280SL 3.5L Engine swap requirements and contact

[GGR]

Have you considered moving the battery in the trunk or behind the passenger seat? This would restore the car balance close to stock, given that the 3.5 is heavier than the original engine.

Keep up the good work !

[justininia]

We thought about it but wanted to try and fit it up front.  Right now, we are still after a few other issues.  If it needs to be relocated, we can run new wiring before the interior carpet get put into place.

Thanks,
Justin

Have you considered moving the battery in the trunk or behind the passenger seat? This would restore the car balance close to stock, given that the 3.5 is heavier than the original engine.

Keep up the good work !

[justininia]

Progress updates:

We have been putting in more time on the car and made a little progress.  There has be a little three steps forward, two steps back but things are heading in a good direction.  The biggest chunk of time has been spent in the dash with various tasks.  I have been trying to refit the vents and duct work.  There is definitely a process to making sure all the bits fit correctly.

Other work has included-
Charging and bleeding the brake lines
Fitting the speedometer cable
Connecting all the dash lights
Driver and passenger vents
Installing the exhaust manifolds
New spark plugs
Windshield trim
Front cabin air flap/housing/trim installation
Fitting the fuel lines

What we are working on now includes-
Connecting up the various wiring harnesses
Grounding the dash connections
Getting the radio repaired and reinstalled
Re-installing the remaining heater parts
Installing the windshield
Installing sensors

Eventually I will remember to take pictures. 

Have a great week,
Justin

[justininia]

Photos -

[GGR]

That's really good looking !

You should make sure you have enough clearance between the closed hood and the power steering reservoir. Put the hood in before the radiator, close it and look through the grill opening. You need enough clearance for engine to bounce around when you hit a pothole.

[justininia]

Good day!

Clearance is going to be an issue for a couple of things.  The accelerator linkage arm is a little too close to the valve covers and there is a piece for the cooling system that also sits up pretty high.  When we get our electrical issues sorted out (the car has suffered a stroke on the right side signals), we will be doing some fit work.  It feels like we are hitting the downside of the hill and hopefully will be out driving the car for summer.

Thanks and good luck with your projects.
Justin

That's really good looking !

You should make sure you have enough clearance between the closed hood and the power steering reservoir. Put the hood in before the radiator, close it and look through the grill opening. You need enough clearance for engine to bounce around when you hit a pothole.

[Jim Rosenthal]

I don't know if you did the radiator yet, but if not, one of your options might be to have the radiator recored with a high-performance core which will increase the cooling area and capacity while retaining the same external dimensions. A good radiator shop (of which, sadly, there are fewer and fewer) should be able to spec this and do it for you. It involves removing the old core and soldering in the new one and then tank-testing it for leaks. I've done this with a couple of my Mercedes which needed the radiators cleaned and have been very satisfied with the results.

[justininia]

Good day folks!

We actually are right on board with you Mr. Rosenthal.  We've already taken the original radiator in and had it re-cored to increase it's cooling capacity.  Now it is just a matter of finding a fan capable of pulling enough air through it to keep things running right.

The car is coming along after our struggles with the electrical.  We're still sorting out a couple of issues with the cabin wiring but it's to the radio at this point.  The engine bay is the current focus.  We've been getting the oil lines run for the cooler as well as filter assembly.  Transmission lines are also being fitted and run.

One of the custom things we've done is to relocate the fuel filter to a bracket on the driver's side front frame.  It's the 280SL fuel filter assembling but run more like the 300SEL. 

The vacuum lines are run and most of the injection system is in place.  The accelerator linkage is getting some tuning to make sure the pedal gives the full range throttle.  Plug wires and distribution have also been done.  There is a lot of little miscellaneous stuff to deal with in the engine bay yet but we're getting closer.

