DIY - Triple Weber install

OK I have pulled the trigger and am heading to the Dark Side with a set of Italian triple 40 DCOE webers - I will be detailing the trials and tribulations of rebuild and install in the coming weeks. I love my Zeniths but am fascinated with the plumbing and exotic potential of 3 side drafts. So for this experiment I am thinking:

-Ramflo style foam filters for brake booster clearance (or are low profile paper filters better?)
-Carter 4070 low psi/high volume pump mounted underneath and heavily insulated/isolated for noise reduction
-Regular base gaskets instead of soft mount o-ring ones
-metal can fuel filter
-inertia cutoff switch
-old mechanical fuel pump cover plate from Carl N.

I would appreciate hearing from current triple owners on any tips/advice to consider so I minimize noob mistakes.

Do I need to relay the pump and/or how should I wire it?

What else to consider (besides saving for gas money)?

I want max induction music :mrgreen:
 

Stevehose

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Cool...so I just stumbled on a very rare and valuable Alpina induction system worth more than my car :razz:

What about the vacuum ports - suitable for advance?


http://www.bmwe21.net/forum/viewtopic.php?f=2&t=17191#p176021


German importer of Webers. Been around since the cars were new. Rumored to be some collaboration with Alpina. Definately did some interesting things for the hill climb boys with downdrafts.

Still in business.
 

61porsche

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Before

or after the butterfly ? will answer the question. I have a feeling the answer is yes.
 

Stevehose

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Will check this evening - I am not getting much work done today...

or after the butterfly ? will answer the question. I have a feeling the answer is yes.


If not Alpina it appears that GS tuning used these, my manifold and linkage are identical to this, and apparantly there was also an airbox available:

mote9gs197201.jpg

Bf4hrBQCGkKGrHqUOKisErzizjoH5BLDCsC.jpg
 

jmackro

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So for this experiment I am thinking:

-Regular base gaskets instead of soft mount o-ring ones

By "regular base gaskets" do you mean simple, paper gaskets?

I use dual DCOE's on my Alfas. The lore in Alfa-land is that there needs to be flexible mounts between the carbs and manifold to isolate vibration. Otherwise, fuel in the carb bowls will froth, and/or the mounting "ears" on the carbs can develop fatigue cracks.

Transmitting vibration to the carbs may be more of an issue with a 4 cyl engine than with a 6. But on Alfas we either use the factory-style flex mounts (see photo below) which have quite a bit of rubber between the two steel faces, or aftermarket mounts with O rings.

3945_0_0.jpg
 
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Stevehose

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I've seen the info on the frothing etc. but also some that says these flexible ones can leak air? The gaskets I am looking at are about 1/8 - 1/4" thick, not paper ones so hopefully some heat and vibration damping will happen. If not I will go with the flex ones if you feel that they hold their seal well over time in the heat of these engine compartments.

By "regular base gaskets" do you mean simple, paper gaskets?

I use dual DCOE's on my Alfas. The lore in Alfa-land is that there needs to be flexible mounts between the carbs and manifold to isolate vibration. Otherwise, fuel in the carb bowls will froth, and/or the mounting "ears" on the carbs can develop fatigue cracks.

Transmitting vibration to the carbs may be more of an issue with a 4 cyl engine than with a 6. But on Alfas we either use the factory-style flex mounts (see photo below) which have quite a bit of rubber between the two steel faces, or aftermarket mounts with O rings.
 

jmackro

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I've seen the info on the frothing etc. but also some that says these flexible ones can leak air? The gaskets I am looking at are about 1/8 - 1/4" thick, not paper ones so hopefully some heat and vibration damping will happen.

What are the 1/8 - 1/4" thick gaskets made from? Something rigid like phenolic would provide heat isolation, but not much flexibility. Neoprene maybe. You need something flexible on both sides of the carb mounting - those mounts with O rings generally have a short, stiff spring (called "thackeray washers") on the air filter side that look like:

.
thack.jpg


If not I will go with the flex ones if you feel that they hold their seal well over time in the heat of these engine compartments.

