Resurrection of a Deutz MAH 914, 1952? Lets see!

[sirpedrosa]

Gentles

My German friends states the correct pressure for the injector is 120 Bar. (https://www.deutzforum.de/threads/deutz-mah-914-1952-to-be-restored.63951/post-605164)

Cheers
VP

[ajaffa1]

Hi VP, it looks to me that the pop pressure is adjusted by adding or removing shims above the spring. As springs age/wear they loose some of their strength. So clean it all up and reassemble it as it was. Do a pop pressure test. My guess is it will pop a little under the 120 Bar, recommended by the German forum. Add shims until you get it to pop at 120 Bar. Look for a nice spray pattern with no dribbling, you might find you need a new injector nozzle.
Keep up the good work,

Bob

[sirpedrosa]

Bob, Gentles

Many thanks for your support.

You know I dont need to make trails on injectors. I have a near me an expert company with laboratory (see here: https://listerengine.com/smf/index.php?topic=8333.msg100298#msg100298; and here: https://listerengine.com/smf/index.php?topic=8320.msg96965#msg96965) - and I have good relationship with manager, just because I hull to there stuf he doesnt see from years.

Therefore I'll take this one to them also.

And yes, I got shims (from my 12/2, to make clearence to throtlle linkage) that could do the job, even if company doesnt got them.

Lets see, and finger crossed (I think nozzle is prestine).

Cheers
VP

PS: A pic with injector reassembled to keeps bits together.

[cobbadog]

I agree that over time springs do loose some pressure, especially if it was compressed after shutting sown last. You mentioned to add a shim to lift the pressure but to me that sounds back to front. If it has lost pressure I thought you would remove shim/s.

[ajaffa1]

Hi VP, I am surprised the local diesel engineers don`t know what the pop pressure should be, but I`m very happy you have a good relationship with them and they like fixing old stuff.
Hi Cobbadog, I`m pretty sure that if you want to increase the tension in a spring, you need to shorten it. Blonde moment?

Bob

[sirpedrosa]

Bob, Gentles

I dindnt said local diesel dont know. They are a Bosch Laboratory (state of the art). This kind of injectors are legacy a long a go and machines now are set to do just only a few kind of jobs.

Do you can get my point?

Cheers
VP

[sirpedrosa]

Hi Gentles

A few more bits out, and preparing flys extractor.

Pics by order:

1 - 18mm threaded rod 8.8 to make flyes extractor and save it to fix it later to kart;
2 - Ups... IP tappet guide is cast iron, and is britle. STUPIDITY STRIKES AGAIN; (late night... Hum let me see if pry bar take it out!)
3 - Head is clean and limestone dissolved with chemical;
4 - One more pan of bits to derust.

Cheers
VP

[sirpedrosa]

Gentles

Head is finally empty. Got to extract valve guides, because exhaust guide is lubricated and was completely clogged, and removed anti freeze plug.

Save banjos from (remnants) of fuel tank.

Straighten pushrods, and remove stuck rings from piston.

A few pics for the show:

1 - The little red pushing down guides;
2 - Guides clean, and intake guide shows a DIY adjustment!
3 - Valve spring recess shows this engine will have thousands of working hours.
4 - Jig to extrat anti freeze plug. (Remember this jig from the Lister? See here: https://listerengine.com/smf/index.php?topic=8320.msg97397#msg97397;
5 - Special square key (mild steel) twisted doing the job, first with french wrench... but only the pipe wrench done it;
6 - Plug out and all clogged.

To be continued...

[sirpedrosa]

A few more:

1 - A bit of scale at bottom of head;
2 - Straighten pushrods with jig mande of pipe with some heat to help;
3 - Pushrods made true;
4 - Saving banjos of fuel tank;
5 - Rings stuck removed.

Some conclusions I can made about this Deutz:

I think it was installed in plant from a 2nd hand owner, with fresh (gray) paint (it has the brown under);

I think it has thousands of working hours, and it had water in fuel circuit till injector - therefore I think someone in time sabotaged it.

For sure it was overhauled in 1996 - at least piston and rings.

Cheers
VP

[ajaffa1]

Hi VP, it doesn`t look as if the damage to the guide is anything to worry about. Working when tired often leads to poor decisions.

Cleaning nuts, bolts and other small pieces is the bit I hate doing. I have tried all sorts of chemical cleaners and rust removers. Some will remove old paint while others will remove rust. I have never found one that will do both. Now I tend to remove the paint with a wire wheel and then drop everything into a bath of molasses for a week. Molasses contains an acid that eats rust and is very cheap at about $1 per litre. Available as horse feed from agricultural stores.

Keep up the good work
Bob

[ajaffa1]

Everything looks good except for that fuel tank which needs replacing.
I doubt it was sabotaged deliberately, much more likely someone put contaminated fuel in it. When it wouldn`t start they didn`t have the knowledge or skills to fix it, so it never ran again. Hopefully it will soon. 
Bob

[cobbadog]

I have tried over the years many ways to clean up paint and rust. It is hard to find one product that does both but that is ok. I have use oven cleaner (caustic) for light paint removal but the wire wheel is quicker. I have used molasses mixed with water and it does work on rust but slow. To do it quicker I used the molasses mix and then fitted up the electrolysis set up and that worked but the smell was not good. Electrolysis using soda ash works very well and many different metals too. Rust converter on flat steel does a good job providing you are going to paint the surface otherwise it turns the steel a bluish colour.

[sirpedrosa]

Bob, Cobba, Gentles

After several products, end up using deoxidiser, as pic shows. (10€/L. Recipe is mix it with water, and quantity measure done by eyeball)

Tried electrolysis but process is slow and sacrifice metal (brake disc) made a mess.

In the 12/2 i've use oxalic acid. It's good but requires more wire brush after job done, and bit start to rust quick if you dont oil it after dry it.

Ring wrench is rough cut, now need to file it till it feats.

Cheers
VP

[sirpedrosa]

Gentles

After more than 1h filing and 'calipering' to fine tuning the ring wrench, it feels as a glove.

Mount the jig to hold flys steady with a chain and 12mm rods...

Nothing like having a well-fed belly to put on top of extender of wrench to unscrew the main nuts! 

NOTE: RIGHT FLY NUT IS LEFT THREADED, AND LEFT FLY NUT (GOVERNOR SIDE) IS RIGHT THREADED.

a few pic for the chow.

Cheers
VP

PS: Next task is to make jig to extract flys. Got some ideas on mind!

[sirpedrosa]

Gentles

Things seam to get on track.

Small bits are derust and on basket with WD40, just to stay nice.

As usual, I like to correct threads in order to give them the right pitch... but this guy catch me with pants on hands (popular saying).

Nuts use metric wrenches... but inside... SURPRISE, SURPRISE... BSW and BSF(?) pitches. Holy Moly!!!

1 - Crank shaft screw (60 wrench) - 33mm ~ 11/16" - 11G (BSW);
2 - Governor controller screw  - 12,7mm ~ 1/2" - 19G - what a hell, is there chart for this pitch?
3 - Rockers stand - 20,8mm - 13/16" 14G - Another?
4 - Injector studs - ~13mm  - 1/2" 12G (BSW)

Some help here, please!

Cheers
VP

PS: I think this was a cost of 2nd World War. German industry was destroyed.