Oil filter bulge, Jiffy Pop NEW concern, 1 cyl intermittently pre-detonates help! Michigan Build, 2016 Build-Off Options

[Mark Henry]

I love the DCNF, infact I have a set of Gene Berg 42 specials on my '67 bus...but you won't like them on a 914.

DCNF are the ultimate cruiser carb in a straight line, for highway use.
In a 914, as soon as you hit the twisties, every hard corner you will have one carb cut out from fuel starvation. Turn left and one carb cuts out, turn right and it's the other.
Berg did several things to help this issue in his 42 specials, but it didn't eliminate the problem.
I had a set of non -berg 42mm DCNF's in my old VW squareback and just going around a cloverleaf my carbs would cut out.

In a Ferrari or the Maserati (with the Ferrari engine) this isn't an issue, as the carb is turned 90* and the fuel starvation fault is under deceleration/braking. It's how Weber designed the fuel bowl and float to get around this issue.

[Garland]

Mark, I am aware of that but I have read a number of articles that gives some possible and creative solutions.

[Mark Henry]

Mark, I am aware of that but I have read a number of articles that gives some possible and creative solutions.

Link?

Not saying something new hasn't been figured out, but a local member told me the same thing 10 years ago, while rolling his eyes implying I was a debbie downer and didn't know jack shit. He did every trick and battled the issue for 2 years before he gave up and bought IDF's.
Gene berg was a DCNF tuning master and although he did make thing better even he could never fix the issue. Other VW guys have also been using this carb since the early 70's...and they couldn't fix it.

Spirited 914 cornering abilities, which is what the 914 is all about is just too much for the DCNF bowl design.

I love the DCNF's I have used them for 25+ years, I had to buy a whole Gene Berg engine kit to get my 42 specials.
For a highway there's no better carb, I just know and accept their limitations.

[stugray]

Mark, I am aware of that but I have read a number of articles that gives some possible and creative solutions.

Link?

Not saying something new hasn't been figured out, but a local member told me the same thing 10 years ago, while rolling his eyes implying I was a debbie downer and didn't know jack shit. He did every trick and battled the issue for 2 years before he gave up and bought IDF's.
Gene berg was a DCNF tuning master and although he did make thing better even he could never fix the issue. Other VW guys have also been using this carb since the early 70's...and they couldn't fix it.

Spirited 914 cornering abilities, which is what the 914 is all about is just too much for the DCNF bowl design.

I love the DCNF's I have used them for 25+ years, I had to buy a whole Gene Berg engine kit to get my 42 specials.
For a highway there's no better carb, I just know and accept their limitations.

A guy at the track was telling me about a setup in 914s and how he configured the floatbowls, etc. What he was saying didn't make any sense for IDFs, so maybe he was talking about these carbs?
I thought he was remembering the wrong car.

He said that he had a pair setup with no floats, and no float valve.
He said that the float bowls would fill up and overflow into a capture bowl of some sort and be recycled back to the tank.
With that setup there was no float to get stuck or affected by cornering or braking G-force.
(IMG:style_emoticons/default/confused24.gif)

[Garland]

Here's is the track I was following, and it didn't end well. Sound familial?

"Weber DCNF experiences ?
Postby Stufenheck » Mon Feb 17, 2003 8:57 pm
If you decide to use DCNF's, the change that makes the most inprovement is the needle valves from Gene Berg, I only wish I had done that right of the back I would have been done by now.

Back in 1999 when I taught it would be neat idea to install a 2L 914 engine in my Notchback, after scrapping a 74 that was damaged beyond repair, kept the engine and wheels. I had intially taught of using the F/I set up that was in the 914.

A year later I found the short intakes for the 40 DCNF that bolted up to the 914 engine in England. So with limited choices I went with the 40 DCNF's. I had purchased the DCNF's in 1999 for $40 at a swap meet for possible use on a type 3 motor.

3 years and $600+ in carburator parts and linkage later, I've been driving a 1965 Notchback with 2L engine for the past 2 year. It has been a challenge to figure these carbs out.

