73. 2.0. Original cam,currently running Webber 34.should I go to Webber 40s with original fit cam and get more power and still run well.will 34 Webber manifolds need to b changed.

I doubt you will see any power increase to talk about just changing the carbs to larger ones unless the 34's are way to small which I doubt they are as you are running a stock cam.

34 Webers are singles. The 40's are duals. You'd need new manifolds. IMHO, without a cam change, the 40's won't do much for you except decrease fuel mileage and give you lean transition headaches.

Changing only the carbs will probably result in more problems

Apologies if this is a thread hijack, but I have exaclty the same question, since my 914 is some way off completion I was thinking of putting in my original 914 motor into my beetle temporarily, but with Dellorto 40's.

Obviously there are people who have done this and as you say have had really poor results. I have another new case which i was hoping to build up for something else but youy may have forced my hand, is it really that bad?

In case anybody is curious I was going to use this.

http://www.typ4shop.de/product_info.php?in...4-Geblaese.html

for cooling.


Roman

Nothing is bad about it but with the original FI cam you won't get the performance you're hoping for out of the 40's. Keeping it FI would be optimal. 34's will be easier to tune than the 40's. Carbs like overlap which the FI cam is lacking.

I say no, too many things that can go wrong with all those turns and pulleys and in general 911 fans push too much air for a T4.
KISS is my motto.

Get the DTM kit and be done with it, not near as quick as Jake used to promote, but definitely the quickest method to put a T4 into a bug.

If you are stuck on putting a 911 fan (on a T4) into a bug then the best kit is a Sharpbuilt, does need some minor cutting needed where the cooler is mounted.

The other method if you have welding and fab skills is to do a Cali conversion using two sets of cylinder tins and a beetle fan shroud.

Voice of experience, I have at least a couple dozen conversions under my belt.
My '67 bug is a 2.6 liter T4 with a 901/911 trans, shoehorning that in with no body cutting was a pain, using a regular T1 trans is easy peasy compared to that.

I made my shroud from scratch, copied elements of the DTM and the Cali, all metal.

Carbs + Carb Cam = OK
Carbs + FI Cam = Not OK

40's would be minimum for a cammed 1.7 - 1.8 build.

Eric is spot on (as usual). Unless you change cams, you'll be disappointed in the results.

Many thanks as always.. looks like I have to spend some money. Not good.

You will get no performance gain going from the 36mm to the 40mm webers on a stock engine. Not worth the investment unless an upgrade is in the plan.