Looking for advice/info re: my webers -- stay or go?

[mimregi]

http://www.classiczcars.com/photopost/showgallery.php?ppuser=8707&cat=500

I just added a bunch of pics of my carbs to my gallery (the "my carbs" photo album does not appear to have photos in it... not sure how that works). I have been kicking around what to do next (carbs need a rebuild at minimum, may be an excuse to go to SUs, and I need to educate myself on tuning and maintaining the carbs -- I want to make that investment into whatever system I am going to have for the long term). Trying to figure out a few things...

-I have been trying to figure out for a while what I even had... weber DGVs on cannons is my best disgnosis after a bunch of homework (http://www.webercarbsdirect.com/inc/pdetail?v=1&pid=76). The site lists them as "32/36 DGV 5A" -- anyone clue me in as to what the numbers designate (if more than just an arbitrary model number designation). Of course, if anyone who knows these things really well can tell me that I am mistaken about the model altogether, please educate me =)

-If I do invest in some round tops, will they mount properly on the cannons? I am currently the high bidder on a set of round-tops off of a '71 (I figure even if I dont use them in the car, I can take them apart and learn a thing or two)? I dont know if they are the four screw or three screw model, but I don't figure it much matters at this stage (does it?).

-The bulk of folks here seem to be big believers in teh SUs, but cost being a factor for me, can anyone with any experience with the DGVs share a story or two about how much they loved or hated them and why? I am really jazzed about pulling the carbs and working on them, but I don't want to spend money I don't need to, and I don't want to spend a huge amount of time on something is it isnt the right thing.

Thanks!!

-m

[jmortensen]

I think 32mm/36mm are the sizes of the primary and secondary holes in the DGV's. Kind of like 44 Mikunis or 45 Webers.

You'll have to take the question mark shaped Cannon manifold extension off of the stock manifold to bolt the SU's on, so no problem there.

Any round top SU in good shape will perform better than DGV's IMO.

[EScanlon]

FWIW: When I bought my car it had Webers. Mileage was awful (like 10mpg), performance was....well, I wasn't buying the car for what performance it ~had~ at that time, and it took a l o n g crank to get the car started.

Took the car to a specialist in Datsun (M.B.Anderson), he said that he could ~probably~ get them tuned "somewhat", but that he would neither warrant the tune up, nor stand behind the engine tune-up, simply because of the problems he knew the Webers caused. He recommended I swap them for a pair of "regular SU carbs" "just like it came with originally".

I bought a pair from a boneyard and had him clean and rebuild them then replace the Webers with them. That was ....4 years ago, going on 5. I've not had problems, my mileage is up to 20-24 (on occasion I do idle the engine without driving), it starts even on cold days with relative ease and it accelerates very nicely.

So, FWIW, I recommend the SU carburators.

I'm not a mechanic and I'm sure that someone else feels differently about the Webers. Since I'm not into racing, neither street nor track, the putative claims of more power (when tuned right) or acceleration (again when maintained in tune) without reference to gas mileage, weren't sufficient for me to maintain them. Also, since I don't mess with the engine mechanics, I needed to adjust the car in order for a REAL mechanic to willingly work on the vehicle.

So, hope this helps you make an informed decision.

Enrique

[Arne]

I do perform all my own mechanical work, and I'll second Enrique's comments above. While it is possible (but still subject to debate) that the Webers - if properly set up and tuned - MIGHT deliver more performance, the sad fact is that they are far more complex that the SUs, and getting them to run optimally takes a specialist who really knows how to tune them.

On the other hand, SUs are a very simple device, with a very limited number of variables. While I don't have a clue where to start on properly jetting a pair of Webers, I totally understand the theory and operation of the SUs, which means I can set them up and tune them myself.

My car had a hack-job '83 fuel injection on it when I bought it. The person who installed it messed it all up badly. I either had to redo their job, or go back to carbs. If I went to carbs, I could install anything I wanted. After looking to ease of install, tuning and future maintenance, I went back to the original SUs. While my car isn't on the road yet, I'm still happy with that decision.

[mimregi]

You sound like me =) The car is basically fast enough for me at stock, I'm not trying to eke extra horses out of it (of course, I want it to run powerfully, but I'm not racing it, nor do I even get on it all that much). MPG is a concern for me.

I should have included this info in the OP, but it's worth saying that I am getting decent performance, it starts fine 85% of the time (sometimes takes some more cranking, sometimes gives me bad white smoke, usually starts very quickly) and I am getting around 15 mpg for the most part. I get some rough running sometimes like the timing is a bit off, but this is often solved by a few strong revs of the engine.

I appreciate the input though. I am still leaning towards the SUs if I can find a way to do it affordably. Any idea if they will bolt on fairly cleanly? Looking on e-bay, what exactly should I be looking for? Mine is a '73...

[Arne]

The Canon manifold adapters bolted up to the original SU manifolds. So once you remove the Webers and manifold adapters, you should be able to bolt up the SUs very easily. Looking at your pictures, you should be able to use the existing fuel rail, although new fuel lines may be needed. The linkage for the Webers on the manifold would need to be swapped for the appropriate Datsun parts. You will also need the insulator blocks for the SUs.

