V6 engine: Need opinions

McCracken

McCracken

Logan Can't See This
Joined
Jul 9, 2005
Location
With your mom at a nice seafood dinner
I might have a new project on the way but this one will be much different than what I drive now. I want this to be much lighter and sadly, more fuel efficient.

With that said, what is the best V6 to run? The only experience I've had is with I6s out of Cherokees and old Fords. I did have a 3.8L V6 in a Mustang once but I was less than impressed. What I'm looking for is:

1) Fuel efficiency (20mpg minimum... is this even possible?)
2) Power
3) Good trans/t-case options
 
I have had great luck (knock on wood) with the 4.3L in my 92 S10 Blazer. Just rolled over to 241,000 miles. Getting about 18mpg. Always heard the 4.3 is like a 350 minus two cylinders.
 
I put a 93 4.3 in the jeep I used to have. I had the CPI Vortec, not the TBI. It was a badass little motor. If you go that route, let me know, I still have all the research I did saved to an Excel or Word.
 
Yota v6 engine.. Seems they get decent mileage.. Trans/t-case options unknown to me.

I get 19-23mpg out of my Jeep XJ 4.0 I6(3500# empty, usually about 3800#)

Father in law's s10 blazer (4500#-4700#) with 4.3 CPI gets 17-19mpg. (4.3L is a cut down 350. made on same line, or was originally at least) SFI may get a little better mileage. Beware head/block interchange issues. 4.3L is a TALL motor. barely got it in the back of my XJ. 4.0L is at least 5"-6" shorter

3.1L, 3.4L, 3.8L GMC motors..

3.9L dodge v6, about same as 4.3 for mileage in a dakota, less power than 4.0 or 4.3, maybe difficult to find?

3.5L chrysler V6 (don't bother with 3.3L, they are notorious to blow up), FWD applications mainly, unknown trans/tcase options to me. good power in the intrepid. mileage should be better than or same as the 4.0L.
 
Vortec, I'd like to see that if you wouldn't mind sending it to me. My email is my screen name @yahoo.com.

I'm sure I could compensate on power if I regear accordingly. I believe if I cut down on the weight and gear it right I should have some decent numbers. The reason I don't want to say what my project might be is because I'm afraid I'll jinx it and it won't happen. I've put a lot of thought into it and research. When it's parked in my driveway I'll let the cat out of the bag. Pretty much it's an old auto that I'm trying to bring into the 21st century. The old iron V8 just isn't going to cut it.
 
The thing about 4.3 is your tranny and t-case options are almost UNlimited and are known to hold together when you need'em to. The CPI units they made from late 92 to 95 IMO where the best choice becuase of simplicity and the added balance shaft.
 
20mpg will be difficult. I'm getting 22/25 mpg w/ a 2wd 1500 with 3.08s and P235 tires.. I think anything you do to load the engine will burn more fuel. Large tires, lift, gearing etc..

That said I got 13mpg on the highway with my 1ton YJ/CJ on 38s. So if that brick can do that you should land safely somewhere in the middle..

Don't forget Zukes and sidekicks or other small light weight pocket machines ! They regularly get 20+ even with mods. Nothing wrong with having a goal in mind when your planning.
 
exactly, the lighter the better. I'm used to driving a iron block 360, with a cast 465 mated to more cast (203/205). Add to that a huge cage and other mods and the weight really starts to add up.

Well, I talked the guy today and it's official. I am the new owner of a J-truck. Now you can see where I'm coming from. The truck is just flat out heavy. I'm 6'3" and need the leg room. I looked for a toyota but I like the Gen I style better the others. No extra cab there so I figured I could make something work with the old J-truck. I want this to be my new DD but if it needs to hit the trails it can.

I don't think a 22RE can handle this truck or am I wrong?
 
orangecherokee said:
Well, I talked the guy today and it's official. I am the new owner of a J-truck. Now you can see where I'm coming from. The truck is just flat out heavy. I'm 6'3" and need the leg room.
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Maybe RQ will chime in, but after his D44/9"/36" IROC upgrade a few years back, he was unhappy with the 4.3L. Pretty sure it wasn't the FI, maybe just lack of cubes?

