carbs

Author
Discussion

deanwilson

Original Poster:

42 posts

207 months

Friday 5th September 2008
quotequote all
how hard is it to convert a injected engine to run on carbs and what are the advantages of doin if there are any.

Mr2Mike

20,143 posts

256 months

Friday 5th September 2008
quotequote all
Depends on availability of a suitable manifold. In terms of advantages, there are very few apart from simplicity.

People tend to do this for engine transplants when they are scared of fuel injection systems, or the OEM system won't fit the car and they don't want to splash out on an aftermarket solution.

//j17

4,486 posts

224 months

Tuesday 9th September 2008
quotequote all
Advantages of carbs over EFi
1) Higher fuel consumption.
2) Less power.

As stated people tend to switch back from EFi because they are scared of wires and still see a magic aura around every Webber carb. (that they get off a different car and it runs like a bag of rocks because they are also scared of how much the guy with the rolling road wants to set them up properly with the correct jets, emulsion tubes/progression holes.

Stick with the EFi, even if it does mean taking the ignition key/imobiliser/etc with source kit - or go mappable with MegaSquert/Emerald M3D/etc.

100SRV

2,136 posts

243 months

Tuesday 9th September 2008
quotequote all
Advantages of carbs over EFi
1) Higher fuel consumption.
2) Less power.

3) All the parts you need fit in one shoe box
4) You can diagnose faults more easily - either fuel or ignition, no sensors or black boxes to cloud diagnosis
5) They can be repaired with basic hand tools


Points 3, 4 and 5 win out in my application ;-)

CNHSS1

942 posts

218 months

Tuesday 9th September 2008
quotequote all
carbs are great!!

they are heavy and ideal to prop open the garage door or hold bits of paper down in the wind. cant see an automotive use for them this side of a museum though sorry.

they'll be loads who love the 'authentic' running they give a 'real' car, you know the rarely starts on a cold morning, fouls plugs, misfires on a day with a Y in it. when investigating the issues, the lovely aroma of first pure petrol (or liquid gold as it now seems to be) is often mixed with the faint smell of singed eyebrow and fringe after a particularly hearty backfire thru the filters scenrio.

OK above is a tad tongue in cheek but to be fair im not bright enough to fathom the mechanical trickery that is the offspring of Weber...

felga

184 posts

196 months

Saturday 13th September 2008
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Hi Sorry to steal the topic . Is it worth buying gunsons cabalancer or it will make a huge difference if i`ll go for different balancer with 4 seperate guages ? I`m converting 16sv vauxhall engine form one pierburg 2e3 to 2 dcoe`s 40.

Thanks
Andy

wildoliver

8,794 posts

217 months

Saturday 13th September 2008
quotequote all
I set all my carb engines up to start with using a gunsons carb balancer and colourtune. I then tweak further on either rolling road or real road. They work fine.

300bhp/ton

41,030 posts

191 months

Tuesday 16th September 2008
quotequote all
//j17 said:
Advantages of carbs over EFi
1) Higher fuel consumption.
2) Less power.

As stated people tend to switch back from EFi because they are scared of wires and still see a magic aura around every Webber carb. (that they get off a different car and it runs like a bag of rocks because they are also scared of how much the guy with the rolling road wants to set them up properly with the correct jets, emulsion tubes/progression holes.

Stick with the EFi, even if it does mean taking the ignition key/imobiliser/etc with source kit - or go mappable with MegaSquert/Emerald M3D/etc.
There was a test a few years back on a LS1 running EFI and the GM Performance parts carb conversion kit.

They made almost identical numbers on an engine dyno, think the carby had the edge on low end torque too.


Personally I see the real world benefit of a proper tunable EFI system. But many are more clunky and hard to work on.

But on the flip side I can't really see a problem with good carb setup either. They generally look nicer, give a different sound and arguably a sharper more responsive throttle.

While I can't reference EFI to carb, all I can say is I've got a 3.5 Rover V8 in my TR7 running an offy and a Webber 500. It tends to average around the 24mpg mark for commuting, has always run well and started (in all weather conditions and temps) and when on the rollers was making a tad under 200rwhp.

EFI 4.0 litre units in a TVR weighing less often perform no better and often worse in several area's.

Pigeon

18,535 posts

247 months

Wednesday 17th September 2008
quotequote all
Carbs are so much bleeding simpler.

I took one of a pair of 1.25" SUs that I had originally been using on an A-series, bolted it onto my MZ, and with a little twiddling of the jet nut it was fine. Can't do that with EFI...

I want my vital systems to be fixable at the roadside... which generally means an SU... if it's got to be EFI then it more or less has to be a system I design myself, so I have enough detail about it to be able to do some sensible fault-finding rather than wildly swapping sensors on a wing and a prayer.