swapping IN a 292 straight six

[Robert79K5]

A long while ago there was a post here on the merrits of the venerable chevy straight six. As I am evidently search impaired I havn't yet found it.

Anyways.. I was thinking about swapping in a 292 straight six into my k5 because of the low rpm torque and general bulletproffness of the engine. I dont do a lot of deep mud stuff that would require high horse power and wheel speed. my off roading consists of lugging around trails in low gear.
if I take the mildly hopped up 350 out of my K5 and replace it with a 292 can I expect any increase in fuel mileage. That would be a big plus to me.
Will the bell housing and flywheel on my 350/sm465 bolt up to the 292?

I run 35 inch tires with 4.56 gears and an sm465. I don't mind loosing some horsepower in exchange for better economy and low speed lugging ability, but my 350 pulls good and lugs well like it is so would it even be worth it?

what about on the highway? By the time I get up to speed my engines turning some pretty decent RPMs will the fuel efficiency of the 292 be reduced exponentially on the highway as the RPMs increase?

Also what years was the 292 produced?

Your flames are appreciated /forums/images/graemlins/grin.gif

 

[nvrenuf]

The bellhousing will work but I'm pretty sure the flywheel is different. I also know there is a slight difference in the passenger side motor mount placement.

Search for posts by TARussell, he's currently building a 292 for his 87 K5. He's done a TON of research on this motor so he'd be a good source of info. /forums/images/graemlins/thumb.gif

 

[sled_dog]

my buddy swapped a 292 into his 86 K5. Has a 465 behind it with a 205. Hes looking to get rid of it. I will go take some pictures some time soon.

 

[diesel4me]

The 292 is a rugged and tourquey motor,it gets its tourque from the long stroke(over 4 inches I think!)so it wont like high revs much,but you can lug it way down without bucking or stalling.They used them a lot in the "P" series step vans,and one ton and larger trucks like the C60 series,I've seen many in older school busses too!.I'm not sure of the number of years they used them,but I'm geussing they first apperaed in 1963 o so,and ran up to the late 80's.They are not that easy to come by around here,I know of only 2 in all the junkyards I frequent.They are about the same or slightly worse than a V8 on fuel economy.If you can get the whole truck the 292 is in for a donor you will be far ahead of the game--the passenger side motor mount is in a different spot than the other sixes(230,250)the mount is where the fuel pump is on a 230 or 250,so you need the 292 bracket off the frame,and the plates that bolt to the 292 motor.The flywheel might be an oddball--I'm not sure but it may be externally balanced,making it a loner.Your bellhousing will bolt right up,as will just about any gm tranny.Be aware many other things will need to be modified or changed,like throttle cables and brackets,etc--that where the donor truck saves many hours of junkyard searches.Whether or not its worth it is debateable--I liked the one I had in a 65 GMC 3/4 ton 4x4 ,it plowed much better with the 292 than the 350 I swapped in after the 292 started smoking badly(previous owner put most of the piston rings in upside down when he "rebuilt"it /forums/images/graemlins/tongue.gif)--it seemed like it had too much power with the 350 and would spin the wheels too easy--the 292 would just idle along with no hopping and spinning--it might be it weighed more than the 350 and the extra weight helped? /forums/images/graemlins/confused.gif.I read online you can bump up the compression ratio by swapping a 230 cylinder head onto it.Clifford performance made 4 barrel manifolds and headers for inline chevy sixes,along with cams and other goodies,but I have heard they have not been a good place to deal with since the father that started the company passed away a few years ago.Good luck with your swap--I nearly bought one of the 292's I saw in the junkyard to put in my 79 C10 when the camel humper integral head 250 died a few months ago,but I got a 305 from a friend cheaper--not sure if it was worth all the hassle,but its in,and its MUCH faster than it was with the 250--and its better on gas by about 3 mpg!. /forums/images/graemlins/crazy.gif

 

[K5MONSTERCHEV]

The guy I work with had a hopped up 6 in his car (cant remember what) and he loved it, said it was fas as hell, smoked muscle cars and all, even twisted the axle tube! Ended up selling the car kept the engine, and I got it off of him for the 6 in my '78.

