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-   -   Turbo 6.2 or 292 swap (https://67-72chevytrucks.com/vboard/showthread.php?t=834364)

evoLnivleK 05-11-2022 12:54 PM

Turbo 6.2 or 292 swap
 
Victim: 87 V2500 utility bed. 6.2 th400 np208 gears I haven't checked. Daily work truck 40-80 miles a day in town. Haven't put more than 4500 pounds behind it, but regularly use it for trash outs, hauling gravel and the like. I cruise at 60-65 and have no need to win any races in my work truck. I need off idle grunt.

6.2 runs pretty good, but been fighting an issue where it is very sluggish pulling off from a light and zero power in reverse which sucks when trying to back up a trailer. Im guessing IP light load advance issues, but I haven't nailed it down yet. Motor has maybe 120k on it.

Have a complete 6 5 "turbo kit" for it. I have been piecing it together for a few months.


I also have a good running 292 from a 69 c30 that I bagged and bodied.

Get 6.2 up to snuff and turbo it or swap in the 292 for the cool factor. Fuel consumption is of no consequence. Work foots the bill.

Which route would you take? Thanks

hatzie 05-11-2022 01:23 PM

Re: Turbo 6.2 or 292 swap
 
Put the 292 in it. Long term reliability is a lot better on the big inline 6.
The problems with the AMG Detroit 6.x engines aside. Diesel fuel is in short supply at the moment and it's unlikely to get any better in the near future.

The numbers will speak for themselves.

The 292 Inline 6 has a fair amount of torque down low just like a diesel should.
165hp @ 3,800 rpm and 280 Ft-Lb @ 1,600 rpm dropping to 262 Ft-Lb @ 2,000 rpm.

In comparison the 6.2 Diesel is a dog. And an expensive dog at that.
130hp @ 3,600 rpm and 240 Ft-Lb @ 2,000 rpm

Real world fuel mileage is high teens on the 6.2 and 11-15 on the 292 so not that different in reality.
Upgrading to a progressive bore two barrel carburetor with a small main and larger secondary bore like the Weber carbs from the 70's rather than the stock single barrel Rochester will help a lot on fuel mileage. Similar to the difference between the Rochester 2G and the Quadrajet.
A progressive bore Weber on my 258 in my AMC Eagle got me over the 20mpg mark.
An overdrive transmission will help as well but just the carburetor helped a lot.

I doubt those carbs are easy to find anymore. You will have to re-jet the little monster to mate with your 292 and that's a fiddly task. You'll have to factor the time and effort to tune an odd carb against the just run it simplicity of the Rochester single.

44th Miss Inf 05-11-2022 02:59 PM

Re: Turbo 6.2 or 292 swap
 
My turbo 6.2 with 4speed (SM465) 1/2t 4wd with 3.42s gets consistent 22-24mpg, and if a gas burner isn’t careful, he can get surprised by that old slouch 6.2 with 9 lbs of boost. (Early Banks setup)

I’ve been looking for a 292 for a project, but plan to tbi it with a factory unit.

Either to me, would be a nice setup. Keep us updated

hatzie 05-11-2022 07:11 PM

Re: Turbo 6.2 or 292 swap
 
TBI should make the 292 fairly fuel efficient. I bet it runs 18-23mpg.
I can get that with a TBI 4.9L 300 Ford with a C6 in an F350. Roughly the same size Inline 6.

In any case the 292 has more torque than the 6.2 or the 6.5 even with a turbo and turned up injection pump.

The 292 main webs and cylinder head won't crack like the 6.2L.
If the governor on that DB2 is going out it's going to cost several weeks and a fair chunk of change. I had a 4911 DB2 rebuilt 15 years ago for around $600.

Injectors will usually need service at the same time as the pump. China has poisoned the repair parts market in the extreme. It's going to cost a pretty penny to do the injectors with decent nozzles. Even if you can avoid the labor by pop testing the injectors and adjust the breaking pressure yourself you'll have to find nozzles that'll hang together for more than 25,000 miles. Hunt around for decent replacement nozzles made in Eastern Europe to fit the Bosch 6.2L injectors. If you can find nozzles made in the Baltic states, Poland, Slovakia, Hungary, The Czech Republic, or Germany sacrifice a carburetor to the gods cause they're smiling on you.

