Announcement

Collapse
No announcement yet.

upgrading carburetors

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • upgrading carburetors

    I have a stock 74 TR6 that I would like to perform some upgrades on in order to make it a performance street vehicle and not a race car. I read an article named "Six Pack: Easy Triumph TR6 Performance Upgrades" in Classic Motorsports which I chose as my initial guide. My question is regarding upgrading carburetors. The article calls for two Weber 45MCHH which are no longer made, but for which other appropriate Webers could be substituted for. I'm in agreement with two rather than three as I'm not building a race car, but why Webers? I've read that they're very difficult. I then considered staying with the original ZS's, but read they were emissions friendly taking away performance. My choices are then SU's or maybe Mikuni's. Thus my confusion. Any direction would be greatly appreciated.

  • #2
    What other enhancements are you planning besides carbs?
    72 Pimento w/overdrive - Lilred
    67 4A Royal Blue - Lilblue

    Comment


    • #3
      The highlights of the other enhancements that I'm planning so far are increased compression, GP2 cam, electric fan, rewiring, headers and exhaust, suspension work and limited slip differential. No transmission work as I have OD. Are there any others I should be considering?

      Comment


      • #4
        Send your ZS carbs via USPS priority box to poolboy to rebuild them- you really won't get better than that- and very reasonable.
        Headers are a waste of money- everybody seems to agree on that. Limited slip, why bother.
        The other stuff makes some sense.
        Walt
        CC80954U '72 TR6 original condition/sold 16.500.
        poolboy rebuilt the Z-S Carbs. Philstr6 rebuilt both rear hubs.

        Comment


        • #5
          Well the reason I ask is that the TR6 is already over carbureted with 2 ZS. I am going to link an article from Classic Motorsports that you can read and come up with your own conclusions. Yeah, it says MG but if you read it and look at the third table you will see the TR6 listed.

          As far the performance robbing emission stuff like temp compensators and by pass valves - most of us have disabled those. I find that once properly checked and adjusted, ZSs are pretty trouble free.
          Which is better, SU or Weber carburetors? We put an MG Midget on the dyno to find out.
          72 Pimento w/overdrive - Lilred
          67 4A Royal Blue - Lilblue

          Comment


          • skootch13
            skootch13 commented
            Editing a comment
            Great article. I have mentioned before and will always say (with no dyno, engineering or mathmatical evidence to back it), that any HP gains from triple ZS carbs is from the straighter intake runners and them being uniform and shorter in length. So, maybe 1 HP per carb? Is it worth the time and effort. Not for the street of course. I just like the look.

            What did Kastner run?

            I made an aside in another thread yesterday about triple carbs on a 440 magnum engine. Why does a 6-pack on a 440 make more HP than a four barrel? Why didn't Chrysler just put bigger jets/a higher CFM 4 barrel on it rather than three carbs? Wikipedia is saying the six pack was good for 15 HP. That's huge.

          • skootch13
            skootch13 commented
            Editing a comment
            I just went down the google rabbit hole. Six Pack 440s got a bump in CR from 9.5 to 10.5:1 . So why the triple carbs?????? I give up.

        • #6
          I'm still running the stock ZS's on my '73, which has the later PI cam and increased CR (ca. 9.2) and she runs great, even on mid grade fuel. I had them rebuilt by Poolboy (Ken), when I overhauled the motor back in 2015.
          As noted above, twin 175CD Strombergs are plenty of carb for a street run TR. They're even enough carb for the 4.2 liter XK engine.
          Side draft Webers are good carbs and sexy looking, but notoriusly difficult to set up. The down draft Webers for the TR6 with the "gooseneck" intake are a very poor replacement for the stock units.
          SU's give no performance improvement and present their own issues with plumbing etc. on the TR.
          CF1634U+O Pimento/Chestnut
          2nd owner, since 1975
          Now in Fair Oaks, CA

          Comment


          • #7
            Have you considered a EDIS based ignition system and a little dyno time to dial in the advance so that you have maximum torque at all operating conditions?

            Comment


            • #8
              I doubt that anything you've mentioned will allow a TR6 to win a drag race from a stop light with a Japanese sedan or a US pickup.....but a stock TR6 can be a lot of fun and get your adrenaline pumping out in the country on a twisty road....It is what it is.
              Keep the ZS carbs, make sure they are in good shape and properly tuned, learn how to tune the ignition timing without using the manual, give the suspension and tires some attention...then go for it.
              Driving a 1973 TR6
              Doing ZS carb repairs
              email kencorsaw"at"aol.com

              Comment


              • #9
                A couple of TRs in our club have the Mikuni carbs, and they seem to perform well. They include an accelerator pump, which may be a compelling reason to make the switch.

                I'd also recommend recurving (and maybe rebuilding) your distributor to match the new cam, it'll help make the most of the extra lift. If you're considering electronic ignition, look at the FAST optical system (formerly made by Crane). They're more durable and reliable than the Pertronix systems, at least in our local experience over a handful of cars.
                Bill Connell
                1969 TR6 CC28790
                TR6 project log
                St. Paul MN

                Comment


                • #10
                  Thank you all very much for your replies. I think I'll stick with the ZS's and get some help from poolboy.

