What is the part number: rubber mounting block for MFI lines

Crachian · 01-09-2006, 05:39 AM

On my 73 between the intake runners are small, crumbling rubber blocks with three channels in each for the MFI lines and spark plug wires. They are screwed to the throttle assemblies.

On PET, I could only find pn 91611033000 (#31 in ill. 107-20, page 82 of 491), which appears on PPBS as a special order injection line support for $29.80 each. But PET only shows this part being used up to 1971.

Has anyone who has replaced these know the part number or whether this one is it?

Thanks,
Cab

304065 · 01-09-2006, 08:55 AM

That's the right number. The later TB's have slightly different linkages, but I believe they still have the holes for these.

See this photo of a set of TBs from an RS to see what I mean.

http://www.eurometrix.ws/throttleBodies.html

I heard these were NLA, and that people have been fabricating them from blocks of rubber.

Rot 911 · 01-09-2006, 08:57 AM

John is correct both the blocks and the plastic "t's" for the cold start injectors are unobtanium.

svandamme · svandamme's Garage

how badly are these things required? what part of the engine will explode if they are missing?

304065 · 01-09-2006, 09:51 AM

Stijn,

These are used to dampen vibration of the injection lines. With the injectors chirping open 30 times a second, evidently the factory felt that these were a good addition to keep the lines from flexing, which I suppose could lead to a fracture.

In reality, I have a couple hundred hours on my race engine which is missing one of these from each side with no observed ill effects.

Then again, keeping the ignition wires off the stacks is always a good thing, but there are other solutions for that.

svandamme · svandamme's Garage

thx, i'll fab something up when i reinstall my pump

Crachian · 01-09-2006, 11:32 AM

I swear that everytime I do something minor (change plug wires in this case), I screw up something NLA. My blocks are all there, but are brittle, and when I went to unscrew them and remove the plug wires, a couple broke.

With everything being routed around and through there, keeping the high pressure fuel lines from rubbing anything seems a good idea.

So, is the $29 part from Pelican something else, or is that what's NLA?

(by the way, I'm never trying to save a little money buying non-OEM plug wires. I got a set made by Kingsborne and they are total garbage. I want my money back.)

dtw · 04-11-2006, 12:04 PM

This thread turned up in a search I just ran for the referenced part number. If these were NLA, Porsche has apparently done a production run. There are 5 in Stoddard's warehouse (they had 9 five minutes ago

), there are ~100 in the NA distribution network, and about 1100 worldwide. So order all you like...there are enough out there for a couple hundred cars. The Stoddard price is $29.80 also, but you get 10% off if you're in their '800 club'. Ask for Sandy...