Fitting two double carbs on 1.3 GT

TheFog · Post by **TheFog** » Tue Apr 12, 2005 10:14 pm

As I'm fitting two double carbs (Solex 40) on my '81. 1.3 (polo mk1), I encountered one problem....or doubt.
What should I do with this exhaust holes on cylinder head that lead exhaust gasses through inlet manifold and as I found out are used for heating inlet and prevent carbs icing: close those holes on head as well as on exhaust pipe or should I connect them like there were with some pipeing?
One guy told me that closing these channels on their exit from head will create rough vortex of exhaust gasses and bad work of that two cylinders and that I should weld them right behind exhaust valves inside cylinder head.
Please help! Thanks!
Here are some pictures to give a better view of what's bodering me:

D4V1D · Post by **D4V1D** » Wed Apr 13, 2005 7:18 pm

get a head from a mk2?

on another note though, have you not found that the 1st carb doesnt clear the brake master cylinder.
this has been my problem and is making me think about selling it

TheFog · Post by **TheFog** » Wed Apr 13, 2005 8:37 pm

I would like avoid buying any additional parts, expeciali such as engine head since this is pretty well "tunned"-polished channals, lowered, etc.
Oh come on, someone must have done this already, I don't belive I'm the first one!!!

Don't quite understand what you're trying to say about brake servo

If you're thinking about the first picture, that's only choke hose stucked inside servo so it ain't in my way while taking that apart. My servo is broken anyway.

ste mk1lx · Post by **ste mk1lx** » Wed Apr 13, 2005 10:00 pm

TheFogDon't quite understand what you're trying to say about brake servo

your car is a LHD mk1 which is fitted with a servo as standard, the uk mk1 Polos did not have one fitted and clearance near the uk master cylinder is minimum hence D4VID's problems when fitting his carb set up

TheFog · Post by **TheFog** » Wed Apr 13, 2005 11:13 pm

there is enough space for both carbs if that's what you're trying to tell me

ste mk1lx · Post by **ste mk1lx** » Thu Apr 14, 2005 12:17 am

looking at your top picture yes there should be enough clearance to fit both carbs.

TheFog · Post by **TheFog** » Thu Apr 14, 2005 9:59 am

ok, we solved that, now we can return to THE PROBLEM

GroovyCarrot · Post by **GroovyCarrot** » Thu Apr 14, 2005 12:01 pm

Are those two ports simply a takeoff from the exhaust on cylinders 2 and 3?

D4V1D · Post by **D4V1D** » Thu Apr 14, 2005 2:45 pm

weld a plate over the holes?

your certainly not the 1st but youve got it alot easier with a lhd car u lucky bugger.

is the car in england?

check out some german sites and see what theyve done...

ste mk1lx · Post by **ste mk1lx** » Thu Apr 14, 2005 2:56 pm

you should be able to block them off IIRC they are inlet ports for spent exhaust gases used for the inlet manifold heating to be reburned in the engine (some body correct me if I'm wrong please)

TheFog · Post by **TheFog** » Fri Apr 15, 2005 4:42 pm

ste mk1lx wrote:you should be able to block them off IIRC they are inlet ports for spent exhaust gases used for the inlet manifold heating to be reburned in the engine (some body correct me if I'm wrong please)

I lurked on some German sites and forums but it's all in german (and I'm weak with it)

I'm from Croatia (D4V1D: this answers your question) and I don't uderstand some english terms that you're using like IIRC(???)

D4V1D: why am I lucky, because of the brake servo?

ste mk1lx: you're right about the purpose part (heating inlet) but intake air channels and these "heating" channels are totally seperated, and direction of flow of these gasses are from engine head through inlet manifold towards exhaust, not the other way around as you said it (if I understood you corectly) - and this is where the problem is: I'm afraid that simply closing these two channels at their exit from engine head would crate eradical creating vortex of exhaust gasses inside engine head -> questionable work of that 2 cylinders... One bloke told me to weld these channels at their beginning right behind exhaust valves, but I'm in a search of a simlier, cheaper solution that I can do myself.

bstardchild · Post by **bstardchild** » Fri Apr 15, 2005 8:16 pm

TheFog wrote:I'm from Croatia (D4V1D: this answers your question) and I don't uderstand some english terms that you're using like IIRC(???)

IIRC = If I recall correctly

TheFog wrote:I'm in a search of a simlier, cheaper solution that I can do myself.

Just plate over them - it'll be fine

TheFog · Post by **TheFog** » Sat Apr 16, 2005 2:16 pm

bstardchild wrote: Just plate over them - it'll be fine

you seem were sure there....

(had an experience with it or just a speculation?)
I'll do that and if it behaves weirdly, then I'll take some other measures.
Thanks!

bstardchild · Post by **bstardchild** » Sat Apr 16, 2005 8:06 pm

TheFog wrote:
bstardchild wrote: Just plate over them - it'll be fine
you seem were sure there.... (had an experience with it or just a speculation?)
I'll do that and if it behaves weirdly, then I'll take some other measures.
Thanks!

No experience on VW - but I've stripped an awfull lot of exhaust gas recirc systems over the years to know it will 99.9% make bugger all difference to the gas flows and 110% the car will run a whole lot better without it....

OK this isn't exhaust gas recirc it's using exhaust gases to heat the manifold but the gasses will always find the easiest route so it probably doesn't do that much anyway......

TheFog · Post by **TheFog** » Sun Apr 17, 2005 10:06 am

bstardchild> ok, thanks
yes, I thought the same that exhaust gasses will simply go to out through exaust manifold more because these channels are much thicker

Just hope that there will be no vortexing to decrease the performance