Enjoy!
Justin

[pagoden]

So good to hear you folks' progress.  I got to meet Jim Rosenthal recently at a very enjoyable Mid-Atlantic spring gathering; another good fellow.  He'll be having a thread to follow here on the 5-spd Getrag conversion he's in the midst of.  And GGR was there with his very successful, sweet-running aluminum 560 transplant.  Looks like the soonest I can see your handiwork again will be in late May/early June.  Tom Phillips says he's going to an MBCA Iowa Section event of some sort in May, will take one or both 113s if possible, but I won't be there to handle his lovely old 250sl, alas.  Keep him and his R&D dept. in mind for that fan challenge of yours; I've even seen an instance (photo somewhere) of the drive motor of a SPAL fan fitted inside the barrel structure of the 113 grill star when there was no room for a fan pulling on the back side (though there ought to be with the newer fan motors and shorter V8 too, no?).
One of our members summers in WDM and is stirring up another micro Pagoda gathering this year: might be half a dozen cars attending.  Date not set but I hope I can make it, and you gents would make a fine and very popular addition.  [And how about that long-standing multi-county rod and custom run: DR have any appetite for that?  Could be good for some grins.]
P.S. I think you gents should hang on to that 'lacework' rusted-out heater box, just to give posterity an idea of how far gone the whole central cowl/firewall area must have been when you first got to it.  

  

[shanghaitom]

Quite a project you have been working on and it looks like it is turning out great!  Denny pointed me toward your posts.  I think we met at the car show in Johnston last summer...are you related to Dick?  Anyway, if you are looking for an electric cooling fan, SPAL is #1.  Drop me a line if I can help.

[justininia]

You met me out at Green Days as well but I am just a wrencher on the car - Dick is the owner.  We will definitely be looking you and Spal up if we can cross a few more hurdles and get to putting the radiator back in the car.  Definitely not enough clearance in ours to go with an engine mounted fan.

Hope your Mercedes is still running right along,
Justin

[justininia]

Good day to all.

Since the homestead is powerless thanks to some inclement weather, I figure it's a good time to post an update.

We are still working on two fronts - the driver's side door and the electrical.  Fool that I am, I am taking on the electrical.  I have been working on tracing wiring from the ECU to the parts that would need to link up with the main harness.  I think there is not a whole lot of interaction, just some at the engine start safety/backup light switch on the transmission.  Power also needs to make it back to the starter relay so I think I am going to grab it off of either fuse four or six.  Mr. Remer happens to have a 300sel owner's manual complete with wiring diagram.  Once I get done tracing and modifying, I will try and scan in a copy for folks to look at.  Then it will be time to build some connectors for the relays.

 Our door is just a no fun step right now as the paint continues to misbehave.  Enough said.

I am hopeful we will get past these issues this week and start on the few other little tasks that remain.  We test fit the hood once and found the brake fluid reservoir and battery were too high.  That led to some shims in the brake booster bracket and dropping the battery tray a little lower.  The hood fits like a champ now.  We still need some pieces back from the chromer to finish up the dash, a windshield, the fuel tank evap installed, and the door put back together.  If we get the wiring done and locate an oil cooler line or two, we might be able to put in the radiator and possibly try to start the car.

Doesn't sound like too much, right?

Cheers!
Justin

[justininia]

Look kids! Progress...

Well, we got most of the front of the car put back together.  We've discovered that the radiator outlet at the bottom is pointed right at the front sway bar.  That one is going to need some fixing.  Otherwise, we have the grille and bumper on, put on the bumperettes, managed to find a few belts, and got the expansion tank mounted.  The relays are wired for the ECU but I haven't connected them to the fuse panel yet.

The door is painted and needs polished, soon to be reassembled.  Thank you paint for finally working correctly. 

Now it will be time to find all the things not yet on the wire and get the fuse panel fully wired.  I am also on the lookout for some smooth jacketing for the wire (as opposed to the corrugated wire loom stuff).  The evap tank in the back needs to be hooked up, relays mounted, fluids added, sensors checked, and (knocking on wood) no blown fuses means we might be able to start the engine.

Summer motoring around the corner...

Cheers,
Justin

[Garry]

That looks like it is going in nicely.  How do you go for bonnet/hood clearance at the forward part of the engine.

[justininia]

Good day and thank you.

We are doing pretty well on the clearance.  The radiator and tank clear nicely.  The little vacuum at the firewall was up too high and needed to be lowered.  The brake fluid reservoir was also up too high so I used some shims on the brake booster bracket to get it pointed lower.  The battery continues to be at issue, especially since my attempt to run the tank line underneath it raised it up slightly so one corned was touching the hood.  We're still sorting out that problem as well making sure the relays don't stick up too much.  I created a bracket to mount right next to the ECU but haven't mounted anything yet.