Mathew21 05-11-2022 08:25 PM

Re: Turbo 6.2 or 292 swap
 
LS swap it and sell me the 292.:bann:

1957 Chief 05-12-2022 08:06 AM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by Mathew21 (Post 9078077)
LS swap it and sell me the 292.:bann:

Bwaaaaaaa ha ha ha. I seriously laughed out loud. I support this choice as well.

Bubba

evoLnivleK 05-12-2022 12:11 PM

Re: Turbo 6.2 or 292 swap
 
Thanks for the replies. I absolutely love inlines. Admittedly, this is my first domestic 6. I had realistic expectations about the 6.2 when I bought it, but it just hasn't inspired any confidence.

I used the c30 a few times to haul a few yards of gravel for work and fell in love with the 292. I think it would be a fun engine in my V2500.

evoLnivleK 05-12-2022 03:49 PM

Re: Turbo 6.2 or 292 swap
 
2 Attachment(s)
Trucks in question just for reference

special-K 05-13-2022 08:02 AM

Re: Turbo 6.2 or 292 swap
 
The 6.2s I've run, three and all with 35" tires, had grunt right off the line. I think yours isn't running right. I'd look into fixing that, first. I think the 6.2 will last longer w/o a turbo. From what I have seen, 6.2s outlive 6.5TDs. That has been my experience. I love the 292s and had no idea they got any better MPG than a small block. But I did used to get that kind of mileage from a 307, which I had in a 4spd '71 K/20 set up like your '87. I ran 37/14.50 rubber on that one and it was always loaded up, bed, bins, and rack.

It's fun to swap things around, so the 292 would be cool. I'd put a small spread bore 4bbl on it. My experience has been better mileage from a spread bore 4bbl than a 2bbl. Primaries are way less CFM that the factory 2bbl

hatzie 05-13-2022 09:17 AM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by special-K (Post 9078551)
The 6.2s I've run, three and all with 35" tires, had grunt right off the line. I think yours isn't running right. I'd look into fixing that, first. I think the 6.2 will last longer w/o a turbo. From what I have seen, 6.2s outlive 6.5TDs. That has been my experience. I love the 292s and had no idea they got any better MPG than a small block. But I did used to get that kind of mileage from a 307, which I had in a 4spd '71 K/20 set up like your '87. I ran 37/14.50 rubber on that one and it was always loaded up, bed, bins, and rack.

It's fun to swap things around, so the 292 would be cool. I'd put a small spread bore 4bbl on it. My experience has been better mileage from a spread bore 4bbl than a 2bbl. Primaries are way less CFM that the factory 2bbl

The 6.x comes apart with a turbo. Fun to play with for a while but they get expensive.
The 307 was really a pretty good engine without some of the design problems of the 305.

The Rochester Quadrajet is a progressive carburetor. It has two throttle shafts opening two small primary bores that you use most of the time and two large secondary bores that open past half throttle for more power. It's a lot more common than any two barrel progressives, much easier to bolt onto the 292, and should be noticeably better on fuel than the Rochester Monojet 1G & Rochester 2G carbs if you stay out of the secondaries.

Your garden variety two barrel Rochester 2G, Carter 2 barrel, Holley 2 barrel, Motorcraft 2100, ... have two throttle plates on the same throttle shaft.

The VW Zenith Solex 2B2, Mopar Mikuni Solex, and Weber Progressive two barrel carbs are similar to the Quadrajet. Progressive two barrels have two separately actuated throttle shafts like all four barrel carbs. Progressive two barrels run a single small primary bore and a single large secondary bore that opens past half throttle like the Quadrajet.

Having used both a Rochester Quad and a Weber 32/36 Progressive two barrel on my AMC I can tell you the Weber Progressive will use less fuel than the four barrel but they don't have the ease of install that you'll get with the Rochester Quadrajet. I did kindof abuse the fun pedal just a little bit tho. It's actually kinda miserable to tune the Weber but once it's properly setup it's a really good all around carb.

