I'm Back! S-10 OM617 Project - Page 18 - PeachParts Mercedes-Benz Forum

Dan Stokes · #**256** 11-08-2014, 06:53 PM

Got a little more done today.

The bed is back in place and bolted down. It doesn't fit as well as the one on my Dodge but it's just the way it is. I made a different bed lifter for the reinstallation and it worked great. 2X4's on edge are plenty stout enough to elevate a pickup bed.

Enjoy!

Dan

t walgamuth · #**257** 11-09-2014, 05:01 PM

Can you legally tape the joint between the bed and cab when running?

Dan Stokes · #**258** 11-09-2014, 08:23 PM

That moves me into "Modified Diesel Truck" (MDT) which is a weird class for me. The displacement for mid/mini truck bodies is 500 CID and NO engine classes. My only hope would be if no one else has run the class! The 2013 rule book shows MDT as open but I don't know if anyone ran it last year (I'd need to explore the website).

So basically - no, I can't tape the seam. Not sure that it would help all that much but it would take a trip to the wind tunnel to really find out. I'd like to do that one of these days.

Dan

Dan Stokes · #**259** 12-17-2014, 09:19 AM

A few more things are done.

1) The battery is in place and bolted down. The truck came with the 5/8" rod that you see on the tailgate side of the top clamp so I kept it. If you look in the lower right you'll also see the rear power switch as required to race. I still have to check everything out but I think it's ready.

2) The rear of the cage downbars were welded to the frame when I got the truck. To move the bed for paint I had to cut that loose and I hit on a scheme to make this joint boltable. This pic shows the 2X3X 3/8 angle brace that I welded side to side as a bolt point, essentially adding another crossmember to the frame. In this shot it's the black painted member.

3) View from the top with everything bolted in. There are 7 ea. Grade 8X 1/2" bolts doing the job - a hyperadequacy! I sized the bolts such that there's a straight shank (not threads) in the area that goes thru the metal to reduce the possibility of shearing in the event of a rollover. This is an interesting engineering challenge as the bolts are partially in shear and partially in stretch as in the event of an accident they would be forced both backwards and would also try to stretch as the bar tries to move back. Grade 5 bolts are better for shear and 8s are better for stretch so I solved it but using way too many 8s (there are 7). I also shimmed all the bolts to compensate for the ribs in the bed floor so all the bolt connections are solid - you can see the shims under the end bolts but all the bolted connections have them.

Dan

Dan Stokes · #**260** 01-16-2015, 09:42 PM

I've done a bunch of little stuff but here's something worth a pic:

Fans are in and working. They just come on with a driver-actuated switch. I expect that I'll only need them on the return road and maybe in the pits so I expect that'll be adequate. Remember, this won't see a regular road ever.

Notice the wiring up front of the radiator. I try to keep electrical stuff as cool as possible so that was the best I could do on this vehicle.

The fans are 2ea. 10" units from Speedway and are their house brand, rated at 800 CFM. Also cheap! I saved 2 M-B fans (about 12") that I suspect had more flow but both were FUBAR'd. So this was the next best solution.

Dan

Dan Stokes · #**261** 01-17-2015, 06:56 PM

IT'S ALIVE!!!!

I fiddled with it today - installed a new Bosch fuel primer pump and attempted to bleed the system. I seemed to get a little fuel out of the injection line nuts (I was expecting to get a shower like I did with the ISBs at work) and then I figured "what the heck" and gave it a shot. It cranked fine but no noise. I didn't plan to use the glowplugs and they're not wired so I decided to give the little guy a shot of starting fluid. With just a bit more cranking he fired right up!

It was a bit smokey at first but as I ran it a bit it settled down to "normal" Diesel smokiness - a bit when accelerating then clearing out pretty well. Everything important seems OK. The oil pressure is a bit lower than expected but I'm starting to think I should hook up the lights in the gages - pretty hard to read. The digital gages worked as expected though the EGT sensor seems to be wired backwards. Auber warns that that can happen and you just switch the leads - no harm done.

I found an oil leak or two. My modified pan has a small leak and I may pull it and epoxy my seam. NOT the world's best welder! I also found that I had missed a bolt between the head and block where there used to be a bracket (either AC or PS - can't remember which) and evidently it is required to keep the slippery stuff inside. I found a bolt on the bench and that seems to have fixed that one. Tomorrow I'll check to see if the rear main seal repair worked (remember THAT entry - over a year ago).

Rack response is a bit sluggish. You guys have any insight on that one? It just may be that it isn't fully warm yet but I don't have coolant in it.

Feels pretty good!!

Dan

greazzer · #**262** 01-17-2015, 08:46 PM

How's the injectors ??

Dan Stokes · #**263** 01-17-2015, 10:35 PM

They seem OK. Of course, so far all I've done is idle it for a couple of 5 minute sessions. Seriously, I think they're great. The engine runs smooth and clean.

When you coming to Wilmington!?? I'd love to have you go over the tune with me - timing, that sort of thing. Also help disable the ALDA if that's the best way to go. Open to suggestions here! And an experienced shoulder to lean on. And besides, we could get you some billet.

