Recommend Carb Sync Tools?
Discussion
Hello~
I am looking to buy a carb sync tool, and wondering what is a good name to go for. What are the things I need to look out for?
Zak_62,
You do not want a traditional Carb Sync® for use on an Esprit. They are innacurate and difficult to use. You must disassemble the airbox and place the tool into the airstream you are trying to measure and adjust. This makes tuning fairly innaccurate. Also, it's difficult to maintain a steady idle.
You could use an exhaust gas analyzer such as Gastester® from Gunson, but these will tune mostly for emissions rather than performance and again are somewhat innaccurate as they measure the average HC and CO content from all cylinders rather than each individual one, not to mention they are around $200.
A Colortune® could be used, but again, these are highly subjective (remember most guys are somewhat color blind) and difficult to use due to the long reach and recessed sparkplug holes on the Esprit. Plus, as they are not very bright, you must use it in a dark place such as a closed garage, not recommended. And you have to switch it between sparkplugs for each individual carb barrel.
The proper tool to tune the dellortos is a 4-tube Hg manometer. The problem with these is that they are bulky (must be at least 24" tall to be accurate), and due to the toxicity of the Hg, must be used and stored vertically at all times.
The best option is to use a mechanical manometer. These use 4 precision Stainless Steel pistons inside 4 calibrated glass tubes which are calibrated to extrapolate inches of Hg. The best one I've found is the CarbTune II®. It is sold through EuroCarb in the UK and will run you slightly less than $100 incl. shipping. Contact Matthew Cooper at Sales@dellorto.co.uk.
To use the CarbTune II®, you remove the covers for the test ports on top of the carbs (no need to remove the airbox) and screw in the 5mm adapter ports w/ rubber 'O' rings, supplied with the CarbTune II®. Next you close the 2 balance screws on each carb (take care not to 'grauch' the screws), start the car, let it warm up and adjust the idle to 1,000 RPM using the idle adjustment screw.
Next, you adjust the mixture screw on each carb barrel until it produces the strongest vacuum (highest reading on the CarbTune II®).
Then, you turn the closed balance screw on the stronger of the two barrels on a particular carb until it matches the level on it's weaker 'brother' barrel (you can weaken the stronger one, but cannot strengthen the weaker one). Do this for both carbs. At this point you should have only one balance screw open on each carb. Also, adjusting these screws will affect your idle speed, when it does, re-adjust your idle speed adjustment screw to keep it at 1,000 RPM. Now each carb is tuned for maximum performance. You will have two columns of pistons on the CarbTune II® for each carb which match each other, but probably won't match the pair on the other carb meaning your carbs are out of synch.
Next, you must synchronize each carb to the other. To do this, you adjust the carb synchronizing screws (located on the throttle spindle between the two carbs)until the stronger of the two pairs matches the weaker of the two pairs (remember to adjust your idle speed as necessary throughout the procedure). Your carbs are now tuned and synchronized.
You can remove the CarbTune II® hoses and adapters, or you can leave the adapters in place and simply cap them with some vacuum caps available for a buck or two at any local car parts store. This makes tuning the carbs even easier the next time. I have capped my adapter ports and carry the CarbTune II® in my boot (it's very compact). This way, I can adjust my carbs on the road or track in less than 5 min. - very convenient. Hope this helps. Happy Motoring! Jim'85TE
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