47 replies to this topic

[paulrockliffe]

Can anyone advise me whether I should put a Weber 40 on my MG Metro (standard) engine or whether I should hold out for a 45?

How easy is it to find out what the appropriate jets are for my engine?

Anything else I need to know?

Cheers.

[Paul Wiginton]

Dont bother, itll just use more gas and probably lose power. You only want a HIF44 for under 100bhp

Paul

[bebbinator]

if you really want a webber get a 40 because the 45 leeks petrol

[paulrockliffe]

Can you explain the petrol burning thing for me?

To my mind if I'm burning more fuel, either the engine is running rich (ie carb not setup properly) or I'm driving faster. or am I missing something?

I have considered a single HIF44/HS4, but it won't fit under the bonnet of my Minus without spoiling my beautiful lines and it won't sound as good as my twin HS2s or the Weber. An important consideration!

If you've followed my project thread you'll know that I can't get the twin HS2 to work without a custom needle profile and I can't get close enough myself to be able to get the car to someone who can sort it, so it's going to be cheaper to change the carb to something a bit more reliable.

Anyway, the more advice the better, keep it coming!

[bebbinator]

no what i mean is they leek petrol out of the inlet

[paulrockliffe]

no what i mean is they leek petrol out of the inlet

I'm sure that can be sorted though?

[In-a-mini]

well the 40's and 45's both leak fuel a little they are a git to get setup then they fall out of tune so need continual playing with (if you do some milage) what paul has said about more fuel is spot on they are not the most fuel efficient carb they use more fuel generaly you cannot get them setup all the way through the rev range so it comes to a comprimise. They are great carbs but for the right job which i beleave is flat out and racing not best suited for a road car. if you do go for a webber i would use a 40 as they are alot cheaper to get hold of and help with bottom end power and torque.

Edited by In-a-mini, 11 January 2009 - 08:18 PM.

[bebbinator]

no what i mean is they leek petrol out of the inlet

I'm sure that can be sorted though?

you cant honestly my father used to be an official weber carb rebuilder and every single webber 45 wand 50 leeked, they dont leek much but on a mini because its above the manifold you will be able to smell the petrol

[paulrockliffe]

no what i mean is they leek petrol out of the inlet

I'm sure that can be sorted though?

you cant honestly my father used to be an official weber carb rebuilder and every single webber 45 wand 50 leeked, they dont leek much but on a mini because its above the manifold you will be able to smell the petrol

But I like the smell of petrol..........!

Hmmmm, might have a re-think, it's right pain because the HIF won't fit without bonnet mods!

[morley]

i just want to have one for the noise but if it was me, i would just get a 40, 45 sounds like overkill!

[bebbinator]

if i was you i would get a 32 or a 38 they sound just as good

[Kerrin]

Will a 40 fit in the minus? unless you have a swan neck manifold you need to put a bulkhead box in.

Its all down to how well its setup, there is also some overlap on the choke sizes, as both carbs have changable chokes venturi's and jets to suit each type of engne.

if you have a standard MG metro and dont plan to tune it up to much in the future a 40 may well be plenty. 40's tend to be cheaper (due to bar bragging points) and also the way the chokes fit is more robust, on a 45 the chokes bolt in, if these bolts are overtightened the body of the carb cracks. On a 40 the chokes are held by springs.

They do use more fuel as they inject fuel as you push the throttle but mine always accelerated more fiercely with a webber. nowadays i prefer a HIF as they are smoother, and easier to set up myself, and i am an old f&&t

Choice is yours, go for it if it will fit!!

Make sure you use the proper mounting onto the manifold. Webber DCOE's use rubber rings and spring or special rubber washers washers, this effectively allows the carb to bounce on the manifold and stops the fuel frothing from the vibration of the engine. the best ones to go for are MISAB plates and COSWORTH washers.

Edited by Kerrin, 12 January 2009 - 11:47 PM.

[JetBLICK]

something a bit more reliable.

Reliable webers are not. By all means, if you can put up with the small extra fuel cost, bulkhead mods, and noise then go for it. Go for a 40, they're cheaper to get 2nd hand, i've got a pretty feirce engine on a 300deg cam and it runs lovely on a 40. Be warned tho, webers dont like the cold, and until the engines warm they're an arse to drive with. They are also much harder and more expensive to tune. Its also worth mentioning that the quality of 2nd hand webers varies massively, even ones that look presentable on the outside may be filled with gunk or had a bent spindle, which would require a rebuild.

If you can embrase the noise tho, it is adictive... makes you want to drive everywhere with your foot planted.

[mini7boy]

Can anyone advise me whether I should put a Weber 40 on my MG Metro (standard) engine or whether I should hold out for a 45?

How easy is it to find out what the appropriate jets are for my engine?

Anything else I need to know?

Cheers.

you absolutely don't need any Weber DCOE, 40 or 45, on a standard 1275 engine.

Your engine will not process nearly enough airflow to justify a Weber.

a single 1.75 inch SU is plenty of carb for your engine. Modify or build an intake manifold if necessary.

You need to read Vizard on this subject if you have not already done so.

There are VERY few road 1275s that need a Weber and yours is definitely not one of them.

Where did you get such an idea?

[maccers]

I had a set of twin 45mm choke Webbers on my Caterham, that used an 8 Valve Ford 1700 Cross Flow enginge. They lost the sharp edge really quickly after being set up and I always had popping back through them, and even had a small engine fire as they blew back so much once. Yes they sound good, but I'd probably leave them to track cars or if you do install them, get a plumbed remote pull fire system.