That looks like it is going in nicely.  How do you go for bonnet/hood clearance at the forward part of the engine.

[justininia]

Greeting folks.

We have been getting a little bit done but running across a few problems along the way.  What project doesn't have those lovely memories?

The hoses are all run now to the various parts of the cooling system.  Several of the hoses had to be customized (as expected) to reach the various destinations but so far, none are leaking. 

The transmission has been a little less cooperative.  It is an automatic transmission with P-4.  The gear selector shaft out of the transmission is leaking fluid ever so slightly.  More importantly, the bracket we built to attach to the shift linkage did not line up quite right to properly get the starter lockout and back up lights working.  That was a long time ordeal as the bracket is tight in against the tunnel wall.  Nothing like cramped space to try and work in.  The shifting and switch now are in good order.

That leaves the wiring.  We've been putting in new wiring to accommodate the different relays and connections.  Alas, that part is not going as well.  I am still troubleshooting the connections trying to find the problems that prevent the engine from turning over.  The ECU complicates matters a little but the old wiring harness is available for referencing wire colors and guessing relay locations.  The other half is making sure things are tied to the fuse panel in proper spots.  I've attached the 300SEL wiring diagram with colors so people can see what I am doing.  When I have stuff working, I am going to attempt to reconcile the two wiring systems and create a unified diagram.

Other wise, we are still waiting on chrome pieces for the dash to finish that bit up.  And I need to reach out to SPAL and find a fan that is going to work for the car.  If the wiring can be sorted, we should be able to get to work on the interior and finishing up the exhaust.  It's definitely starting to feel downhill.

Onwards and happy motoring to all,
Justin

[justininia]

Greetings!

I really want to rename this thread "The 3-2 Step Dance".  Three steps forwards, two steps back.

Over the weekend, the engine was turned by key switch for the first time.  It was really fun to hear the chuff-chuff sound, especially with no exhaust pipes on.  However, it was zero fun trying to sort out the problems in the prior week or so to get to this point.

First, we had to pull the starter.  When directly energized from the battery, nothing would happen.  Once out of the car, we learned that the solenoid was locked open and the motor was having issues.  Not a big deal except the work it takes to get the starter out with the bigger motor.  The transmission had to be drained so the filler tube (which now obstructs one of the starter bolts) could be moved.  Then the wiring and harness bracket had to come off the starter.  Finally, the starter had to be fished out the right front tire as there is no other way to take it out.  A good thing for those contemplating this project to keep in mind.

Starter repaired, it was time to look at why there was no power to the trigger.  Dismantled and jumpered, the wiring issue was traced back to the module on the back of the key switch, under the dash.  The proper way to dismantle it would be to take out the speedometer and center instrument cluster.  The only problem is that the speedometer cable is really tight which would require all sorts of work to be able to re-attach it.  Since the windshield is still out, we used a different method.  The plastic vent box at the bottom of the dash was disconnected from the fan.  With some wiggle room, we bent two cabinet flat blade screwdrivers to 100 degrees and used them to take out the three screws on the back of the key switch (two from the bottom, one from the upper vent hole).  With the module out, testing confirmed that it was getting inconsistent resistance across the 15 to 50 terminals.  And yes, getting it back in was no fun either.

Reassembled with all the wiring attached and the relays checked, the key finally turned the engine.  Feeling brave at that point, we put some gas in the tank and thought how awesome it would be to see if it fired.  The car repair gods chortled mightily.  After trying the key and getting nothing, a timing light revealed that there was no juice getting to the plugs.  That was only a temporary distraction.   I initially inspected the lines for leaks when we put gas in but quit watching when we were trying to start the car.  Under pressure, the fuel pump began leaking in a steady stream from multiple spots.  Luckily, nothing caught fire.  The fuel pump removed and inspected.  It is missing at least one o-ring and possibly was rebuilt incorrectly.  Argh.

The moral of the story is that whenever possible, test those used components before putting them into the car.  We tested the fuel pump but not with gas in it.  The module on the backside of the key was never tested.  The starter was tested and working but apparently decided to quit. 

