MFI pump question

[Alan.uk]

Hi,

Can anyone please confirm that the differences in MFI pump produced in 1970 are down to the cam? Or are there also differences in the sizes of the fuel plungers. I ask as I have seen size? Numbers on different fuel plungers and am thus not sure if they are specific to S or E MFI pumps.

Or to put it another way can I put an S MFI cam in the same year E MFI pump to make an exact S pump

Thanks in advance for any advice

Alan

[kenikh]

Hopefully this helps:

http://www.early911sregistry.org/for...t=14293&page=2

[Alan.uk]

Thanks for the link Kenikh, but I am still unsure if the plunger sizes are different across the E and S MFI pump, in this case specfically the 2.2ltr pump.


I am hoping I can put an S cam in an E pump and thus become a correct S pump?

Anyone?

Alan

[spydr32000]

Alan, the S cam will fit and it will make the pump operate as a 'S' pump after it has been fitted and re-calibrated. The calibration is always reset when the pump is dismantled. It will work fine as long as the person fitting the cam does the job right.

[Alan.uk]

Brilliant, just what I needed to know.
Thanks for the info Mike.

Alan

[Bobboloo]

Alan,

There are two cams in the pump. The space cam and the cam shaft that drives the plungers. The cam you want to change is the space cam which is located in the regulator housing.

The cam shaft in the pump housing that drive the plungers should be identical between E and S pumps so no need to change that.

Here's a jpeg of the regulator housing. The cam you need to change I believe is #153. Some of the other parts 149 thru 154 may be involved as well.

Disclaimer: I haven't done this myself but I wanted to point out the two cams because I mistakenly thout the camshaft was what you changed until Tyson Schmit told me otherwise.

Here's a link to Pelicans' tech page for MFI. there are high res pics and parts number lists.

http://www.pelicanparts.com/techarti...MFI/TipMFI.htm

[spydr32000]

Alan, Bobby is right the space cam is the one you will need to replace in this diagram it is part #12

[Alan.uk]

Thanks for the info. I did think the cam that drives the plungers would also be different for E and S but the fact that they are not does make the change over a little easier.

I will take some pics when I get round to doing it

Alan

[Bobboloo]

Alan, Bobby is right the space cam is the one you will need to replace in this diagram it is part #12

Well not exactly right. I thought it might be part #153 but #12 it is. The contured cam.