Dan Zink told me about the STF and it has been helpful in understanding the endevour we each take on when doing this type of engine conversion.

I have experience the fuel boiling/perculating in the bowl when the car stops even in the winter. Sounds like an old coffee maker.

To try and combat this problem I have contacted a vendor that I saw in ad in HVW who makes phenolic spaces for carbs. I'm waiting for a reply. He may not even get back to me due to limited quantity only asked him for two sets. I have a 1/2" thick piece of Phenolic in the garage, I may try to make my own.

Another idea is to get cold air to the carbs. I have some 4" high temperature duct hose that I got from a friend at work. The idea is to get cold air from the interior and plumb the hose from the rear shelf to the top of the engine cover near the carburetors.

So I battle on with my conversion making small improvements along the way.




But this idea I like, have to work on that, a bit later.

"He said that he had a pair setup with no floats, and no float valve.
He said that the float bowls would fill up and overflow into a capture bowl of some sort and be recycled back to the tank.
With that setup there was no float to get stuck or affected by cornering or braking G-force."

[Mark Henry]

But this idea I like, have to work on that, a bit later.

"He said that he had a pair setup with no floats, and no float valve.
He said that the float bowls would fill up and overflow into a capture bowl of some sort and be recycled back to the tank.
With that setup there was no float to get stuck or affected by cornering or braking G-force."

I don't know how you would do this, the top of the carb isn't fully sealed and would overflow the top. It can't be sealed as it requires a vent.

Thing is to me is you could trade or sell the DCNF's on the samba easy and get a set of mint italian IDF's. Then you won't have all the fuching around to do.

DCNF's sell easy, some series are sought after by the Ferrari guys, as they need 6 of them in the same series and the bug guy bought up all the spares. DCNF carbs have many different series, as the tooling wore weber would start a different series. Type one guys also search out these carbs.

Once you modify, drill holes, baffles, etc the carbs can quickly become worthless.

Good luck (IMG:style_emoticons/default/bye1.gif)

[Garland]

Mark, I like your idea I do not plan on trying to modify these after some thought. The thing is I just had them rebuilt and completely gone through so I will just hate to part with such a nice looking pair of carbs

[Garland]

Everything buttoned up and ran for 30 minutes at around 2000 rpm. All good. No leaks, and sounding strong. Doing an oil change, and carb adjust I'll be ready to install in the "build " car. Here the link to Michigan Build / Build-Off Challenge 2015/16

[stugray]

Everything buttoned up and ran for 30 minutes at around 2000 rpm. All good. No leaks, and sounding strong.

What does the oil pressure read at the pressure sender port?

[porschetub]

Everything buttoned up and ran for 30 minutes at around 2000 rpm. All good. No leaks, and sounding strong. Doing an oil change, and carb adjust I'll be ready to install in the "build " car. Here the link to Michigan Build / Build-Off Challenge 2015/16

Nice linkage set up and looking good,funny I took Marks info in about these carbs to be accurate but I have not had issues with these on my 75 1.8 carb T4 (bus motor) powered speedster replica,it has been driven on the road in anger (not legal) and had excellent power out of the corners.
My carbs are different however they are off a European 80's car called the Talbot Alpine and are stamped 36DNVA ,they look like the DCNF maybe they changed the design I really don't know.

[Garland]

Engines running, timed like stock. The only concern I seem to have is one cylinder pops. The engine at idle you can here a small explosion or pop or unburnt fuel mist occasionally on #3 carb. In addition I've had a white smoke briefly twice on hot soak.

Going to check intake valve clearance.

[Garland]

Valve clearance is ok. I back down the timing a bit, and 90% sloved. Can anyone tell me if the timing would be set diffenent with a cam?

[Mark Henry]

My carbs are different however they are off a European 80's car called the Talbot Alpine and are stamped 36DNVA ,they look like the DCNF maybe they changed the design I really don't know.

I don't know anything about them, but they look like the have a 2nd accelerator pump on the bottom of the bowl. (IMG:style_emoticons/default/confused24.gif)