This week will be waiting on a new fuel pump and tidying up the wiring.  Other than ironing out the problems that pop up, we are getting closer.  We still have to figure out what is going wrong with the ignition, possibly a bad resistor (already had one go bad) or the transistorized ignition box.  If we get lucky, it may result in a running car. 

Enjoy,
Justin

[justininia]

Greetings!

Vroom, deafening vroom!  We managed to sort out our fuel leaks and fired up the engine for the first time this weekend.  Major milestone achieved.  The timing wasn't all that great but the engine was running on it's own after about two seconds of turning the key. 

I make it sound like it was all well and good after the fuel system troubleshooting but we also ran into a problem with the armature in the distributor.  The switch was made to a Pertronix ignitor and FlameThrower coil.  We couldn't get any fire out of the ignitor so switched back to points.  It may be that a bad part got sent our way but the points fired up like a champ.   

The wiring is mostly sorted at this point.  The electronic tachometer out of a 280SE Cabriolet is getting used which means some additional wiring is needed.  There's something called an Adapter (tachometer) needed and I haven't been able to find its part number on EPC.  Otherwise, the wiring is pretty simple and leaves only the lights in the tach to be figured out.

Other fun resolutions included replacing the brake fluid reservoir.  The original one had a small leak and repairs to it were unsuccessful.  We are still fiddling with the accelerator travel.  The peddle can either fully close the throttle or fully open it but not both.  It may require a modification to the spring arm on the linkage to give it greater travel distance.  Unfortunately, that arm is currently going right into a vacuum line.

The next steps include fixing the timing and finding out what would be needed to fabricate the front half of the exhaust.  Still waiting on the windshield installation and a few pieces of chrome.  Once those are in hand, it will be time to put together the interior. 

Getting there,
Justin

[justininia]

Good day, everyone.

It has been some time since I have posted.  We have been slowly trying to troubleshoot the problems on the 280 while also working on another car. 

The engine is running fairly well.  It appears the timing is still a bit of an issue even though the engine idles at 1100 RPM.  The idle is revving, then relaxing before revving again.  No misfires during fire but it appears the vacuum advance may be causing the issue.  We are continuing to troubleshoot the issue.

Another fun problem is in the wiring.  We have to track down whatever is backfeeding power as the car will not shut off with the driver side door open.  That's a bit of a weird one as the door circuit is fairly isolated from everything else.  Having done the engine wiring, I suspect I may have gotten something crossed where it shouldn't be. 

I am also researching if the connectors and parts can be purchased to remake the engine wiring loom.  The one we have is very brittle and might be causing some other bits of fun.  Hopefully someone out in the world still makes the plastic injector connectors.

We have also been searching for a Mercedes mechanic in the Des Moines area to take a look over everything.  We are kind of to the point where some more expert advice on a few of the problems is needed. 

In the things that have gone right category, I did manage to get the engine fan cut down and balanced.  This doesn't remove the need to consider an electric fan but it gives us the ability to run the engine.  Mr. Hatch recommended using a larger radiator out of a different Mercedes but we have stuck with the re-cored 280SL radiator for the time being.  The radiator he liked is much larger and would require additional modification to the engine bay.

That's pretty much the updates for now.  Hope everyone had a great summer.
Justin

[GGR]

Hi,

Good progress! For idle running high and going up and down, make sure the throttle closes completely and that the throttle position sensor is positioned properly (test it as per W/shop manual procedure) and tells the calculator that throttle is closed when it is so. This is quite a common issue on D-jet and I would rather look on the injection side ratherthan to the ignition side.

Engine not shutting with the open door rings a bell, but I don't remember what. You may want to post the issue in the electrical section of the forum.

I 'm curious about the radiator Hatch recommended you. I've been trying many and it's quite tricky due to the position of the hood when open and its travel path while shutting. Make sure you position whatever radiator with the hood in place to make sure it all works well. Fitting a bigger radiator may be possible by mounting it more backwards. But then clearance with the fan will be an issue. Hatch used home made engine brackets and I guess their engine sits a bit more backwards compared to yours.

Are you still using the oil cooler? If not it will give you more options for the radiator.

I've been looking and wiring connectors a couple of years ago when I was building my coupe and they were still available on the net. However, I heard about this engine loom being refabricated. Not cheap, but building one is time consuming.