Since the base manifold is a '73, the easiest swap would be SUs from a '72, since they are fitted for the water passages that your manifold has. If the coolant to the manifold has been removed already (or you would consider doing so for the swap), the '70-71 SUs will go on just as simply.

[mimregi]

I'll bave to check on the coolant manifold, I know one of the previous owners had done quite a bit of work (this car was raced at one point before being restored for street use). I lost an auction on a set from a '72, the ones I am bidding on now are from a '71, and if I decide to go that route, I'll do what I need to fit them in.

Thanks a ton for the info =) Happy to listen to anything else you (or others have to say)!

-m

[mimregi]

OMG Arne I just realized who you are! I have read nearly your whole site =) I actually forwarded it to a friend with the note "this is EXACTLY what I would like to do at some point". You are an inspiration!

Quick update -- I was just outbid on a third set of SU's and have a better feel for what that will cost me. I definitely want to move to the SU's, but at this point, I am going to order a $25 rebuild kit for the webers and a couple of books and see what I can learn. I may still go to the SUs in the long run, but this will be a good learning experience for me =)

Thanks all! Still happy to take any advice/anecdotes.

-m

[Arne]

OMG Arne I just realized who you are! I have read nearly your whole site =) I actually forwarded it to a friend with the note "this is EXACTLY what I would like to do at some point". You are an inspiration!

Well, thanks for the compliments! Although I must say that judging from the pictures in your gallery, your car's body is in much better shape than mine is. Anyway, I'm glad you've enjoyed my car's story so far.

[cremmenga]

If you guys need su's or webers I have both!!! I have dual webbers on my parts car, it does run and well at that!!! and the engine I pulled out of the car i'm restoring, was said to be an L28 with the su's but i'm not sure if it is an L28 or a L24. Anyway I need to get rid of both engines and get them out of my friends garage so if you guys want them or just the manifolds and carbs, shoot me a price!

[mimregi]

...I must say that judging from the pictures in your gallery, your car's body is in much better shape than mine is. Anyway, I'm glad you've enjoyed my car's story so far.

Wish I could take credit for that =) I got a real find, someone did a helluva job with it, I am just doing my best to keep it up!

I've already at this point bought rebuild kits for the webers -- decided to try the less expensive route first, see how it goes. I would like to see if I can get them running well and keep on top of them, shold be a good learning experience.

I really wouldn't mind at all having a set of SUs as backup or just a project on the side, but you could probably get more for them on e-bay then I have to spend (i was bidding as high as $125 not including shipping etc. and consistently getting outbid, generally into the $170's). If you want to blow them (or the webers for that matter) out cheap (in the $100 range), I'll take them off your hands, but I am hesitant to out and out make an offer -- don't want to insult you

The only other major thing I am really looking for is an AC system, if you have one on an extra car.

-m

[Dickf]

Nice photos. I enjoy seeing what other's engine compartments look like.

I've got a couple of questions about the photos then I'll discuss the carburetors. First, what kind of fuel line/connectors do you have and where did you get them? I really like that look and want to do something similar.

Also, where did you get the bolt covers. They look really nice.

I have a 73 with the original engine although it has been re-built. These cars originally ran very lean because of the implementation of environmental regulations. Thus a previous owner changed to Weber DGV carbs. Since I took possession of the car a couple of years ago it has never really run well; but I wasn't driving it that much and had other priorities so I didn't try to address the issue. This fall I started working on the car and knew that the carburetion was one of those items which I would have to address.

I went through some of the soul searching which you have described - should I work with the Webers or change to SUs. After a lot of research and reading opinions on line, I decided to stay with what I have and try to make it better. Although they aren't particularly liked by the Z community, the Webers seem to be quite popular with other communities and, of course, they have a rich racing heritage.

Anyhow, my car was getting poor gas mileage, didn't start particularly well, and didn't accelerate smoothly. I decided that I would start by looking at re-jetting the carbs. In doing some research I have determined that (I think anyway) the jetting is way off. Way too rich. I bought some jets and changed them out, but still didn't get the response that I was looking for. The car started better and the gas mileage was better; but the smoothness still was not there. Thus, I have just recently decided to rebuild the carbs. Probably should have done that the first thing, but I'm cheap. Anyhow, as of last evening, I have one carburetor re-built and I'm starting on the second one.

The beauty of the Weber carbs is that they are really quite simple and very adjustable. The latter, of course, is a blessing and a curse. After reading and researching though, I am confident that I can make them work. Don't get me wrong, I know that it won't be an easy or quick process, but for me it is a learning experience. From my reading it appears that you need to tune these carburetors in the progression order as everything builds on the prior progressions. That is: Primary Idle (Progression) Jets, Primary Main jets, Secondary Idle (Progression) Jets, and then Secondary Main Jets.

The jury is still out, and I may yet change to the SUs or to Fuel Injection sometime down the line, but for now I'm learning a lot about this car and enjoying the challenge.

Good luck with your project.

d***