Drilling and tapping manifolds

[dannyboy]

Hi all

Finally got round to upgrading my Solex carb to twin Webber ICT34's and an EMPI linkage kit from Eurocarb

But having fitted it all, I can't get it to idle on all four cylinders - it's only using 2 and 4.

From reading around the forums, two fixes for this are suggested:

1. Add a balance pipe between the inlet manifolds (see the post from Moog here http://www.volkszone.com/VZi/showthread.php?t=1033129&page=3); and/or
2. Use longer inlet manifolds so the fuel can fully vaporize properly (see fifth post down here http://www.thesamba.com/vw/forum/viewtopic.php?t=495681)

I strongly suspect the former is the more likely fix. So I've got suitable high pressure/temperature 1/2" fuel hose and 1/4" BSP to 1/2" barb fittings. Just need to drill and tap the manifolds.

• Any advice on how hard this is? Two local machine shops have declined to help....! So fearless me is going to buy a 1/4" tap and the right drill bit (11.5mm?)
• Where is best to drill? Seems the obvious places are bang in the way of the spark plug cables.
• Do I tap all the way through and seal with PTFE tape or red silicone gasket or something?

Cheers all
Dan

 

[rlepecha]

I drilled and tapped it myself exactly where you are talking about. The two round flats on the manifolds. Tap all the way and seal with hylomar blue.

The spark plug wires just fit in.

Sent from my 02_jbla668 using Tapatalk

 

[dannyboy]

Thanks. Think I'll get some elbow fittings which may give marginally more clearance. Also seems sensible to attach the balance pipe to the rear (of the bus) side of the manifolds so it's in sight in case of leaks etc.

Suitable elbows: http://www.ebay.co.uk/itm/321255173815

Dan

 

[trowel]

Don't want to teach you how to suck egg but, the recommended tapping drill for a 1/4 bsp is accually 11.8 so if you are only using an 11.5 make sure you go easy and use some sort of cutting compound like treflex. If you are using a new tap it should be fine, just remember to keep clearing the swarf and don't force it. Good luck.

 

[dannyboy]

Cheers. Don't anyone ever assume I have the faintest clue what I'm doing! I'd much rather look stupid on here than knacker my bus...

I've managed to find an old boy round the corner with one of those workshops that contains about 60 years worth of fabrication kit who's going to drill and tap the manifolds for me.

By the way, crankcase breather (next to oil filler) and petrol tank vent both used to feed into the OEM oil bath filter - what should I do with them now?

D

 

[neilswheels]

A lot of people run the crankase breather into the top of one aircleaner, usually the one on the right. Again a simple bolt in 90 with a nut on the inside of the filter and a suitable length of hose.
Tank Breather can just run down and out of the engine bay, tho not near the exhaust. Bug tank vent tubes just run forward and exit behind the spare wheel well.
I think you'll find the fittings have a tapered thread so the seal as they screw into the hole, but it sounds like that bit is sorted now. Have you got a servo? If so you'll need to hook that up as well.

Just found this pick in forsale section, see filter top for breather hose
http://s126.photobucket.com/user/stuartrx7/media/IMG_2291.jpg.html" onclick="window.open(this.href);return false;

 

[dannyboy]

Thanks, makes sense.

Servo packed up years ago - replacing it will be the next project, at which time I'll tee it into the balance pipe...

D