Newer 4 cylinder?

Hi, I'm new here. I just got an 52 cj3a and was wondering. Has anyone put an AMC 150 4 banger in thier flattie? JC Whitney use to sell a converstion kit to put a 2.3 pinto engine in them. Or would I be better to keep my flathead? Will the flathead keep on to road speeds?, I heard about 45 or 50 mph max.

 

45-50 is faster than you will want to go in the old flatty anyways. They where not designed for high way speeds. I have a cj3a with a buick v6 in it, it would go 80 no problem but you would have to change your undies afterwards.

 

Yup, if you are in a hurry, use something else. The old Flatties and the pre-'72 CJ5s are not built for speed (or comfort, really). But they will get you where you want to go, when nothing else will.

On the other hand, that flat head in your 3A can be built up to really haul if you want it to.

There is still stuff available, or if your fabricating skill are good you can make your own.
Headers, intakes and reworked heads that raise the compression level. Done right you can get around 80 horsepower out of the L134.monkeys

 

Oh, yeah. Forgive my rudeness!

Welcome from Arizona!

 

Thanks for the welcome. I was hopeing it would do 45-55 to not hold back traffic ha ha. I live in the country with a lot of country, so it's not that big of deal, more just curious. I grewup with flatties back in W,Va, but we didn't take them off the mountain much. When we did hit the road, I remember them whinning at around 45 mpg or so.

 

Yeah, they do. If you get an overdrive unit for it, that will lower the engine rpm's at 50 mph and make it so it won't scream so much. As long as you stay at 55 or so and under the differential gears will last for quite a while too.:hurrican:

 

Mmm well. IMO you can drive Jeeps on the highway safely with the proper attitude and preparation/repair of the Jeep. Lots of discussion is available on this topic if you search.

An AMC 150 can be fitted. An inline 4 would be a comparatively easy engine to install. The 2000/2300 Pinto kit is still available from Novak too if that interests you http://www.novak-adapt.com/catalog/kit_pc2.htm (avoid JCW for Jeep parts). You can easily fit either the Chevy 153 inline 4 (Used in Chevy IIs and postal Jeeps), its larger brother the 181 (3.0L) Mercruiser, or the 151 cid "Iron Duke" inline 4 used in GM RWD cars. There are several easy options for a modern inline 4.

The AMC 150 would be a neat swap, with 3 versions available: carbureted, throttle body injected (TBI), or multi-port injected (MPI). The bellhousing pattern is the 60 degree GM pattern, so I'd expect if you get a bellhousing from, say a S-10, and the GM-to-T-90 conversion kit, it should work. Here's an article about adapting the 150 to a SM420 GM truck transmission http://www.jeeptech.com/convtrans/sm420yj/ - this indicates that you could, instead of adapting a GM transmission, use the T-90 and GM adapter in a similar way. Not a common swap, but looks doable.

 

If a stock mill swap is wanted look into the Iron Duke like stated above, if want a built 4 cly, and this just my opinion, I'd go 2.3 Ford. Esslenger ( I think thats how it's spelled) builds the 2.3 out 500 horse power! They make all kinds of stuff for that mill.
Lots of sand car guys used to run them.

 

The obvious appeal of the Pinto 2000/2300/2500 is the use of the existing input shaft on the T-90. The shallow Pinto bellhousing makes this possible. This is a fine choice, especially if you already have the T-90C transmission. I believe this adapter will also work with the 144/170/200 Ford inline 6s, but putting an inline 6 in a short hood Jeep is a messy process.

Any of the GM engines or the AMC will require the long T-90J input shaft, though the difficulty of the whole swap package seems about the same. The GM-to-T90 adapter can be found on the used market, with the potential for a very inexpensive project.

I'd think the Pontiac 151 would likely be the cheapest and most available engine of the whole group. The 153/181 is a more conventional engine, but very highly regarded for strength and durability - the 153 was a popular engine for midget racers for many years. Great engine, and shares a lot of parts with Chevy inline 6s, being essentially 2/3s fo the 230 Chevy inline 6.

