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Hey, I’m new here and am hoping to get some input on a ‘63 122s that I purchased from my Uncle. First question is, what is the proper amount of ATF to put in the damping units? Second issue I have is the idle seems real high after the car warms up. How do I tune the idle down? Any help would be appreciated, I have no experience with these carbs.
Thanks,
Jeff
 

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Jeff;

Congratulations on your new Swedish oldie and welcome to this forum.

You're in the right place with questions...SU Carbs used on these cars are like nothing you might be used to from American cars...so you have some leaning to do...but don't fret...there is no magic going on either...just good science, physics, and precision mechanics, and it is explained very well indeed in the John Twist/University Motor Videos on YT.

Regarding the Damping oil (ATF is fine!), I've never really measured how much, and amount is really not critical (but it must be present!)...effective practice is to lift Dashpot to top (Filters and Damping Valve Assy removed) until you see the inner tube, then pour oil in until its about 1/4" from the top of the inner tube...if you then screw in the Damper Valve (finger tight only and NEVER tightened with a wrench!), and lift the Dashpot a few times, while holding a rag above the vent hole in the black Damper Valve Thumbscrew, any excess will be caught in the rag an stay off the underside of your hood...

The Idle can be adjusted with Idle screw (duh!), but it shouldn't be that different from cold to warmed up, unless Choke (fast Idle) Linkage is somehow misadjusted and getting in the act...where everything is and nomenclatures are in the links below.

I recommend you view the JT vids (SU Part 1. https://www.youtube.com/watch?v=7GRAcqDySog SU Part 2. https://www.youtube.com/watch?v=60Bj_2cZQnc ), and go through my SU Carb Servce Lite, and Expanded Tech Article: http://www.sw-em.com/SU Carb Service.htm ...that should lift some of the mystery...

A Haynes manual will also be a good reference, and the best $20 you ever spent on epay!

Cheers
 

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Also check the throttle shaft bushes for play and air leaks, un metered air can enter the manifold at the throttle plate which is after the venturi where the metering needle is located, and this un metered air will lean out the mixture at certain throttle/torque settings. Thereby making precise adjustment difficult. (but you can tune the carbs to allow the engine to run OK , but will run a bit rich or lean until the leaks in the Throttle shafts have been addressed) This may be part of what your seeing once the car warms up. The later HIF carbs have replaceable throttle shaft seals, however the earlier carbs with the separate float bowl may need to have new bronze bushes installed and machined to fit new throttle shafts.

The Haynes manual is good, but here also is some free litrature that will guide you while you await arrival of your Haynes 122/1800 manual

This link has a SU carb tuning guide included
http://volvo1800pictures.com/sweden/Volvo_1800_dokumentation_misc_en.php

This page has the 1800 GreenBook, ( includes lots of cross reference to the 122 and 140, NOTE : SU carb setup on the B20B is the same for all 3 models)
http://volvo1800pictures.com/sweden/Volvo_1800_dokumentation_Service_manuals_en.php
 
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