The Spreadbore four barrel manifold can be adapted to a two barrel or TBI throttle body with a bolt-on plate or left as is, depending on what direction you want to go with it.

Good luck finding a VW Zenith Solex 2B2 and you really don't want to. Jetting the 2B2 for the 292 would be a special kind of torture. I had one that came stock on my 1975 Scirocco. It was an uncommon carburetor even in the 1970s. All kinds of nasty to rebuild that one. Super complicated with lots of fiddly adjustments off and then on the engine.

I bought a RAM50 in the late 1980s with a gummed up Mikuni progressive two barrel carb. WOW!! :lol: I figure the Germans in Wolfsburg said to the Japanese at Mikuni "You can't make anything more complicated than the Zenith Solex 2B2" and the Mikuni engineers said "We'll take that challenge". The Mikuni Solex Carburetor on my 1983 Dodge RAM 50 took miserable and fiddly to the next level. I actually fixed the little bugger but I think that's just a testament to my stubborn streak.

44th Miss Inf 05-13-2022 03:07 PM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by hatzie (Post 9078589)
The 6.x comes apart with a turbo. Fun to play with for a while but they get expensive.

My 84 has had a turbo on it since the 80s (I’ve known the truck since day one, as a buddy ordered it new) and the engine has never been out of the truck. The achilles heel of the 6.2/6.5 engines are the balancers, and those that have turbo issues I feel are the ones who are trying to boost them too much. Most I’ve ever seen on my truck is 11-12lbs. Truck has never been babied, and even had a gooseneck hitch in it and was used as a farm truck for years.

Or maybe I’m just lucky, but do believe the diesels are not as forgiving as a gas burner for neglected maintenance.

evoLnivleK 05-13-2022 04:39 PM

Re: Turbo 6.2 or 292 swap
 
My 6.2 2500 spent its entire life as a farm truck. It had only had that red diesel in it for many years. Don't know if that has had any long term effects.

If I went the turbo route I had only planned 6-7 pounds of boost. I know the limitations and I have other cars for going fast/being dumb.

This is strictly for towing/hauling/work purposes.

I'm getting older(40s) and depending on an old truck every day isn't as much fun as it used it be. I hate that I'm starting to feel that way.

special-K 05-14-2022 10:59 AM

Re: Turbo 6.2 or 292 swap
 
One thing I'm thinking is I don't think of a turbo for off the line grunt. I'm not naysaying, just giving food for thought.

My first diesel truck was an '84 6.2 with Banks Sidewinder. It ran great and held up. It held up beyond my three years of working it. And I sold it to a friend's brother who used it for years including on the farm. Those didn't bump a lot of boast. I've had better luck with 6.2s in general.

But the '92 6.5TD gave me 22 years/335k miles of work. For about 15k it ran a different motor, but that '92 motor went over 300k without any work. The motor for 15k of it's life I salvaged from my '95 I had totalled. That was a custom MFI 6.5TD from Peninsular Marine in MI. That came in 300hp form. I fitted up an intercooler. Avant Diesel in SC came out with a performance cam, so I ran it down for them to install one. That got it to around 325hp. That thing ran great. At the time it had as much or more power than the other stock diesels. Dropped a lot of jaws. But that fun lasted about 30k miles before it grenaded. I forget how much boost it had or what size. It was a Switzer medium duty

evoLnivleK 05-14-2022 04:42 PM

Re: Turbo 6.2 or 292 swap
 
I know something isn't right with the 6.2. So addressing those issues would be done before the turbo. I bought a lot of maintenance parts to do at the same time. Turbo is mostly for fun within acceptable boost levels.

I also think I would be pleased with the 292.

I'm still 50/50 either way.

Every chevy I have had has been a 1 ton w/ 4 spd. Maybe I should be thinking nv4500 instead.