 

Thanks for all the replies. As you can tell, I'm a ford man. I concidered the AMC 150 because it doesn't use a timming belt, but thats no biggy. A GM engine just wouldn't cut it, would rather push it ha ha. Ensllinger has all kinds of cool stuff for the ford I-4, 4 barrel intakes, cam, header and so on. Like I say, we have a lot of back country roads around here, so may even leave in the stocker. The problem is, that the jeep has set for a long time and may even be locked up. The frame is excellent and everything is there, it's a whole complete cj3a. However the tub is rotted. I talked to willys overland out of Toledo, they sell body parts with the willys markings, they seem like a knowledable company. Has anyone delt with them before? I would like to upgrade the brakes and switch to 12 volt no matter which engine I use. What gears do these things have, like 4:88's or 5:13's, something like that? I have had lots of jeeps over the years, but this will be my first flat fender that I've owned, even though I've grown up around them. It needs restored, but there's alot there to work with and I'm looking forward to it with your alls help. I want to keep it as original as possable except for maybe the engine, 12 volt and brakes. The rear diff should be a danna 44, but what is the front diff? Thanks again for all the replies and looking foreward to talking and getting to know you all.

 

The gears are more than likely 5.38's but 4.27's were a factory option for the 4 banger. As far as driving it at higher speeds, make sure the brakes are redone or upgraded, check the steering and set the caster at about 5* and the little jeep with good tires will track pretty good at 65-70mph. I drive my 71 on the interstate quite a bit at 70-75mph, there is a bit of pucker factor but most of it comes from the other idiots and the sway you get from a semi flying by you.

Good luck with your project and keep us posted!!

Oh and pics would be nice, we like pics!!!!!!!!!!!!!

 

55 or 60 mph would be good for me on the state routes, but 45 or 50 is fast enough on the back roads. I just read about novaks ford I-4 conversion kits, sounds interesting. I wonder if the newer 2.5 block would adapt to a carb .FI would be cool, but don't want the hassle of an electric fuel pump and all the sensors, plus computer. A holley 4 barrel, cam and header would be sweet, keep it simple and old school. I would like to use the holley truck avenger 4 barrel as they can take some hellaous angles, but the smallest cfm is a 490 I believe, would that be too much for a 4 banger with a cam you think? You can get a 390, but it's not a truck avenger set up for the steep angles. With a cam and header, still should work. Just P&P the head a little and a good cam and get it some juice from MSD, should work. That ought to get me my 55 or 60 mph for the state routes and good off/road power with those steep gears. Should climb a tree if it can reach the first branch hee hee.

 

Another option with the 2300 is a turbo.
Find a factory set up and youd be set. See a few Turbo Coupes from time to time still.

 

JMO - one of the main advantages of a newer engine is the availability of easy factory fuel injection. Fuel injection has many advantages including drivabiltiy, economy, power, reliability, and total immunity from bumps, jolts, hills, etc. If you want a carburetor, I'd suggest you go with a 2000/2300 Pinto which came with the Holley-Weber progressive carb. If you need more carburetion, the Weber DGEV is available from Redline in several sizes.

I think you've wildly veered into the realm of the unrealistic. If you stay with a four banger, you should do it because of the modest increase in power you'll get because of the more sophisticated design. Any of these engines will have a shorter stroke and will consequently make more power because the torque curve peaks higher (power = torque * RPM ! ), and this will be an advantage on the highway. If the modest increase in power is not enough, then you are entering a whole different realm, and your best choice is likely a V6. I'd go with a modern 4 banger because it would be more drivable and would provide a modest increase in highway power, without stressing the rest of the stock drivetrain. It just doesn't make sense to substitute one of these engines for the L134, and then try to make V8 power with it ... instead, start with a V8, or at least a V6.

But if you want to make your flatty more drivable, and keep the complications of an engine swap to a minimum, the modern inline 4 would be a good choice.

 

Well yeah, but not like dropping in a V8 or a 2300 turbo. Depends on your definitions ... the absolute change is modest, though a small absolute change compared to a small number is large in relative terms. Do you think the 150 is in the same class as the 225 or 4.3L, which are arguably the default upgrades for 4 banger Jeep?

The next isn't so relevant - but I was thinking about why the 150 numbers seem like such a large change. I think the relative efficiencies of the two engines isn't that different.

How do the torque numbers compare? Let's see if we can make a rational comparison. The L134 makes 105 lb-ft of torque at 2000 RPM. The torque peak of the 150 is at 3250. So power should increase by 3250/2000 = 1.625 or 62.5%. The there's also the larger displacement, 150/134 = 1.12 ore 12% increase in power simply due to displacement, roughly. Ok, so 60 *1.625*1.12 = 109 HP of an L134 with the same displacement and bore:stroke as the 150. The 150 makes 123 HP nominally, but we can chalk the difference up to better breathing etc. Not that different...