Dan

greazzer · #**264** 01-17-2015, 10:40 PM

I really do need to head your way to hit the scrapyard since I need a bunch of 7" x 2" pieces. We are getting 55F weather again, so once it starts back at 60-ish, I will shoot you a PM to firm up date.

I've waited almost a year to hear about this engine running .... I was getting a little nervous. Glad the ol'e girl fired up.

Dan Stokes · #**265** 01-25-2015, 09:01 PM

Here's my abbreviated glowplug system. As I mentioned I couldn't find the OEM glowplug harness so this shows the one that I built out of 12 gage wire. I'm 99% sure that's bigger than what came from the factory. The next time I'm at PnP I'll try to remember to snip a chunk and measure it so we'll have that knowledge.

The system is the basic Ford-style solenoid, power cable (8 gage) and a trigger wire from the cab. Several of the guys recommend installing a monitor light from the glowplug side of the solenoid to the dash so I can tell if the solenoid has stuck "ON". I'll pick up a lamp assembly tomorrow and do that - cheap insurance. I left a spot for it right over the push button.

Here's the pic:

If you folks want a pic of the dash button and light I can do that but it's just a sheet of aluminum with a button and a lamp - nothin' special.

Dan

Dan Stokes · #**266** 01-31-2015, 10:34 AM

I'm still searching for a good, fail-safe engine shutdown system. As a reminder, when the tech inspector flips the rear-mounted main power switch the entire electrical system of the truck needs to go dead AND the engine needs to stop. If I have an accident the first thing the safety crew will do is flip that rear switch and it MUST work.

So here's Plan B. It works but....... if the power fails to the solenoid the solenoid will extend (it's spring loaded OUT - toward the cam cover in these pics) and the accelerator linkage will bind - not a good thing!

Anyhow, Plan B........

First pic is "Stop" position. Again, this is "power off".

Second pic is "Run" position - "power on".

Plan C!

The concept is to cut the top off of the vacuum can (I think it;s dead anyhow) and attach a linkage to allow the actuation hook to be mechanically operated. Just a reminder of the space I have to work in. The screwdriver tip points to the vacuum pot. I'll need a bellcrank to reverse the motion and then attach my nifty solenoid parallel to the IP. Lots of brackets to make but I like doing that. More pics to come as I work this out.

Dan

OM617YOTA · #**267** 01-31-2015, 10:54 AM

On my truck, I use a normally open solenoid to control vacuum. Apply power, solenoid closes, keeps vacuum from getting to the vacuum shut off, truck starts and runs normally. When I shut off the key, the solenoid opens, vacuum reaches the vacuum shut off, and the engine shuts down. Could you do something similar? If you're not running any vacuum system, there are itty bitty 12v cruise control vacuum pumps that could be added. Solenoids are available all over the place in junk yards, or I have a couple spares I could send you.

Now I'll go read back and make sure this wasn't suggested five or six times already, and your reason for going a different direction.

ROLLGUY · #**268** 01-31-2015, 10:57 AM

How about putting the solenoid so it pushes on the linkage when powered up to keep the engine at idle. The return spring will pull the linkage to the engine stop position without power (effectively doing what the stop lever would do when pressed). This way, the engine will be made to not even be able to start if power is not applied to the solenoid. Then again, maybe that is kinda the way you have it anyway. I just see it in my mind (the solenoid) being mounted perpendicular to the valve cover behind the linkage, thereby holding the linkage against the spring pressure (wanting to cut off fuel supply if power is lost to the solenoid). You would also need some form of adjustment for idle speed, as the adjusting screw on the back of the IP will need to be backed out enough to allow complete shutdown should power be taken from the sol. Just my .02........Rich

Dan Stokes · #**269** 01-31-2015, 05:42 PM

I've puzzled this about every way you can puzzle it - I think. The issue with the vacuum systems is that they are dependent on a vacuum source which could fail. It MUST be dead reliable.

Rich - I thought of the scheme you mentioned, too. The trouble is getting the darn shut-off solenoid out of the way when it's time to accelerate. The way I have it positioned in the pics it removes itself from the equation as soon as it activates.

I'll wade into this (probably on Monday) and we'll all learn what that vacuum pot looks like inside - pics to come.

Dan

ROLLGUY · #**270** 01-31-2015, 11:17 PM

Quote:

Originally Posted by Dan Stokes

Rick - I thought of the scheme you mentioned, too. The trouble is getting the darn shut-off solenoid out of the way when it's time to accelerate. The way I have it positioned in the pics it removes itself from the equation as soon as it activates.

Dan

Maybe I did not explain it correctly, but the way I envision it, it would not be in the way at any time. All the solenoid does is keep the throttle raised just enough to make it idle. Anything above idle is going further away from the solenoid. With the solenoid un-powered, the spring pulls the linkage to the fuel shutoff position (solenoid not there to hold it back). I guess it seems pretty simple in my mind, and fool proof. Also, it would not hurt to have a redundant system= the vac shutoff as well (same loss of power from the relay coil switches vac to the shutoff).