Monday, September 27, 2010

W116 280SE Project Car



Friday last, we found a European spec 1978 Mercedes 280SE.
Technical data: W116 E28 chassis
2.8 Litre DOHC Inline 6 cylinder gas engine
182 hp @ 6000 RPM
Bosch K-Jetronic (mechanical) fuel injection
3670 lb unloaded weight.

The Euro spec W116 is faster and lighter than its American counterpart, it has 40 more horsepower and  about a hundred pounds less weight. American regulations required large "park bench" bumpers, which, thankfully, were not required on grey market imports. The paint color is called "Milan Brown Metallic" I think, at least that is the closest color I can find in MB's color charts. It's not bad, but I prefer this car in lighter metallic color, as in the 450SEL 6.9's silver metallic with chrome door panels and wheel arches.

The Good:
The doors, rocker panels, and most exterior surfaces are clean and very straight. The doors open and close without any rubbing or signs of a bent frame. This is normal for an S-class tank that hasn't been in any accidents. Unit-body construction this heavy won't tend to sag or pinch the doors, but an accident could be told in doors that rub.
The engine cranks, runs and sounds good. We didn't have enough carburetor cleaner to run it for long, fortunately. I expect we will be going through the engine a bit, although there's not much there that needs doing. Valve timing is provided by duplex chain and dual over head cams, so I expect these to be in good order. A good steam clean and compression check with a tune up will turn up any unexpected top end issues.
The Bad:
A typical problem with Bosch mechanical fuel injection is condensation on the top of the gas tank, as witnessed by our VW Vanagon from the 1980s which very nearly blew Dad up one day.
The owner of this Mercedes said his mechanic told him there was a leak in the gas tank, and not to drive it. Typically what will happen is the gas evaporates through a small hole into the trunk, which will smell strongly of gasoline and perhaps explode if you should open it whilst smoking a pipe. I didn't find any gas smells in the trunk (or a spare tire), but I did find that the gas cap had been run over and completely deformed at some point. This may or may not be the cause of their leak. Pressure testing the gas tank with a new lid might be in order. If that fails, the tank will need to be pulled out, welded or replaced.

The Ugly:
I can't remember driving any Mercedes with a plush/velour interior. I know they exist, but if you're paying that much for a car, why not make it at least Pleather, if not the real stuff. Either way, UV rays have not been kind to the velour, and the inside of this car looks like a Star Trek uniform left to the weather. It has to go to the upholstery shop for a tear down and re-hide.
The only thing you can do about rotting wheel wells is make them entirely out of plastic. I don't know why this isn't done, but it isn't. The wheel wells show the usual rust and will require work and a complete repaint. This is not some cheap Maaco job for $300 either. Getting the real paint from MB, having a professional spray it after perfect preparation is the only way to go. Whether or not we will go that way is to be decided later..


There are many options for this kind of thing. You could go all-black AMG for example. With this look, you have to wear all black (Members Only of course) all the time. And a German stainless steel watch, not Swiss.


OR, you could go all negative on the colors with black on white, more of a tuning car apparel. In this case you would have to wear a white track suit with black piping ALL the time. You will also need a large digital chronograph on a lanyard.



Tuesday, September 21, 2010

GL1000 nearly complete

<-- HIDEOUS
I was able to get rid of the Comstar wheels and replaced them with Older, Vintage(er) Wire spoked wheels from a 1977 GL1000 that was parted out in Nevada (thanks, NV guy).
The 'Comstar' wheels were the cheap way of making a 'Mag', ie magnesium rim popular in racing. The Comstars have 5 spokes made of either stainless steel or aluminum in some cases, which are cut and stamped to shape. They are then riveted to an aluminum rim. There are 10 rivets out the rim and another 10 on the hub I think. Just looking at them makes you think "That is unsafe". They are cheap, cheap looking and cheap to make. Honda and others tried to pitch them as better and lighter than spoked wheels, but really they were just cheaper.
The rivets on mine were rotted through, and I was able to pop some of the blades off with a little pressure. Unsafe at any speed. Anyhow they are gone, replaced with much better wire ones, new tires, tubes etc.
Switching back in time to older wheels was not just a straight bolt in deal. The 75-77 front brakes had 2 piece cast rotors rather than the one piece stainless ones on the later bikes. The spacing of the rotors is a few millimeters off, so it was necessary to machine the caliper brackets to line up the braking surfaces.
With a salvaged 5/8" Nissin master cylinder, Speigler stainless/teflon lines, new pads and all of the correct retaining springs in place, bled up, the front brakes feel just right.
The CBR600 5/8" dia. master cylinder on the rear is now linked up to the original caliper and bled. I used the CBR's brake line, as it was in good shape and had the right length. So far it also feels right. That is linked to a Tarozzi rear-set on the right side.

This bike is nearly complete, just needs final touches, new oil and some test riding to make sure everything behaves.
The following is a hint on what the next project might be:
http://www.diagnostic-assistance.co.uk/mech_inj.htm
Not much of a hint, as the Bosch K-Jetronic mechanical injection system was used on pretty much everything.