911 CIS fuel distributor

4329ray · 09-12-2011, 10:44 PM

I have a FD 0 438 100 004 in my 74' 911 that needs rebuilding. I found a 0 438 100 006 which looks the same. Can someone tell me if it would work and what is the difference ? Thank you.

Jim Williams · 09-13-2011, 04:41 AM

The 004 has the nipple fuel connections on the rear; the 006 has threaded connections. The other specs are the same as far as I know.

E Sully · E Sully's Garage

From my reading the 004 was originaly used for the '73.5 and early '74 2.7. It changed to the 006 on later 2.7 engines. The air metering plate is probably different also, with a different venturi shape. This would affect the air fuel ratio at part throttle load, but I would think that it can be substituted without any problems.

4329ray · 09-13-2011, 08:35 AM

Thank you for the info. It seems the 006 are easier to obtain than the 004 and the rebuild cost is cheaper.

exc911ence · exc911ence's Garage

Since we're chatting about fuel distributors, what's special about the "Euro" one I have in my '75 S?

Jim Williams · 09-13-2011, 11:08 AM

Quote:

Originally Posted by exc911ence

Since we're chatting about fuel distributors, what's special about the "Euro" one I have in my '75 S?

If it's stock, nothing. It will be a 0 438 100 006.

handdrawnsquare · 09-16-2011, 08:27 AM

the 0 438 100 006 is on my 1975 s. while we are on the subject does anybody know if there was a sealant used between the 2 halves from the factory? i have one apart and i can't find any trace of sealant. maybe if it is torqued properly or the metal valve plate is re annealed will it seal?
i .can't imagine getting sealant on the two halves evenly. if i could thin something down i was thinking of spaying it on if in fact sealant was nessesary.

i have been searching for a definitive answer for this any help would be great

thanks

E Sully · E Sully's Garage

Good luck, they are hard to reseal.
CIS fuel distributer cleanout w/pics

manbridge 74 · 09-16-2011, 01:31 PM

@handdrrawn

No sealant was used that I can see. I thinned down some aircraft sealer with rubbing alcohol to reseal. Copper spray gasket would also likely work.

A word of advice on metal to metal sealing. FLAT. As in no deviation in surfaces past .001 inch. How is one to arrive at this? Lapping both sides on 1500 grit wet/dry over glass. Use WD40 or kerosene as a cutting fluid. Using figure 8 motions, I was able to achieve leak free nirvana.

handdrawnsquare · 09-17-2011, 03:11 AM

thanks for the reply, i work with glass actually so lapping the faces isn't a problem. but i'm still not sure if i need it. they made the fuel dist to very tight tolerances. i find it amazing that the main plunger doesn't leak. it has free movement very tight so i'm sorta inclined to think that maybe no sealant. i bought a cis system complete for a very low price. it had a frozen plunger which i freed up so i an using that fuel distributor as my guinea pig.

when i track down the o-rings i might try a test assemblage without sealant and pressurize it with compressed air for a leak down test.

will post my results

robert
1975s targa
1968 bsa a50

manbridge 74 · 09-17-2011, 07:36 AM

I actually took mine back apart just to see if the amount of sealant used was too much or too little. I used a very minute amount of thinned sealer. There was barely any sealant pushed out into the large openings. I could have used even less or perhaps none.

I also found that the cast iron parts clean up very well with naval jelly if there is rust present.

I did not polish my plunger as it was just a bit gummed with old gas. I wanted to leave clearances as tight as possible but still have free movement.