Cummins 4BT & Diesel Conversions Forums banner
1 - 20 of 31 Posts

·
Registered
Joined
·
72 Posts
Discussion Starter · #1 ·
Hello. My name is david and I live in Fort lee VA. Im an active Duty Marine and I have an 88 F250 with a 300-6 in it. It is a 5 speed 4x4. I want to swap a 4BT because I think it will help make the truck unique and hoepfully pull better with better fuel economy. My questions are mostly about the performance aspect of the 4bt.
How does it accelerate?
What can I compare it to get an idea of what its going to be like?
How much noise is it going to make?
About how much with this whole thing cost just to get it driving?
What fuel economy can I expect?

Thanks in advance for your info.
 

·
Registered
Joined
·
1,203 Posts
the Ford guys might be able to help a little more

my 4BT Durango does not accelerate as fast as the 360, no surprise there, but it is not slow. On the highway, i can easily pass someone by just touching the throttle and letting it build some boost.

It makes lots of noise, mainly engine noise at Idle. On the highway, my Durango is not very loud, at idle with the windows down, it is loud. I don't have any additional insullation, acctually less because there is no hood liner. So, it may be able to be improved some.

I have 5k or so in mine, if i didn't have to buy a new trans, I would probably be around 4k.
 

·
Registered
Joined
·
1,462 Posts
The untouched 105 4BT has less sack then an EFI 300, but not too bad.

The 4BT will bolt right into your truck with the common ford pieces. You have the easiest truck in the world to swap a 4BT into. The cost is what you can pick up an engine with the right mounts/adapter and power steering pump for.
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #4 ·
The untouched 105 4BT has less sack then an EFI 300, but not too bad.

The 4BT will bolt right into your truck with the common ford pieces. You have the easiest truck in the world to swap a 4BT into. The cost is what you can pick up an engine with the right mounts/adapter and power steering pump for.
So the 4bt isn't as powerful then a EFI 300-6, Would I be better off doing a 6BT 12V swap? Could I mod the 4BT to help it make more power? What kind of fuel economy can I expect from the 4BT? 6BT?

I have another quick body swap question. How hard would it be to bolt the 95 style fenders, hood, and grill on my truck?
 

·
Registered
Joined
·
4,090 Posts
So the 4bt isn't as powerful then a EFI 300-6, Would I be better off doing a 6BT 12V swap? Could I mod the 4BT to help it make more power? What kind of fuel economy can I expect from the 4BT? 6BT?

I have another quick body swap question. How hard would it be to bolt the 95 style fenders, hood, and grill on my truck?
go to the 6b section ,the F350 will give you idea what a 6b is like in the year of a ford.

The 4bt can have all kinds of mods just like the 6bt and it will wake it up ,if you plan on pulling a lot or heavy loads might thinks about which way you want to go.

Take some time and search ,there is a lot of info that you 'll need .
 

·
Registered
Joined
·
84 Posts
I replaced the 300 in my 1989 f 150 with a 4bt. The power levels are pretty close. The 4bt is louder than the 300 but I was really surprised on how quiet it is. I am getting 30 mpg without overdrive. I will be getting an overdrive tranny soon.
My cost was:

breadvan $2700
1989 f150 $1250
28' fuel line $24
misc. steel (that I had already) $5
TOTAL =$3979

I will either scrap the rest of the breadvan or build a trailer out of it. As average250 said this has got to be the easiest swap that there is. The only thing that I had to modify were the frame stands.
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #7 ·
This truck will be used to pull stuff very very rarlely. At most it will be a few ATVs or a 1993 Mustang to and from the track. I'm thinking the 4BT will be a nice engine and I dont plan on doing any pull offs or Sled Pulling. Maby some offroading. Cornfeed, Can you post a video of your truck in action on youtube or something? I really wanna do this swap and put a manual tranny behind it.
 

