Duffman

No, CO, I did not create a thread about this in the past. I read other threads about fuel levels, fuel pressure, etc. I even learned how to rebuild SUs and bought old sets, rebuilt them and sold about 15 sets on eBay! I learned a lot about how they worked, but I could never get my SUs to attain desired performance on my Z. I guess after a while I just decided to live with it! My triple Weber adventure taught me that I can get more from my Z than what I was able to get with SUs. There had to be something I was missing, that other people were able to attain great results with SUs and there was no reason I could not either. So, pursued a variable I thought would make a difference and solve my problem; needles that allow more fuel on acceleration or WOT!

Thanks, Phil, I should have included the link! Sent from my iPhone using Classic Zcar Club mobile

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CP or Competition Products is the name on eBay, but the direct website is sumidel.com, they provided the SB needles for around $40 delivered to Arizona.

I am one of the many Z owners, with SUs, that has battled a lean condition on hard acceleration, or WOT. My idle and cruise AFR readings (have AFM attached to header) are great at 14.5 or so, so have adjusted it as best as i could. Along with SM needles, I adjusted fuel levels and tried to do anything I could think of to resolve this issue, to no avail. I even switched to triple Webers, which allowed me to see how my car could really perform with appropriate AFR! I decided to switch back to SUs, as I had some linkage sticking and fuel dripping that bugged me. So, I started looking into the different available SU needles to see if I could find something richer. I looked at various charts and saw that the SB needle had the same configuration at the top two levels (so idle is the same), and was slightly richer heading down the needle. I thought, let's give it a shot! I could not find anyone locally that provides SB needles, so I went down under to Australia and ordered a set of SB needles from Competition Products for about $40 delivered (less than 2 weeks for delivery). I was stunned at the improvement! My idle and cruise AFR remained around 14.5, but my lean (16 to 17+ AFR) condition at WOT was gone, now hitting around 13.5 AFR!! That is ideal! I cannot believe the difference. My L28 was rebuilt with flat top pistons years ago, but outside of that, there is nothing else outside of the norm. I would strongly recommend this solution to those with similar issues! I strongly urge you to make sure your fuel level (and flow) is appropriate before you go this route, as that can resolve many of the lean issues.

Very cool, Phil! My buddy, Randalla, created the Float Sync tool that is used with SU carbs that looks similar to this. He is now looking to make more of them for sale to the Z crowd!

Thx, Ollie, very well could be the factory position, mine comes out under my firewall carb linkage. Sent from my iPhone using Classic Zcar Club mobile

Ollie, where are your choke cables coming out of your firewall? You have the cables coming over the top of the engine, just wondering if they are going out of the normal driver side firewall opening, or you moved them over to the passenger side. Also, like the cable clamps on the valve cover!

Thanks, Ollie, for being the guinea pig for the group! I am always interested in new carb balancing tools!!! Sent from my iPhone using Classic Zcar Club mobile

Impressive results! Congrats, for all the efforts!!

Wow, nice fit! They look great!!

James, I have a set for sale, they are too deep for me. I believe the studs can be removed, will have to look and see how it can be done. If you send me an email address, I can send you pics of the spacers and you can see for yourself.

Absolutely, following along to increase my limited knowledge, even though my triples are pretty well set. Love the tinkering with jets, etc!

Thanks, Stanley and Jarvo2, appreciate the responses! I was just told it is not the needles, but the nozzles, which are difficult to find new. I guess Ztherapy will rebuild your used ones, if you send to them. My friend is reluctant to do so, so he is finding a set of used nozzles to send in to get rebuilt. That seems like the best answer so far!

A friend of mine is renovating a Z for his son (that is love!!). He reached out to Bruce at Ztherapy and found that there are currently out of SM needles and nozzles, not sure when new stock will be in. I have looked at other sources, without much success, and was hoping someone might have any ideas? Thanks!

I have some 25 mm spacers, not quite what you are looking for.

Just bought the volume deal from Spruell, 10 for $30. Unfortunately, the DCOE jets were all sold out some time ago, they said. Sent from my iPhone using Classic Zcar Club mobile

Are these still for sale? I may be interested, not sure if I want 3/4” or 1” thickness. Sent from my iPhone using Classic Zcar Club mobile

After seeing both cars in person today at BJ, I agree with you, Lonetreesteve!

BJ charges the seller 10% and the buyer 10%, a great arrangement for BJ! I live down here and go every year, will be there today.

Home Depot special!!

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Never found any great solutions, contemplating having someone make cylinder shapes to fit wheels. Other option is using spacers to push wheels out to make caps fit. Sent from my iPhone using Classic Zcar Club mobile

Could there be any throttle plate issues on carb #2? Maybe the plates are not aligned and one is letting in more air than the other. I noticed a big imbalance on one of my Weber DCOE carbs when I replaced one of the throttle plates due to damage. The other plate let in more air due to leaking. Replaced other plate with a new one, problem solved.

I don't have logging software to graph my results, unfortunately, but I did the same thing you did with consistent runs from 3000 to 5500 rpm on a flat road. I was getting solid readings on my gauge. Sent from my iPhone using Classic Zcar Club mobile