Oh yeah, a Toneau cover for the bed not only looks cool, but it can help economy too (or at least it did for the Mythbusters).
You absolutely can get decent mileage with a 292. I get 20 mpg around town with my foot in it and 25+ on the highway at 70mph. Like others have said, make it breath. I've got Stovebolt headers, a Holley 390 cfm carb, Clifford intake with heater and HEI ignition. Not integrated but a propane head for higher compression. Power is transferred via a 200R4 ****** to a Jag rear with 3.53 gears. I run a 235/15 tire on the rear. It can be done! Don't listen to the naysayers. My car has enough torque to pull a house off its foundation and enough get up and go to blow away most V8s.
The '80s trucks had a good trans for mileage, the Turbo 200. It is a tough trans, I think the six was 250, but we used to pull a weigh wagon/auger around with a 1/2 ton like it was a toy. It had better grunt in the field than a 305 easily and the mileage was about 18-20. They made the trans with the Chevy and BOP patterns, so you will need to look close. I liked the Turbo 200 better than the 700. It just seemed to be geared better for a six and running in the muck. Sixes are really nice with an automatic trans and a lockup OD, the torque multiplication gets you underway well, and they are just mice. My son has a '94 F150 with a 300/5-speed OD with 3.55s, and you really are shifting a lot, but at least he gets 20 mpg out of it on the highway, around town though be doesn't want to brag on it. We drove one with an auto and a taller gear and it was really in its element. Stop and go in traffic gets tiring too with the 5 speed.
In stock configuration(valvetrain/carb/intake/exhaust)-- which is was what I was pointing out in my post. Otherwise- the 292 has got to be a great choice for a heavy vehicle due to it's undersquare bore/stroke and few extra cubic inches.
Fro carb choice, I think it comes down to preference. I've got an Edelbrock 600 on mine, and it ran fine right outta the box - still monkeying with it to get best overall power and drivability. Side note: I intend to put a cam and 307 Chevy pistons in it at some point, which lead to buy the bigger carb. From posts on Inliners, definitely go with an Offy intake. The Clifford might make more power, but the Offy is more drivable. Also...highly recommend HEI. HEI dizzys are pretty cheap even brand new ($150 or so off eBay)...used ones off of Chevy sixes can be damn near free. The switch from points to HEI made a big difference on my 292.
I admit I have no experience with anything but the stock 1/2 ton pickups of the 60s-70s. I did run a repair shop and also worked at a GMC dealership breifly so I got a lot of feedback from the owners on milage. Do stay away from the integrated head, those are junk. A 194 head will yeild the highest compression I believe. As with any straight six, the smallish one barrel carb is a huge restriction to breathing. I also know the 300 really wakes up with some moderate head clean up so I would ***ume this pricipal would apply to a 292 also.
I thank you very much for your responses! Alot of this is confirmation I was thinking the right direction. The great thing is I have gotten a few more specifics I didn't have before: Carb 4bbl with around 400cfm Clifford or Offy, but the Offy is more drivable. Exhaust should be opened up a bit, about 2-1/2" into a 3" if staying single exhaust. 5spd transmission - best found from a 90 or earlier chevy truck (last year for the 292) after the transmission is placed spec a gear that will not make the truck to sluggish. If I go for a TBI use a TBI from a Chevy and get the adapter plate for the 4bbl intake. Use the electronics from the donor vehicle. MPI does not work with the 292 because of the issue with the cylinder timing. I will post pics of my PU once I have it completed and will let you know what I have gotten with mileage after each piece has been applied. I do think that moving from the 1bbl to a 4bbl will be the first biggest improvement. Thanks guys!
This was posted earlier in the thread. From what I know it makes sense. I had not considered the Siamese when thinking of the MPI, though if I put my head towards it, I am sure I could come up with a working solution. This would require quite a bit of programming , testing and tuning however.
Some other 6 experience. I have a 46 Plymouth, stock it got 16/17 mpg with is 6.0 to 1 compression ration 218 single 1bbl carb. Swapped in a 30 over 230 engine from a 56. took ,050 off the head/block added a fenton intake, dual carbs (same as stock Carter B1B's) advance the timing a bit. opened the exhaust from 1 3/4 to 2 1/2 id. with a dynomax turbo flow muffler. 225 75 rear tires. with a 1 to 1 top gear and 4.10 to 1 rear it now gets 19/20. Breathing and compression and taller tires equaled 2 to 3 mpg 56 miles per tank. And on a small truck; Back in the first fuel crises I had a 73 Datsun Pickup. 1.8 liter 4 speed. It got about 22 mph. I added the dual carb intake and shaved head from a 510 sedan, headers into single exhaust 2 in id with a dumpster resonator from a buick dual set up. swapped the c 78 14 tires for d 78 15's. Took off the big west coast mirrors, added a chin spoiler made of coroplast. blocked off all the grille except the area directly infront of the radiator, made plexigl*** covers for the head light area. Put a fibregl*** camper top on the bed with a Kamm back type spoiler on the trailing end. And then lowered the truck by 2 inches. Result was 27 mph highway driving 65 miles per tank.
