Sand Rail Project

[crowew]

I had a little posting before about my rail, but the title asked for help when I no longer needed it, so I'm gonna keep this one up to date with my project and some updates.
Story:

I've wanted a sandrail for almost 10 years now and finally got one a year ago. The engine had gotten water in it and was rusted in the pistons and wasn't in the rail any more. The chassis had some rust, no brakes worked, and everything was covered in a film of crud. So i took it home (Thankfully the hubs didn't seize while dragging it home) and spent last winter rebuilding the motor in my free time and working on stopping that rust. Finally the rust is dead (mostly) and the engine is rebuilt. I have been combing through the brake and stuff trying to get those sorted out, but I'll post problems and solutions I have.

Interesting bits:

It's got a 1836cc stroker kit on it in addition to a stroker kit, I believe it's right at 1900ccs now.
The carbs are 40DCNF carbs off of a Ferrari 308 GTB
There aren't any shocks in the rear (I have no idea why...)

Here is a video of where I am right now!
https://youtu.be/QX2u99Nn_pg

Current problems: As you can probably tell, the engine isn't running quite smoothly. I believe the carbs aren't properly tuned, which isn't surprising since these are the first one's I've tried to tune, my only other experience with carbs is some SU carbs on a 260Z I used to have.

My brakes suck. I think the rear brakes just aren't doing anything and the fronts just slide because there's no weight there. I'll have to look into that more. I might invest in a dual circuit master cylinder as well.


Any questions, comments, help, whatever is totally wanted. So let me have it!

[Multi69s]

There are a couple of different models of the 40 DCNF carbs. Some have built in velocity stacks, while others don't. Mine are the flat top DCNFs that do not have velocity stacks. However, when you look down the top of the throats, there is a small recessed area at the top. This is where external velocity stacks are supposed to be bolted on. I haven't gotten mine fully jetted yet, but I did notice, that as soon as I bolted on the stacks (got from Berg), it made a major improvement.

Also, Throw up what jets, emulsion tubes, etc, you are running. There are a couple of us playing with jets right now and comparing notes.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
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[crowew]

I'll have to tear into the carbs and find out. When I did the carb rebuild I was just kinda clearing things out and cleaning more than playing with the jets. It'll be a while before I get into that, but when I do I'l be sure to post up what I find!

[crowew]

Another video from yesterday:
https://www.youtube.com/watch?v=V9dJPUOWDDo

[dustymojave]

By the way, the 40DCNF-12 with the cast-in air horns on the carb top was used for the Ferrari 246 Dino. This is the model by far most often used for VW engines and thus PROBABLY what you have on yours.

The 40DCNF-35/36/37/38 or 45/46/47/48, or 56... with the flat top were used for the 308. The dash numbers basically indicate the linkage difference depending on the intended position on the 308 engine which used 4 carbs. There are some minor differences inside,but all 40DCNF carbs use the same jets and gaskets.

The buggy in my avatar ran with a 40DCNF-12 for decades and so did my 65 Baja Bug.

What sort of birds was it you were hunting in that last video? Did ya bag any?

_________________
Richard
Offroading VW based cars since 1965
Tech Inspection 1963 - 2012 SCCA/SCORE/HDRA/MORE/MDR +
Retired from building Bajas, Fiberglass Buggies and Rails in the Mojave Desert. Also Sprints & Midgets, Dry Lakes, Road Race cars. All types New and Vintage
SoCalBajas Member
Kicked Cancer's A$$...1st and 2nd round...Fight ain't over yet.

[crowew]

Thanks a ton for that information. I'm sure that'll help me out when I tear into them.

For now my real concern is being able to at least occasionally stop.

I'll post a real update near thanksgiving.

[crowew]

I keep forgetting to update this thread.

I finally got a pretronix module and installed it so yay electronic ignition. Made a huge difference, just like everyone says it does.

Kinda tuned the carbs so now it idles and doesn't try to die all the time.

It's getting there, but nothing too exciting to update yet. It's too cold to be outside messing with it a whole lot.

It still just doesn't have any power when I floor it 8/10 of the time.

[crowew]

Rail runs pretty nicely sometimes now. I've synchronized the carbs (kind of) and played with the brakes more.

Has anyone had any experience with the master cylinders going out alot? I'm on my 4th one now and they keep just going to the floor after a few months. It's a single circuit cylinder, and I feel like maybe I'm breaking them somehow!

[cbeck]

Have you tried adjusting the brakes yet?