Zedyone_kenobi

Physically it makes no sense. The torque required to get you moving is exponentially more than when you are already moving and the motor spins from 3000-5000 rpm. NO offense, but your motor does not 'come on' that strong at 4000 rpm to cause slippage. Unless something is really messed up with the pressure plate... Again something is weird here.

That is a holley carb if I am not mistaken.

Looking at the wiring diagram, I see that you are right!! I cannot believe I never thought about that. May explain my sluggish oil pressure gage.

Wait, sorry to bring back an older thread, but the sending unit cannot have teflon tape on it?

I fully expect my mains and airs to go up with the 32's. I think I will end up with the 55's. I am glad to hear the 32mm will have zero effect on my idle and progression. As they are very nice right now! I do not have a micro drill, but I do have a nice soldering torch... man you are an enabler!

grannyknot, I have made an in car video that was darn near 10 minutes long. It was fun to make. I have rigged up a tripod on the deck of my car and wire tied it to the rear strut bar. it is very stable. However, when listening to the video, all you can hear is the DAMN electric fuel pump. It is so God Aweful loud in the video you can barely hear the L28 music. So annoyed I was with this, I am ordering a 81 RX7 pump as many veteran members here have. I will be giving that a shot in the week to come. I just cannot stand the constant BUZZZZZZZZZ anymore. The carter pump has been reliable, but nothing I have done has made it less annoying!!!!

We last left our hero with a very functional setup of the following: 120 Main Jets 170 Air Corrector F11 Emulsion Tube 60F9 Idle jets This yielded a decently smooth idle and a steady state cruise AFR of around 12.9:1. Going to lunch the other day though, my friend who was following me told me that I was reeking of gas behind the car. This concerned me. Needlessly running rich does not yield any advantages at all. so lets try to figure out what was happening. First at around 2600 rpm in 4th, the throttle plates are barely cracked. I think it is very safe to say I am NOT pulling form the main circuit at this time. So it has to be in the idle jet. The more I thought about this, the more clear it seemed. Simple tests for idle jet 'correctness' at least from an AFR point of view. When I was idling at 12.5:1 the mixture screws were barely 1.5 turns out. As Blue noted and I confirmed through more reading, the 151's really need more than this. More like 2 full turns. But I will get back to that. Keeping in mind the mixture screw does not adjust Air/Fuel mixture. It is merely an opening that allows premixed air and fuel to enter the throat of the carb. The more you open it, the more premixed air and fuel enters. This means that you can get the car to idle with darn near any idle jet by making adjustments to the idle screws to get enough fuel in there. I would wager that there are limits to this, but for the most part if you are close you can get her to idle. So how do you know if you are crazy rich on the idle jet? My moment of clarity came as I was taking a long tuning drive down the freeway. Any tip in I did in 4th gear at around 60 mph I immediately dropped to 10:1 AFR. If I kept my foot more in it (meaning I introduced the main circuit into the equation), my AFR got closer to 13:1. So my webers were talking to me and I was not listening!! What do I mean? Well since I had to go so far down on my mixture screws to get my idle AFR in a happy place (deemed as 12.5:1 by popular opinion) and my AFR while solely in the progression circuit (which is also fed by the idle jet) was dipping in to the 10's it tells me that the premixed air/fuel from the 60F9's was too rich! Now post #34 seems to contradict this, but looking back at my hand written notes, I made that assumption too quickly. I did not take her on the freeway long enough or do a long enough drive. I think I was getting into the main circuit when I stated that my part throttle AFR were spot on. When I carefully drove on the free way at very slight openings of the throttle, the AFR is indeed in the 10's. My biggest problem is that I never have enough time to do more than one test per week. I need more time to test and document these things. GRRRR. my quickie fix was to remove the 60F9 and install the 50F9's. I was able to adjust the mixture screws 2.25 turns from fully seated, when I attained the 12.5:1 AFR at 1000 rpm. Also of note, my idle did get smoother and the AFR reading was not as bouncy. I may still need to install the 55F9s. We will see. But all of this will be thrown out the window as I have ordered my 32mm chokes from www.carbsunlimited.com. So we will have to tweak these all over again at a later date. If you wonder if I am having fun messing around with these. Well the answer is a resounding yes!!! I love carburetors. I love the fact that it requires a certain skill set to make them work correctly. I love the trial and error portion of the work.

I removed the aux venturi just now trying to play with it after a rejet (yes another one). More on that later. The Aux Venturi are held in place by the set screw that is about 45 degrees from horizontal toward the bottom of the carb. It was a snap to slide out by hand. I think the screw holding in the chokes are in place are just beside the pump jet cover screw.

I can tell you I am blown away with how much mid range torque I have. It is just so usable. The ability to scoot up and around things with the flex of your toe on the accelerator is a joy. Almost no need to down shift form 4th when just driving around town. It pulls almost from 1500 rpm up. I have taken her as high as 4500 rpm so far and she is running well. Has not burned a drop of oil and seems to be extremely tight. If I get aggressive with the throttle in first gear some tire spin occurs. I have yet to really to full tilt through all the gears at WOT, so I cannot comment how fast that would be, but she feels like a rocket ship compared to my OEM L24. The webers have a whole new sound to them with the L28. With Timing set at 14 BTDC with a max of 35 degrees was running into some pinging in 3rd and 4th gear at 1500 rpm while loading up the engine. It was barely audible, but I could hear it. If I eased off the gas it would be a non issue, even while loading up the engine in a tall gear at low rpm. However, I backed off to 10 deg BTDC and max advance of 30-31 and there is zero pining ever. Pulls strong, and idles very well. I cannot make it ping right now. I may try to advance it one degree at a time to see what I can get away with. But the car seems to like where I have it. When I get my Mallory back from summit racing (bad ignition module) I plan to run it at 10 degrees BTDC and max at 34. I may later buy an adapter kit to make it run 14 BTDC with a max of 31 ish. We will see. Without a dyno to really measure results, it is hard to tell any real improvement. To be honest, I am not sure changing out a perfectly working pertronix with a Mallory will yeild any results what so ever.

