carb conversion thread, could be classic Options

[machina]

found some sporadic info doing a search but is there a comprehensive faq on converting to carbs covering stuff like:

which carbs
which linkage
which dizzy (mallory)
which mallory (there are about 8 types at CB perfomance
which ignition to use if you want, MSD,...

no need to tell me about why it is so great to keep the FI

thanks,
dave

[pat4]

Here is my contribution to the debate, according my choices for rebuilding my 2.0 this winter :

- which carbs: 2x Weber 44 IDFs with velocity stacks and 6" air filters
- which jettings : venturi: 36 mainjet: 155 Air correction: 200 Idle: 60
- which fuel pump: Mitsuba 4psi regulated located in spare tire compartment
- which linkage: CB Performance Cross Bar Linkage
- which dizzy : not Mallory but Bosch 050
- which ignition : MSD 6A (#6200) with tach adaptor

- which coil: MSD Blaster 2
- which C/P : stock 94mm cylinders + 94mm VW Type 1 forged pistons (100gr. lighter each than Type 4 pistons) and that increase CR up to 8.7
- Which camshaft : Webcam #86a (290° duration)
- Balanced pistons and rods (adjusted weight)
- Lightened and balanced flywheel
- Balanced crankshaft
- Mittelmotor stainless steel exhaust or Triad exhaust
- New lifters, new heavy duty springs
- Three angles job on valve & seats
- Polishing heads ports
- Combo gauge Oil temp + Fuel level
- Oil pressure gauge in center console
- Large breather box

Expected power: 115-120 hp

[MJHanna]

If you run MSD run their dizzy

[thesey914]

Dave, good idea! Best carbs for 1.7 /1.8/ 2.0 with relevant jet/choke size info. Also which fuel pump and where to /mount wire it up.
Are the manifolds all the same (I mean apart from 3/4 stud)

My 1911 has Dell 45 with CB hex bar linkage ( I think -see pic ) which works well.
Distributor is 914 1.8 f.i. with vacuum advance operating - retard is plugged.
Just use an Ignitor for spark although MSD or Crane capacitive discharge would be the way to go.
Pump is just a plain old Facet which is wired to the relay board and mounted on the firewall -I reckon front trunk would be a good place.
Always worth match porting the manifolds to the heads too.

[fuch toy]

44s are normally a little big for stock bore mild cammed motors. "I" would use 40s. 44s can be necked down but you need to do homework on set ups....no two engines are alike. The "book" can give you a starting point but a lot is tweeking, balancing and reading plugs.

BTW....my 2.44 has the 44s and I like them.....does about 18 mpg. Uses an 050 dizzy and a Crane Fireball system.

[pat4]

I added to my previous post informations about carburetors jetting, fuel pump ...

If you run MSD run their dizzy

Why ? I do not want a drag 914 but a street car. The MSD PN 8485 allows different advance curves and different total advance from 18° to 28°... The 050 is well known to match type 4 engines characteristics and it is $80, not $ 200 (IMG:style_emoticons/default/rolleyes.gif)

So, I agree that 44s are a little bigger but I have them at this time. The mixture will be probably a little bit too rich at low RPMs. It is the reason of the MSD system choice. The multi sparks system will help to burn all gas under 3000 rpms ...

[SirAndy]

Expected power: 115-120 hp

what's the expected price-tag?

that might be of interest too ... (IMG:style_emoticons/default/wink.gif)
Andy

[pat4]

what's the expected price-tag?

Not really easy to answer before open the engine. If heads are nice it will be cheaper than if they are cracked. etc, etc ...

I will answer definitively in March

[Brad Roberts]

What if we had a laptop programmable injection system that utilized all the stock injection components except for the pressure sensor/throttle position switch for the same price (if not less than a carb kit/dizzy) The system also has multi coil packs like late model cars triggered from a dummy dizzy in the case. Open the engine lid and all would appear stock.

If your car currently has injection... it is plug and play. We can email you engine programs that get uploaded and make it run. Tuning time will be less than a set of carbs (stock cammed engines will run perfectly out of the box).

