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TR2/3/3A TR3A choke geometry questions

jdubois

Jedi Warrior
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So I got the Spitfire all tuned up and ready for Spring, and the 308 is off getting it's engine rebuilt (if you're ever considering buying a Ferrari, just don't :nonod:). Now I'm working on getting the TR3A ready. It needed a new starter, so I took the carbs off the car to make it easy to get the starter in and out. It's never run quite right when cold, and I noticed a few things while the carbs are on the bench that I wanted to check with folks here.

First, both jet levers, and especially the rear one, look like they're bent. The rear one even looks like it's got some tooling marks where somebody was fooling with it. Now, forgive my ignorance, but... these shouldn't have any bend in them, right? They should be completely vertical?

Second, the jet control connecting rod between the two carbs was screwed almost all the way down the threads on the rear carb and about 1/3 of the way down on the front carb. This caused the jets to not drop down the same amount when the choke cable was engaged. I centered the rod and that seemed to fix the issue, but I can't find anywhere that tells me how many threads in they should be set to, or some other way to measure the correct positioning. Anybody know?

Many thanks for any help.
 
I try to set the linkage to take up most of the slop in that rear connection, else very little action gets transfered to the rear jet.

If it is of any use, here is a pic from the 'Practical Guide' which shows the rather counter-intuitive way the linkages are hooked up:

Carb%20Linkage.jpg
 
Thanks Geo. I knew the rod wasn't hooked up correctly, but forgot where the picture was that showed the correct way.
 
Hmm, it's hard to tell from that picture. Clearly on the rear connection the rod goes entirely behind the lever, but on the front one is it in front of the lever or straddling it?
 
Should be in front of the lever according to Bob Schaller's(TR3 guru)handbook "More BS about TRs" In the book there is a sketch showing the correct set up..
 
Thanks Karl. Hmm, "More BS about TRs". Don't know that one. Must buy. Doesn't seem to be readily available...
 
Take more than that to keep me from a 308
 
DNK said:
Take more than that to keep me from a 308

You seen the parts prices? I could buy another TR3 in show condition for what this engine rebuild is gonna cost me. :eeek:
 
I've gotta spare Flathead Ford around here somewhere and a chunk of 1/2" steel plate for a trans adaptor you could use.
GUARANTEED to last longer than that 308 (only 300K on my last Flattie).
 
What ever posessed you to get a 308?!?!

iS IT A CLAMSHELL 'GLASS ONE? or alloy... :shocked:
 
Gone fer th' "Tubie" pipes? :devilgrin:
 
TOC said:
I've gotta spare Flathead Ford around here somewhere and a chunk of 1/2" steel plate for a trans adaptor you could use.
GUARANTEED to last longer than that 308 (only 300K on my last Flattie).

If you can figure out how to mate this tranny with nothing but a steel plate... :thumbsup:

308engine.jpg
 
DrEntropy said:
What ever posessed you to get a 308?!?!

Many hours of Magnum P.I. as a child, with a bit of reckless stupidity thrown in. My biggest surprise with it, though, is that everybody in the Ferrari community thinks the TR3 is totally awesome.
 
It's a "Karma" thing.

I've a passin' familiarity with th' beasties...

So is it alloy or glass?
 
DrEntropy said:
So is it alloy or glass?

No, it's not a glass car. They stopped making those in '77. This one is an '85, last of the line before they moved to the 328.

side.jpg
 
Anyway, I bent the rear lever back into shape and attached the rod the correct way. The choke geometry makes much more sense now. I think that should work fine, so I'm moving on to draining the coolant and removing all the hoses while I wait for the new starter and fresh hoses to get here.
 
Well, th' 308 has Chromies....Whazat thing onna back lid?

Sell it to a Ferrari Enzo owner who wants to go racin'!!
 
DrEntropy said:
Whazat thing onna back lid?

You mean the black 'wing'-ish thing up at the top? Just a bit of decoration they added in '83 for the four valve cars.

DrEntropy said:
Sell it to a Ferrari Enzo owner who wants to go racin'!!

You kidding? The 'modern' Ferrari folks don't talk to us 'classic' folks... and they get snubbed by the 'vintage' folks, who won't talk to anybody. :rolleyes:
 
You're close to Watkins. There's "clubby" guys there who'd Kill fer that 308. :wink:
 
jdubois said:
Thanks Karl. Hmm, "More BS about TRs". Don't know that one. Must buy. Doesn't seem to be readily available...
TRF P/N RFP128

I set the linkage so both jets are lowered equally just after they start to move.
 
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