Another 292 build

[Nessmuk]

Hey all,
Finally found a 292, so now to perk it up.
It is for low rpm, replace a diesel use in a pick up.
So, what cam, what carb (2 or 4 barrel), are high compression pistons worth while, large valve, lump port the head?

[Ziegelsteinfaust]

There was a guy I met once that had put a turbo on a Type F 300 I6. He gave me a ride in it, and wow it reminded me of a less noisy diesel. Or atleast a pre 97 diesel. I am not mister diesel here.

It was like power/torque 4500 rpm falls on its face pretty much, and shift repeat.

From what he told me it was a stock fuel injected 300 I6 with a mega squirt fuel injection control. I do not know what he did for a turbo manifold.

I want to build a turbo engine one day, but at my heart I am a NA guy through+through.

[Scott Liggett]

This is going back 30 years to HS, I had a friend who had a 292 in his 67 Camaro. It was originally a 250, 4 spd car. What I do remember was: it came out to a 302 ci after it was bored (He put 302 badges on the fenders) He had a four barrel intake and split header on it. Not sure what cam, but it sounded weird when idling. But, oh man the torque!! He beat a lot of V8 cars street light to street light.

It was pretty much finished around 4500 rpm. I would look at a cam that had higher lift, but keeping duration below 224 @.050. It's all about torque here. Getting with a cam company tech to pick one for your needs would be recommended.

Personally, for a truck engine, I would want to keep the compression around 9-9.25:1. An iron headed engine that deals with heavy loads, anymore would need high octane gas all the time and not much gained in HP. With 9:1, I would run 87 octane unless I was towing. Again personal preference.

these things powered tons of medium duty trucks without a problem for years. There are still old grain trucks around here with those 292's humming away.

['68OrangeSunshine]

I've built two 292s. Once in 1977 and again in 2005. Ran the '77 build until 2002, for 250,000 miles and started the next build.
The current block is the original engine, which I put up in crates after the '77 project. It was well-preserved, so I had the machine shop hot tank and bead blast the exterior and bore out the cylinders to .030 over. Chrome-moly rings. ARP fasteners. Stock con rods and 12 lobe crank were good, so they were balanced by the shop. New Badger cast pistons. [First build, I had TRW forged pistons, but they were NLA in '02]. Head got new stellite valves and seats. Intake valves were 1.84'' [V8 307 type] while stock intake valves are 1.6''. Exhaust valves still 1.5'' stock size.
Crane Cam 260H. GM L6 ''lowboy'' HEI. Edelbrock 1404 [500 CFM] on Offy 4V intake and Clifford long tube headers w/ 'N' pipe crossover, dual turbo mufflers.
Vehicle is '68 C/10 stepside shortbed, originally optioned w/ 292 L6, SM 465, and 12-bolt Corp 3.73 rear. Eaton posi and Centerforce II clutch added later.
When running best, gauges show: 700 RPM, 185* H2O, 40 PSI O.P., 17.5'' Hg at idle.
Runs well in city traffic. Freeways, I like to hold at 70-75 MPH, as 51 y.o. chassis tends to rattle.
I prefer it to the stock 350 V8 in my '71 GMC Jimmy.

[Joaquin.pueblos]

Orange, do you have a machine shop you would recommend in Tucson? I am going to be rebuilding a 292 very soon now. I am in Florence so was going to get it machined down there.

[67 twins]

Originally Posted by '68OrangeSunshine

I've built two 292s. Once in 1977 and again in 2005. Ran the '77 build until 2002, for 250,000 miles and started the next build.
The current block is the original engine, which I put up in crates after the '77 project. It was well-preserved, so I had the machine shop hot tank and bead blast the exterior and bore out the cylinders to .030 over. Chrome-moly rings. ARP fasteners. Stock con rods and 12 lobe crank were good, so they were balanced by the shop. New Badger cast pistons. [First build, I had TRW forged pistons, but they were NLA in '02]. Head got new stellite valves and seats. Intake valves were 1.84'' [V8 307 type] while stock intake valves are 1.6''. Exhaust valves still 1.5'' stock size.
Crane Cam 260H. GM L6 ''lowboy'' HEI. Edelbrock 1404 [500 CFM] on Offy 4V intake and Clifford long tube headers w/ 'N' pipe crossover, dual turbo mufflers.
Vehicle is '68 C/10 stepside shortbed, originally optioned w/ 292 L6, SM 465, and 12-bolt Corp 3.73 rear. Eaton posi and Centerforce II clutch added later.
When running best, gauges show: 700 RPM, 185* H2O, 40 PSI O.P., 17.5'' Hg at idle.
Runs well in city traffic. Freeways, I like to hold at 70-75 MPH, as 51 y.o. chassis tends to rattle.
I prefer it to the stock 350 V8 in my '71 GMC Jimmy.

Just two things I wanted to note. First stock intake valve size is 1.72 not 1.6. Second I too prefer to drive my 292 4 speed truck over any of the other trucks in my signature.

['68OrangeSunshine]

Originally Posted by 67 twins

Just two things I wanted to note. First stock intake valve size is 1.72 not 1.6. Second I too prefer to drive my 292 4 speed truck over any of the other trucks in my signature.

I'll look that up. I might have bounced the numbers.

But I'm glad the joy of a well-made 292 is something we share.

[67 twins]

Originally Posted by '68OrangeSunshine

I'll look that up. I might have bounced the numbers.

But I'm glad the joy of a well-made 292 is something we share.

Yes I believe it to be GMs best kept secret. So few people these days even know this engine exists.

['68OrangeSunshine]

Originally Posted by Joaquin.pueblos

Orange, do you have a machine shop you would recommend in Tucson? I am going to be rebuilding a 292 very soon now. I am in Florence so was going to get it machined down there.

I used John Redgate at PO Machine.
520-888-4010

[Joaquin.pueblos]

Thanks, will give them a call. Glad to hear you guys both like 292/465 combo, it is what I decided to go with, hopefully it will be a nice driver.

[67 twins]

Originally Posted by Joaquin.pueblos

Thanks, will give them a call. Glad to hear you guys both like 292/465 combo, it is what I decided to go with, hopefully it will be a nice driver.

Just to be accurate, since my truck is a 67 it has the SM420. Last year for it.