For comparison sake, his '6x Jeepster with frame reinforcement/cage/SM420/D20 (no top or doors) might equal a stripped to the gills auto J-truck? :shaking:

*How* light are you thinking? Minimal everything?

:popcorn:
 
I got a 4.3 vortec SFI in my 96. The motor is out of a 2001 blazer and it runs really good. I really like these v6 engines, very simple to work on. I drive mine 2 and from work though with 33's and 4.10s and not going over 40 mph (less than 3 miles one way) and it gets about 12-15 I suspect. If you get it out on the highway which this one rarely sees it gets alot better. I used to get 18-19 when it was stock with 3.42's and p235/75/r15 GY ATS on it.

I used to have the 4.3 CPI in my 1992 (still have the motor and trans, it was rear-ended and totalled) and it had 3.73's and got the same mileage that my current one got with 3.42s and the same size tires. Just got to watch the fuel injection spiders in them, they have a tendency to dry rot and go bad, then you gotta pull the plenum and replace it. Oh and the FPR's under the plenum will go out too.
 
3800 sc motor to a 700r4 is a good milage setup...
 
Hmmm....

a J-truck huh?

Kinda heavy for a v6. Why not 4bt diesel? with the right combo, you should see mid 20's on mileage.

Guy run them in their fj60s all the time and they are heavy. Same with Jtrucks, its a common swap.
 
you can get great mileage out of the 4bt but it has some issues.. one being weight the engine weighs around 700lbs so you will need to beef the front end a little then emissions related obstacles for inspection to just name a few. I have been really thinking about a 4bt swap in my rubicon but have not yet looked into emissions which i think will be a road block for me
 
The way I see it, diesel is $$$. Maybe not the swap but the fuel. It consistently comes in $.40 higher per gallon around here. If I can squeeze 20 out of gasser i'll save money in the long run. On a side note, the only way I'd run diesel is if I made my own...

So I figure if I get the 4.3 I can regear the axles back to an acceptable rpm range and that's where I can pick up my mileage. I'd like to hear from the guy with the d44/9in combo.

As far as stripped down goes, I figure all I can do is make the drivetrain as light as possible. I've got a trail rig, I don't need to cut the world up to get what i'm after. I did have an idea about trimming the cab down. I thought about cutting 4 inches out of the body all the way around and cutting 6 more down the middle to make it more narrow. Something along the lines of making a J about the same dimensions as a yota but with more leg room.
 
3800 GM V6 MAY or may not get better mileage than 4.3. I would think less displacement, more mileage. Either one has the standard GM bellhousing pattern and would be ideal. Manual and automatic transmissions from GM, one ton transfercases, Dana transfercases, right- or lefthand front outputs, etc. can all be done with factory adapters from the junkyard. Motor and transmission mounts would be easy to fab too. Definately wouldn't use yota v6 because of the lack of trans and transfercase options and the expense of aftermarket adapters.
 
discjoki said:
3800 GM V6 MAY or may not get better mileage than 4.3. I would think less displacement, more mileage. Either one has the standard GM bellhousing pattern and would be ideal. Manual and automatic transmissions from GM, one ton transfercases, Dana transfercases, right- or lefthand front outputs, etc. can all be done with factory adapters from the junkyard. Motor and transmission mounts would be easy to fab too. Definately wouldn't use yota v6 because of the lack of trans and transfercase options and the expense of aftermarket adapters.
Click to expand...

I'm definitely liking this. The more options the better IMO. I think I'll go with a stick just because I think fast cars and trucks should have one.

so it looks like the consensus is the 4.3. This was my knee jerk reaciton when I first thought about it. thanks for the input.
 
FYI the 3800 is a 60* and will not directly bolt up to a small block 90* trannies. They make an adapter or you can get a 700r4 from a 2.8l blazer or a tf903/4 from a 2.8l jeep.... They make an adpater to use the standard trannies from GM.
 
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