drla vac balancing

Early Bay Forum

Help Support Early Bay Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

six

Well-known member
Joined
Oct 11, 2009
Messages
878
Reaction score
0
Chaps

Ive just put on a pair of drla 36s onto a 2027cc t1 motor. ive set the up as per the super performance book, eg for idle screw settings mixture an so on.

so i put on the vac guages as fired up the engine bank 3 and 4 show a lower (a lot lower) vac reading to 1 and 2 at idle.

Surely they should be close just a loss really any ideas? i will change the 2 carbs over to see if the issue swaps with sides .. anthing else im missing?
 
The base settings in the book are just to enable you to start the engine.

You next use the gauge and the adjustment screws to tweak the settings and get the carbs fully balanced.

A significant difference in vac reading means they are out of balance and one pair of cylinders will be firing more powerfully causing and uneven beat and engine shake.

If adjustment will not correct it your prime suspect on a new installation would be air leaks at the gaskets - carb to manifold and manifold to head.

That is of course assuming theres no swarf in the carbs :lol:
 
Comp test the engine. If they are all pretty close then the carbs or an air leak is at fault. The matched barrels on the carbs should act the same. If they are anything like IDFs then you have a mixture screw to tune every cylinder into 'best fast idle' and one idle screw that affects on both carbs. If one carb is miles out on one bank then I'd check strip and clean the carb. Matching the jets and lastly you can 'tune' the accelerator pump a touch.
 
i thought 36s were too small past 2 ltr ?? are you balancing them with the linkage removed ?? mine were pretty close with feelers and required only slight adjustment when running with airflow meter . Carbs are handed so you can`t swap round
 
of course you can swap round you just end up with the throttle arms the wrong way round! :lol: I didnt even get that far pulled them of and can see the butterflies on one side is slightly out and will casue that behaviour. I need more screws etc now , im gunna putthem to one side a sec, buy some icts so at least i can drive it round a bit get teh engine broke in then look at the drlas when i get 5 mins.. getting there though1
 
You forgot to mention in your original post that the carbs were s/h / of unknown provenance / had been messed with by somebody who didnt know what they were doing etc. :lol:
 
they were second had that got overhauled by a chap up near my brother in aberdeen. not sure of the finite details the family got to gether and bought them for my 30th.

i think they have been dropped but i have not evidence to accuse my suspect! ggrrr oh well. ill sort them at some point. ive got icts in mean time..
 

Latest posts

Top