I'm no expert on installing sidedrafts on BMW 6's. I use the factory flex mounts on my Alfas, but those require an intake manifold with the mounting holes offset (notice how the two pairs of studs on the mount shown in post #25 are not aligned). So, that style of mount wouldn't work on a BMW manifold.

The flex mounts that employ a large O ring to provide "give" are prone to leakage. And the O rings tend to swell from exposure to gasoline, making them difficult to re-use. So I can't really recommend them.

Bottom line: It would be great to hear from someone with experience in installing DCOE's on a BMW 6. Are flexible mounts necessary? And if so, what type have you used?
 
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Stevehose

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I don't have the gaskets yet so I don't know what they are made of. I also read that the soft mounts need a carb support because the carbs can bounce up and down without one. I would also like to hear others chime in on what they use for the gaskets.


What are these 1/8 - 1/4" thick gaskets made from? I wouldn't think that a phenolic gasket would provide any flexibility. Neoprene maybe. You need something flexible on both sides of the carb mounting - typically an O ring on the engine side, and a short spring on the air filter side.



I'm no expert on installing sidedrafts on BMW 6's. I use the factory flex mounts on my Alfas, but those require an intake manifold with the mounting holes offset (notice how the two pairs of studs on the mount in my photo are not aligned). So, that style of mount wouldn't work on a BMW.

The flex mounts that employ a large O ring to provide "give" are prone to leakage. And the O rings tend to swell from exposure to gasoline, making them difficult to re-use. So I can't really recommend them.

Bottom line: It would be great to hear from someone with experience in installing DCOE's on a BMW 6. Are flexible mounts necessary? And if so, what type have you used?
 

Stevehose

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Looks like the holes are between the manifold and the butterfly which indicates manifold not ported vacuum - bummer - so what purpose would these be for?

or after the butterfly ? will answer the question. I have a feeling the answer is yes.
 

JFENG

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In my experience, no

I ran dcoe's on BMW sixes and fours without the fancy vib isolating mounts for a combined decade and never noticed any frothing and float bowl level issues. An insulating gasket, however, is a good idea (thermal). Yes i4's do have a lot more vib (big second order harmonic), but my 2002's with dcoe's ran faultlessly thru five years of Michigan weather (all four seasons) without any issues. My experience with dcoe's on sixes was even better.

If the isolating gaskets had no down side, I'd say used them. But, if they tend to leak it could put your engine at risk. Why not try it without first as you can always add them later I'd you wish.
 

Stevehose

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Fuel pump installed

After several trips to 3 different brands of auto parts stores for some fittings etc, the fuel pump is in, isolated with rubber bushings, and wired:

IMG-20120602-00474.jpg



I wired the power lead through the trunk and back through the interior to a cutoff switch under the hood which detects rpm (thanks Nicad). The fuel hoses come through the existing hole in the trunk into a pre-pump filter then to the pump then back to the regulator:

TInljebfYptp-pKsj9M1k3baBAdCaRtAFQ5hlkf8rHgY16cJm0ZdfbQqR9SBX0-VH2tF0GwxYhSlqAPz08CgWE96JRQyE7Jyc8Nwc3xzmIyHIxk3Y3tQAO9SOczwyXkIBvvjfzDzpVQ3CG6YMfPAY9uAt8JZqHyovCEjVhXGyTrkq99S0AbSZlh9tcLslGkY81yUtNnfShS_SW0PFEjAPO-1ns8kvsFTPyI6hesQFAf8iLZybX-Wd-flxffaFxYOmoVPjd_T-8JSWfx1cqNQdy8Zcts_DdHM9PlReCq5Anm3gDBB10Zc2MywiDfCENBQB08wuGFdqxsX_sGFlOqsAJ5wO80e9E_mRYWFB53X16HJok5M4dpA3-4xd9c1tmtreCYVOrYvmu-GX5a3s1GijR5Xday3sCeRlSAsbO_asJhtQ-GkfUb7QbSO-Arw_1258rIsfMjCPaJod-weWBnkdV5vsE42XXo17iyxUCw0SchmOhaYCuecRHBRg3R-J8ec8ftGtpQgvlu_v5QpHJ1SgXP3zw5jAV9BItRWzwZWOId7gWMdNEuSmqRiQ6Y5yGcPxRre=w879-h659-no


Waiting for new phenolic spacers (was sent the wrong ones) and linkage from Pierce so hopefully these will be installed next weekend and I can install the manifold and the carbs and work towards firing it up.
 
