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blocking off exhaust heat to manifold

t_tuffnut - January 2nd, 2011 at 09:12 AM

Hi,

Just wondering what is involved. Is it as simple as removing the connecting tubing? or do I have to block it off at the exhaust end to prevent excess heat entering the engine bay, or do I also have to block it off at the dog house shroud? Or both?

bugzla - January 2nd, 2011 at 09:24 AM

1 cent piece then back together

HappyDaze - January 2nd, 2011 at 09:59 AM

That sounds like a cheap fix. :lol:

Joel - January 2nd, 2011 at 11:51 AM

Wtf do you wanna remove it for?
It's there for a reason, fuel burns as a vapour not condensed into a puddle on the bottom of the manifold which is what happens with no preheat.

If its just because your preheat is rusted through replace the manifold

t_tuffnut - January 3rd, 2011 at 06:42 AM

I was reading in a book by Bill Fisher - How to Hot Rod Volkswagen Engines, that it was an inexpensive way to generate a few more hp. It is a book from the 70s in which he upgrades different bits of his engine and runs it on the dyno to show the improvement at each stage. He gained 3hp by blocking it off, which isn't much but it is a start.

Joel - January 3rd, 2011 at 07:38 AM

Yea I know I used to have that book, car tuning has come along way in 40 years.
You will also read in it they had to run a cable into the car for a flap so they could duct heat into the carb off the exhaust cos it ran like crap in town.

A few extra HP that you wont even be able to feel is not worth having a car that wants to stall at the bottom of each hill and stumbles on accelaration cause the manifold is sweating.

The worst part is fuel economy sux with no pre-heat.
Trust me I spent way too long messing round with single solexs, webers and holleys before I went twin carbs and didn't look back.

t_tuffnut - January 4th, 2011 at 08:43 AM

So you reckon skip the single holley bug spray and go straight for a twin set up?

Is it a pain to keep them synched? That's what has put me off the twin set up.

Joel - January 4th, 2011 at 09:34 AM

Oh shit yea, bugsprays were the VW enemy of the 70s
i got given one 15 years ago and had a tinker with it, as everyone will tell you theyre all wrong for a vw engine,

They came off a huge 4.5L ford truck engine and have no progression circuit what so ever it's either Idle or flat bickey, no in between

I chucked mine in the bin, stupid move seeing as people are stupid enough to pay $200 for them on ebay now :rolleyes:

millions of people run kadrons and other twin carbs, once you get a feel for sync'ing carbs its a piece of piss, it's usually the linkages that are the let down, they hardly need touching once set.

Stock k-dog one sucks big time

Aussie Dubbin - January 4th, 2011 at 09:50 AM

if youve got the cash why don't you try the dell carb kit craig torrens is selling? Use the topic activity button at the top of this website

HappyDaze - January 4th, 2011 at 09:57 AM

If you don't want sync. problems, go for 'vertical' type linkage - such as the type that Craig Torrens is selling.

t_tuffnut - January 4th, 2011 at 12:34 PM

Tah, thanks for the heads up!

I've lined up a 1600 tp which I'll be buying later this month. The seller said they had some kads to go with it, so I'll ask them for more info first.

Craigs kit sounds awesome, but I need the engine first. I've got a sad 1300sp that is atleast running. The engine I'm looking to buy needs a freshen up, so it will be good to keep the bug running while that is happening.

Thanks for setting me straight on it all. The fiance would have been even more pissed if I had gone the bug spray route only to undo it all and start again when we have a wedding to pay for! She won't believe me that a twin carb set up would be better for us as a couple than floral table arrangements at the reception!

Smiley - January 5th, 2011 at 12:14 PM

Quote:

Originally posted by Joel
people are stupid enough to pay $200 for them on ebay now :rolleyes:

Oh really? :ninja:

Smiley

Joel - January 6th, 2011 at 08:30 AM

Yeah them and DCN/DCNF webers.
Last one I saw on ebay went for $330
Thats 3/4 the way to paying for a set of twin kads :crazy:

I still have a few under the house, maybe i can retire early.
I wasnt expecting the $455 I got for the last SC14 supercharger i sold on ebay either

Craig Torrens - January 6th, 2011 at 09:38 AM

Quote:

Originally posted by HappyDaze
If you don't want sync. problems, go for 'vertical' type linkage - such as the type that Craig Torrens is selling.

Yep a VW motor expands when its hot, meaning the distance between the carbs when the motor is hot is greater than when the motor is cold. The vertical style linkages allow for this expansion as they have a 'non fixed' ball socket on they crossbar. If you have a twin carb setup that has both carbs connected directly to each other (like Kadrons) then your carbs will have a sync problem between hot and cold temps, as the linkage bar does not expand at the same rate as the motor..............thats why you should always set Kadrons at operating temps, which unfortunately means they are out of sync (run like crap) when the motor is cold !

Another good linkage setup is the CSP centre mount which is like a oem type 3 setup, this also allows for motor heat expansion as both carbs are not directly connected :cool:

Joel - January 7th, 2011 at 08:39 AM

Well if you listen to this guy he fkn hates twin carbs but fkn progressives are the best fkn thing ever.........fkn :rolleyes:

http://www.youtube.com/watch?v=Gh3KZsPpJGA&

caution contains just a few F-bombs
Gotta love redneck yanks :lol:

Craig Torrens - January 7th, 2011 at 08:55 AM

that is SOOOOOO funny.......he's been "do'n this shit for 30 years", but he didnt even know how to get the BASICS right with the twin carbs !!

donn - January 7th, 2011 at 09:19 AM

F...kn funny as f...k, f....kn havn't been f....kn entertained so f....kn good in a f....kn long f....kn time, that f...kn bloke is f...kn the f...kn best, f...kn luv him, f....k yeh.

Craig Torrens - January 7th, 2011 at 09:22 AM