Destroke? 199 crank in 4L?

[O-Gauge Steamer]

Oh crap, I forgot that forced induction engines are limited to 3.3 liters, so turbo'ing would probably be out anyway.

I have a 5.2 in my garage, but it's not aluminum, so it's just as heavy. Cam'd and tuned, it can make power, but a stock 5.7 makes more right off the bat.

Hemi swaps are exactly cheap, but ebay has them for between $2500-$3500. I know, not exactly pocket change, but compared to buying a crate motor, it's cheap enough. Plus, V8s are awesome.

In the end, I'll probably end up with a high compression stroker. I have an extra motor kicking around that I can build at my leisure.

About 6 months ago, I saw, on Ebay, a complete Hemi 4x4 Driveline with all of the wiring and the computers (Engine, Transmission and Transfercase) needed for $5k plus shipping. I think it came out of a Dodge Ram. That would have made a nice starting point for a project...

 

[sureshot007]

oops, didn't mean to post.

 

[ChevelleSSLS6]

You might want to check out some AMC specific message boards.

 

[kastein]

What could you get by stroking a 2.5? This might be a super stupid idea, and I'm not even sure there are similarly available cranks for stroking 4cyls... but it's something to think about.

 

[5-90]

What could you get by stroking a 2.5? This might be a super stupid idea, and I'm not even sure there are similarly available cranks for stroking 4cyls... but it's something to think about.

I don't know of any "drop-in" stroker cranks for the 4-150 - the problem you run into is that it was based on the AMC six, not off of any other four-cylinder engine (so no real common dimensions.)

The only real way to stroke the 4-150 that I know of would be to have the crank offset ground or welded & ground - neither of which would be horribly cheap.

 

[sureshot007]

I've blown up more 2.5s than I care to count. They just can't handle the punishment I throw at them.

 

[kastein]

Rebuilt or junkyard/pulled running ones?

5-90, that's about what I was afraid of.

 

[sureshot007]

Both. They just don't like being run at 5000 rpms for extended periods of time.

 

[Dr. Dyno]

I don't know of any "drop-in" stroker cranks for the 4-150 - the problem you run into is that it was based on the AMC six

Funnily enough it was the other way round. The 4.0L I6 was based on the 2.5L I4 and shared most things with it apart from the deck height, stroke length, cylinder count, compression ratio, and cam timing.

 

[O-Gauge Steamer]

The weld and grind method is how I stroked a Triumph 6 cylinder back in 1975... It started life as a 2 Litre and after a healthy dose of bore and stroke, it was a 2.45 Litre. Three Weber DCOE carbs, Headers to dual exhaust, British Leyland S-5 Camshaft (the one they ran at LeMans that year) massively reworked cylinder head and viola! North of 250hp at sea level.

But the expense was just stupid. Plus, I had to have custom con rods made. Went with Carillo as it was going to be spendy any which way I went.

 

[5-90]

Funnily enough it was the other way round. The 4.0L I6 was based on the 2.5L I4 and shared most things with it apart from the deck height, stroke length, cylinder count, compression ratio, and cam timing.

But wasn't the 4-150 based, in its turn, on the 6-199/232/258? That's how I always understood it (which is why there's some commonality in parts between the 4-150 and the sixes in general - at least, as far as timing chains, covers, seals, and stuff like that.)

 

[cruiser54]

The way it was explained to me by a friend at Jeep Tech.

When we did development we didn't have any money, so we took a 4.2/4.0L and cut # 3 and 4 cylinders out and welded the block back together to get a prototype "go-power" engine for development. The testing went so well that we went forward with the design. The original 2.5L has the same stroke as the 4.2/4.0L but less horsepower. Good low-end torque but sucks at high end.

 

[5-90]

The way it was explained to me by a friend at Jeep Tech.

When we did development we didn't have any money, so we took a 4.2/4.0L and cut # 3 and 4 cylinders out and welded the block back together to get a prototype "go-power" engine for development. The testing went so well that we went forward with the design. The original 2.5L has the same stroke as the 4.2/4.0L but less horsepower. Good low-end torque but sucks at high end.