I know I'm going in circles. I just want to take the best route for 10 more years of good service.

special-K 05-15-2022 09:06 AM

Re: Turbo 6.2 or 292 swap
 
I always wanted to put a turbo on a 292 :cool:

LT7A 05-15-2022 01:54 PM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by special-K (Post 9079258)
I always wanted to put a turbo on a 292 :cool:

I'm kind of partial to getting the most out of original engines. But, I will say, that I'm not driving them daily or for work. That said, it looks like you've got a couple of cool trucks and maybe it's easier to modify the engines in place? And then turbo them both... eventually... :devil:

special-K 05-16-2022 07:57 AM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by LT7A (Post 9079352)
I'm kind of partial to getting the most out of original engines. But, I will say, that I'm not driving them daily or for work. That said, it looks like you've got a couple of cool trucks and maybe it's easier to modify the engines in place? And then turbo them both... eventually... :devil:

Me too. I wouldn't put a turbo on anything but a complete rebuild. Just thought I'd mention it since all the ingredients are here

D13 05-16-2022 11:34 AM

Re: Turbo 6.2 or 292 swap
 
I used to own 87 R10 6.2, 25+mpg, repair was $$ (you have to remove the front cover to get the water pump off!). Loved it, sold it a couple years ago and moved on.

Next up, 292 , get running, convert to TBI, then add turbo. Probably will go to lighter pistons and longer rods at the same time, more efficient set up than the original. But hose old 6's, feed them oil and drive, with HEI, no issues for many many miles.

Honest Bob 05-16-2022 12:02 PM

Re: Turbo 6.2 or 292 swap
 
A 6.2 is the most fuel efficient way of driving a squarebody. My m1009 (6.2/th400/3.08gr blazer) gets 23mpg.

jcramsey 05-25-2022 06:37 AM

Re: Turbo 6.2 or 292 swap
 
I go back and forth on whether or not to rebuild the 292 that was in my crew cab truck or swap in something else. I love the inline sixes, but I've never had any real world experience with a healthy 292. Mine was on its last legs when I pulled it....was a dog trying to go up any type of significant grade.

I probably shouldn't have sold the Clifford intake, Fenton headers and 2 barrel Holley sniper setup I had lol.

special-K 05-25-2022 07:35 AM

Re: Turbo 6.2 or 292 swap
 
I know we are talking work truck grunt here. But I can no longer fight the temptation to show this 292 powered drag truck cuz it's just too dang cool!


evoLnivleK 06-28-2022 11:03 AM

Re: Turbo 6.2 or 292 swap
 
1 Attachment(s)
So...I'm sticking with the 6 2 for now. Took it out of service to do a few upgrades while I do some much needed maintenance. Should be a totally different truck when it gets back on the road. Thanks for everyones input.

dagnabbitt 06-29-2022 01:01 AM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by evoLnivleK (Post 9077926)
6.2 runs pretty good, but been fighting an issue where it is very sluggish pulling off from a light and zero power in reverse which sucks when trying to back up a trailer.

This might be dumb of me, but it sounds like your trans may be the issue. Have you ruled that out? I read the thread above and if it was mentioned I did not see it.

evoLnivleK 06-29-2022 06:18 AM

Re: Turbo 6.2 or 292 swap
 
Quote:

Originally Posted by dagnabbitt (Post 9095822)
This might be dumb of me, but it sounds like your trans may be the issue. Have you ruled that out? I read the thread above and if it was mentioned I did not see it.

I have been chasing what I thought was an engine issue. Then my transmission took a crap last week. Then it made sense. My problem has been the transmission the whole time. I've read so many horror stories about the 6.2, I was convinced the problem was in the motor.

Transmission is on the ground as of last night, ready to go to the rebuilder. 1600+ quote to fix.

evoLnivleK 07-31-2022 08:40 PM

Re: Turbo 6.2 or 292 swap
 
Well, the saga continues...

Ditching the th400. Picked up an nv4500 today. Along with column, pedals, and a few other needed bits. Just couldn't justify rebuilding the 400 with the amount of towing I do.

Turbo is on. Manual swap next weekend. This will truly be a different truck when it is back on the road.


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