Chevrolet S10 V8 pickup designed for maximum gas mileage !!!!
 

Hello guys I'm starting a new project for my main transportation vehicle. I have a 1993 S10, 2 WD, 5 speed, 3.08 gear and want to swap a Gen 1 V8 into. I want to be able to accelerate decently. I want a truck so I can haul engines I build to the machine shop and back.
I have a ton of parts and motors to experiment with and want to create the best combination possible. Here is my thoughts.
1979 267 sbc
Holley 7448 350 cfm 2bbl
Light weight crankshaft.
Lunati fuel efficiency cam
Edelbrock EPS intake
MSD ignition with manual retard/advance controller
Long tube 1.5" headers
Aluminum reduction pulleys
No Power Steering
No A/C
Electrical fan
Electric fuel pump
0w-20 Royal Purple
Synthetic Fluids throughout
Vacuum Gauge
AFR meter
TPS gauge for monitoring throttle position
Light weight (15 pound) flywheel and clutch

I have a 267,283, 302, 305, 327, 350 and a 400 to choose from.
I would like to keep the cruise rpm at 45 (speed limit is 50 MPH) at around 1300 to 1400 so the carb will stay in the idle circuit.

Any experience or ideas would be appreciated !!!!

Thanks Mark.

Why a Gen 1 v8? A LS 4.8 or 5.3 would perform better than much of the old stuff... MSD makes ignition control boxes for em, and carb intakes are available... I imagine a 4.8mor 5.3 would be fairly cheap too...

Barring going to new technology, id go with at least the 327... That 267ci might not make enough power at that low RPM to lug around an S-10 going 45mph... In fact, I would almost like to see what could be done with a 10:1 400ci with economy cam, 2bbl, etc...

I would forget the carby and ancient ignition. Why don't you go for a tunable injection setup. Being GM based I would look at a hacked Delco ECU and GM bits. Www.pcmhacking.net is where I would look. Their code is free and supports lean burn and live tuning.

Simon

I would think the 267 would provide the most fuel economy for what you want to do. More displacement means more fuel wasted at idle and low loading. It takes power (therefore, fuel) to generate the vacuum present in the intake manifold and each cylinder. More displacement volume = more required power.

I like the 267 idea. I have had good success using a small Carter AFB and disconnecting the secondary linkage. They are so tunable with a strip kit. This was back in the 80s on a 231 in a Le Sabre. The car was originally a turbo coupe that came undone. We built a na engine with the AFB and dual exhaust and got low 30s mpg out of it.

I guess I'm getting old and enjoy the simplicity of older more simpler engines. I don't want to use a computer to program a computer just to get to work. I want to use what I got !!!!

Im using a 1995 K3500 454 for an acceleration baseline. It makes about 1 pound feet of torque for every 10 pounds of vehicle weight. This means the S10 has to have about 154 pound-ft. of torque at 1600 rpm.

I just purchased the Fuel Economy Calculator from Performance Trends for comparing combination. I want to have the most efficient small engine possible. The 267 beat the 283 by 2 MPG and the 305 by 3 MPG.

Been considering a 305 with a 400 SBC crankshaft....😃

Check out the six speed manual transmission in the 2016 Chevrolet Colorado. The ratios look ideal for your intended use.

You could stick that 3.75 stroke crank in the 267 also. It is about square now at 3.5x3.48. Make it more like a Buick 350, they were over square lots of torque.

You definitely want as much stroke as possible, relative to bore... That tends to be the trend in car engines now... Subaru FB20 is way under square and has lots of torque down low...

This is cool.

Dreamed about building an analog hypermiler m'self

Hmm....corvette engine with displacement on demand? slap a carb on it, and a toggle switch to turn on and off the DOD...

Probably more involved than that, but hey, one can dream, right?

I kinda disagree with the small v8, go with a 350. You can make an engine idle right down low. I had one idle so slow you could read the belt as it went around. A good low rpm torquer cam, and you can probably drive at 1000 rpm if its stick. Keep it carbed, quadra jet, manual choke, lean the primary sob right out till you run 15:1 or leaner. Make the secondary open soon in case you want to get on it you don't stay lean. Overdrive tranny for sure. May not be the most efficient, but it will be fun.

Problem with a low idle like that is the alternator won't build up to 12 volts.

My firebird has a 6 speed and will putt along at 1,000rpm doing about 45mph.
I would like to put a bigger engine in and 3:1 or 3.25: rear gears and a T-56 that has the 0.5:1 top gear. The current T-56 has 0.6:top gear.

