Last Saturday I attended the Drobot Diesel Shop Day/BBQ hosted by Mike Drobot of Drobot Diesel in Highland Park. It was a great GTG. There was tons of great food, stories and camaraderie. The venison burgers with Dubliner cheese were especially good. We got a chance to socialize, see each other’s vehicles and mods close-up. The highlight of the GTG for many of us was the 1959 Mercedes Benz bus that was just jaw dropping gorgeous.

Only two vehicles actually made it on the lift. Mike was working on the front air suspension strut of his wife’s classy black supercharged V8 when we arrived. He fixed it and treated us to the sights and sounds of his suspension road test in the parking lot…Vrooom, Chirrrrppp, clouds of smoke, Screeeech!!! The anti-dive capability was restored successfully.

‘Desert Rose’ also made it on the lift for an undercarriage inspection. We found some minor problems that need to be addressed: 2 torn tie rod boots, fluid leaks from the steering box and injection pump, and one loose exhaust hanger donut (re-installed right then). Otherwise everything was okay.

As one purpose of the GTG was to have a Shop Day, I brought a modded exhaust manifold to swap in place of the rusty exhaust manifold. I want to install a pyrometer pre-turbo to monitor EGTs before I do any injection pump mods.

I had previously pulled the replacement manifold from the Richmond junkyard. What an ordeal. Even with turbo already removed by someone else, it took many hours, over the period of two days, and lots of penetrating oil to liberate the manifold. The lower turbo flange mounting nuts are very difficult to remove. My local indie let me use his tools to drill and tap a new EGT/Pyrometer probe port. I used a center punch to create a starting point for the 1/8 inch pilot hole. Then I used his drill press to very slowly drill the pilot hole. Afterwards, (I believe) I used a 7 mm titanium drill bit, to very slowly take small bites to enlarge the pilot hole without cracking the manifold. Lastly I slowly tapped the hole with a NPT tap and lots of cutting fluid. The exhaust manifold was then sent out to Accessories Plus in Belmont, CA for a high-temp silver ceramic coating both inside and outside. Two weeks later, I put some high-temp nickel anti-seize on the threads of the brass NPT fitting before installing it in the EGT port.

Mike graciously agreed to assist in swapping the exhaust manifold. I was not very confident about removing and re-installing the turbo as I had not ever done that job before. Mike actually did more than 90 percent of the work, but I was able to help free the one very stubborn lower turbo flange mounting nut. Now that I’ve assisted, and seen it done properly, I am confident I can now pull and re-install a turbo when I need to do it again.

Reassembly went very smoothly over all. Only one small hitch…was that a plastic fitting (PN 617 016 04 28 A) in the crankcase vapor recovery plumbing cracked as it was being re-connected to the air box fitting. No worries. I was able to source a replacement fitting from a dead, absolutely filthy, W116 300SD greasecar at the North San Jose junkyard on Sunday. The same car also yielded a correctly clocking oil cap and safety triangle with all the trunk lid mounting bits (the round quarter-sized rubber piece has a PN 123 997 0286 molded on it).

That is all for now.

Attached Thumbnails

         

__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022