Yeah, I forgot what board I was on. There is a fairly detailed thread on the Inliners forum where a guy did put MPI on a 292 (with lump ports and the whole bit). I keep trying to post links to threads on Inliners here and they never work (goes everywhere but where it needs to). IIRC he put two injectors per port with each at an angle (I don't remember how much). Still working from memory, he had it wired and programmed to fire as two batches of 3 injectors each. He said before (when he tried it as one batch of 6) that #1 would indeed hog the fuel from #2, at low speed. Claimed the effect diminished by 1500 or so. I mis read your statement as it being a physical imposibility to put MPI on a 292. My mistake, I appologise. Thank you for clairifying.
i went with the Offy intake after finding out (exactly what you said) that clifford is good, but more geared around "racing" and bigger HP. the Offy is what i would recomend for a daily. as for the carb...the Carter AFB i picked up, had some issues with it at first. rebuilt it. easiest carb ever! edle is just about the same! for me at least, they're both easiest to work with over Holley, but i know everyone has their thing.
NP, man! I have been all over inliners looking for good solutions and came in with pretty good idea. I have been a V8 guy my whole life, but I just couldn't throw out the 292 on the truck. I can see it doing some good for a while yet. That said, I have been lucky to find some good open minders here. Again, Thanks ya'll!
This is my plan for a 292 I was going to put in my 63 Chevy II. I may need to replace the 350 in my 66 c-10. Since putting the 292 in the truck will be much easier, it may end up in the c-10 and the II may end up with a small v8. I already have: T5 (wc camaro ****** w/ s-10 tailhousing) offy intake stovebolt headers 390 cfm holley cam - 264-H 264 duration 214 @ .050" .498" lift 110 lobe center I need: head from 194 L6 (bump up compression, I have one, it needs to be rebuilt) 3.08 rear (currently has 4.10) The truck is lowered and doesn't have the big mirrors anymore. The truck is a daily driver. I hope the gas mileage won't be too horrible.
Carefull with the gears there 63C2. I don't know what OD you have in your T-5 but with the one in my A (.68) a 3.70 w/ 28 inch tall tires is a bit too steep on the freeway (lugging in 5th). I have a somewhat cammed up V8, so the 292 will likely be happy crusing at a lower RPM, but 3.08 W/ OD sounds kinda tall (ie 3.08X.75= 2.31 final). Not saying it won't work, but it won't help economy any if you gear it to be in or right at the power enrichment point for manifold vacuum at cruise (it's the problem I'm having currently). Slick lookin' truck BTW.
I will agree, I have heard that keeping it around 4.10 with the T5 actually is going to be better with the mileage. Maybe even down to 3.9. Any lower and you may end up ****ing down the fuel in OD.
63ChevyII you may also want to think about lump porting that head to improve the air flow It will also help the over all performance.
Although I've built hundreds of engines over the years for fun and/or profit, I certainly don't consider myself an engine guru. I can't quote fancy engine theory chapter and verse. What I do know how to do however is research and homework for the project at hand. An ongoing project/daily driver for going on five years now is an electronically managed SBC. It's an LT1 in a 3400# car that's been bored and stroked to 388 cid. It has a lightweight rotating ***'y, fully ported heads and intake, internal coatings for heat retention-rejection and low friction, a 10" 3000 stall lock-up converter, 4L60E trans., 3.07 gears, underdrive ATI damper, effecient exhaust, etc. Short story, although in a body that cuts a much smaller profile than a pick-up, it is capable of nearly 29 mpg on the highway and I know there's still more there. It also makes 400 HP and 450 lb-ft of torque at the rear wheels. I feel very sure that a 292 in a heavier vehicle is fully capable of similar mileage, depending upon how deep you want to go as a starting point. You'd obviously want to concentrate on maximizing flow velocity, quench and other things that optimize combustion efficiency and also well tuned fuel and ignition systems. Sequential fire injection would be your best starting point. A torque engine such as your 292 should be an excellent start for your vehicle. I worked on quite a few of these years ago and since have always been quite impressed by them. There's lots of good advice in this thread that should get you thinking.
34hupmobile has the answer with his real world combo. did you figure his final gear ratio. right at 2.50.
Hey Twisted6, I have been thinking about that for a while, esp after spending some time on the phone with you and looking at your website. For now I think I am going to run it with the stock 292 head and as time and money allows, get the 194 head rebuilt and possibly add some lump ports. What is the approx cost on this? I haven't touched the engine since Nov or so. I picked up another harmonic balancer and a distributor for it. Hopefully that takes care of the problems I am having with the engine.
FWIW - I've been driving the Biscayne as a daily for the last week...that means a good deal of stop-and-go and surface street driving; although I've discovered that the motor is strong enough to allow me 2nd gear starts. When traffic opens up, 65MPH = 2500RPM so I'm not exactly lugging the motor...and since I still really really like the sound of the secondaries opening up, there's the occasional WOT test. You know...just to check. But, I digress... I filled it up today and I'm getting just a hair better than 17 to the gallon. I could probably lean out the carb a touch, and if I avoid the loud pedal a bit, I oughta be able to touch 20.
Update: we took the Biscayne on a ~250 mile road trip - me, the spousal unit, her sister and fiance, and two kids, plus requisite kid-gear and entertainment. Fairly steady 60-65 MPH, and we got just shy of 20MPG...with the 4/65 air conditioning going the whole way out.
It’s been 15 years; still hoping for those pics and updates after each piece has been applied. What final mpg was ultimately achieved with your 292? My son’s getting 8mph on his ‘84 Chevy K20 4WD 3/4T, manual (L, 1, 2, 3) Longbed PU with a 292 inline 6, 4.8L, running new 235/85-16 tires…so we’re all ears.
The Jalopy Journal
