Bosch MFI pump red oil cap

[gled49]

If you are going to build a 2.5S, use a 2.4 pump. If you are building a high RPM race type motor, you will need a race built pump.

[matteo68]

If you are going to build a 2.5S, use a 2.4 pump. If you are building a high RPM race type motor, you will need a race built pump.

Hi Gordon, can you explain why / expand please because Eisenbrandt advise that they cannot do their usual RSR / ST optic (RV1668) conversion on pumps later than 012 and cannot install cold start levers on pumps later than 008?

Thanks.

[gled49]

The only pump number in production cars for conversion I see are 2.0: 005-006, 2.2: 009-010, 2.4: 013-014-015-021 2.7: 019. A 2.5 S just needs a volume adjustment as rpm etc are the same as 2.4. 2.4 pumps have different fuel cams than 2.0-2.2. A normal fuel rpm curve might max out the flyweights at 5000 rpm. With an 8000 rpm engine, the flyweights are cut down so they max out at 7000 rpm so the fuel curve covers more territory. The pumps here that Guss does use copies of RSR fuel cams with cut down flyweights on 2.0 pumps. I’m not sure where they are getting their pump numbers but a 2.0-2.2 pump would be consistent with fuel cam dimensions for RSR spec. And 2.0 pump would be consistent with cold start lever only pumps. If I use their numbers loosely, the 008 would precede 2.2 & 012 would precede 2.4. Don’t know if helping or confusing.

[matteo68]

Thanks Gordon.

I found this on a Pelican thread which is quite useful:

5C9499AD-1F6E-492C-A177-36DFC811C671.png

My engine is being built to type 911/70 long stroke specs hence why Eisenbrandt are doing a race pump conversion (RV1668 / EP/RLA1-V1058 regulator) of my 69 2.0S / 001.