Béla Barényi rides again!

[abl567]

Styria: Here are pics of my 300SE fuel pump, taken this morning. Can you identify it from these pics?

Thanks.

From the pics I think it the short version of the correct pump, it is not a CIS pump.
If it is the short version rebuild kits are available from Tom Hanson at the classic centre.
The benefit of these pumps is they provide the high volume flow required for the MFIP at around 14 psi as opposed the 28 psi with the CIS pump so are quieter and stress the fuel lines and fittings less.
My 6.3 has a CIS pump and I have had a couple of fuel leaks when I first got it due to the high pressure.
If anyone has a spare pump like the one in the pics I'd be interested as my 3.5 needs a fuel pump just like the one in my 6.3 and I'm interested to see if the higher fuel supply pressure is affecting my tune.

 

[Styria]

Hi OBH, that is indeed the original style pump - very, very expensive to replace. There were, in fact, an early and late style of these pumps, but I do not know the difference in characteristics and specifications. The change came with the 6.3s, so I daresay you have the early model pump.

As far as converting to CIS pumps is concerned, I have seen both the large and small CIS pumps being used on 6.3s. The small unit can be either Bosch or Pierburg and are used as a pair (in other words, two of them) on the majority of 126 models.

Now, I am a bit 'on ice' here as far as the 126 range is concerned - if anyone can be more precise, I am happy to be corrected. Regards Styria

N.B. I do have some spare pumps of the old type - I believe all are running, but no warranty with any of them.

 

[OzBenzHead]

Thanks, chaps.

Now, how about this: A hole in the head?

Tinkering with the 300SE coupé today I noticed, on the top of my nice, newly cleaned suspension air compressor a collection of black sludgy goo like cooked engine oil. It can't have come from anywhere other than a hole in the head. I could see a small glob at one point against a cooling-vane base and a run in either direction between two cooling vanes from that glob point outward toward (but not quite to) the head edges, but could see no actual bubbling (engine running) nor hear any hissing (but then an M189 is a tad noisy and my hearing is stuffed).

Has anyone seen or experienced this apparent hole-in-the-head phenomenon?

I have a spare compressor that appears to be okay, so I'll buy a kit and see what I can make out of the two compressors.

Didn't have the presence of mind to photograph it today, as it was about 38 degrees when I saw it, and I was eager to get the car back to its storage shed some 6 km from home in case a storm arrived. Shall take pics tomorrow and post them here.

 

[s class]

Thanks for posting the brochure pics styria. I don't have that brochure, though I have some of its companions from the same era.

 

[OzBenzHead]

Here are some pics of my compressor's suspected hole in the head.













A spare compressor and a kit (both in hand) might be the fix.

 

[Styria]

Hi OBH, as a matter of interest, what does the kit consist of and where did you purchase it from. I would imagine that you'd need an oversized ring, or perhaps get the barrel bored out with new piston/ring assembly. Regards Styria

 

[OzBenzHead]

Hi OBH, as a matter of interest, what does the kit consist of and where did you purchase it from. I would imagine that you'd need an oversized ring, or perhaps get the barrel bored out with new piston/ring assembly. Regards Styria

Styria: I've not yet seen the kit. The friend who gifted me my spare parts told me that he has the kit (and the spare compressor is still at his place, too). He described the kit as comprising gaskets, o-ring, and reed valves - no piston ring/s. He is of the opinion that these compressors can't be, or commonly aren't, rebuilt. Is a rebore / re-ring / oversize possible?

Of course, it also remains to be seen if the spare compressor is (a) any good and (b) suited to the car. Friend can't remember if it's from one of his former W112 300SEs or W109 6.3.