                  Comment


                  • #11
                    I do not see any benefit with Mikuni carbs. The better alternative Weber DCOE. Lots of experience, data and parts available (jets etc.)
                    But it is a common misconception to gain more horsepower by just switching carbs. Before my EFI I had my engine with ZS tuned upto 140 BHP......this was with a 270° Cam.
                    Use a 280° and get another 10 Hp. All doable with ZS carbs. SUs are inferior to the ZS carbs.
                    Flying Dutchman drives: TR6 - 1973 - 56/11 - CF1xxxxUO - J-OD - Kent 280° - EFI EMU Black - Phoenix - 205/60 on 7x16

                    Comment


                    • #12
                      Originally posted by bluetr6 View Post
                      The highlights of the other enhancements that I'm planning so far are increased compression, GP2 cam, electric fan, rewiring, headers and exhaust, suspension work and limited slip differential. No transmission work as I have OD. Are there any others I should be considering?
                      Having traveled this path, I say don't spend any money on the upgrades. I did the max on my TR6 equipment all to disappointment. The most I got at the rear wheels before I sold the drive-train was 118HP which is about 135 at the flywheel. Not satisfied with the results I bailed. An engine conversion is the most cost effective trip to take. The stock 6, tuned is pretty comfy for a non sprited owner/driver. Stay stock or get yourself another bullet. That's my tuppence.
                      Best Therapy
                      http://www.britishv8.org/Triumph/AlbertGary.htm
                      Zoom Zoom

                      Comment


                      • #13
                        I went through the same calculations in my build and settled on aftermarket mikunis at just under $100 each. Tons of jet choices and some great tuning info on the web. Just under 2 years on the car in all temps and I am still on the final tune set up. I went for the stability, any HP gains would not be felt on my fairly stock engine build. Usually starts with the turn of the key, no choke unless it is really cold. Linkage, mounting, accessories and choke can be purchased as a package from a company called V-Performance. I sourced all of my own parts and did some simple fab work using Lokar parts and am very happy. Under $400 all in with K&N filters to boot.
                        1976 TR6 originally white now Porsche Voodoo Blue
                        Frame off resto started May 2015
                        Tshirts and TA boxes replaced
                        Diff braced and reinforced
                        Engine and head rebuilt
                        Header and Intake ported
                        SS exhaust
                        Floors repaired, new metal at rear bumper mounting points
                        New Rockers
                        AAW wiring - GM alternator
                        Complete suspension and brake rebuild, poly bushings

                        Comment


                        • #14
                          Here's my vote for sending the carbs to Poolboy.
                          I pulled them out of the box, bolted them on the car and have not touched them since. It just idles and runs like a brand new car.
                          I am amazed and delighted every time I turn the key and the 6 springs to life without drama.
                          2 thumbs up to Poolboy carbs.
                          1976 TR6
                          Carbs by Poolboy !

                          Comment


                          • poolboy
                            poolboy commented
                            Editing a comment
                            Thank you so much for your endorsement.

                        • #15
                          If bur.xare.forums.6-pack.org.jpt.nu pneumoperitoneum foster silences online arimidex mentat ohne rezept deutschland vpxl hydroxychloroquine order toradol injection in canada retin a cream to buy sinequan nizagara lumigan eye drop commercial extra-super-cialis costi farmacia where to buy maxolon retin a cream 0.1 best places to buy nizagara buy online us triamterene purchase grifulvin online desquamated gradient arimidex best price mentat vpxl walmart hydroxychloroquine price tarifs toradol injection generic toradol-injection india pharmacy purchasing retin a sinequan nizagara tablets lumigan eye drop no prescription extra super cialis maxolon price retin a nizagara in bulgaria nizagara generico comprar triamterene for sale overnight generic grifulvin in canada mannitol reticularis, liver; http://damcf.org/arimidex/ arimidex for sale http://postfallsonthego.com/mentat/ generic mentat http://couponsss.com/item/vpxl/ vpxl http://solepost.com/item/hydroxychloroquine-coupon/ canadian hydroxychloroquine http://healthkosh.com/toradol-injection/ low cost authentic toradol injection http://altavillaspa.com/retin-a/ buy retin a pharmacy buy retin a pharmacy http://abdominalbeltrevealed.com/sinequan/ sinequan without a doctors prescription http://goldpanningtools.com/nizagara/ nizagara.com generic nizagara canada http://sadlerland.com/lumigan-eye-drop/ lumigan eye drop http://americanazachary.com/extra-super-cialis/ extra super cialis online usa http://eatliveandlove.com/maxolon/ maxolon md http://a1sewcraft.com/retin-a-micro/ order retin a online http://techonepost.com/nizagara/ nizagara buy internet http://thegrizzlygrowler.com/triamterene/ triamterene 75 mg tablet http://umichicago.com/drugs/grifulvin/ grifulvin immunocompromised, extended, fasciculation, colluding.

                          Comment

                          upgrading carburetors

                          Collapse

                          Search

                          Collapse

                          There are no results that meet this criteria.

                          6-Pack Car Club of the Americas Statistics

                          Collapse

                          Topics: 39,577   Posts: 490,758   Members: 29,602   Active Members: 7,490
                          Welcome to our newest member, zehelihote.

                          Upcoming Events

                          Collapse

                          There are no results that meet this criteria.

                          Working...
                          X