question- benz to jeep swap 4.5 450sel motor

[grimgaunt]

I have a chance to get a well maintained 450sel engine (M117) out of a 1978 450SEL.
A couple of questions:
- What are the hp, torque ratings of this motor ?
- I plan to swap this into a jeep grand wagoneer
I know the K-jet system well from owning a couple of Volvos. Is this a good torquey motor for a jeep ? (The AMC 360 in it puts out 160 hp and 270 torque when new)

I want a good, cool running v8 in the Jeep, is the 4.5 a good candidate ?

Next big question - is the 4-speed manual tranny from a 70's 115 body diesel a good fit for this motor ? Can they take the torque and keep chugging without shredding synchros ?

If not, is the 3-spd auto a better choice ?

[Tomguy]

The 4.0L High-output Jeep engine may be a better candidate. The 450SEL w/K-Jet is highly-underpowered compared to its older 4.5 cousin with D-Jet due to stricter emissions controls. Stock is about 200HP. This is what the 4.0L high-output I6s made and they have more low-end torque and are lighter, and should fit in much easier. The 4.5 w/D-jet is 280ft/lbs of torque I believe, so this 4.5 w/K-jet is probably a dismal 220 or so.

You CAN do it, but the engine will be a huge gas-hog compared to the 4.0 and it won't perform like you want it to. A 3.5 or 4.5 from the early 70's with D-Jet would be a much better candidate.

[cth350]

As for a transmission, the benz v8 will eat a 4-speed from a smaller motor. Maybe not eventually, but it's close to the end of the specs.

From doing a bit of research into what others have done, it seems a Tremec transmission is the way to go. expecially if you go to the 6.3 or 6.9. -CTH

[Litton]

I think Tomguy is probably right on the 4.0 HO engine. You also have to look at where the peak torque occurs in the rpm range. Typically, MB likes their torque up around 3,000 or so while that 360 was probably at 2300 or thereabouts. Same with the 4.0. Pluse the 4.0 will give you over 20 mpg and has 210 HP while the 78 4.5 MB is probably about 160 -180 HP because of the smog. One other thing is that that 4.0 Jeep engine is boderline indistuctable and routinely will go 200K plus.

I would have the 360 rebuilt. There is no way that either the MB 4.5 or the Jeep 4.0 will offer the low-rpm torque curve that such a tank requires.

[Tomguy]

You COULD always get an AMC 401 for it...

[grimgaunt]

got 2 of them

they get 9 mpg

overheat sometimes, stall at angles because of the edelbrock carb , etc

I used to race AMCs, I have been dealing with 401s for 22 years (and I am only 34 yrs old)

[Tomguy]

9MPG is probably what you'd get with the 450, you'd have to give it heavy throttle to accel the way you're used to!

[grimgaunt]

9 mpg, are you serious !!!! I thought with a good set of gears (4.11s) that thing would move without burning too much gas, the 560 sels of the late 80's get almost 20 mpg
I know its not the same motor, but WTF !!!!

More than anything, I'd like to save this pristine drivetrain (all for $200)

[cth350]

I had a 280se 4.5 parts car and then a friend blew the engine on her VW rabbit. I figured this would be a great combination. You put the 4.5 in the trunk and regear a benz differential to be backwards. The hard part I never did figure out was how to run the cooling lines and how to mount the differential at the nose of the rabbit.

Some engine swaps just aren't ment to be. -CTH

[Tomguy]

The smogged 450 has 180-190HP
The 560 has like 300 I elieve

HUGE difference. Plus the 5.6 is more efficient with a lot more modern engine controls.

The 4.5 with D-Jet and hot cams beats the smogged 4.5 anyday!