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Nicad

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Check to see if 123 make a BMW distributor.
http://www.123ignition.nl/

How can they make one for a Citroen and no BMW six listing? Anyway, certainly looks like an interesting product. I was wondering if people running the standalone ignition side of a megasquirt had much success with webers?

Nice looking air box Steve. Never seen a photo of such a box. Did you buy it, or just contemplating buying it? Also, are you planning to glue the connectors to the Carter fuel pump? At this point, mine just fall off if I look at them. ( I must have taken them on and off 20 times while installing my pump in the trunk. ) I like the spot yours is installed.
 
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Stevehose

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Unfortunately that's not my VGS airbox but I have a eBay.de autosearch for one, and a member here has one he is checking fitment on.

I did put a dab of epoxy on the connectors to hold them tight.

The install instructions say to mount the pump as close to and underneath the tank as possible and this location seems to fit the requirements nicely, as well as provide some noise reduction and vapor lock prevention.

Nice looking air box Steve. Never seen a photo of such box. DId you buy it, or just contemplating buying it? Also, are you planning to glue the connectors to the Carter fuel pump? At this point, mine just fall off if I look at them. ( I must have taken them on and off 20 times while installing my pump in the trunk. ) I like the spot yours is installed.
 

61porsche

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My opinion

is that for those who aren't particulary tied to originality, megajolt or megasquirt can better control your spark than a distributer. Both are mappable which means you can tune for a given parameter of running.This represents the best compromise for those who have or wish for webers but also have the advantage of Fuel Injection on the spark side. It requires the same setup from a damper standpoint of triggering. It appears to be a relatively cheap solution for some applications.

I guess the best response is to listen to the others that have made the choice- a little more power, better idle, etc. But not least is that the wear factor goes away ( mostly) and you can change things as you upgrade for more power.

There's nothing wrong with a well set up distributer either. On triples, It's my opinion to recurve and convert to mechanical advance. Preventative maintenace is the key to keep things working well. Like that drop of oil for your advance plate even if you have Pertronix.

We all benefit from technical advances when it comes down to making a choice. In the end it is just a choice for each of us.
 

Stevehose

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Fuel pump controller

This may be of interest to those with electric fuel pumps, it is a cutoff switch in case of an accident and for cold starting it pumps for 3 seconds before shutting off if it doesn't detect a tach signal. This allows for priming of the carbs which an oil pressure sensor lacks and it's easy to install. Has a resettable circuit breaker built in. I needed to install a diode between the ground and the power input (supplied in the kit for certain situations-mine would not cut off) and the tech support responded quickly over the weekend. Haven't run with it yet but it tests out and all seems good. Available on eBay for $60.


http://revolutionelectronics.com/Fuel_Pump.html

shapeimage_2.jpg
 

Nicad

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One thing you might add Steve is an Impact cut off. You could get in an accident that causes a fuel leak and have the engine continue running and Pumping fuel. The Ford one used in Mustangs, Crown Vics and Town Cars, etc. is very cheap. I have one I'll incorporate. I wished I'd gone this electronic route on mine rater than the oil pressure switch shutoff.
 

Stevehose

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I have read about those and probably will intall one as well, add it to the $$ list!



One thing you might add Steve is an Impact cut off. You could get in an accident that causes a fuel leak and have the engine continue running and Pumping fuel. The Ford one used in Mustangs, Crown Vics and Town Cars, etc. is very cheap. I have one I'll incorporate. I wished I'd gone this electronic route on mine rater than the oil pressure switch shutoff.
 
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