Optimusglen's build off challenge, 6-cylinders of goodness. Ready for my next cross-country trip. Options

[Dion]

Nice to hear ya have it fired up Glen. Not a bad punch list. Car looks sweet. Good
Luck with all. Looking forward to more….. (IMG:style_emoticons/default/driving.gif)

[Optimusglen]

update time

I've had several wrinkles to iron out, but I'm happy to say that the oil temp, oil pressure, and tach are all working as they should now. I got a real alignment done and it drives straight, and had the wheels balanced so it drives smooth. I also swapped Bens muffler on.

I'm still struggling with the carb tune, I had it over to Dave Cheney the other day and he got it pretty good but questioned the timing.

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1630547477.1.jpg)

Today I found that when the shop did the static timing with the 123Ignition distributor I think they referenced the TDC mark I made on the flywheel from a slightly different angle than when I made it, resulting in static timing being off. When I reset the static timing using the pulley marks it was noticeably easier to start and I was feeling really good about it.

Then I thought that maybe that was the cause of the tuning trouble of the carbs, so I reset them to baseline and began trying to do the tune myself. After watching a couple of guys do it I felt like I might be able to get it close now that the timing was good.

Well, I was wrong. I'm following the factory manual on Zeniths and I get to the point where you synchronize the throats. Cyl 4 is much lower than the rest. When the air screw is backed all the way out it's hovering around 3.5-4. Cyl 5, for comparison, is the baseline with air screw all the way in and is sucking 7. All the rest I can get pretty close to 7, but 4 is way off.

I also tried my hand at the mixture adjustment using the leans-best method and I just can't identify when it's time to turn it back.

So all in all I'm feeling pretty defeated on the carbs. The next step is to check compression on #4 and 1-2 other cyls for reference. If compression is good I'll pull the carb and Dave will look into it.

I'm now terrified that the compression is bad, or I managed to screw the pooch on the cam timing, or some other rookie mistake.

[rgalla9146]

I recently heard of a similar case that turned out to be a poorly installed butterfly.
I can't recall if 40 TINs have a split shaft like Webers. If so it could be rotated compared to cyls. 5&6
Easy first step is to remove that carb for a look.

[jcambo7]

update time

I've had several wrinkles to iron out, but I'm happy to say that the oil temp, oil pressure, and tach are all working as they should now. I got a real alignment done and it drives straight, and had the wheels balanced so it drives smooth. I also swapped Bens muffler on.

I'm still struggling with the carb tune, I had it over to Dave Cheney the other day and he got it pretty good but questioned the timing.

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1630547477.1.jpg)

Today I found that when the shop did the static timing with the 123Ignition distributor I think they referenced the TDC mark I made on the flywheel from a slightly different angle than when I made it, resulting in static timing being off. When I reset the static timing using the pulley marks it was noticeably easier to start and I was feeling really good about it.

Then I thought that maybe that was the cause of the tuning trouble of the carbs, so I reset them to baseline and began trying to do the tune myself. After watching a couple of guys do it I felt like I might be able to get it close now that the timing was good.

Well, I was wrong. I'm following the factory manual on Zeniths and I get to the point where you synchronize the throats. Cyl 4 is much lower than the rest. When the air screw is backed all the way out it's hovering around 3.5-4. Cyl 5, for comparison, is the baseline with air screw all the way in and is sucking 7. All the rest I can get pretty close to 7, but 4 is way off.

I also tried my hand at the mixture adjustment using the leans-best method and I just can't identify when it's time to turn it back.

So all in all I'm feeling pretty defeated on the carbs. The next step is to check compression on #4 and 1-2 other cyls for reference. If compression is good I'll pull the carb and Dave will look into it.

I'm now terrified that the compression is bad, or I managed to screw the pooch on the cam timing, or some other rookie mistake.

I know how you feel about the carbs. I spent a few years really tweaking my zeniths and trying to understand the manual and how carbs work. I had never worked with carbs before. Eventually I got a pretty decent understanding of how mine work and its become much easier to tune them. They may not be tuned to perfection but my car runs great now compared to when I first started. Just wondering though, what manual are you using?

