EDELBROCK CARBURETTOR SET UP

[gerty]

Hi all !

I am about to instal an Edelbrock 1404 carburettor on my TV8 engine using the Canadian 7 degree adapter on the standard inletmanifold.This will also include a 14" Low Rider air cleaner and a fuel pressure regulator ( I already have the Phoenix exhaust manifolds fitted ). Standard cams are used.

I am familiar with setting up these carbs but to save a bit of setting up time prior to a final setup on a rolling road I would appreciate any needle and jet settings that have been establishedby other peopleon the same or similar installations.

The breathing system will also be changedto the nomal US V8 configuration with a suitablePCV Valve from the existingRH cam cover plus a second breather port installedon the LH cam cover Any information on part numers for PCV's would also be helpful.

Thanks ! David

[Kevin Garrod]

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Hi David

I have an almost identical set-up, at least I did until I fitted a modified inlet manifold to do away with the adapter plate.

When I first fitted the carb it ran OK straight out of the box, but I took it to a rolling road for tuning and they were able to adjust out a few flat spots. I'm still using the stock jets etc. all adjustments were to the 2 mixture screws at the front.

I didn't use a fuel regulator and I ran the breather pipe straight to the airfilter without a PCV, seems OK for me.

Incidently the rolling road gave a figure of 170BHP, but a much more conservative (and probably more realistic) 133BHP was achieved at the Power Challenge day at Enguinuity last year.

I don't know how that compares to my current set-up, I think it could do with some more fine tuning.

[TimShoubridge]

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I'm no engineer so treat these words carefully.

I have this setup and I am using standard jets supplied. DO NOT USE A PCV. I did (amongst others) and we have all established that it caused too much pressure and we sprang oil leaks. I just have my cam box connected direcly to the filter now and my leak has disappeared.

My concern at the moment is that I'm running rich. I do not know if that is because of bad adjustment or incorrect jets, so your feedback will be useful

Tim

[gerty]

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Thanks Tim and Kevin for your inputs, hopefully I will have the conversion on in a couple of weeks, just waiting for a few O &S's to arrive.

As you know it is a really easy conversion to carry out, I just need to think a bit more on the breathing system !

I will post the results and my eventual settings.

Thanks, David

[stagmuffin]

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hi gerty, i run a similar set with a holly and a modified manifold with tubular headers and straight through exhaust with soon to be installed hot cams and vastly improved heads and valves.initialy all my runs with a pcv proved to be a fast route to oil leaks.so ran the breather straight to carb which is ok when crising at 70 or gunning in lower gears but oils up the filter at any othertime .so now i run through a custom ally catch tank and back to the air box no problems clean air and filter and it goes like stink.the engine just begs to be revved and does it freely.

good luck with your project im sure it will go well and make the drive more fun.

steve..............

[GATS]

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hi Steve, i am interested in your catch tank, where did you buy it from, there seem to be a lot for sale , but which one should i buy.I am getting oil in my filter too, and this seems a good idea to stop it . Paul

[stagmuffin]

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GATS wrote:

hi Steve, i am interested in your catch tank, where did you buy it from, there seem to be a lot for sale , but which one should i buy.I am getting oil in my filter too, and this seems a good idea to stop it . Paul

paul have a look in the search option fo ( holly carbs) a post started by bill burrell.there are some good pictures of my set up in there.i think i bought the tank from matt lewis racing but would need to check it was a long time back.

steve........

[KOY 23]

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I bought a rectangular black one off ebay around £20. I mounted it where the rad overflow bottle should be. The return pipe has a flame arrester, I think off a V8 rover, again e bay, around £5. Russ specified what I needed. The catch tank is mounted low so that liquid drops into it and vapour rises into the air cleaner. After 1000+ miles I collected half a medium size jam jar of gunge split 50% oil and 50% water. Air cleaner now dry.

John.

[SAP]

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Hi v.intersting - what sort of ball park figure are u looking at for all the mods and parts very curious - Steve

[stoutgoose]

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The problem with the Weber 500 is that it does work nicely out of the box, however on a small capacity engine such as the TV8 it will definitely be over-fuelling to the detriment of your bores.

This carb comes with the standard primary jets of 0.86 and secondaries of 0.95, with metering rods calibrated at 65-52. As an example I was running my tuned 3.9 RV8 with 67-55 rods (which reduce fuelling) and the standard jets, and it was slightly rich at wide open throttle (WOT). When I changed the engine to 5.0 litre, I found that the stock jets worked well, however this was after purchasing a jetting kit and using a Wide Band AFR meter via a lamda bung welded into the down-pipe, and a lot of trialling various jet/rod combinations; thus if the stock jetted carb correctly fuels a tuned engine which is 2 litres greater in capacity, a rolling road/AFR session is definitely a good investment unless you want to cause significant bore wear through over-fuelling.

I found some useful information about the jet/rod combinations and principles on this web-site (it's RV8 oriented, however still very relevent):



http://how-to-build-a-pilgrim-sumo.w...fueling-system

[Kevin Garrod]

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stoutgoose wrote:

The problem with the Weber 500 is that it does work nicely out of the box, however on a small capacity engine such as the TV8 it will definitely be over-fuelling to the detriment of your bores.

I hear what you're saying, what I don't understand is why I'm getting perfectly acceptable CO and HC readings, a good power and torque curve on the dyno and no plug fouling problems if my Weber is over-fueling. What am I missing here?

[grahamb]

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Does driving style have any bearig on how efficient the engine is running with these carb conversions?

[Kevin Garrod]

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It doesn't seem to affect the mpg too much however I drive:?

[stoutgoose]

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The lack of plug fouling is a good 'rough' indicator that the carb isn't significantly over-fuelling; what distance was covered before you checked the plugs (it needs to be at least 50 miles at road speeds for a reasonable indication).

The CO and HC readings; were these at tick-over or on a rolling road; again, if at tick over, this is only using the idle circuit and not the main jets.

Lastly, do you have a carb calibration kit? (available from V8 tuner for around £39). If so, try using the calibration chart from the carb set up instructions/edelbrock website and try the nextstage downand see if it makes a difference, I'd be suprised if you cannot reduce the jets/rods by at least one or two stages with little change in performance.

[Kevin Garrod]

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When I first fitted the carb I took it to a rolling road and after the guy fiddled with it, it was running better and showing a good graph, no jets were changed.

It's been on over a year now and been through an MOT twice, I checked the plugs recently and they look fine.

I reckon you could still be right though, a jet change may improve things further. Especially as I've changed the inlet manifold now.