WJ V-8

[bigdaddyjlove]

Can anyone tell me the difference in the 4.7 and the 4.7 HO?

I kow the differnece in power and torque, just wondering if it is physical (cam, head and such) or all in the computer.

Friend of mine is looking at one

 

[5-90]

Can anyone tell me the difference in the 4.7 and the 4.7 HO?

I kow the differnece in power and torque, just wondering if it is physical (cam, head and such) or all in the computer.

Friend of mine is looking at one

I would think it's more to do with cylinder head ports and electronics, if the 242ci/242ciHO is any indication (sorry, I think in inches. 4.7L is 287ci, in case you see me reference it...)

That was the primary difference over the 1990/1991 break - the intake ports were raised 5/8" from where AMC put them to make for a less drastic angle into the bowl, and the controls were "upgraded" to OBD (I'm not so sure that was a good idea...) The primary reason for the power upgrade was due to the intake ports, tho - even the camshaft didn't change overmuch. The deletion of the EGR valve probably also helped (ask me if I'm surprised about that.)

Considering the 287ci V8 has always been an OBD-II engine, it's probably a head porting and possible programming change. I don't have data on the bumpsticks to either side of that break to make any assertions - but it's possible that valve event timing could have been changed slightly as well.

How significant is the difference in output? If it's more than 20 pound-feet/15BHP, the changes may be more significant than what I'm on about...

 

[Bryan C.]

Can anyone tell me the difference in the 4.7 and the 4.7 HO?

I kow the differnece in power and torque, just wondering if it is physical (cam, head and such) or all in the computer.

Friend of mine is looking at one

Cams, head porting, computer tweaks, and a slightly different air filter box.

I remember some of the WJ guys swapping the HO cams into their non-HO engines and there was a gain in power. How much more? I have no clue...

 

[jneary]

definately different heads.