[Optimusglen]

I did a compression test today and all cylinders are between 140-150, so we're good there. Then I removed that carb and brought it over to Dave. Turns out that one was off a tiny amount. He adjusted and sent me on my way.

When I got home I measured too, I've got a very nice micrometer. I'm not sure what the tolerance is but there's still a variation of about 0.09mm between those three. Should I try to get it closer or should that be ok?

[mb911]

Sorry no insight on the throttle shaft.. I again don't love carbs but they work Ok and sound great.

[targa72e]

I had similar issue with one throat on my Zenith being low and had to adjust shaft connector. I did my synchronizing with engine on a test stand and only way I could tell idle changed while adjusting was to look at the tach. No doubt carbs are fiddly.

john

[porschetub]

I had similar issue with one throat on my Zenith being low and had to adjust shaft connector. I did my synchronizing with engine on a test stand and only way I could tell idle changed while adjusting was to look at the tach. No doubt carbs are fiddly.

john

Had the similar issue due to PO applying gorilla torque to many of the fastenings on my Zenith carbs,one of the throttle shaft couplers was damaged ,removed the throttle shaft and found that was also the same way.
Spent a long time trying to sort it but the damage was done so ordered replacement coupler, throttle shaft and butterfly screws.
I found this while rebuilding my carbs so was kinda lucky in that respect,all put back together I was able to set that throat closed even to the others and much improved movement, I was pretty sure the coupler was twisted and the throttle shaft could have been bent ever so slightly.
Keep up the good work Glen (IMG:style_emoticons/default/first.gif) .

[Optimusglen]

Well today was a good day. I installed the carb without any further butterfly adjustments. Off the bat I was able to get all cylinders balanced pretty well. Then I started again at mixtures, 1/4 turn at a time, waiting 10 seconds between adjustments. I couldn't make anything work and when I was done it was popping out both ends and nearly undriveable. One pmug definitely fouled. Once again threw in the towel and messaged Dave to see if he would be willing to help again.

Fortunately he was planning on going to a hangout a few of my friends do on Friday nights, so I limped it down there for him to check out and swapped in New plugs when I arrived.

On the highway cruising at 3200 it was ok, get on or off the throttle and it was kinda bad.

Spent some time messing with it and decided to give the advance curve some attention. He found a good curve online and I replicated it in the 123Ignition app. A bit more tuning and it's now running better than it ever has.

I still get some lean popcorn through the carbs occasionally. Typically if I've been on the throttle, then completely off, and then very lightly on it'll pop through the throats.

Very happy driving it now. Still terrified and nervous, but happy.

[mb911]

Well today was a good day. I installed the carb without any further butterfly adjustments. Off the bat I was able to get all cylinders balanced pretty well. Then I started again at mixtures, 1/4 turn at a time, waiting 10 seconds between adjustments. I couldn't make anything work and when I was done it was popping out both ends and nearly undriveable. One pmug definitely fouled. Once again threw in the towel and messaged Dave to see if he would be willing to help again.

Fortunately he was planning on going to a hangout a few of my friends do on Friday nights, so I limped it down there for him to check out and swapped in New plugs when I arrived.

On the highway cruising at 3200 it was ok, get on or off the throttle and it was kinda bad.

Spent some time messing with it and decided to give the advance curve some attention. He found a good curve online and I replicated it in the 123Ignition app. A bit more tuning and it's now running better than it ever has.

I still get some lean popcorn through the carbs occasionally. Typically if I've been on the throttle, then completely off, and then very lightly on it'll pop through the throats.

Very happy driving it now. Still terrified and nervous, but happy.

What curve are you using? Mine is pretty sweet for my setup and took a while to get right

[Optimusglen]

This is what I'm running now.



I'd like to try this

[Optimusglen]

Figured I would update here too.

I've had the car on a couple longer drives so far and found myself dealing with a dragging caliper which heats up and gradually locks up the brakes. I dove into the rear pad adjusters again and noted an issue. tried to recify it with my tools (no air tools) but I can't get one of the adjusters to un-bind.

I rebuilt my rear calipers a few years back when I was first getting this on the road. With them being the only not-new parts in my brake system I felt more comfortable replacing them with fresh rears than trying to correct these ones.

