Simple Question : Simple Answer

Okay guys;

Number 1 - I am not a Jeep guy. I have searched the posts and don't see what I am looking for anywhere. You can fit my Jeep knowledge on the head of a pin. Want to talk LS SWAPS, give me a call.

Number 2 - Looking for the simple and logical answer, not the wish list answer.

I just had a customer drop off a 1971 CJ5, 4cyl. Lets for the sake of argument say he thrashed the engine (spun a main bearing). He wants to get the Jeep up and running again and is now considering a 6cyl upgrade. I know that there was a V6 option for this Jeep but I hear that it is hard to get parts for, much less an entire engine.

Question: What is more cost effective? 4cyl rebuild or V6 SWAP.

I want to make the customer happy but I have no earthly idea what is involved (mechanically or financially) in a 6cyl SWAP.

 

I have a 4 cyl, it works well, and can be repaired easily. A swap for a 6 cyl is more complex of course, and more expensive.

 

rebuild what is already there . will save a lot of time

 

Based on the question...........Easy answer: Re-build what you have.

The Buick V6 oddfire swap has been done thousands of times starting with the Willys factory adding that option in late 1965.........parts are out there but finding good used core's is getting harder to find. Most blocks will need to be re-bored and the crank , rods, camshaft , oil pump , timing gears and valve train reconditioned.........add the expense of a bellhousing , clutch, adapters , new clutch linkage some driveline & radiator work and new motor & transmission mounts and that cost could easily exceed $3000 + labor

 

I have both a 225 Dauntless and a Vortec 4.3 in my Jeeps. If I were going Dauntless swap, I would rather rebuild the F134. (unless you have a donor jeep with Dauntless) If I were doing another 4.3 Vortec, its well worth the money of that motor with fuel injection and running on pump fuel. But it will cost aprox. 300 for a descent running used motor, with computer. (mine cost $150 with 116 K and runs like new) then reflash of computer and wiring harness (Hollywood harness) $700, bell housing used $75, Adapter (used) $100 and rebuilt T-15, $330, Clutch, pleasure plate and TO bearing in kit form, $ 250 (168 tooth, 11 inch PP and Clutch) New TO bearing and fork, aprox. $100 and motor mounts, $130, "Tahdah" aprox. $1800--$2200 or you can reuse the original tranny, but still have to buy adapter. I'm sure you can rebuild the 134 cheaper, but man its nice having a 4.3 fuel injected motor. No comparison to the 134. Ask the customer what he wants to do, may surprise you.

 

None of the above.

Most cost efficient for the customer - sell the 4-cyl Jeep without any repairs and buy a replacement with a six or V8. Let the Jeep's purchaser handle the cost of an upgrade or repair. An engine upgrade does not make sense unless you can do the work yourself. There are lots of DIYers out there looking for a bargain, perceived or actual. JMO.

Jeep used the Buick V6 for a while, but today the 4.3L Chevy V6 is likely the most popular choice for a swap. Complete donor vehicles are available for low prices, and the native fuel injection is a big plus. Parts for either the Buick or Chevy V6s are not a problem, but the Chevy is a Chevy, and thus parts are absurdly cheap and widely available.

 

Flipping a known commodity Jeep with an abandoned project Jeep smells of wasted time and spiraling unforeseen costs. If someone has a motor swapped Jeep, and they are selling it, expect a project (unless you personally know the history). You could get lucky.. but likely will not. They are selling for a reason.

Rebuild the FHead unless the customer wants more power, and will pay extra.

 

F head rebuilds are way more expensive then most think. The biggest problem is that when you rebuild a very low hp motor like a F head the customer will most likely be very unhappy with the outcome. Many have rebuilt motors that had zero wrong with them only to find out they really had no power to begin with. Unless there is a strong Sentimental tie to the Jeep, have him sell it and find a good runner for less then what a rebuild can cost.

 

The original poster has a RARE Jeep...there, I said it.
How many 71 F4s exist ?
Rebuild what you have.
Simple answer.

 

If the owner "thrashed" the last one, as said, he'll probably try to do it a again.

 

If he is trying for a hiway cruiser, then getting a newer Jeep would be the thing to do. The F-head engines are just not hiway cruisers. Even with the overdrive.

 

My $0,02, I bought a 66 V-6 donor 27k miles, before I started my restoration of my Tuxedo Park 134 cu in. I toyed with the idea of making my Tux a V-6, even though I already had a NOS. surplus F head. I made my Jeep original, made the V-6 frame a 4 cyl. frame, and put the new 134 in it with all the V-6 drivetrain. It worked out good for what I do with my Jeep. I gave the V-6 to a friend and he rebuilt it, new rings, done the heads, new bearings. He put it all together, didn't have it Magna fluxed, after he got it running he found out why it only had 27K on it, it had a cracked cylinder, water in the oil. He had to pull it out and sleeve the bad cylinder, made me glad I didn't use the V-6 motor. I enjoy driving the original 4 cylinder, antique, Jeep. The V-6 axels and stock size tires make it street able, but it is still good for forest viewing on the trails. It's all in what you want to do with your Jeep I guess, Good Luck what ever you do.

 

Where in Oklahoma are you? You and your customer can come check out my 71 v6 if you want to bring him over. He is probably not running 3.73s, but it may help with the decision.

My engine has about 30k since the last rebuild, my next engine will probably be the 4.3, mainly because of the lower cost, fuel injection and parts availability. I would love to have a Cummins diesel, but I don't think there are adapter kits readily available.

 

When I bought my Jeep I had to bring it back home with 400 miles of highway.
That was very interesting. The F4 is good on flat roads... When I had to climb... the truck drivers used to say hello, except some.
It is a philosophy to drive a F4 on a highway. In France we have no minimum speed limit (on the right lane).
On these 400 miles I found probably one truck slower than me.
But I don't believe that a CJ5 is made for highway, except a good transformed model.
The other problem is brakes, more if it is wet. Not useful to make a drawing!

 

That would be the easy option, however, the customer has "history" with the vehicle and getting rid of it is not an option.

 

Didn't know it was that rare but what I am seeing in these posts are two lines of thought, one I expected and one is a surprise. I am surprised to see the number of people who don't like the idea of a V6 SWAP into this Jeep.