Carbs Or Injection?

[johnboy]

Got myself an early distributor type redtop today for my 1800 manta, got a few questions now,

Carbs or injection, are twin 40's reliable for everyday use or need tweaking all the time,

bike carbs, are they any good for everyday use, not had any dealings with them,

injection, easy, reliable and trouble free usually but if I go injection can I use the standard injection with the 1800 dizzy set up using the rear dizzy wiring loom, ie will the standard injection/dizzy type loom fit into and work with the side mounted 1800 dizzy, what have you red top guys done?

[Volksdevil]

My vote is carbs. There's somewhat of a myth about them being unreliable. If Carbs are in good order then you should be fine, it's when things are worn (Spindles etc) that can cause issues. And many of them out there are probably in need of rebuild etc.

 

I ran a set of brand new 45 webers on my 16v golf for around 3 years, initially had them setup on a rolling road and then never touched again, best to maybe have a general checkup/tune every now and again but I didn't get chance as I took the car off the road. But It started on the button, and ticked over perfectly every single day of those 3 years anyway. (God I miss it!)

 

That said, you can sometimes suffer with Carb icing in colder weather, although I never suffered with it myself. With the XE having a coolant channel in the weber inlet manifold (My golf didn't) and being Longitudinally mounted (My golf was transverse) I can't imagine it would be an issue, but perhaps those already running an XE on carbs can comment further.

 

As for bike carbs, they can be a little harder to setup (Sharp throttle openings etc) and that's about all I know...

 

Neil.

[garymanc]

just putting the final touches to my car swapped injection to R1 carbs , fired it up for the first time tonight sounds awesome  as i bought mine that had already been in a manta so no need to get carbs balanced ect

and not many wires in the engine bay as thats always got on my nerves 

[gary6303]

Throttle body's for me, best of both worlds.

[Snowy]

Nothing wrong with carbs but if you like throwing fuel away and not release the full potential of your engine go for it.

 

1. Throttle bodies are the way forward if you want the best set up in terms of power, economy and reliability.
2. Fuel injection if you just want a good setup combined with economy.
3. Carbs if you want high power but dont care about economy.

 

But each to there own. As Garymanc said if you just want a clean looking bay then carbs are good. It does depend on exactly what you are trying to acheive.

 

But i will say this. If you run that car with an XE with over 150 bhp then you will need to do something with the rear end. Otherwsie it will not be fun to drive on all but the driest days.

[garymanc]

http://www.classicfordmag.co.uk/files/2011/07/CLF166.bike_.pdf

 

good little guide on bike carbs

[Snowy]

Just don't forget to get the bike fuel pump when you get the carbs.

[mantasrme]

If its a Hatchback and you don't already have an injection tank then go for carbs, because finding a hatch inj tank is an issue.

 

Personally i prefer bike carbs, much friendlier for daily driving due to their CV design (so they work just as well at slight throttle as they do at full throttle, unlike dcoe's)

They also sound glorious  

 

Throttle bodies are the ultimate option but the cost is way more than any other setup.

Standard injection is very good and lovely to drive/reliable and the cheapest option, simple to do aswell only 6 or 7 wires and a bit of time re-doing the loom to sit the ecu inside

Webers unless you already have them will also be expensive as hey change for good money second hand

[droop snoot hp firenza]

my fiat strada abarth was superb on fuel running standard factory fitted twin 40 solex carbs, i could get 40 mpg quite easy, un real could not believe it.

 

my hp firenza had twin 45 webbers on, that used to do around 25 mpg, which is ok for a slant 4.

but all the other twin 40s i ran have been have been poor on fuel, i think mostly down to wrong jetting.

 

if you can get a set of twin 40s jetted correctly they should be good on fuel,

i can not see them being quite as good on fuel an injection though,

 

 i also like the great throttle response you seam to get of twin carbs, and the great sound,

but a down side to side draft carbs is, you can sometimes get a smell of fuel from them,

Edited April 24, 2015 by droop snoot hp firenza

[johnboy]

Thanks for all the comments guys, that bike carb article was interesting thank you, I think the car will handle a good xe on carbs or injection as the rear torque tube bushes and trailing arm bushes are knackered, lot of play in the front prop mount area as well plus the tyres are date stamped 02 so 13 year old, gone off, hard and cracking quite bad in the treads so a new set of boots on her this weekend should make a difference.

