Crazy idea. Gen 1 500 into Gen 2 420. - Mercedes-Benz Forum
 
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 01-17-2019, 10:35 AM Thread Starter
BenzWorld Veteran
 
corellian corvette's Avatar
 
Date registered: Dec 2014
Vehicle: 1991 560SEC
Location: Woodinville, WA
Posts: 641
Mentioned: 3 Post(s)
Quoted: 166 Post(s)
(Thread Starter)
Crazy idea. Gen 1 500 into Gen 2 420.

Ok work this through with me. Right now, I have an extra US 500 motor from my euro motor swap project. it's a good running motor, pretty clean (needs typical chains/guides but not urgent)

Meanwhile, I have an excellent running Gen2 420SEL that I've been contemplating doing a motor swap to a 560.

SO here's my question (it's twofold)

First, what's the HP difference between an early US 500 motor and a Gen 2 420 motor. Is there an appreciable difference in performance?

Second, is this swap even possible? Just thinking it through, the only two components that distinguish Gen1 from Gen2 is the ignition distributor and the fuel distributor. Both physically fit on the Gen 1 Motor.

So I'm thinking (again, not in detail) that the only things required to put a Gen1 motor in a Gen2 car is to use the Gen2 fuel distributor (Direct swap) and the ignition distributor, and use the Gen2 electronics.

All of the sensors should be in the same location. I know the water pump configurations but the inlet and outlets are in the same place (no problem). Exhaust should swap over (no problem). The crossover hoses for the injectors are different because the fuel distributor is different shape on the base (no problem). Motor mounts and transmission bolt patterns are exactly the same (no problem).

So physically the motors are the same. There are probably more subtle differences in the intake manifold then I am expecting, but I'm thinking it would be super easy to use the Gen2 420 intake if there are too many other differences.

At first glance this should be a straightforward swap. What am I missing? Is there any reason this is more difficult then I am thinking?

1991 560 SEC Euro
1986 420 SEL
1985 500 SEC (US)
1983 500 SEC (Euro)
corellian corvette is offline  
Sponsored Links
Advertisement
 
post #2 of 3 (permalink) Old 01-17-2019, 11:00 AM
BenzWorld Elite
 
Date registered: Nov 2002
Vehicle: '82 500sec euro, '95 Ford F150
Location: West Palm Beach, Fl
Posts: 1,530
Mentioned: 3 Post(s)
Quoted: 148 Post(s)
Horsepower-wise the two are pretty close. Having driven and owned both (gen1 500 and gen2 420) neither is super impressive, and quite thirsty for what you get in return.
Having said that, even tho on the surface it looks pretty straight forward, there are many differences.
The gen1 uses a WUR, (warm up regulator), the gen2 an EHA,
The gen2 has a CPS (crank position sensor) in the rear, the gen1 does not.
The 420 is an M116 -shorter block, the 500 is an M117 -taller block. This means that you can’t just swap over the intake to make the gen2 fuel management work.
The list goes on and on.

In short, it can be done, but why? You’re really not gaining anything perfomance-wise and there are way too many hurdles you have to clear.

If it was a high compression, gen1 Euro 500, that would be a different story. Still not ideal, but better. The best and easiest option is a US 560 swap.
roadhouse is online now  
post #3 of 3 (permalink) Old 01-17-2019, 01:48 PM Thread Starter
BenzWorld Veteran
 
corellian corvette's Avatar
 
Date registered: Dec 2014
Vehicle: 1991 560SEC
Location: Woodinville, WA
Posts: 641
Mentioned: 3 Post(s)
Quoted: 166 Post(s)
(Thread Starter)
@roadhouse thanks for that. Wasn't aware of the intake differences and the CPS change.

the WUR part would have been covered by the swap to the Gen2 Fuel Distributor and Electronics.

The intake specifically worries me since looking further at pics online there are more differences in sensor location and small layout changes then i saw at first glance.

I may have attempted to take this on if there were a big perf boost.

Now back to looking for a 560 + trans.

1991 560 SEC Euro
1986 420 SEL
1985 500 SEC (US)
1983 500 SEC (Euro)
corellian corvette is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W126 S,SE,SEC,SEL,SD,SDL Class

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome