down drafts

[Twinkle]

i am doing a little research and back ground work and would appreciate some info about some weber carbs.

 

they have 40-DCNF-100-250 3F on them, the manifold doesnt appear to be a ford one.

 

what are they off? are they suitable for pinto? can you still get manifolds for them, and what are they worth?

 

ta muchly

[mk1mexico]

i believe the downdraught DCNF is popular with the CVH boys

[Jay_harrier]

often found on Fiats, alfa, even the old pre injection MG Maestro - sadly not worth a huge amount

[davreeve]

i use ebay special DCNF,S on my cvh.Came as complete kit with manifold,fuel lines ,airbox etc

[boXXer]

dont they also lose power in comparison to sidedraughts due to the angle of the air flow?

[Fiesta Steve]

i believe the downdraught DCNF is popular with the CVH boys

 

Yes they are but only because of the lack of room when fitted in a fwd application.

[Toby]

dont they also lose power in comparison to sidedraughts due to the angle of the air flow?

 

Andy Harris runs down drafts and says they make better torque on his pinto and to be fair that goes alright!

[Col-ashtonmobile]

i run triple 42 dcnf,s on the old v6

[Guest H.P.E ANDY]

Your spot on toby more torque and 3 bhp down to 50/48 sidedraughts but the power curve is 9 bhp prouder on the way up through the rev range

[V8ian]

I think the 40DCNF fitted to the Montegos were the same as what was fitted to the V6 X pack, but Colin is running 42s on an x pack manifold,

I run downdraft throttle bods, for no other reason than they were cheaper [including the ECU!!!!] than buying a used IDA set up for a TVR

[Toby]

Your spot on toby more torque and 3 bhp down to 50/48 sidedraughts but the power curve is 9 bhp prouder on the way up through the rev range

 

I know it works as your dads car is awesome but........

Can anyone explain how this can be the case? If more torque is made by filling the cylinders better why does a more bendy pathway make sence?

[Fiesta Steve]

Your spot on toby more torque and 3 bhp down to 50/48 sidedraughts but the power curve is 9 bhp prouder on the way up through the rev range

 

I know it works as your dads car is awesome but........

Can anyone explain how this can be the case? If more torque is made by filling the cylinders better why does a more bendy pathway make sence?

 

The air speed must be increased by the restriction of the bends somehow thus giving more torque/power lower down the rev range but at the expense of top end power.

[Guest H.P.E ANDY]

Don't no the answer to that mate but have had another brand new pair of downdraught's on the same engine and is down on torque and bhp on the same manifold can you work this out for us my answer would be new carbs are shit

[Toby]

Don't no the answer to that mate but have had another brand new pair of downdraught's on the same engine and is down on torque and bhp on the same manifold can you work this out for us my answer would be new carbs are shit

 

I am a big believer in old shit is good shit - have you seen what i drive!!

[Guest H.P.E ANDY]

No mate dont like the new carb's youve only got to look at the outside of them to no what they are that's why brand new 50's are laying up in me dad's garage catching dust after 10mins of use

[Toby]

No mate dont like the new carb's youve only got to look at the outside of them to no what they are that's why brand new 50's are laying up in me dad's garage catching dust after 10mins of use

 

Sell them to James?

[Guest MK1gaz]

Your spot on toby more torque and 3 bhp down to 50/48 sidedraughts but the power curve is 9 bhp prouder on the way up through the rev range

 

I know it works as your dads car is awesome but........

Can anyone explain how this can be the case? If more torque is made by filling the cylinders better why does a more bendy pathway make sence?

The inlet path to the engine on the downdraught manifold is longer than on the sidedraught manifold , this increase in length changes the pulse of air into the engine and gives more torque on the engine in question

[Toby]

So you think it's a length thing!?

 

Could be that and the air speed is spead up by the bends aswell then.

 

Do I need some??

[Guest H.P.E ANDY]

No mate dont like the new carb's youve only got to look at the outside of them to no what they are that's why brand new 50's are laying up in me dad's garage catching dust after 10mins of use

 

Sell them to James?

should do they now have gas fitted to them

[Fiesta Steve]

I have a longer manifold somewhere

[Baz.]

No mate dont like the new carb's youve only got to look at the outside of them to no what they are that's why brand new 50's are laying up in me dad's garage catching dust after 10mins of use

 

Sell them to James?

should do they now have gas fitted to them

 

has your dad got noz then andy?

[Guest H.P.E ANDY]

No mate dont like the new carb's youve only got to look at the outside of them to no what they are that's why brand new 50's are laying up in me dad's garage catching dust after 10mins of use

 

Sell them to James?

should do they now have gas fitted to them

 

has your dad got noz then andy?

He had it fitted about 3 month's ago used it on the road was well impressed 50 shot went to pod with it when he hit it the trigger switch broke so he took it off and is trying it next year

[Toby]

Cant wait to see that

[bob wiggins]

tell your dad thanks for dropping that gearbox off earlier Andy i must have just missed him

[Guest H.P.E ANDY]

Cant wait to see that

Toby,that's all right bob