37 replies to this topic

[Dusky]

There are two things to balance

Idle

load

You set the balance with a flow meter at around 1k idle (its a lumpy camshaft you have)

The balance under load is determined by piston rise-fall time, springs, dampers and yes, dashpot oil

Bear in mind that switching to standard airbox will affect mixture to the point you'll need another pair of needles different to those you use with cones and stacks

Yeah

But ( when looking to keith calver's tests) the standard airbox with K&N inlay filters etc should flow similar/even a bit better, so the fuelling won't be as drastic 'out' as it is now
I picked M needles initially, because I'm running a cooper setup ( or similar) only the cam is a bit wilder than the standard cooper cam it seems

[Leonrjohnson]

Is the throttle pedal actually fully opening the carb butterflies?

[Dusky]

Is the throttle pedal actually fully opening the carb butterflies?

I think so

There is no slack in the throttle cable, so I don't know how I could open te throttle even further ?

 

cheers

Edited by Dusky, 11 November 2014 - 07:03 PM.

[sonikk4]

Is the throttle pedal actually fully opening the carb butterflies?

I think what he's getting at here is are you getting full range of movement on the linkage in relation to pedal movement. You need two of you to check this out.

[Dusky]

 

Is the throttle pedal actually fully opening the carb butterflies?

I think what he's getting at here is are you getting full range of movement on the linkage in relation to pedal movement. You need two of you to check this out.

 

I'll have a look with my dad this afternoon  
SHould the throttle pedal be to the floor on full throttle, Because it is now... If I can't open the throttle fully, should I probably bend the pedal or something?

[jaydee]

When the throttle is set with butterfly closed and pedal fully up you wont have a problem, there was a problem when installing HIF44 carbs, but not with twin HS2s

The last 1-2 mm of butterfly travel wont affect full power, and i have to say at 70 mph your pedal should sit at about half of the travel and it should pick up more speed with light pressure

On topic of airbox and stacks, i dont know how calver took that figures i imagine the comparison is between a drilled airbox and a cone filter without a stack fitted to an engine with poor volumetric efficency. But fitting cone filters with short stub stack inside dramatically change the airflow and so the fuel requirements, its the stack itself that does the main change in flow and speed.

[jaydee]

 

See in red the throttle stop, you can easly meter butterfly openings on thrttle by checking its travel.

[Ethel]

A rolling road could still be worthwhile, even if they aren't up to any tuning they can still measure the advance and exhaust gas. A lambda gauge may be better value though, if you're having to do your own adjustments.

 

You can still plot the centrifugal advance right through the rev range with the car sat in neutral - the best place to start.

[Dusky]

When the throttle is set with butterfly closed and pedal fully up you wont have a problem, there was a problem when installing HIF44 carbs, but not with twin HS2s

The last 1-2 mm of butterfly travel wont affect full power, and i have to say at 70 mph your pedal should sit at about half of the travel and it should pick up more speed with light pressure

On topic of airbox and stacks, i dont know how calver took that figures i imagine the comparison is between a drilled airbox and a cone filter without a stack fitted to an engine with poor volumetric efficency. But fitting cone filters with short stub stack inside dramatically change the airflow and so the fuel requirements, its the stack itself that does the main change in flow and speed.

http://www.calverst....filter_test.htm

On the twin airbox the nozzle isn't restrictive.

I'm thinking about drilling it though..

 

Could I try to fit the stubstacks and the elbow toghether?

 

 

 

 

See in red the throttle stop, you can easly meter butterfly openings on thrttle by checking its travel.

 

will have a look :)

[jaydee]

No you cant fit stacks to an elbow

If you have to run the box due to the regs in belgium i'd fit the box then profile the needle to suit its own airflow

[KernowCooper]

You cant check the mixture revving it at stationary, a small throttle opening will get the engine to rev to 5000rpm it needs to be done underload, borrow the co meter if its 12v and put it in the car and test it that way on road.

[minidaves]

big question what fuel you using?

[Dusky]

You cant check the mixture revving it at stationary, a small throttle opening will get the engine to rev to 5000rpm it needs to be done underload, borrow the co meter if its 12v and put it in the car and test it that way on road.

I'll ask him if he will lend me the CO meter

 

big question what fuel you using?

Using 98 RON fuel + unleaded additive

[Dusky]

I did also experience the car running on a lower temperature since I'm using the lead additive ( actually since I isntalled the 12G295 head, but I started using lead additive the same moment)

[jaydee]

Did you change the termostat along with the 295?