I also ordered all new soft lines since I was going to be bleeding the whole system again. My soft lines were new back when I rebuilt the calipers, but hey, while you're in there right?

The new calipers and lines are both scheduled to be delivered today.


Last night I went through the axle/CV bolts. Removed each of them (all 40) cleaned and placed a new Schnorr lock washer under each one. There are 40 because I have the upgraded Renegade axles. So 4 bolts under each adapter, and 6 on each CV.

I also replaced the passenger door handle, the old one snapped off last week.


REALLY getting down to the line, I'm scheduled to hit the road for Utah in 6 days. Still need to put some more miles on then do an oil change, valve adjustment, and check rocker shaft torques.


On the topic of checking the rocker shafts... I have a small torque wrench that was recommended for fitting in the cam towers. Has anyone been successful at doing this without dropping the motor? That would save some time...


And because pictures are the lifeblood of project threads, here's a snap from the 100mile drive I did. I swung by to see a bud before he headed out for Luft the next day. Tangerine '70 911T

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1631640036.1.jpg)

[nditiz1]

I have been able to torque them in the 911 with a thin torque wrench. I imagine it would be just as much access in the 914. I also cut a 8mm allen down for the large side. Lastly, I used a set of tiny allen sockets for more space (you need a 5mm). wrench was a 1/4in

[Optimusglen]

My car has always been a bit of a rat when I've had it, which is why I don't feel bad about this cobbled-together 9146 badge.

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1631650766.1.jpg)


Calipers and lines have arrived, I also went out to pick up some brake fluid. Might get all this installed tonight.

[mb911]

What axles are you using? I need/want to upgrade my cvs

[Optimusglen]

What axles are you using? I need/want to upgrade my cvs

I have the Renegade Hybrids axels, rated at something like 500hp?

It's really just a CNC adapter at each end and a standard heavy duty axel that was originally intended for something else (what, I don't know)

way way overkill for my current build, but pretty future proof

[mb911]

What axles are you using? I need/want to upgrade my cvs

I have the Renegade Hybrids axels, rated at something like 500hp?

It's really just a CNC adapter at each end and a standard heavy duty axel that was originally intended for something else (what, I don't know)

way way overkill for my current build, but pretty future proof

Do they have a link? Interested to learn more

[Optimusglen]

Do they have a link? Interested to learn more

http://renegadehybrids.com/

Listed under the 914 drop down in any of their packages as optional extras. $700 for the pair but they don't list much else about them. Picked mine up from a guy who sold off his project before installation.

[Optimusglen]

I stayed up late last night to get the brakes dialed in.

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1631737465.1.jpg)

Everything went smoothly and the new calipers are great. I had a little trouble, again, with the passenger side inner adjuster. The same one I was dealing with on the originals... eventually, I did get it close enough that it wouldn't rub the caliper and the venting distance was acceptable. Buttoned everything up and stabbed the brakes for good measure, then the rears were dragging slightly again. Frustrated, I called it for the night and went to bed.

This morning both calipers had returned to "home" and were no longer rubbing. It was a very slight rub, so I took it from a trusted source that it would be fine. I'll bed the brakes in and re-bleed then bed again and report back.

With that done I took it for another drive. This time NO BINDING! but... pedal feel isn't as good. My guess is that the additional bleed and pad bedding will help it. If not, I can live with it for now.

Found a little spot for some photos...

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1631737466.2.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-19709-1631737467.3.jpg)

I'm not entirely pleased with this muffler. I wish I could run Bens for the trip because it looks and sounds WAY better, but just a little loud for extended highway action.

I'm not going to lie, I have considered bringing the other muffler along and swapping it out once I get there. I do have another 2 sets of muffler gaskets...


I'm also not happy with how crooked the muffler is. I'm not sure if it's the headers or if my rear transmission mounts are sagging to different extents...

[horizontally-opposed]

Looking good, Glen!

Re: the muffler you love vs the muffler you think you'll be able to deal with…I've kept one of those blister packs full of ear plugs in the car ever since switching to a six—and that's for a fairly mild sport muffler.

Only time I've used ear plugs, really, was back and forth to LA. (IMG:style_emoticons/default/happy11.gif)