Question for you out there that have run a 292 in a truck

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75gmck25

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The inline six is a very good engine design for balance and form factor, but I believe it was abandoned by US manufacturers because a 60 degree V6 was easier to fit in most engine compartments. The old Datsun 240/260/280Z inline six was a great performance engine, and BMW had multiple inline sixes that work very well.

The only major challenge I've heard of with an inline engine is that its harder to get good fuel distribution because of the large difference in manifold runner length. It can be resolved with a good intake manifold design, but most old OEM systems use a very simple intake with wide variations in runner length.

Bruce
 

Rickf

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Fuel distribution issues can be minimized with a multi carb manifold.

I was going to put this in my '37, but the rear carb is in the way of the master cylinder.

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legopnuematic

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The inline six is a very good engine design for balance and form factor, but I believe it was abandoned by US manufacturers because a 60 degree V6 was easier to fit in most engine compartments. The old Datsun 240/260/280Z inline six was a great performance engine, and BMW had multiple inline sixes that work very well.

The only major challenge I've heard of with an inline engine is that its harder to get good fuel distribution because of the large difference in manifold runner length. It can be resolved with a good intake manifold design, but most old OEM systems use a very simple intake with wide variations in runner length.

Bruce

That is the biggest issue is the manifolds, GM really never seemed to bother much with an improved design. Chrysler did pretty good on the slant six with every cylinder having a dedicated runner and some length (still uneven, bit closer than a Chevy) in the runners. I suppose it was a lack of demand for hopped up sixes that led to them never being offered as a performance package, besides the hyper Pak slant six and the Pontiac OHC Sprint which both lived short lives and are largely forgotten
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CorvairGeek

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A 'lump port' kit and cutting the bosses out of the intake ports of the head of the 194-292 I6 are supposed to do wonders for the flow characteristics, which are fairly poor in stock form. I just want efficiency and to get away from the hot soak issues with the original design with modern fuel.

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CorvairGeek

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Incidentally, some of the older Ford I6s (not the 300) and the Chrysler Slant 6 only had 4 main bearings. The Chevy 6 (194-292) shares a lot of design (and some actual parts) with the small block, so it is plenty stout.
 

Blue Ox

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And the Flathead Ford only had three mains. But I agree, seven is better than four.

If you're really concerned about fuel distribution I'd wager that somebody makes a multi-port kit for a six.
 

trukman1

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I had a '77 K20 with 292 that was an absolute torgue monster and got incredible gas mileage. Only thing was it was SOOOO slow starting out. Had a 465 with 4:56 gears (GM posi units) and it would go anywhere I wanted on the farm and in the woods/mud.

Before "computer" became a household word my friend with a stock 454 said he checked and the bottom end torque (rpm?) was almost as much as the BBC. Didn't dig into that, didn't care.

Driving with the front hubs locked took off 3 mpg right of the top. Took a tank of gas to realize those were still locked in.

Then after my daughter was born I stopped doing what I think 90% of big six drivers do and that is try to get it to go somewhere in a hurry, or at least in a V8'ish manner of speaking.

I drove slow as I could to conserve gas since I needed that money for diapers. (Don't laugh, odds are you've either been there or will be.) Result was great mileage.

I thought I was calculating mileage wrong (and I kept thinking I wasn't going to tell this 'cuz I'll catch a load of chit over it) but I kept coming up with 18-21 mpg. My friend thought I was trying to pull a joke on him so he checked it when I filled up and got the same. At work my buddy told about it and, of course, someone called me out on it. I allowed the guys to come to the station to let me fill it up then put a locking gas cap on it with one of the non-believers holding the keys. Bets were taken and I got a nice bundle of cash when they found I had gotten 21.3 mpg! Of course I drove it easier than ever before but bet was it couldn't possible get 20 mpg.

Was the best truck I EVER owned. Now let me go cry 'cuz I'm thinking about it again....
 

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I'll ask the guy, and hope for an honest answer, what kind of mileage he got out of it, and if it was rebuilt during the time he had it. Once I get this engine (Thursday the 15th), I'll try to do a compression test on a stand if one of my old starters will fit it. I am tempted to just install the thing and run it. Very tempting since he pulled it out his truck on Friday the 9th.
 

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I have to agree. It's pretty hard to fark up an inline six. More main bearings than cylinders makes for a pretty stout bottom end, and everything is straight lines, no angles of the dangles to figure out. Six divides nicely into 360. It's engineering 101.

360 divided by 6 is not 101.
 

Frankenchevy

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Now I want a 292, lol!

I spend 90% of my time below 20% throttle. Sounds like it’s where the 6 is happy. Although, that sm465 has less parasitic loss than my th400.
 

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That's how I like to drive too. I mash the throttle once in a while, but normally it's light pedal to save fuel, not wear things out, and save fuel. Yes I meant to say that twice. Since the 292 likes low rpm's, and my ranger/sm420/3.54 setup will be 2.58 final if I put it in OD, the 292 will turn 2054 rpms at 75 mph. Out of OD will be 2814 rpms at 75 mph.
 

73454GMC

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I have a 1980 C20 with a 292. Plenty of power and 15 MPG with 4 speed and 4.10 gears. Do yourself a favor and put headers and duals on it if nothing else. They breathe a lot easier that way!
 

DoubleDingo

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I have a 1980 C20 with a 292. Plenty of power and 15 MPG with 4 speed and 4.10 gears. Do yourself a favor and put headers and duals on it if nothing else. They breathe a lot easier that way!

15 isn't bad at all.

This engine I just got has 155k on it. Tempted to just run it until I can collect parts for a rebuild. No matter which direction I go, I've read dual exhaust and the hump modification makes the engine way more efficient and the torque curve jumps a lot. A small cam modification will increase the torque numbers even more dramatically.

You saying that about the dual exhaust just makes more concrete that it's a good mod for the engine
 

legopnuematic

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You may consider a 6 into 1 header instead of dual 3 into 1 headers, or have a merge and a large diameter single exhaust (like 3 inch or so), it helps with the scavenging and can help mileage a wee bit too. Keeps them quiet too, they get loud when split into duals.

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