There is little point on saving $1200 a-year on fuel, if you had to spend $7200 on the engine to do it. That would take you 6 years just to break even.

I have $800 in my all-roller 305. It was a 15k mile engine when I got it.

With too-tall gears, it was getting 28 mpg, in my A. After this round of thrashing the chassis, and the gear change, it should be even better.

 

I think this would be the correct mindset. A small block of you choice, something around 300 cu in, say 302, 305. Aluminum heads would lighten up the motor and will work as long as you don't go crazy with big valve and large runners. You could use some with smaller combustion chambers to help raise the compression ratio and make the motor more efficient. A small, 500-600 cfm carb will help, or use a spread bore like a thermal quad or quadrajet. Add an "rv" cam for good low rpm torque, an overdrive, and a high geared rear. 700R4's and 200r4's both have a fairly low first gear, an AOD can be built with a 4r70w gear set to add a low first, this will help make up for a high geared rear. Or for a manual you could use a t5 or tremec 5 or 6 speed.

 

i know what a hemi is, but had to assume that "6-97s" refers to an unfamiliar style of carburation, Strombergs perhaps?

I'll get there, i'm studying up on it, but it takes time. At least i know what I like nowadays.

 

Six stromberg 97's is what he was trying to say.

 

Guess you missed the part about running a hood and that it wouldnt be tradtional but still go fast and get good mpg?

 

I got a buddy who drives a giant '93 Crapiece wagon with the LT-1 with tuned port injection and a 700-4R tranny....believe it or not he's gotten 24 MPG on the freeway.

 

usin an auto trans instead of a manual you're gonna give away alot of mileage... nothin like a fluid coupling to really slurp that dinosaur juice.

 

My coupe I built a couple of years ago had a 350 with 2 four bbls and 350/350 HP cam th 350 trans and 323 gears and it got a little over 20 MPG on the HWY. Probably couldn't be done again but it was amazing!

 

That is what the lockup torque converter is for. At the flip of the switch, it is no longer a fluid coupling.

 

sorry to say that it's a torque converter not a fluid coupling the old 4 speed hydros had fluid couplings! I would like to update what I said above I still think a 305sbc would be the best but I would go with a vortec 305 a 360degree intake an a quadrajet

 

nothing runs like a scalded dog:

http://www.secretsofspeed.com/PARTS.htm

 

For mileage, reliability, ease of fit, and semi-traditional look, I would go find a running 4 cyl/5 speed 87-93 Mustang (read:cheap, and you could probably resell the body to a racer for most of, if not all, of what you pay for it). Lots of roundyround guys have used 2.3s (don't ask me what class, I remember they used to be everywhere), and its known to be reliable. Ditch the EFI (or not), and go with an aftermarket intake and a small 2 or 4 barrel carb, and a nice cam. You could dress it up to look fairly traditional,too.