V8 guys, Is this an AMC block?

Nostril Cheese · 10-27-2013, 04:26 PM

Any of you guys know these motors? I've been tasked with getting this thing running decently again. Nearest I can tell, this is an AMC block swapped into a Jeep Gladiator.

Currently it guzzles fuel and barley stays running under load. Any help would be appreciated. Has a pretty nice HEI Mallory on it and an Edelbrock carb. I'm guessing
its overjetted and the timing's off.

Rick V · 10-27-2013, 04:34 PM

Those trucks are very high on the cool scale.
You should be able to find numbers on the block and google them. If I had to guess I would say it is a 304, it's a very popular swap

fastfredracing · 10-27-2013, 04:35 PM

Looks like a 304

GWN7 · 10-27-2013, 04:49 PM

Carbs a 750 (1406). No wonder it eats gas.

Nostril Cheese · 10-27-2013, 04:58 PM

Quote:

Originally Posted by GWN7

Carbs a 750 (1406). No wonder it eats gas.

What would you reccomend for a work truck and get reasonable economy?

johnsjmc · 10-27-2013, 05:20 PM

I think Edelbrock makes a 600 cfm which is factory tuned for better economy .(ie slightly leaner cruise ). I think Holley also makes a small 4 bbl like a 450 cfm.
I wouldn,t expect miracles with fuel mileage with any changes though.

Nostril Cheese · 10-27-2013, 05:23 PM

I just spoke to the owner and he mentioned something about it being a 360. Is this possible?

GWN7 · 10-27-2013, 05:23 PM

Well if it's a 304 like the other guy have said they are not a huge HP engine. It could also be the original engine.

Per Wikipedia: The 304 had a displacement of 303.92 CID (4,980.3 cc) which produced 210 hp (157 kW; 213 PS) in 1970-71 and was built starting in 1970.[14] Later models produced less power from the factory, going down yearly. 1972-78 models were rated at 150 hp (112 kW; 152 PS). It was rated at 130.5 hp (97 kW; 132 PS) in 1979, the last year it was installed in passenger cars, and 125 hp (93 kW; 127 PS) in 1980-81, the last years it was used in Jeep vehicles.

Check the engine numbers and the serial number. They should help determine if it was a swap and which engine it is.

210 hp, 150 hp, 130 hp and 125 hp

The carb should be between 500 cfm and 600 cfm I would guess.

GWN7 · 10-27-2013, 05:23 PM

Quote:

Originally Posted by Nostril Cheese

I just spoke to the owner and he mentioned something about it being a 360. Is this possible?

Yes....

The AMC 360 had a displacement of 359.80 CID (5,896.1 cc).[14] The 2-barrel produced 235 hp (175 kW; 238 PS) to 245 hp (183 kW; 248 PS) in 1970 to early 1971 while the 4-barrel produced 285 hp (213 kW; 289 PS) to 295 hp (220 kW; 299 PS), 175 hp (130 kW; 177 PS) to 220 hp (164 kW; 223 PS) from mid-1971 to 1975, 140 hp (104 kW; 142 PS) to 180 hp (134 kW; 182 PS) in 1976, 129 hp (96 kW; 131 PS) in 1977, and 160 hp (119 kW; 162 PS) from 1978 to 1991.

It was the last AMC V8 to be manufactured. It was used exclusively in Jeep J-series Trucks 1970-1987, Jeep Wagoneer models from 1972 to 1984, Cherokee from 1974 to 1983, and Grand Wagoneer from 1984 to 1991 - becoming the last carbureted engine used in an American-built vehicle. It was also installed in the Bricklin SV-1 sports car for 1974 model year.

Nostril Cheese · 05:35 PM

Quote:

Originally Posted by GWN7

Carbs a 750 (1406). No wonder it eats gas.

Edelbrock's website lists the 1406 as a 600cfm. Im not sure whats up with the thing because it drinks fuel just at idle. Like half a gallon of gas in 90 seconds.

Edelbrock.com - Carburetors & Accessories - Performer Series Carburetors

Nostril Cheese · 10-27-2013, 05:39 PM

It's a badass truck for sure.