·
Registered
Joined
·
84 Posts
I have a 3.08 rear and and 235 75 R15 tires (29"). I'm afraid that my pickup isn't much to see "in action". I built it for mileage I rarely drive over 55 MPH, I accelerate slowly and plan my stops far in advance.
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #10 ·
I have a 3.08 rear and and 235 75 R15 tires (29"). I'm afraid that my pickup isn't much to see "in action". I built it for mileage I rarely drive over 55 MPH, I accelerate slowly and plan my stops far in advance.
Sounds good. I found some vids on youtube. Thanks for your input.
 

·
Registered
Joined
·
1,462 Posts
Personally, I'd take an EFI 300 over a stock 4BT anyday for driveability, but with some tweaking and the right gears/tires the 4BT can be just as nice. The 4BT will get better MPG.

The 5.9 swap will cost you a good bit more.
 

·
Registered
Joined
·
84 Posts
I Agree. I had a hard time taking out a good running 300. It almost felt sacrilegious. I am enjoying the better mileage though.
 

·
Registered
Joined
·
854 Posts
The 5.9 swap will cost you a good bit more.
The horrendous weight is what killed it for me. I didn't want anything heavier than the 400 that was in the truck, and I thought it was too heavy. The mileage is what really sold it for me on the 4BT, and knowing that getting 400+ lbs ft of torque from the 4BT would be easy enough really sealed the deal. I didn't need the extra power of the 6bt.
 

·
Registered
Joined
·
98 Posts
The untouched 105 4BT has less sack then an EFI 300, but not too bad.

The 4BT will bolt right into your truck with the common ford pieces. You have the easiest truck in the world to swap a 4BT into. The cost is what you can pick up an engine with the right mounts/adapter and power steering pump for.
My 4bt gets my truck out of it's own way, which is more than can be said of the 302 I replaced it with... Crappy 302, 3.55 gears, 3 spd w/ od & 35" tires=NO BALLS! The 4bt scoots its way nicely, Its almost as quick as my 01' F-150 w/ a 5.4, beats my girlfriends 4.6, and Dodges w/ 360s :)
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #16 ·
My 4bt gets my truck out of it's own way, which is more than can be said of the 302 I replaced it with... Crappy 302, 3.55 gears, 3 spd w/ od & 35" tires=NO BALLS! The 4bt scoots its way nicely, Its almost as quick as my 01' F-150 w/ a 5.4, beats my girlfriends 4.6, and Dodges w/ 360s :)


And thats why Im swapping


BTW I have an EFI 300-6 for sell, LOL.
 

·
Registered
Joined
·
84 Posts
My 4bt gets my truck out of it's own way, which is more than can be said of the 302 I replaced it with... Crappy 302, 3.55 gears, 3 spd w/ od & 35" tires=NO BALLS! The 4bt scoots its way nicely, Its almost as quick as my 01' F-150 w/ a 5.4, beats my girlfriends 4.6, and Dodges w/ 360s :)
How is that tranny holding up for you? There is one for sale nearby, I was thinking about giving it a try. What make is yours? Thanks for the input.
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #18 ·
My 4bt gets my truck out of it's own way, which is more than can be said of the 302 I replaced it with... Crappy 302, 3.55 gears, 3 spd w/ od & 35" tires=NO BALLS! The 4bt scoots its way nicely, Its almost as quick as my 01' F-150 w/ a 5.4, beats my girlfriends 4.6, and Dodges w/ 360s :)
What mods do you have done to your 4BT?
 

·
Registered
Joined
·
1,462 Posts
The 302 and 300 six are apples and oranges. The 302 has a place, but it's surely nowhere near under the hood of a fullsize truck. The 300 will walk all over any 302 pulling a load.

The 300 has an amazing powerband and has never ceased to surprise me as to what the 145 HP EFI version will do. You will lose a lot of useful powerband going to the 4BT, but the good thing is most of the late 80's early 90's 300 six Fords are geared rather tall for the six anyway, the six likes to cruise around 2500-2800. These trucks seam to be about perfect for the cummins 1700-1800 power.

The easy modifications are 12cm turbine housing, 366 governor spring and aftercooling. With that and proper tuning you'll be atleast a bit ahead of the stock 300.

That said, upgrade to a walker downpipe and non-cat 2.5" single exhaust on the EFI 300 and you'll be suprised how much they wake up.
 
1 - 20 of 31 Posts
Top