I think you'd be better off with EFI... but if you are sticking to old school:
I'd avoid the 267. That oddball 3.5 bore engine will likely prove difficult to find decent heads for. Valve shrouding a problem in the small bore engines, and most aftermarket support is for larger displacement/more power. I'd stick with the 305, for smaller displacement with readily available parts. You could even dip your toes into EFI and find a TBI engine to swap in...

If you want old school put a 5.7 diesel in there.

Oversize the counterbalance and fear her up for 50mpg

It's possible to have too slow a cruise rpm to be efficient.

V8 in small truck with max fe seems like it won't happen. How/why have so much torque available only to be confronted with the choice between using it and getting poor economy or having all that power available and not being able to tap into it without ruining the fe for the tank?

Assuming the V8 is a good idea I'd think the smaller the better. Valve shrouding = no issue because if it is an econo build it will have small valve heads and it will live in the low rpm operating range where heavy breathing doesn't happen.

Id also vote for a 305. Go high compression and do an e85 build, low speed/high compression/big displacement.

If you keep power levels low, build for a 13 or 14:1 compression ratio. That should be nice. If I had cash I'd try even higher.

The good old Vortec 4300 seems to be more suitable to such project than a 267 SBC.

I was thinking about that myself... If staying with such small displacement, why not do up a nice 11:1CR, low RPM cam, 4.3 V6? Same displacement as that v8(nearly), but less frictional losses due to two less cylinders... I'm still in favor of a small displacement LS swap though

Roller cam, reduced friction and you dont need the additives to keep the cam alive fuel is not the only thing to consider in hypermiling.
2010 oil report

4 Barrel carb a 500cfm carb only has 125cfm per barrel summit racing used to have a 350cfm 4b Holly avaliable (was going to put it in place of the Holly 4412 /500cfm on grandmas 61GMC 1/2T 305b v6) . if you can stay out of the 4 it is smaller more tunable. In anEdelbrock all4 are the same size. I'd go with a rodchester ,supper small primary huge secondary .dirve it on the primary.
Msd 6 Digital has built-in 2stage revlimiter primary for broken driveshaft protection secondary for lowning out the vehicle
Timing retard add nock sensor or micro switch to the carb linkage + your desired toggle.. and a 20° retard in start-up mode
Rpm
the 350 I had in my79 K-20was happy @400 the alt was happy at 600 rpm https://alternatorparts.com/alternator-pulley-size.html theas guys have the overdrive pully for your alternator to allow your desired ultra low idle

Knoxville at 50, hey? Sounds like you're spending most of your time on Middlebrook Pike.

Don't be too creeped out, I work in Knoxville.

I know you like the older engines and I totally get that, and for my money I would say stick with the 305 you already have on hand. The volume/surface area ratio in that engine isn't too bad, so you don't lose quite as much heat through the cylinder walls. And the depth of support for the SBC is huge, so someone, somewhere has already done whatever you're going to do and you have a shot at picking that guy's brain for advice if you need it.

Having said that, consider an LLV, the big 2.9l four-banger the General screwed into the Colorado/Canyon twins. That's a bigger truck than your S10, but the engine's power output is right in line with what you're shooting for. You'll save about 150 lbs over just about any SBC, nearly the weight of an entire passenger. You'd have to swap over the EFI system but that just opens up all the EFI tuning options to you, and in that regard I just have to echo what everyone else has said: you're better off injected if you want the best possible economy.

When GM switched over to the rooler cam in sbc in the 90s they said it would give about a 1 to 1.5mpg improvement.

I'm not a big fan of the iron dukes, but from a boat you can get a 3.0L 4 banger that is similar. That could be fun in a s10

My Canyon has the 2.8L previous version of that engine. It has plenty of power and torque. I keep up with traffic shifting at 2500 RPM, 3000 if I'm pulling out onto a highway. I've wondered what mileage I could get if I had that engine in a smaller truck such as an S10, especially if I added the six speed manual transmission from the new Chevy Colorado connected to a 3.42 rear end.

Please do this, I want to see the results.

I have had some great luck with an L05 350 with the 7747 ecm and lean highway mode paired with a Mallory Hyfire VIA msd. Don't be scared of the EFI. It's very simple with a little bit of effort. The 3.08 is great!

Your truck was what I was thinking of when I made the suggestion. His S10, even if he has the heaviest one, is already at least 400 lbs lighter than your truck (when it was stock) even if you have the lightest one. The Atlas engine is going to feel like a really lively mill in that circumstance.

