SX/4 AMC-258

[SX/290]

What is the power ratngs for the 258 I6 ? ? ?

Just curious as the HP n TQ numbers.

Mike

[Sunny]

Pretty bad 

From what I researched before..
110 Horsepower
205 TQ
0-60: 15.2 seconds [15.8 Auto]
1/4 Mile: 19.6 seconds [20.5 Auto]
Top speed: 88MPH.

[Draekon]

Pretty bad 

From what I researched before..
110 Horsepower
205 TQ
0-60: 15.2 seconds [15.8 Auto]
1/4 Mile: 19.6 seconds [20.5 Auto]
Top speed: 88MPH.

Its not too horrible considering its an '80s car.  My '84 firebird came with 150hp/245ft-lbs tq on the stock 305 v8.  Take into consideration the .8L size difference between the motors, and its not far off.

The 258 is 84.5% the size of a 305, so 84.5% of 245ft lbs is 207ft lbs, right where the 258 sits.  The horsepower doesn't come out to be as close, but the torque curve of the 258 is going to put the torque down lower in the RPMs, and HP is a function of RPMs.

Overall, I'd say not bad for an early 80s motor.  But is there room for improvement?  Definitely!

[Sunny]

LG4's [305s] are only good for boat anchors anyway.
Even the HO 305's were 190HP with a 4barrel.
TPI/TBI made an improvement on that.
TPI's made GREAT torque, horrible power in upper RPM's


I'll agree the 80's were not too kind to power numbers though.

It's really a shame AMC never offered a small block Eagle.
Even a 304 would have done wonder's.

I know the Eagle wasn't built for speed, or power.. but 0-60 in almost 16 seconds for an auto, at full throttle?..

Even your 84 Firebird did it in about half that.

Does it really seem THAT slow driving it?.. that's just..horrible?

Now I know why the 4.0 conversion is so popular, and will be my first mod. 

[thereverendbill]

the HEI and MC 2100 really wakes up these motors.  I have yet to do any sort of highway driving with the new carb but up and down my lane with it I can feel the difference 

[Sunny]

the HEI and MC 2100 really wakes up these motors.  I have yet to do any sort of highway driving with the new carb but up and down my lane with it I can feel the difference 

I've actually heard that.
I actually wondered if it was just a case of AMC threw them together, but going bankrupt couldn't afford to give them the parts they really wanted to?

I've never been a fan of Carter carbs.

[BenM]

They were working on the new 2.5 4 at the time, and shortly after that the 4.0. Had things gone differently in the late 80's, AMC may have had the 4.0 in everything by 1990, and really been able to ride the SUV wave.

I think they were ready to drop the 258 as soon as they could get a 4.0 on the market and were just trying to keep things going for another couple of years.

[eaglefreek]

LG4's [305s]  .
Even a 304 would have done wonder's.

.............

Now I know why the 4.0 conversion is so popular, and will be my first mod. 

Strike Eagle installed a 304 in his eagle and was disappointed. He has since installed a 4.0L and is quite happy.

[Budwisr]

the HEI and MC 2100 really wakes up these motors.  I have yet to do any sort of highway driving with the new carb but up and down my lane with it I can feel the difference 

I've actually heard that.
I actually wondered if it was just a case of AMC threw them together, but going bankrupt couldn't afford to give them the parts they really wanted to?

I've never been a fan of Carter carbs.

AMC never went bankrupt. Offically they "merged" with Chrysler but in reality Chrysler bought them out. Then of course Chrysler did go bankrupt in 2009.

[68AMXGOPAC]

The stock 304 isn't much over on the I6.A set of headers, high rise intake and 4 barrell will wake it up, but still low in HP range for what you can squeeze out of the I6 , and it still looks stock on the outside. I have been checking out Titan Motors website and drooling for weeks now.............

[Sunny]

 AMC never went bankrupt. Offically they "merged" with Chrysler but in reality Chrysler bought them out. Then of course Chrysler did go bankrupt in 2009.

I meant they were going bankrupt, not had declared.
Especially when Renault owned them and was experiencing severe financial issues.

Maybe it's a curse?

[El Matador]

Top speed: 88MPH

Just enough for the flux capacitor to kick in.  

I actually wondered if it was just a case of AMC threw them together, but going bankrupt couldn't afford to give them the parts they really wanted to?

AMC was actually a profitable company in its final couple of years prior to the Chrysler buyout.  Because of this, Renault initially refused :Lee the Bulldozer Boy:'s purchase offer.  Then the president of Renault was assassinated in Paris, and his successor resumed the talks with Iacocca.  And the rest, as they say...  

EDIT: Funny how a certain name gets edited out by the profanity filter and changed to "Lee the bulldozer boy". 

[Budwisr]

I guess you could say AMC was "going bankrupt" throughout it's whole existence. Financial "difficulties" aided AMCs innovation in a lot of ways. Sorry, it's a pet peeve of mine when anyone tells me AMC went "under", "down the toilet" or "bankrupt". As El Matador says, they were in pretty good shape when Chrysler bought them. They just built a new state-of-the-art factory, had a new line of cars coming out and the Jeep division was booming with the new Wrangler and the new Grand Cherokee not far behind. They were actually under valued and that made them a great buy. Sometimes being too successful leads to ones demise.

[AMCKen]

the HEI and MC 2100 really wakes up these motors.  I have yet to do any sort of highway driving with the new carb but up and down my lane with it I can feel the difference 

How much improvement is from the different carb or just from a richer mixture? ; )
Any engine jetted lean for emissions will wake up with jet a metering rod fixes. I've done a couple BBDs and they do work well for me.

[SX/290]

The 304 was a low compression smog dawg 150hp n 225tq, the 290HO in net power made 165hp n 240tq when figuring in a 20% drop from gross to net ;-)

Now your comparing an 8.5:1 to a 10:1 compression ratio and a 2bbl (304) ? To a 4bbl (290) !

The 4L only hit a max power of 195hp n 235tq so torque wise the 290 was hangin right with it, Now if ya installed the multipoint injection like the 4L had and the 290Lo stays right with it and the 290hipo surpasses the 4L.

Well there lots of other goodies that work on the 290's you make it a 295-297ci 12.5:1 duel quad 7,500rpm beast should one so choose to do so ;-)

Mike