AMC was usually behind the 8-ball on engineering & design - that's why they used forged internals for heir V8s. Didn't have time to try to do them lightweight, so they just went with what was proven.

I think they used a similar high-Ni alloy in their iron castings as ChryCo did with the Gen-II Hemi - which would have a lot to do with why their engines are so tough (the last AMC V8 was poured in 1991, and it can be difficult to find parts, but they'll run damned near forever! They're still used as cores for performance buildups - the 401 especially, and the last one of those was poured in 1978...)

 

[cruiser54]

My friend at JeepTech, reflecting back to the AMC days and just before the XJ was introduced, once told me this:

"We got so used to doing so much with so little, that we found out we could do something with nothing".

 

[Dr. Dyno]

But wasn't the 4-150 based, in its turn, on the 6-199/232/258?

Yeah it was to an extent. The 150ci I4 was given the same crank main/rod journal diameter/width, bore spacing, cam journal diameter/width, timing set, and timing cover. The 4.0 was basically a 2.5 with two extra cylinders and a longer stroke.

 

[O-Gauge Steamer]

AMC is not the only "taker of Engineering shortcuts" out there.

Explain the odd-fire V6 that GM made... OK, let's see, if we lop off two cylinders from a v8, all should be well. Right? What do you mean it runs a bit rough? Then the offset crank to correct the firing angles? Ever see a well worn offset crank? Sort of scary...

A most amazing thing really. History is full of examples. AMCs history is amazing. Nash/Kelvinator merges with Hudson and takes the Hudson front suspension and drops it into the cars. A coil over shock arrangement. They also take the "Monobuilt" idea as well. Monobuilt? We call in unibody. First done by Hudson for the 1948 model year. But the lack of innovation eventually caught up with them. Sales dropped.

Here is a pretty good history snapshot. http://en.wikipedia.org/wiki/American_Motors of what happened and how. You can only go on borrowed ideas for so long. As the corporate war chest lost money, corners got cut, quality dropped and sales dropped along with it. A death spiral.

 

[5-90]

AMC is not the only "taker of Engineering shortcuts" out there.

Explain the odd-fire V6 that GM made... OK, let's see, if we lop off two cylinders from a v8, all should be well. Right? What do you mean it runs a bit rough? Then the offset crank to correct the firing angles? Ever see a well worn offset crank? Sort of scary...

A most amazing thing really. History is full of examples. AMCs history is amazing. Nash/Kelvinator merges with Hudson and takes the Hudson front suspension and drops it into the cars. A coil over shock arrangement. They also take the "Monobuilt" idea as well. Monobuilt? We call in unibody. First done by Hudson for the 1948 model year. But the lack of innovation eventually caught up with them. Sales dropped.

Here is a pretty good history snapshot. http://en.wikipedia.org/wiki/American_Motors of what happened and how. You can only go on borrowed ideas for so long. As the corporate war chest lost money, corners got cut, quality dropped and sales dropped along with it. A death spiral.

Oh, I wasn't saying that AMC was the only one to take engineering shortcuts - and I'm quite familiar with the Buick Odd-fire/Even-fire debacle (there's a very good reason that the G/N Turbo was done with the Odd-fire V6-231! I knew a guy 'way back when who tried to copy the G/N setup with an even-fire crank setup, and ended up snapping the crank inside of ten running hours - hadn't even run the engine in yet. I told him not to do it...)

AMC is far from the only outfit to take shortcuts - they were just the most likely to do it. Some shortcuts worked out, many did not.

Hell, there are plenty of times that I take engineering shortcuts - but those are usually in the direction of "overkill," simply because I don't feel like (or have the time to figure out how to) mimising materials, shapes, et al at the moment.

But, the cornerstone of my own design philosophy is simple - "My stuff don't break." I'd rather come in ten pounds overweight and be solid than come in ten pounds underweight - but worry about durability when it's really going to matter...

 

[O-Gauge Steamer]

^^Here here! You gotta love the even fire crank. What a XXXX-up...