TR5/TR250 Need info for fitting triple ZS carbs to TR-250

[TR_JOE250]

I don't know if I'll do this, but I have seen it done on a TR-6 and a GT-6 and it sure looks cool. If anyone has any info regarding this,where to get manifold and linkage, performance compared to webbers etc. I'd apreciate it.
Thanks /ubbthreads/images/graemlins/cheers.gif

 

[Ab Crevoiserat]

Re: Need info for fitting triple ZS carbs to TR-25

go to Goodparts .com. He has the whole set up for ZS and SU's. If you don't like the linkage set up contact me. I am developing a Throttle cable set up the works pretty nice. I've had some trouble getting the brackets right but all the bugs should be worked out this weekend and ready for sale. If you like you can go to www.abstr6.com and you will get an idea of what I'm doing. Good Luck. And yes to all of you guys that have sent me emails about this I thank you for your paitence.

 

[Andy Blackley]

Re: Need info for fitting triple ZS carbs to TR-25

Joe: As Ab mentioned this is the place to look: https://www.goodparts.com/parts_strom.html
I am also working on this setup. I have already ordered mine from Goodparts. It will take 4 to 5 weeks for delivery I am informed. If you use the stock Z-S carbs you can simply reuse the linkage. All you really need in a third carb and some air cleaners.
I also specified an additional port on the manifold to retain the Smiths "mushroom" PCV, which you will also need to do if you are using the orginal 3150 CD175SE carbs, as these earlier carbs have no provision for a crankcase breather hose. I happen to prefer that valve, as I find it does the job very well, and in any case I am going to be using early 175CD carbs from the TR4. These carbs are fairly simple and do not have some of the later emission modifications that can make the later Z-S carbs a pain to use, especially if they have not been rebuilt.
The early Z-S have adjustable jets like SUs, use the same air cleaners as SUs (I am using pancake K&Ns), and have a very nice choke setup, but they do require a different throttle linkage, hence I am one of those waiting (patiently!) for Abs throttle brackets.
PS To those who already are using the triple carbs, which metering needle are you using?

 

[Guest]

Re: Need info for fitting triple ZS carbs to TR-25

[ QUOTE ]
All you really need in a third carb and some air cleaners.


[/ QUOTE ]

Andy, you need to mention the throttle shafts will have to be modified, especially the middle carb needs a new, longer shaft. Too, the triple setup does not use that little "buffer" spring device between the stock dual carbs, just two stock "zig-zag" spring clips to lock the three shafts together. I had three like Strombergs rebuilt for my setup. The throttle shafts appoximate each other, almost touching where the spring clips hold them as one. The stock, modified (to Richard's specs) linkage is weak at best. That is why I too am awaiting Ab's cable linkage. The problem that I have encounted with using the modified stock linkage is the amount of natural (or because of wear) slop in the system which when I apply maximum pedal I still don't get maximum throttle opening. I can, from under the bonnet have someone sit in the car and in neutral, apply full throttle with the pedal and with by finger, push the throttle even further open and get quite a bit more rpms out of the engine. Thus, I am not able to get maximum acceleration, guessing I am leaving maybe 10% on the table.

Bill

 

[swift6]

Re: Need info for fitting triple ZS carbs to TR-25

Yep, Good stuff. /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/driving.gif

The throttle linkage is a TR6 weak spot even in original form and remains the weak spot of the Goodparts tri-carb conversion. I am also anxiously awaiting Ab's creation and seeing how it works out. I also agree with Bill about not getting full throttle opening. Neither am I. /ubbthreads/images/graemlins/frown.gif

As to the metering needle question. Many tri-carb owners have had good luck using the stock B1AF needles. I was not so lucky as the altitude that I live it had something to say about it. Joe Curto helped me figure out a new needle for my application. I use B1CE's now. Works like a charm but would need to change needles if I were to move to sea level or there abouts.

/ubbthreads/images/graemlins/cheers.gif

 

[Andy Blackley]

Re: Need info for fitting triple ZS carbs to TR-25

Thanks for the insights Bill. Since I am still in the "gathering and planning" stages there a bunch of things I'll need to figure out!
I intend to make a mock-up out of a piece of plank, using the manifold gasket as a template, to mount the Goodparts manifolds and the carbs to work out those details before I strip the old carbs and manifold off the car.
My understanding of the middle carb deal was that you have to use a rear carb, remove the shaft, then reinstall it in the opposite direction, and use a threaded extension nut (AM37 in the TRF TR250 catalog, page29) to facilitate the linkage, per Mr. Goods instructions: https://www.goodparts.com/tech_docs/Triple_Stromberg_Linkage.html
Shawn: Richard Good recommends the B1AF for those of us closer to sea level (600 to 1400 ft in the hills of northeast Ohio, northwest PA; Lake Erie is at about 575 ft. above sea level).
The stock C3150 carbs on the TR250 use the B2Y needle, which is richer than the B1AF throughout the range. I was wondering if any one was using that carb and that needle. I have an excel spreadsheet comparing the needle tapers, with charts, of some standard ZS fixed and biased needles, as well as some SU needles. I'll send anyone a copy who wants it.

 

[TR_JOE250]

Re: Need info for fitting triple ZS carbs to TR-25

I just wanted to thank everyone for all the great info. I hope it's been helpful to others as well. I agree the original linkage leaves much to be desired. I could never get my carbs to open all the way either. It looks like Ab has a pretty good setup.
Thanks again /ubbthreads/images/graemlins/cheers.gif

 

[Guest]

Re: Need info for fitting triple ZS carbs to TR-25

Here are some pics of my carb shafts for what it is worth.
Might give you some insight into what you will be dealing with. The interesting part is these carbs are very tightly linked together, so adjust one, adjust all. Gary Martin in South Dakota did the rebuild on my carbs. You might notice that the front carb is a different model than the rear two, really doesn't matter as long as they are in the same family.

Bill