Carbs

[ZCCOR#109]

Ztherapy has air horns for sale as I remember.

You still are going to have a difficult time finding adequate air filters, or how to install them on naked airhorns.

[Murph]

Hmm..... I think I'll worry about it when I get the thing back on the road.

Any idea what sort of performance hit we're talkin for not having the horns on?

[ZCCOR#109]

Can't give you any real numbers. Just the fact that the smooth flow of air to the carb has been documented over the years with thousands of competitors and manufacturers developing the airhorns.

You need to get ahold of and view Ztherapys video on the SU. It is an excellent document on repair/rebuild and adjustment of the carb. as it applies to the Datsun Z car.

[SuDZ]

Is the Ztherapy a good video for a begginer? I have not really gotten into carbs before so I am a newbie at them. Would you say that the Ztherapy video is good for me or is it more advanced?

SuDZ

[ZCCOR#109]

If you have never touched your SU's you will have to watch the video, then work on the SU, then watch the video. Doing this several times. The video is totally detailed. The situation is there are a number of facts to understand and remember. You have to start somewhere.

Unless you learn the carb, you will have to depend on others to adjust the carbs. That is problematic, there are few who do. It is just about a certainty that no Nissan dealer has a tech that can even say SU, let alone work on one.

If you own a Z with SU's then you need to learn to adjust and do basic maintenance such as removing the piston, adjusting the needle, etc. and of course using a unisyn to balance the two.

You only need to stand over the SU for a 30 minute period, trying to memorize the pieces. Then watch the video, then go work on the things.

Good Luck.

[SuDZ]

Originally posted by Lowell Marx

If you have never touched your SU's you will have to watch the video, then work on the SU, then watch the video. Doing this several times. The video is totally detailed. The situation is there are a number of facts to understand and remember. You have to start somewhere.

Unless you learn the carb, you will have to depend on others to adjust the carbs. That is problematic, there are few who do. It is just about a certainty that no Nissan dealer has a tech that can even say SU, let alone work on one.

If you own a Z with SU's then you need to learn to adjust and do basic maintenance such as removing the piston, adjusting the needle, etc. and of course using a unisyn to balance the two.

You only need to stand over the SU for a 30 minute period, trying to memorize the pieces. Then watch the video, then go work on the things.

Good Luck.

Looks like I will be adding them to my list of thigns to pick up then.

SuDZ

[Victor Laury]

Ya, That tape is pretty dam good stuff. A little disjointed at times, where he forgot to mention something and had to back-track. Have paitence, watch over, I know it's long. If you fall asleep during one part, it's very much to your benefit to watch that section over again.

If you own a Z, 510 or Roadster, it's a "must watch"

[alien-e]

I bought some 71' SU's off of ebay for cheap and they came with the Z therepy video. Helped a lot when I tore them apart and rebuilt them. Unfortunately, I wasn't very careful with the needles and ended up marring and bending them. Mostly because they were stuck in the jet nozzles. I got the carbs to run, but they were very hard to adjust.

There were a few things I don't remember the Ztherepy mentioning. Like making sure the plate that sits under the adjusting screw that controls the butterfly opening can touch the screw as it is screwed in. I don't remember if he mentions that when the choke is pulled out all the way that the butterfly should be somewhat opened either. I fixed both of these problems and I replaced my needles with the Ztherepy SM needles. They run better than they ever have before, but they don't balance well. At low RPMs the rear carb flows less than the front, and at high RPMs it flows more. Not too much of a varience, and the idle is smooth, so I'm not complaining for now. I'll try watching the video again and see if I missed anything.