Injection pump differences - PeachParts Mercedes-Benz Forum

bobterry99 · #1 08-03-2002, 03:01 PM

I have a six-plunger gasoline injection pump that I believe came from a 250SL. It is an "R11" pump. Can anyone tell me if it will work with a 2.3 liter or 2.8 liter engine? What pumps work with which engines?

Bob T.

Arthur Dalton · #2 08-03-2002, 03:50 PM

R11 is 2.3 eng. [230sl]
2.5 eng. is R18 series [250sl]
These are both Independent oil resevoir/dip stick pumps.

2.8 eng use pumps starting with R20 thru R 24 series .
The main change from the earlier resevoir pumps is these pumps no longer have res. and are force feed lubed from engine crancase oil sytem.....different pumps

bobterry99 · #3 08-04-2002, 12:49 AM

Hey Arthur. Good info. Seems to me that the R20 thru R24 pumps that were original to the 2.8L engines clearly must not be used with other engines because these will not provide necessary lubrication from the crankcase. But the R11 pump could be used in a 2.5L or 2.8L. Naturally, it would receive its lubrication from its own reservoir and not the crankcase.

Is this correct? And if so, would an R11 pump need to be setup differently for a 2.8L application?

Arthur Dalton · #4 08-04-2002, 09:44 AM

I know what you mean, but you then have the engine feed to contend with.
There are several differences aside from the lube system of these pumps. I know they upgrade/change R20 with 24y and such, and my info says R11 should/con be replaced with R18, but I have never done either... do they bolt up?-- prob.
do they run right / .. don't know.
However , there is a 113 guy close by here that does know interchangability of these pumps and parts quite well and he does answer questions via email.
His name is Gernold and is a 113 specialist. I am sure he can help you on this one better than I.
Here is his site

http://www.sltechw113.com/sl_question_form.htm

bobterry99 · #5 08-04-2002, 05:31 PM

"...a 280 Pump will actually work on a 230 Engine but can not be calibrated or adjusted to function properly."

I think it follows that a 230 pump (R11) should not be used with a 280 engine.

cth350 · #6 08-05-2002, 04:08 PM

Any chance that an R11 pump is sellable to somebody who really wants it for their 230SL ?

-CTH

bobterry99 · #7 08-05-2002, 08:54 PM

I wanted to fully understand the applications for this R11 pump before I tried to sell it. This was the motivation for beginning the thread here in the forum, as I did not wish to sell this pump to a 280SL owner who would later determine it was useless.

cth350 · #8 08-05-2002, 09:04 PM

Then great minds think alike. -CTH

Wittich · #9 07-16-2005, 10:10 PM

Quote:

Originally Posted by bobterry99

I wanted to fully understand the applications for this R11 pump before I tried to sell it. This was the motivation for beginning the thread here in the forum, as I did not wish to sell this pump to a 280SL owner who would later determine it was useless.

Oh, boy, I thought I was the only one stuck with a R11 pump, totaly rebuilt nice and shiny....but does NOT fit my 1970 280 SL. I got that information from the horses mouth, namely The Veterans Club at Mercedes Benz in Germany: for 230 SL Pagoda ONLY. Seems there are now two R11 pumps for sale !!!
CHEERS !
WITT !