Someone put what looks like a 50's Chevy hood ornament on it at some point. They also made diamond plate bumpers on the rear.

GWN7 · 10-27-2013, 05:39 PM

Quote:

Originally Posted by Nostril Cheese

Edelbrock's website lists the 1406 as a 600cfm. Im not sure whats up with the thing because it drinks fuel just at idle. Like half a gallon of gas in 90 seconds.

Edelbrock.com - Carburetors & Accessories - Performer Series Carburetors

My bad I typed in Edelbrock 1407...... 06 is a 600 cfm which should be good on that engine

johnsjmc · 10-27-2013, 05:50 PM

If it's sucking that much fuel at idle the needle and seat may be leaking causing flooding.
The AMC V8 was available in 290,304,343,360,390 and 401 displacement all within the same block. Hard to tell from the outside but V8s were used in much of the Jeep line even the old CJ wranglers had a V8 option. Unlike other companies with a small and different large block series.

GWN7 · 10-27-2013, 06:06 PM

Could be a 55 Chevy hood ornament.

LWJ · 10-27-2013, 06:13 PM

I had an F250 / 460 that had carb issues. Did a rebuild (cheap) and tuned it a little lean. It ran great, had tons of power and got double digit mpg if I stayed off the gas. It just needs a little attention.

Good luck!
Larry

Joe Bob · Joe Bob's Garage

2 barrel......

mreid · 10-27-2013, 06:52 PM

Edelbrock carbs are very sensitive to fuel pressure. No more than about 5.5 psi. Once that is correct, the carb is very tunable, responsive, and economical.

RANDY P · RANDY P's Garage

****, I don't even know how that thing will survive in the summer with a carb.

Oxygenated fuel boils over so easily that thing will be a treat to restart in the summertime.

Those edelbrocks suck. I've never gotten one I've been happy with. Do a holley with vac 2nd (I'd go around 700 CFM) - just for the sake of convienence, and get it properly jetted with a pipe sniffer.

Ps that fuel usage is gotta be some sort of serious internal leak. Wouldn't surprise me a bit as oxy gas ****s up and rots out carbs.

asphaltgambler · 10-28-2013, 04:51 AM

Quote:

Originally Posted by RANDY P

****, I don't even know how that thing will survive in the summer with a carb.

Oxygenated fuel boils over so easily that thing will be a treat to restart in the summertime.

Those edelbrocks suck. I've never gotten one I've been happy with. Do a holley with vac 2nd..................t as oxy gas ****s up and rots out carbs.

All in for this. They are prolly the worst 'aftermarket' carb out there. Edelbrock bought the all the rights to manufacture from Carter years ago. Carter 4 bbl carbs were kinda OK.............in late 50's / early sixties. Really very crude. They do offer about 100 ways to set the mixture with jets, needles, etc. But the problem is you can never get one "right" from idle all the way through to top end.

Every time I see one today I say: "Makes a great paperweight.............Now do you want it run right?.............................then replace it"

My opinion. Holley electric choke 600 vacuum secondary if it is a 304 / 650 if it is a 360. You may have to do a little tuning but it is very simple. Trust me you'll be much happier

Laneco · 05:09 AM

Asphaltgambler has quite a bit more experience than I in this area and I would tend to go with his judgement above mine. That said, my experience with the Edelbrock 1406 with the electric choke is quite good. I had one my SBC converted Jaguar XJ6 that was a daily driver for about 5 years (no longer have the car). Zero issues. I put one on the 330 horse 350 in my Dad's Monte Carlo SS about 3 or 4 years ago - zero issues (still have the car). With the 330 horse 350, this carb is pretty much tapped out - borderline needing the next size up. We have one on the 72 Blazer that is still in "project car" phase. That one had the car put on a couple of years ago and is only fired up every few months to move it - but again ZERO issues.

I would recommend a fuel return line off the pump which is hopefully already in place, but may not be as that looks like a pretty early 70's truck. That along with a phenolic spacer pretty have cured any hot start issue I've had with this carb setup.

So would I buy another? You bet. Yours has a problem that is likely related to fuel/varnishing/stuck needle valve, etc. This vehicle will never get GOOD mileage, but it should get something fairly reasonable - certainly in the low teens.

angela