has anyone fitted 45 dcoe's to an 1800cc Zetec?

[zetec]

I have a blacktop engine & would like to fit 4 progression hole 45 dcoe's to it.

 

anyone have any jet sizes or experience in this?

[Klunk]

Hi ,

 

My 1800 had 45's on it and they had 3 progression holes. It was set up on an engine dyno and had no hesitation at all, anywhere. That was with Newman 285 cams as well.

 

That's the good news.... The bad news is I sold the car abroad and can't remember what jets it had in it. The only thing I can remember is it had the standard Weber supplied 36mm chokes and F16 emulsions.

 

Sorry, not much use but at least you know they will work

 

Regards,

Giles

[zetec]

Superb!!

 

Great news, just need to buy them & get them fitted!

 

Many thanks gov

[Roger King]

I've just helped someone at work with the same engine/carb set up.

 

He had four progression holes

 

We ended up with

 

Choke - 36

Main - 145

Air - 180

ET - F11, this made a big improvement to high rev flat spots compared to the F16

Slow run - 60 F8, there was slight spitting on the standard 55 F8

Pump - 35, the standard 45's are nearly always too big for a smallish engine

 

I must stress that the exhaust system can make a big difference (this car is not a Caterham - he built it himself, as in he built the chassis, suspension, everything) and it has not been rolling roaded. It has however raced at Anglesey with no problems.

 

He reports a big improvement in driveability compared to the previous set up which had several flat spots.

 

 

 

Edited by - Roger King on 25 Jul 2013 10:15:20

[zetec]

Thank you Roger, great to have your specialist input.

Did he have 40 dcoes before?

[Phil B]

Craig,

 

Stop messing about and go to TBs, you know it makes sense.

 

I justified the conversion to SWMBO on environmental grounds.

TB's give me 30 -40% better fuel consumption, so more power, better driveability and saving the planet. 🥰 🥰 🥰

 

Phil B

[Roger King]

No, he didn't have 40's. He built the car around 15 years ago with a Crossflow and later sold it. He's recently bought it back, but it had the Zetec and 45's fitted. Incidentally, if you don't have 3D mapped ignition fitted, get it. It makes a huge difference to part throttle torque and will generally improve fuel consumption by around 20%

[zetec]

Quoting Phil B: 

Craig,

 

Stop messing about and go to TBs, you know it makes sense.

 

I justified the conversion to SWMBO on environmental grounds.

TB's give me 30 -40% better fuel consumption, so more power, better driveability and saving the planet. 🥰 🥰 🥰

 

Phil B

 

 

Good idea but at huge costs. I also need an omex 600 as mine is just an ignition only set up

[Jaseb]

Every day's a school day, my 2 litre zetec has run on 40s since we fitted it and has a flat spot, it never occured to me that 45s could cure it... Doh!!

 

Daft question, I've now seen 3, 4 and 5 progression hole DCOEs, what's the difference, smoother but more hassle to set up?!

[Roger King]

Flat spots are not related to the size of the carbs, but are down to the set up of the carbs you already have. It takes quite a depth of knowledge and not a little black art to set things up properly, but believe me, done properly, and provided the engine isn't to some horribly unsuitable spec, DCOE's can be set up to drive without any driveability issues at all, particularly if used in conjunction with 3d ignition.

 

It is undeniable that injection is potentially superior, but that is every bit as dependent on being mapped by someone who knows what they're doing. Basically, a properly set up injected car will be a little better than a properly set up carburettor car, generally in the areas of economy and part throttle torque. Max power will normally be about the same unless the engine is to an extreme competition spec. On the other hand a well set up carburettor car is way better than a badly mapped injected car (and vice-versa).

 

Progression hole design is all about getting the carbs to run without flat spots as they come off the idle mixture screws and onto the slow run jets proper. 45's have always been worse at this than 40's and the extra holes are an attempt to eliminate this. Done properly, it can be completely successful.

[Eugene]

As a lot of you will know Eugene is a 2L Black-Top Zetec on 45s...

 

I spent a lot of time working the jetting, and making a bespoke 3D map.

I found the 5 hole 45s made a huge difference to smooth pick-up.

 

And as anyone who has run with me will know, Eugene goes rather well.

Topped 210 BHP on Wilshers Garage's rolling road 😬

[Jaseb]

Sorry, seem to have hijacked the original thread somewhat but...

