Soliciting opinions about AMC304 HP Rating

[DHugg]

I have an AMC 304 Reman in my 1980 CJ7 ; only 8.6K miles on it. The air injection system is capped off in the head ports and the pump removed. All the vacuum-connected heat-activated sensors are gone. She has a little vacuum line from the intake manifold to the advance pot, and the bigger line from MC2100 carb base to the intake manifold. All the rest of the pollution junk was removed. The AC compressor has been pulled. Lighter springs (Mr. Gasket 905) are in the distributor centrifugal advance slots.

Somewhere I captured HP/Torque data on the 304s that reads:

"The AMC 304 uses a cast iron block and heads with over head valves and hydraulic lifters. The AMC 304 was introduced in Jeep vehicles in 1971 in J-series pickups and Wagoneers and in 1972 in the CJ vehicles. Early 304s performed well, so well that frame changes were made to the CJs in '73 to prevent cracks. The AMC 304 used from '72-'78 has the best performance of all the 304s used in the CJ. The AMC 304 was not offered in J-series pickups and Wagoneers after 1972. Meeting legal requirements for smog controls on the AMC 304 severely hurt performance of the engine. The last two years of the AMC 304 in the CJ were in '80-'81. The horse power and torque specifications of the last version of the AMC 304 narrowly beat the AMC 258 i6 / 4.2l use at this time. The AMC 258 i6 / 4.2l used between '80 and '81 was putting out 110 HP @ 3500 and 195 ft/lbs @ 2000.

AMC 304 V8 1972-1978
Bore x Stroke 3.75" x 3.44"
Displacement AMC 304 (4.98L)
Compression Ratio 8.4:1
Horsepower (net) AMC 150 @4200
Torque (net) 245@2500
Main Bearings 5
Valve Configuration OHV
Fuel 2bbl"

Asking for an opinion, please, from one with a greater store of Jeep lore than I.

Are there internal engine changes in the '80-'81 series that accompany external HP-robbing pollution controls?

If the pollution controls are stripped away, is the basic engine output similar to the 1972-1978 series?

I don't want to do burnouts with the 35 inch X 12.5 inch mudders, but I would like to know if the engine output is at parity with earlier blocks.

 

[Hedgehog]

I would have left the EGR and PCV systems alone. EGR makes for a more powerful cooler running engine, doesn't make sense, but it's true. The PCV system improves breathing and makes the engine a little more environmentally friendly without hurting anything. Compared to todays HP numbers the AMC V8 sure looks like a dog doesn't it. Different time, different numbers I guess.

 

[Petescj]

Id pop on over to Bulltear Pro-Parts Forum. You'll get plenty of good info on the AMC 304 there.

 

[DHugg]

Id pop on over to Bulltear Pro-Parts Forum. You'll get plenty of good info on the AMC 304 there.

Good, Petescj. I'll spend the last 30 minutes available to us old guys and smoke over Bulltear. Thanks.