Ignition for side draft carbs

[jls7]

Could anyone running dual DCOE Webers offer some advice?

I've recently bought the dual DCOE 40s side draft kit for my e21 M10 from Top End Performance (haven't had time to install it yet), but after doing more and more reading, I'm wondering wether it will run effectively/at all with my stock ignition, or do I really need to upgrade?

(Currently, my engine is a 1982 stock 1.8L with K-jet, and a 4-2-1 header.)

Also, if anyone has any handy tips for the carb conversion, please post.

[e21-Mark]

If you can get hold of a 2002tii dizzy, that'll work OK or you can just blank the vacuum advance on your standard dizzy. You could also run Lumenition or similar?

[murran]

im surprised anyone is still running stone-age ignition, swap it out for something acurate!
very easy to fit lumenition!
http://www.merlinmotorsport.co.uk/p3975 ... _info.html
slightly cheaper on ebay!
http://cgi.ebay.co.uk/LUMENITION-electr ... 2a10b34a6d

unsure which dizzy fitting kit youd need...
http://shop.ebay.co.uk/i.html?_nkw=lume ... m270.l1313

[Jason_323i]

K jet dizzy is electronic on a 323i so probably the same on a 320/4, so need to upgrade just go with what you have it will work but not be optimised

[jls7]

Ok, good to know there are options. I think I'll try to run it as is initially, then upgrade later on.

I know virtually nothing about ignition. What exactly do you mean by 'blank the advance' on the stock distributor?
How do I do this?
Is it relatively easy?

Thanks for the advice so far.

[e21-Mark]

I was thinking of 2002tii dizzy (doh!) so ignore that. As Jason says, the OE set-up should work OK for now anyway. The alternative is OMEX or Emerald stand-alone but that'll be expensive and more than you need - for now anyway.

[thetomc]

I've just fitted a Weber to one of my other cars.

Here's all the advice I can give;

Blank the vac hose feed on the distributor with something. I used one of these;
Item 7 in the following pic, BMW part number 11611437560 . Cost less than a £1 from a dealer.
http://www.realoem.com/bmw/showparts.do ... g=13&fg=15
You could use anything though so long as its air tight.

The ignition timing will need to be advanced from stock. Try somewhere between 12-17° at 1000 rpm. Don't advance it too much until your happy with the jetting. This should be very close already though as its a well proven conversion and TEP know their stuff.

I swapped out the points and condenser for contact-less ignition with a very reasonably priced kit from here;
http://www.mgbreakers.com/accuspark/accuspark.html
You can get these on ebay, just search for the engine you need it for. For you its probably this one;
http://cgi.ebay.co.uk/BMW-316-318-1975- ... 2a0b792aa2
Simple to fit and seems to work well.

Make sure your coil is good. Get a new one if your not sure.

Buy a new set of plugs. Set the gaps as per the BMW spec. Check plugs regularly for signs of running rich/lean

You must use Misab O-ring gaskets and Thackeray bushes/washers to mount the Carbs to the inlet manifold.

One other crucial thing i noticed is that with the latest Weber castings the contact face where you mount them to the inlet manifold via the Misab's might not be perfectly flat. There are some small pressed in metal blanking slugs and these need to be carefully skimmed (I used a Stanley Knife blade to do this. Took about 5 minutes per barrel) so that the contact face is perfectly flat otherwise the Misabs won't seal and you'll have air leaks and the car will idle and pick up very badly. Also check the contact face on the inlet manifold for any imperfections that might lead to an air leak.

Use a new inlet manifold gasket.

Make sure your Brake servo doesn't leak and that the hose is not cracked.

The key to getting DCOE's to run well is all in the detail and air leaks are your worst enemy.

Hope this helps.

Tom

[jls7]

Only just saw your reply there thetomc
- you're a hero.

I started it yesterday, and have been running into problems, big and small, all day. I did weeks of research before starting this, but there are still a bunch of issues that keep popping up.

My main concern was the vacuum advance on the dizzy. So you reckon i just have to seal that hose off and it'll work fine??
(would i be better off getting a tii mech. advance dizzy if i can find one later on?)

My next big issue is getting a spanner to the bottom right bolt on the manifold (one closest to the rear of the car) to tighten it properly.
- how did you do it? I thought about temporarily removing the starter motor to make some room there, but couldn't find the right spanner at the time.

I've got the top end 'soft mount kit' for between the carbs and manifolds. i'll make sure to check the castings for that before i put them on

I plan to get a bosch red or msd coil soon, but my mechanic said he thinks the standard one will be fine for now. same with plugs and leads.
My car already has electronic ignition as standard, so i don't need to worry about that.

Anyway, back to see what work i can do on it now. I can't tell you how much help you've been already.
cheers.

[jls7]

The other question i have atm is about the emissions charcoal canister..
i have a currently loose hose from that that WAS connected to the original intake manifold/plenum. i don't know what to do with it now.
I've been told that the car will smell strongly of fuel if i get rid of it, so i want to keep it, just don't know how to connect it up with the carbs.

Also, should i just plug the fuel return line?

And..... the heater hose(i think?) gets in the way of the throttle lever on the rear carb, and so can only open part throttle. i guess i just need to buy a new bit of hose that curves a different way?

[jls7]

hard-to-reach bolt drama over. I got it tight.

[e21-Mark]

I bought one of the electronic ignition kits above for my mrs 2002. It works a treat and was a bargain at that price imo.

[thetomc]

I've been thinking more about the vac feed on the distributor. I don't actually think it needs to be blanked off anymore. Tried it on my car yesterday and didn't seen to make any difference. The big thing that jumped out at me is the fact you have a return fuel line. It thought they only came on fuel injection e21s. A fuel injection fuel pump will be running at far too high of a pressure for webers. Webers need a feed of about 3-5 psi.

[thetomc]

oh. And the rocker cover breather can just be vented to atmosphere. Buy one of those nifty little K&N style filters to stop any oil spatter covering your engine bay. Strictly speaking your not meant to do this cos of emissions but its not that big of a deal. I.ll post up a photo of what i mean later when i'm at a computer instead of my phone.

[thetomc]

These are the little breather filters i'm using on my Volvo. One for the rocker cover and one for the crank case breather.

[jls7]

Yeah mine is/was a fuel injection model. that's why i have a couple of hoses that don't go anywhere now.
I've already got a K&N breather for the rocker cover (don't need one for the crank)

I finally finished setting it all up. Went to start it with the stock fuel pump running via a fuel pressure regulator (my mechanic told me he thought that would work) but found out that the pump runs at too high psi and just caused leaks in the hose leading to the pressure reg.

Everything else seems to be right though - it was about to fire when i cut the engine cos of the fuel leak.

I have a Carter fuel pump from Top End that came with the carb kit, so i'll just have to install that and try again tomorrow.