 

Is it the case where carbs - my 40s in this instance - can be set to maximise power at the expense of smoothness (what I was told by my garage man) and maybe 45s would do both?! Or is that complete rubbish and I should get the 40s set up properly?

[Roger King]

The only reason to change from 40's to 45's would be if the engine is capable of producing more power than the 40's will let it. I don't know the state of tune of your engine so I can't answer that, but if it's in standard trim you are probably at the point where either would suit. I certainly wouldn't change just to get rid of flat spots because that has nothing to do with the fact that you have 40's rather than 45's. As a general rule 40's are easier to set up for driveability than 45's but either can be made very good if done properly.

 

It sounds like you need the carbs you already have setting up properly.

[Jaseb]

Thanks Roger, my engine is a Raceline 190/200 spec so I've always believed 40s to be marginal but held off changing anything while I worked out if I wanted to cough up for injection!

 

I'll have a chat with my local chap and see what he thinks, either way I want those flat spots banished!

 

Thanks for your help!

[Drumster]

Jase,

 

I had a Raceline 190 spec engine on 40 DCOEs and as you know the Raceline spec recommends 45s to achieve the 190.

 

With 40s on the engine the Two Steves only managed 170bhp and it was obvious that the 40s were 'strangling' the potential power. I didn't want to invest in 45s as I was prepared to save up for TBs. Once I had the Emerald ECU and TBs fitted the engine then produced a comfortable and driveable 190bhp without further modification.

[Klunk]

Craig,

 

Is the engine standard? As Roger says, if you have not modified the engine so that it needs to breath more at the top end, then you may as well stick with what you have got unless you are planning headwork/cams.

 

What size chokes have you got in the 40's? Standard is 34mm. Standard 45's have 36mm chokes. Without the breathing mods, all that will happen is the air speed will drop, you will get fuel drop out, and the torque will be lower than on 40's through the rev range with possibly a small gain in top end power. (You can of course put 34mm chokes in 45's, but that would make the change a bit pointless ).

 

As Roger says, it's a bit of a black art. Fortunately I have a cracking engine builder near me and the first question he asks is "what do you want to use the car for ?". The answer to this is critical - there is no point in ruining the driveability for the sake of pub banter . You can spend an awful lot of money for no/little benefit and their are plenty of people out there willing to take your cash. Decide what you want and go from there

 

Regards,

Giles

 

 

[zetec]

Its a standard lump at the mo,

 

Head & cams will follow at some point,

I will purchase said 45's in readness

[Klunk]

Any particular reason you want to stay with the 1.8? My tuned 1.8 was great but a bit tiring to drive . My slightly less tuned 2.0 engine on 40s was effortless .

 

 

[zetec]

I take it your talkig silvertop?

 

I dont fancy taking the engine out for the 4th time so its staying unless i blow it up

[Klunk]

They were Silvertops, but the relationship between similarly tuned 1.8 and 2.0 Blacktops will be the same .

 

I dont fancy taking the engine out for the 4th time so its staying unless i blow it up

 

I like your style 😬

[Phil B]

Craig,

 

In answer to your original post, i have dug out the settings of my 5 progression hole 45s as originally fiited to my 2.0 Blacktop.

The carbs were direct from Weber UK (via James Whiting) and they set them up to replicate their original Zetec conversion spec when used with one of their early ignition only ECUs.

Choke 40mm

Aux venturi 4.5

Main jet 150

Air corrector 145

Emulsion tube F5

Idle jet 55F9

A lot of people will say the choke is too large, but this is what Weber determined from a lot of RR work was the optimum setting.

 

Of course you don't have to go down the Jenvey TB route to get an injection set up, there are plenty of folks in the kitcar racing world who have converted using motorbike TBs.

http://www.ebay.co.uk/itm/Ford-Zetec-E-Bike-Throttle-Bodies-Kit-GSXR1000-42mm-Kit-Car-Escort-Fiesta-/231019364178?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item35c9d3bf52

 

Good luck, Phil

 

[zetec]

Thank you Phil, would that jetting work on an 1800 ?

[Klunk]

Phil's will not be ideal for your engine. If you ring Weber's technical department they will give you the recommended settings for a standard engine.

[zetec]

Thanks Klunk