I hate carbs.


B

[bernbomb914]

The hell with the what ifs. when and how much?

Bernie

[Brad Roberts]

Bern,

It is being tested currently. I will have 1-2 cars with me at Dunkels with it installed.


B

[cgnj]

Brad,

Any chance of this working on a 2270? Hang on to my L-jet and D-jet stuff?
Maybe next spring.

Carlos

[Brad Roberts]

Carlos,

The plan is to make the stock injection pieces work with the 2270 and our new "brain".

Andy has been doing the math on the stock 2.0 plenum/injectors/runners.

We feel that there is NO reason why stock components cannot be used with a RAT 2270.

I'm currently gathering the pieces/parts for a 2270 utilizing the 2.0 plenum/injectors/runners and this new "brain" setup.

Stay tuned. Test results will be out soon. This is not something that you will have to solder together. This will be plug and play.

Since the advent of inexpensive programmable injection I have wanted to do a system that could utilize 90% of the stock components but have late model parts mixed in to help keep the cost down of having injection. 550$ pressure sensors dont really excite me when dealing with the old injection. So.. we actually started down the path of finding something we could market/sell... then we found a person way ahead of us in development and basically partnered with him. With Jake Raby building these "moster motors"... we need an injection setup that can cover his combo's. The best part is: not having to remove/replace any of fuel pump crap...


B

[pat4]

If your car currently has injection... [...] I hate carbs.

Brad,

My car lost the EFI in a past life. And this engine had many hard lifes during the previous 30 years !

It is the reason I want to rebuild it and have know and sound foundations about it.

[bernbomb914]

Brad I am putting together a 2258 rat with reworked heads, split-durition cam, etc. I have both a L jet and D jet system and would be willing to be one of your test beds here. Think About It.

Bernie (IMG:style_emoticons/default/driving.gif)

[Brad Roberts]

Pat,

You have done some very good homework on locating what exactly needs to be done for your combination. I was basically answering the original post from synthesisdv (Dave). I knew he still had the original injection and instead of installing carbs I was offering a him a decent solution that would allow him to keep most of his parts.

I went thru your list.. I couldnt find anything you didnt cover.


B

[machina]

I was basically answering the original post from synthesisdv (Dave). I knew he still had the original injection and instead of installing carbs I was offering a him a decent solution that would allow him to keep most of his parts.

Brad, your system sounds great but would bump me out of class. We can run carbs in vintage and in production.

EP and FP allow for weber 40 IDF, solex 40, or 40 dell's. Says original injection also allowed but has to be entire original system. Up to 38mm chokes are allowed.

Sounds like you can machine the weber 34mm venturi to 38mm. I would like to stick with the webers just because of parts availability and I can still get them new.

thanks,
dr

[Part Pricer]

I don't know much about carbs, but why not just buy a kit? Weber has the whole thing, new and packaged for $675. The kit comes complete with two new 40 IDF carburetors, manifold adapter, linkage, chrome air cleaner, hardware kit and fully illustrated instructions.

(IMG:http://www.redlineweber.com/images/kits/VW/K1347A.JPG)

[machina]

I don't know much about carbs, but why not just buy a kit? Weber has the whole thing, new and packaged for $675. The kit comes complete with two new 40 IDF carburetors, manifold adapter, linkage, chrome air cleaner, hardware kit and fully illustrated instructions.

thanks paul,

that is part of the plan, but I was really inquiring about the other components like the dizzy, ignition, cam, etc that go along with it. And also how to set up the carbs. I think aircooled.net will set up the carbs for your application for an extra $100. Maybe its worth it for us amateurs to get a baseline.

dr

[MJHanna]

If you run MSD run their dizzy

Why ? I do not want a drag 914 but a street car. The MSD PN 8485 allows different advance curves and different total advance from 18° to 28°... The 050 is well known to match type 4 engines characteristics and it is $80, not $ 200 (IMG:style_emoticons/default/rolleyes.gif)

No points, plugs directly into a MSD 6AL and you can adjust the curve to what you need. (IMG:style_emoticons/default/wink.gif)