Was thinking of bike carbs as easy to do and reuse my original dizzy on a mount plate for the xe as the 16v loom and ecu are for the dizzy type engine and I am unsure as to weather this can be used on the 1800 dizzy or not, thanks for the help guys, appreciated.

[mantadoc]

Throttle body's for me, best of both worlds.

Bike carbs and SUs have a variable size venture which keeps up air speed and torque. Most fixed choke carbs have an accelerator pump to  squirt in neat fuel when you open the throttle. to try and mask the flatspot when the air speed drops. Throttle bodies still drop the air speed and torque when snapped open from moderate rpm.

 

 

SUs used to be the most accurate fuel metering and economy of any carb (close to EFI)

[garymanc]

Not sure if you can use the 1.8 dizzy think you need one from h&h

[mantadoc]

1.8 Family II engine distributor used to be the one of choice.

[garymanc]

can you advance a 1.8 distributor  can't remember , i think thats the point of a h&h dizzy because you can 

[mantadoc]

can you advance a 1.8 distributor  can't remember , i think thats the point of a h&h dizzy because you can 

Depends what you mean. They have an advance curve, the curves can be customised. With a decent timing light you could set using the maximum advance figure. Mostly right most of the time and for peak performance

[Snowy]

The XE that was in the car originally with R1 bike carbs ran quite well with the standard 1.8 dissy.

 

When I got it the vacuum advance was disconnected. It didn't run too well at lower speeds on light throttle as the dissy had been set up for top end.

 

I drilled and tapped each runner, T'd them in to a 50cc reservoir. then attached the vacuum advance to this. Then set the car up again and I t ran very well right across the rev range.

 

Hope this helps

[mantasrme]

H&H modify the advance curve inside the dizzy itself to better match what engine spec its for. Like playing with the bob weights on really old dizzies but more high tech.

Had one of their dizzies on a bike carb'd SEH and it was spot on everywhere.

 

The problem with the standard 1.8 dizzy is the ignition advance curve is designed for a 1.8 with a Varijet not a 2.0 16v with 4 carbs so the ignition isn't perfect all across the range for peak power.

However if set up on a rolling road they get it right where it matters and acceptable everywhere else.

[johnboy]

Thanks agin for all the info guys, snowy do you have any pictures of the redtop in the car?

[Snowy]

Thanks agin for all the info guys, snowy do you have any pictures of the redtop in the car?

 

This was how it was when I got it...Notice that the vacuum advance to the carb is not connected.

 

 

Edited April 25, 2015 by Snowy

[johnboy]

Thanks Snowy, looks really good, is that a home made distributor mounting plate or are they available from somewhere?

[garymanc]

mine with h&h dizzy 

[rutts]

bragger   

[johnboy]

Seems bike carbs may be the way to go, hearing a lot about r1 carbs, are they the carbs of choice for price or ease of set up or will other carbs do the job, say zx6 or zx9 or maybe other types?

[mantasrme]

Biggest reason everyone goes on about R1 carbs is they are all the same.

Every R1 on carbs had 40mm Mikuni CV carbs fitted, so if you buy R1 carbs you know what you are getting.

 

Other Jap bikes also had large CV mikunis fitted but on most models it depended what year production and engine size it was to what carb was fitted.

I have a set of 39mm Mikunis for mine from a Suzuki GSXR but i don't know what year or engine size they were from, most i see listed are smaller (34 or 36mm versions)

 

Basically any CV carbs will work and they just need to be large enough for the given application. A carb that is small will work but you will get less power from it

There was a size chart somewhere for what you need related to engine size, around 40mm is fine for a 2 litre

 

Also consider if you fit 40mm DCOE's to an XE the largest chokes are 36mm, this hampers top end a bit but is better in the mid range. A 40mm cv carb is 40mm all the way through but doesn't sacrifice low end performance.

Another advantage of the CV setup is, if the carbs are too big you don't loose the low down driveability as you would withj 48dcoes on a 1.3 engine.

[johnboy]

Cheers for that mantasrme, was just wondering why the r1 carbs are so popular but if all r1 carbs are the same regardless then that explains it, just been looking at the nodiz ignition drivers and they look pretty good, might go with r1 carbs and the nodiz set up as my engine is the distributor type and I don't want to mess about with the heater box, was going to get the front dizzy mount for the xe but by the time I buy the mounting bracket, another dizzy, drive wheels etc it starts to get quite pricey and look untidy, where as the nodiz will be relatively hidden and the original cambelt cover won't need a big hole in it for the pulley/belt set up.