Another engine mount question.......4 cylinder to V8

[fzsk4p]

Elwood and CJ7Jim were kind enough to educate me on the 4 vs. 6 engine frame mounts.

What if I wanted to go with a AMC 304 /360/401 ? Does this family of engine use the same engine frame mount as the 6 cylinder ? Aftermarket mounts available by chance ?

Looking at a 4 cylinder CJ7 to rebuild/restore. Trying to educate myself if the 4 cylinder is worthwhile platform to start with. `Cause the 4 isn`t gonna go.....

Thanks

 

[cjbilly]

AMC V8 engine block mounts will work for all the AMC V8's.
As for CJ frame mounts, one (1) frame mount is the same for the 6 cylinder and the other needs to be swapped out. I can't remember which one. I have heard of a few guys using BOTH AMC 258 i6 / 4.2l frame mounts for the AMC V8's.
A good running AMC 258 i6 / 4.2l with a motorcraft carb and HEI is a good combination. I had this sent up in my trail jeep. GREAT running jeep. Can't beat a good running AMC 258 i6 / 4.2l .
As for my "Mid-Life Crisis" jeep, I wanted V8 power. Therefore we rebuilt an AMC 360 for the jeep. In cold storage ('72 Waggie) is a 401 waiting to be swapped in! :drool:
BTW- there is a frame rod that runs underneath both frame mounts that helps stiffen up the frame from flexing. How many guys still have there's installed???

 

[fzsk4p]

Thanks !!

Just tossing some ideas around. Have found a CJ7 on CL that is not far away. Bit rough in the body department but the frame SEEMS to be solid.

Set up with the AMC 150 (thanks again for the link Elwood) and a 4 speed manual.

If the performance of the AMC 150 is anything like my first YJ with the "same" engine then it is`nt gonna cut it.

A 4.X is the logical choice. But a V8 is a consideration.

Need to decide if a 4 cylinder is worth it as a starting point. A strong consideration is the 4.10`s in the axles.

Looking down from 30,000 feet it might be worth it. At sea level it might not make sense. Right now I am somewhere in-between.

 

[IOPort51]

keep looking, a 6 or 8 will find you if you are patient.

 

[CJim7]

No. The passengerside frame mount is different, but even side by side, you almost cant tell...they are that close dimensionally. They are however, different. The driverside is the same frame bracket as is used with the 6cyl.

The attraction to buying a 4cyl jeep is they are usually priced way under what you would expect for a 6cyl. Sure, you will spend some of that savings off swapping an engine in, but the lower axle gearing is already there, and 4.10's work really well in my opinion. And with those 4.10's, you are above the carrier break. Installing 4.56 or 4.88 gears won't require you installing a new carrier.

So in a way....I was glad to have started out with the 4cyl. Not only did I gain a ton of valuable engine swap knowledge, but I didnt have to mess with the stock axles any more then I had to. For the record, I will not do a gearswap on the 20/30 combo...the one piece axles and cheap Lockrights are more money then I wanted to spend on them in the first place But to their credit, they have held up well and have worked even better.

 

[fzsk4p]

Those are the very facts......axles......I`ve been hanging my hat on Jim.

Not to mention a $600 ASKING price. Been seeing AMC 258 i6 / 4.2l `s and V8`s going for quite a bit more.

Cheap(er) upfront cost vs. spending more $$ overall in the end..........

Still at 30,000 feet on this one.

 

[cjbilly]

Those are the very facts......axles......I`ve been hanging my hat on Jim.

Not to mention a $600 ASKING price. Been seeing AMC 258 i6 / 4.2l `s and V8`s going for quite a bit more.

Cheap(er) upfront cost vs. spending more $$ overall in the end..........

Still at 30,000 feet on this one.

I guess I'm finally seeing this whole picture coming together.
You are planning on using a 4 cylinder CJ as your starting point because of the 4.10 gearing and cheaper start-up cost. GOOD.
Now you are looking at maybe swapping in either a 6 or 8 cylinder motor into your 4 cylinder frame in lieu of buying a factory 6/8 cylinder jeep. IMO, that is a great idea. Easier to install a motor then R & P change.
I'm guess you are looking at an '82-'86 CJ?
Glad to see you doing your homework.

 

[fzsk4p]

Yup an 85 it is.

4.X`s are pretty cheap around here. A quickie freshening up should be good enough for what I want to do.

Betcha that the 4 cylinder would need the same attention. If nothing else the seals and gaskets are at least 25 years old. So the engine part would be a bit of a wash.

Plus I have a complete OBD 1 FI system that can be used. Wiring doesn't bother me in the least. Be it a harness or a complete vehicle.

Couple engine mounts, Transmission input and we are good to go with 4.10`s in the axles.