Carb balancing

[daverclasper]

Have been using the hose to the ear, though how reliable is this?. Not after perfection, and mainly looking for any better economy. I do a fair bit of city driving in which my mpg is far less than when cruising (which is usual), though, I understand the lower the rpm, the more important the balance is, as the more the  butterfly flaps move towards horizontal position, the air intake is more equalised anyway?, which makes sense to me?.

Also, if opinion is not positive about using the hose?, any ideas on a DIY tool to make for this please?. have googled it, though no joy.

This would be for CD150 Stroms

Cheers 

 

  

[PeteH]

I had, (may still have?) one of these, last used on the Vitesse circa 1986(Ish) :-  https://www.gunson.co.uk/product/G4053/Carbalancer

P.S. No-where near that price back then.

Pete

Edited March 28, 2023 by PeteH

[johny]

Can really vouch for those and theyre on ebay at 2O delivered using a code from one supplier....

[Pete Lewis]

dave when your car was built the throttles would be set 1.5 turns in of the idle screw from just touching the casting 

you can do that without any balancers  in the the throttles are both set to a mechanical position 

there are many quite simple to use checkers around but one way often not known is 

cut a piece of a tube or straw or anything that you can drop  into the dashpot  make them both identical lengths , have them long enough to be able 

to measure against the top of the top cover   run the engine set the idle so both rise the same amount  

so with a bit of diy and a steel ruler you can measure the lift of each air piston       this realy works 

Pete

[dougbgt6]

I have a Gunson, but I'm now looking for a good supplier of straw. 

Doug

Edited March 28, 2023 by dougbgt6

[daverclasper]

Thanks folks. That's great info Pete. Thinking, I could mark off identical increments on each straw to save measuring with a ruler after each adjustment?.

As I mentioned above, am I correct about balance of the plates/sync, being less of an issue at higher rpm?.

  

Edited March 28, 2023 by daverclasper

[daverclasper]

13 minutes ago, daverclasper said:

Thinking, I could mark off identical increments on each straw to save measuring with a ruler after each adjustment?.

And maybe a biro as well as the straw Doug?

Edited March 28, 2023 by daverclasper

[DanMi]

balance is really most important for a nice idle, once the throttles open a bit any small difference will have a tiny effect

[dannyb]

9 hours ago, Pete Lewis said:

dave when your car was built the throttles would be set 1.5 turns in of the idle screw from just touching the casting 

you can do that without any balancers  in the the throttles are both set to a mechanical position 

there are many quite simple to use checkers around but one way often not known is 

cut a piece of a tube or straw or anything that you can drop  into the dashpot  make them both identical lengths , have them long enough to be able 

to measure against the top of the top cover   run the engine set the idle so both rise the same amount  

so with a bit of diy and a steel ruler you can measure the lift of each air piston       this realy works 

Pete

When my cards were set up on a rolling road the guy had modified dashpot screw tops with a slider marked with different colour segments. 

Danny 

[ahebron]

11 hours ago, PeteH said:

I had, (may still have?) one of these, last used on the Vitesse circa 1986(Ish) :-  https://www.gunson.co.uk/product/G4053/Carbalancer

P.S. No-where near that price back then.

Pete

The problem I had with the gunson was it melted.
I ended up with the similar operation cast metal one with the foam rubber you press on the carb.
I also use a Twinmax which is designed for motorbikes but with a bit of cunning can work on cars

[Pete Lewis]

i made one like the gunson with two large washers drilled  with screen jet in the middle to connect a tube to a simple u tube manometer 

you turned the washers to close the drilled holes like a choke to get a reading 

currently use a Carbsync  which smiply measures air flow and the dash pot type  Jet setter  ( aka   the measure idea ) 

 

[Iain T]

I use an STE synchroniser with adaptor for 1.5" carburetors. I found a new one on auction about two years ago for less than £30. Simple to read. 

Iain 

[1969Mk3Spitfire]

I had a boxed Gunsons carbalancer in my loft for more than 40 years.  It was once more pressed into service when I bought a pair of SU H2 carbs attached to a Spitfire.  

It still worked well, a bit plasticy but, sadly I have a medical condition that manifests as an obsession for buying new tools (probably endemic among many members) so I bought one of these.  Very pleased with it.

https://www.ebay.co.uk/itm/363836050687?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338624526&toolid=20006&customid=a328cf453f1b0d765d03eca52ffd0a39

 

[Gully]

14 minutes ago, 1969Mk3Spitfire said:

so I bought one of these.  Very pleased with it.

https://www.ebay.co.uk/itm/363836050687?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338624526&toolid=20006&customid=a328cf453f1b0d765d03eca52ffd0a39

 

That's what I use - bought off Ebay from Chic Doig some years ago now.

Gully

[Mark B]

I have used a Gunson balancer since early 80's, basic, plasticy, but works. Years ago I had a spitfire set up proffesionally at a rolling road. I had tuned it all my self using Gunson Colourtune, carb balancer, and strobe, operator commented that every thing was pretty much bang on. 

[Stratton Jimmer]

21 hours ago, Mark B said:

Gunson Colourtune, carb balancer, and strobe,

Exactly what I have.

[Pete Lewis]

theres is alot of myths about balancing     its not that difficult to get pretty much spot on and   yes it only affects idle and very small throttle openings

which in turn affects the idle mixture and that affects the mixture across the whole range  so getting close is good but its not rocket science 

a listen to the engine its exhaust and listening for rpm increases as you adjust for best running will support a good drive 

Pete