I understand your puttin it in a truck, not a car, so theres a big weight differrence, but even my stock 250 is fun to drive, and "theres no replacement for displacement", so the 292 will be better then the 250!

I have the clifford intake, headers (yes theres 2), a custom ground cam, and whatever the bottom end was, for a 250. I was going to swap it all onto mine, however, now I might not, just swap in a Duramax.

 

[divorced]

[ QUOTE ]
I'm not sure of the number of years they used them,but I'm geussing they first apperaed in 1963 o so,and ran up to the late 80's.They are not that easy to come by around here,I know of only 2 in all the junkyards I frequent.

[/ QUOTE ]

They are fairly common around here. A lot of old combines used the 292 for an engine, there are several tractor junkyards around with them. A friend of mine bought one complete and running for $100 for his Jeep.

 

[jwduke]

I had a '80 with a 250 & a 4 speed. It ran as good as a 305, but fuel milage sucked big time. I had one of those one piece heads on it. It cracked & I replaced it with one off a '75. That seemed to make it run better. It had 342's & the 4 speed, I think it could of climed a tree!

 

[Hossbaby50]

Like said the 292 has different motor mounts then a 350. I believe that the 250 is more of a direct swap then a 292.

My roommate has a 250 I6 in his 66 Chevy that he pulled from a 80's Chevy Camaro I think and it has HEI dist instead of points. Both his old points 250 and his new 250 made damn good torque and did a fine job of draggin his heavy 66 longbed Chevy around. It is a great motor that makes lots of torque.

292 or 250 would be a great option, but I also a believer in the "don't fix it if it ain't broken" theory. /forums/images/graemlins/dunno.gif

Harley

 

[atho]

I am looking at getting a 292 also. They are harder to find around here too, but luckily one of my friends dads has a '70 C30 rotting away in their backyard with 292/465 and a pto driven dump bed that I could get for free (PTO winch woo hoo!). The HO72 would also be good for some spare parts, and might have a DL (didnt look).

 

[R72K5]

damn a 70 c30 that sux i want one again real bad

i have had quite a few 67-72 trucvks with 292, all have been c-30 chassis cabs so far, did have a 64 c-10 pickup with 292 in it and an 80 something pickup too,

the pass side engine mount sits forward in v8 position they wer enver put in cars, i know a guy who put one in a 76-78 years nova(not 79 square headlights model) he had to do some welding to make that work hehe and couldnt run a fan either the engine is too long for it


bellhousing on 230-up engines is same as v8 yes, so is 305 v6 and 351 v6 and so forth and also 3.8L and 4.3L v6's and some of the old original iron duke 2.5L engines too, good luck

305 v6 and up were used in gm trucks 60s and up and 230 were seen in the gmc's, so was a dana 44 rear in some of them, leaf spring rear only, no trailing arms coil spring type


292 isnt THAt much torquier than a truck sbc, but its all up to you,

i would never spend on a clifford intake and a cam and stuff for a straight six, parts are so much cheaper for sbc youll get more power out of a sbc with the same parts swap than with a straight six and not any better gas mileage really at all

you will need the block mount brackets for the particular engine and era, as sbc's have larger tirangle bolt boss pattern on the sides of the block than 250 and 292 do

and 73-up is not same as 63-72, they changed big time and pass side 292 is unique one of a kind,

good luck


good luck

 

[tarussell]

As stated earlier GM's 292 started in 1963 and was made until the late eighties .
The passenger side motor mount is the same it is the position and frame mount that is different ( the holes already exist in your frame for the frame/mount bracket ) .

As for good gas mileage - they are not known for great mileage but if you drive in the propper power range you should get near comparable economy of a small V-8.

The flywheel is different but any internally balanced SBC flywheel can be made to work . The holes for the bolts that hold it to the crank are 1/2" instead of 7/16" like most every other GM engine that was offered in our trucks . There is also three alignment dowels on a 292 instead of the one found on SBC's and BBC's and the smaller in-line sixes.

I like the 292's because of thier ability to pull hard at such a low RPM. The motor will just pull instead of stalling like a V-8 due to the 4.120" long stroke .
If going SLOW on the trail and lugging the motor down to 300 RPM's or so is your kind of fun than a 292 should make you happy .
Good luck and feel free to ask any questions if you need some help , Tom