If were talking about swapping a modern four cylinder in place of an old one, I have to vote for the 2.4liter LE5... It's got variable valve timing and runs pretty efficiently in the cars they come in... Out of the box(in the cars they originally come in), they're good for 170-175hp and 30+mpg... Half the frictional loss of a V8, and enough power to motivate an older S-10... In fact, I'd love to dig my old Ranger out of the weeds and do a retrofit on it... There are off road swap harnesses made by Alpha Fab industries, so swapping one of these into even the oldest of compact truck becomes just a matter of making it fit...

Tonight I'm tearing the 267 down to see it's condition. I have a ton of racing parts that I could use like 40 pound cranks and light weight rods. I'm looking at several cams and think a flat tappet is the way to go due to reduced spring pressure. I have a Comp 260HR but feel it might be too big. 206/206, .500/.500, 110 LSA.
Lunati makes a fuel milage cam 245/255,195/205,.405/427,108/116, LSA =112.
I think I can get 300 lb. ft. Of torque out of it.
A 3.75 stroke crank would give me about 12% in crease in torque too.

Screw that, build a 406.

IIWIYS - I would put the 400 crank into the 350, and build a 383 stroker (that may be bored .030).

That engine is a torque monster.

Then run a numerically low rear end with the O/D trans of your choice, and you will always be in the sweet spot - torque-wise.

It seems to me that the primary advantage of a FI engine is the tight controls on A/F ratio. What if you had a setup where you could dial in the A/F ratio on the fly as you can with carbed aircraft engines? Am I correct in assuming you can get away with some pretty lean numbers so long as you are puttering around in a low load situation and heat only becomes an issue under higher loads? If this is so, have a setup where he could drive around, very lean and if he wanted to call down to the engine room for more power, all he's have to do is give it a quick turn of a dash mounted knob? I suppose this has already been recommended by someone who said us a 4bbl with the primaries set lean and the secondaries rich. Maybe a combination of the two would be good, as I could see a situation, such as running down the hiway, where you are at a pretty decent sustained load, but not quite into the secondaries yet. In such a case, you would have the abilities to richen the primaries.

Drive it like you could fly it
 

12-Channel Digital EGT and/or CHT Pyrometer Gauge Display
This is a major investment @ 375usd +probs

http://thesensorconnection.com/sites...le_Backlit.jpg

The above Aviation style driving can be achieved with this gage were every cylinder has an alarm. High and low .if one gose wonky the gage can turn on a water /meth injector for that cylinder or the hole motor like a NOS FOG HAT or NOS RUNNER INJECTION ,but water/and or methanol
Sounds like this will be a custom Radio Flyer purpose bult to showcase your engine building skills , a SEMA. TRUCK. And moving non car worthy stuff.
In witch cace this artical will sted some light on how you can use the gage for tuning ,and it has a +-5%accuracy (1000°C or F on gage=950-1050°actual .
The extra probes can be used for other stuff like coolent,diff, trans,intake air . as the device will read and display all the way down past ambant (-148°)

MPG-4 Featured in Fast 20Car Magazine Issue 20332 July 20 2013 .pdf

---
Aerohead this is the gage for your streemliner nabor that we were talking about with the melted pistons.
---
They also have a 4 cylinder version for our 4banger brothers .

I never understood this. Ruin a 400, loose 20 cubic inches, and pay for a crap load of work, for what? The 400 would have the same torque, if not more because of the larger size.

1)Reduced rotating mass 4.0"Vs4.125"bore =faster rev and higher topend 2)closer to square piston/ stroke ratio

You might want to look into it further. I believe you may find things are different than you have described, on several fronts.

Did a comparison last night between the 267 and the 283 w/ 601 305 heads, using the same camshaft and equal Dynamic Compression. The 267 best the 283 by 1/2 mpg but the 283 had 60 more HP at 5500. 😕 The 283 had a lot less horsepower loss than the 267 did.
Where can I find formulas for calculating (approximating) torque at a given rpm using average chamber pressure ???

Would members be interested in seeing the way I modify Holley Booster for better fuel atomization and low flow performance ?

I'd be interested in seeing that modification. I have buddies who still run carbs.

How much weight is .125 larger bore going to add? And over share will make it rev faster, but all things being equal, 20 more cubic inches add 5%more power

Seriously? Same crank. Wider bore. There is a common knowledge, the claim that having something one off is better, the misconception that everybody knows, that a 383 is a torque monster. Having the same stroke as a 400, all things are similar if you were to install (if possible) smaller cylinders. A bigger bore makes more torque because you have a larger piston area, therefore the same psi pushing down has a larger area to push down on.

Kinda why all old hoteods have/ had 350 Chevys. Everybody thinks its the coolest. So take one, make it bigger, into a 383. Still a boring SBC.