Enlarging the venturis in Solex H32 PDSIT carbs
Posted: Tue Jun 19, 2012 12:54 pm
i have a pair of Solex H32 PDSIT carbs on my bus, these are the carbs included in the $300 dual carb type 1 kits @ CB performance. They come with very small venturis in them and I had seen that they sold larger ones. What I could not find was a recommendation if they were indeed an improvement and what size jets to use with them. So I stuck with them stock ones for years. They are great carbs, get me 21 MPG and very good power and cool cyl. heads. Recently I saw that aircooled.net http://vwparts.aircooled.net/34mm-PDSIT ... enturi.htm had a blurb about these larger venturis saying they were indeed needed in 1600 CC and larger engines. and to use the 145 jet with them. So I just got thru installing said parts.
WOW! My bus is much faster. When Colin was here a week ago he did a rough estimate speed test accelerating from 50 to 60 in 4th, it took 10 seconds. I just did it in 7 ! My CHT gauge also seems to like these parts. Need more driving time to confirm this. But |I can confirm if you have these carbs and a 1600 you need the larger venturies and jets!
BTW Colin The idle jet was plugged on the Thing, it now idles off the idle circuit like it should!
A pic of the carb ID so we know for sure what I'm talkin about.
Stock venturi next to a upgraded one
A mod experience has taught me to do, taper the bottom edge of the venturies and this prevents the throttle blade form hanging up on them if they try and slide down. Modded one on left, stock one right
The carb bodies showing the larger vents installed.
WOW! My bus is much faster. When Colin was here a week ago he did a rough estimate speed test accelerating from 50 to 60 in 4th, it took 10 seconds. I just did it in 7 ! My CHT gauge also seems to like these parts. Need more driving time to confirm this. But |I can confirm if you have these carbs and a 1600 you need the larger venturies and jets!
BTW Colin The idle jet was plugged on the Thing, it now idles off the idle circuit like it should!
A pic of the carb ID so we know for sure what I'm talkin about.
Stock venturi next to a upgraded one
A mod experience has taught me to do, taper the bottom edge of the venturies and this prevents the throttle blade form hanging up on them if they try and slide down. Modded one on left, stock one right
The carb bodies showing the larger vents installed.