Engine Swap...

Yep, typo. Thanks Mike. 181 / 61 cid/liter = 3.0L.

 

Did Mercury use the 181 as a Marine engine? A friend of mine has one in his boat I think. Runs really strong. I always thought it'd be a nice Jeep engine.

 

Yes.

Mercury Marine | Mercury® MerCruiser® 3.0L

 

I have the T90 3 speed. They are a dime a dozen.

I have a replaced exhaust, raised compression, better carb and I balanced everything when I put it back together. I think this motor is running about 90 HP or so nothing special but it helps the top end some.

I have helped build one up to 135 HP which had a low boast turbo.

Not worth the trouble really because you are still stuck with a very low redline on RPMs but it was fun to try and did not really cost much. You can actually add a turbo to a stock Fhead and drive it on the highway no problem. That is if you have the over drive of course.

In fact you can add the turbo for only a hundred dollars if you can make the pipes. 3lbs of boast will get you over 100 HP on an otherwise stock engine and that will allow you to run 75 MPH.

But the MPG is still aweful and the engine winds up slow.

 

My humble opinion: yes, you can do all those things to either 134 and what you end up with is still a very marginal engine power wise, with a very shortened life span (not that they have a long life span in stock in my experience). Is it worth it? My subjective opinion is if one isn't doing a complete down to the correct bolts restoration, absolutely not. May as well swap something not based on 90 year old Willys Whippet engineering.

Willys, Kaiser, AMC, and Chrysler (what ever iteration) all have bestowed upon the Jeep line hand-me-down engines. Nary a single one from the chain drive cam 134 L head to the 3.6 L were ever actually derived for the Jeep CJ/Wrangler platform and all have been marginal to the application-they were just conveniently available. Probably the two best of a rather lack luster bunch were the 225 and the 4.2/4L. The rest either lack any sort of real bottom end torque and/or have terrible efficiency. To me, a perfect modern JK Jeep would be one with a 5.3/NV4500/NP241 Rock Trac/and real D44's on both ends. But guess we would need someone other than Fiat to build it.

 

Speaking of Mercury Marine engines, has anyone ever swapped a 3.7 liter inline four (470) in to a Jeep? Yeh, thats 224 cu inches! These are alloy blocks with a Ford 460 iron head, and in 4bbl trim, made 190 hp. Being a huge 4 cylinder, they make gobs of torque. They also happen to have a Chevy bellhousing pattern.
I have one on the shop floor right now, considering it for my FC150 project.
-Donny

 

I had a Chevy 153 (Cousin to the 181) in my flat fender and it ran about 3000 RPM at 65mph, with 4:88 and 31" tires. While a decent engine, the Hp was lower than what I needed. I did a ton of research on a motor swap before I started my 4.3 Vortec. (Out of a 99 S-10) swap. I wish I could give you an update with performance, but $$ has been short and work slowed down. You can follow along with my progress here:Vortec V6 in a flatfender with a power Saginaw conversion. | EarlyCJ5.com

 

I note without comment that in this entire thread, there has been no mention of performance/behavior off road.

 

So Pete, what would you mention?

 

Discussion is way over my head.

Just recalling that once I had the 258-six and it seemed like too much for slow crawling.
In my woods the F-head is ideal, except perhaps when chewing through heavy snow or mud.

I do understand things are different in the wide open spaces where the cruising speed is inadequate.

 

This is why "Not dead set on any engine, just a good one that will not be a total hassle to put in the Jeep. I would just like to be able to drive it on the highway and the F134 is stretched to handle that. I don't like having to rev it close to redline to hit highway speeds."

But I think any of the engines suggested are an upgrade for offroad use also.

 

My jeep saw about 60% off road, 40% on. When ever I get this thing done, I will be more than happy to post re: Offroad capability. Probably within the 1st week....

 

Boy Tim, after reading the product brochure on the GM 3.0L industrial, it makes me really want one. I think it'd be great in a flatfender or early 5.

 

Multiple considerations are required to determine the optimum engine.
Considering the engine compartment one readily understands that various CJ models to have their inherent space restrictions.
Sure most any small block V8 can be stuffed into the space allowed but personally I prefer a bit of working room under the hood.
It's certainly true that the V-6's provide the best power to space and weight ratio.
Yet the more commonly sought after inline 4 bangers always fit very well providing standard appearance.
The various inline 4 bangers look especially nice bolted in the flatty Jeeps.

 

I think the PO did the conversion to the T-98. All I can say is the set up works great. Oh I am also on 33" tires.

 

Here is an example of the off-road performance of the 4.3ltr V-6. At the end of this movie I cross a bolder field. I never once used the clutch or the brake. I was just feathering the gas petal. (655 to 1 first gear and 4.27 axle gears.)

You can hear the Flat fender with a V-8 behind me struggling to get through the field.