355 Throttle Body Question

OK here's a question that likely nobody can answer, but I'll ask it anyway in the unlikely hope that somebody out there might have some knowledge (or access to said parts).....

On the throttle bodies of the f355, there's a small brass union (Part #168100) which allows you to connect an airhose when balancing the throttle bodies. There's 1 of them per intake.

Mine are missing (!!) so I want to replace them. Since they are no longer available to buy, I need to source an equivalent. They're just generic, so any union of the appropriate size will fit.

Does anybody either -

a) Know their dimensions (size and thread pitch)

_or_

b) Have easy access to one (not mounted on a car) that they could possible measure?

They look exactly like the ones that come along with the throttle body balancing kits for motorcycles (with those they have plastic ones supplied), but on F355's (and I'm sure many other cars) it would appear that there are brass ones attached to the throttle bodies.

They pretty much do nothing and are only used when you attach a hose for throttle balancing.

Circled in red, below.

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Thanks chaps.

 

I didn’t see them personally, mechanic just said they were missing during its most recent major..

 

What a hero, thanks.

now do you want to sell them

 

really appreciate the posting..

where have you seen them for sale? I’ve not been able to find them?

 

already wrote to those chaps…. Not available…

you got me all excited there for a while!

 

Hey thanks a lot, really appreciate that. These would then simply work as ports, but you'd need to simply cap them off - right?

I'll write to them and find out if the thread pitch is similar etc.

 

any chance I can get you to remove and photograph/measure part 38 from that diagram??

Thanks again

 

do you recall where? And yes, I’m very impressed !

 

Thanks chaps, I resolved my issue... I sourced 4x complete throttle bodies, like new. Yeah I know I'm insane.

I have the insanity that demands this car be perfect and having slightly messed up throttle bodies just wasn't going to wash it.


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no... Although they are a hollow tube, once they are screwed in they seat into the throttle body preventing any vacuum leaks - similar to how a bleeder valve works.

I'd originally assumed they were just standard tubes (like you'd get on a balancing tool), but they're not - they have a small seat at the bottom of them.

So when you overtighten them and snap them off, there's no issues with leaks - but you can't attach the tool to tune the throttle bodies. Due to their design, they barely need to be tightened, so I've got no idea why these were snapped off... In any event, it's not something I'm happy to live with so I'm getting it sorted out.

The other option was to extract them and replace them with 5mm bolts and O rings. That would have also worked, and all you'd need to do to tune the throttle bodies would have been to remove the bolts and place in standard 5mm balancing fittings... That approach has a tiny chance of leakage, and it's also not stock - so I didn't want to go down that route.

 

None "on hand" as such - but the car has about 1/2 of the unions snapped off inside the TB's - see here for example:

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Everything was sealed correctly, but there was no way you could ever balance the throttle bodies. The mechanic said he's never ever had to balance 355 throttle bodies, but I'm not so sure this is accurate. I'm having to rebalance my Motorcycle's carbs at least once every 5 years or so, and I'd like to be able to do the same with these.

I find it hard to believe that 8 semi- independent throttle bodies can stay completely in sync forever.

Anyhoo, I got these near new TB's for a very fair price so I'm good with that. It's just nice to know you're not driving around with snapped off bolts in your TB's that could suddenly leak (however unlikely that may be) and put your car into a massively lean condition - or ever be able to balance the TB's.

 

Oh yep I think there's about 3 or 4 like that (OK) - the rest are snapped off. I saw at least 4 snapped off, maybe 5 as I couldn't quite see behind all the plumbing when the engine was back in the engine bay.

It does beg the question, if these never need balancing - why were they snapped off in the first place...

Anyway it's a mystery that shall never be solved, so I'll just get to putting it right.