What an amazingly good post Blue.. but reading this makes me want to fiddle that much more! DANG IT. I have ordered 32mm choke tubes for my 151's. I just need to find out how to install them. I would love to install them without having to remove the carbs, but not sure if that is impossible. I have searched for a how to video, but have found nothing. Guess I can just pull one off and experiment! I have never had a flat spot with my 30mm chokes, but I really do think it would make more mid range and top end with 32mm. I think I have an engine that is healthy enough and pulls enough vacuum at low rpm that it can take a bigger choke without losing too much throttle response.

Not fair, I would love to come to this!!! wish he could make a trip to texas

yeah, those two are attached at the hip. I think the best practice method of setting the throttle plates is just to ensure you do not uncover a progression hole too soon. Mine are not uncovered at all, and in fact the throttle plates have to move bit before I uncover them at all. Now one could keep changing jets out I suppose, but I am not sure you could ever get there. I am only 1.5 turns out from closed on my mixture screws. I cannot go too much more closed. Again, I think the rule of thumb is to not uncover the first progression hole at idle, If you have to close it more than that, no harm no foul. by the way, this new L28 I am running has absolutely NO flat spot anywhere. I think that is mostly due to my 30mm chokes than anything else. I wonder if going to 32mm chokes would allow me to open up the plates a bit since the velocity of air coming in at 1000 rpm would be slower. I just have to buy some 32mm chokes and try. GOSH I CANNOT LEAVE A GOOD RUNNING CAR ALONE!!!!!!

Well today in order to get my carbs even better (this is where the issues come in as they were running fine, and I cannot seem to leave well enough alone). I opened up the screw covering the progression holes. Now all manner of weber tuning manuals state that you need to have the butteflies covering the first progression hole. And when you first tip into the throttle you start to uncover it. Well I noticed that mine were not this way. Instead they were almost a full turn more closed that than. Meaning I could move the butterflies a few mm before I would even start to uncover the first holes. Well I figured this had to be wrong (even though I had a reliable running, idling, and starting car) So I loosened up the throttle levers, and then made my fine adjustments with a magnifying glass so that the slightest touch of the throttle would start to uncover the first hole! I was very proud of my overkill on how perfect I got it. I hooked up the throttle levers and started her up expecting a rock solid smooth idle. What happened? Well She started up quickly and then revved to 2300 rpm and stayed there. I then proceeded to muck with my air/fuel mixture screws that were previously perfect to try to drop the idle. Well I got her around 1500 rpm but with an afr of around 19:1!!!! barely struggling to go. So I turned the throttle plate screws back to where they were and she is idling smoothly again and I got the afr back to 12.5:1. Just goes to show you, that general settings are not the same for all cars or even all model weber carbs. Maybe this is a progression hole thing with the 151's. Who knows, but I certainly cannot set mine as factory recommended or else I rev to the moon. Very interesting things these webers!

Well until I get about 400 miles or so. I am up to 200 now. Just did another oil change of VR1 today which should last until about 1000 miles, then it will be just another engine ready to drive and enjoy.

Finally got some video of me, but the quality is just aweful! http://www.flickr.com/photos/sdamico/7965447110/

I have been very busy lately just driving the car. I do owe everybody a video of the car roaring. IT sounds glorious. I ended up using an OEM 240Z clutch to answer your question...

tlorber, you and me, we gotta work on our communication! that picture physically makes me ill. Is there a story behind this poor injured Z?

I would not think mid 13's as being too lean. Everything I read is always pointing you to mid 12's as the most power happy point to be, but mid 13's is still on the rich side of stoich. I would think you would be doing just great if at the high RPM you are consistently in the 13's.

Yeah, that registration has to be done, she has been in my garage for so long getting going I just have not had a chance... 'break'n the law... break'n the law... break'n the law..." tlorber, I am sorry, have you not heard of Murphys Law.... Do a google search. AS for being a trailer queen, not ever going to happen. But your warning is not unheard by my ears my friend!

Driving it would be fun but having a means of getting it home in case Murphy strikes is priceless. Plus towing it means I can bring almost limitless spares, camera equipment, etc. I have gone back and forth on driving it or towing it. Both have advantages

OH my I love that car Mally! Beautiful.

BRING A TRAILER?? Well I sent in my last payment for my TEXAS 1000 rally. The new engine is well under way to being broken in. I have one more oil change left. I have fitted 205/55/15 yokohama S drives on my old Panasports which I wholeheartedly love. I have started a packing list and a tool bag that I can stash inside my tool box in back. I contacted the rally folks and they are prepared. I have a few more things I would like to ask? Has anybody used a UHAUL car transporter before? I wonder if my front spook will have issues going on and off the ramps.

Mike I have to disagree with you. I wholeheartedly do NOT want to change the way I look at transportation. I like cars to be fun fossil fuel burning fun machines. I think that the green movement is a wad of garbage made to boost the green industry and make them billions of dollars. The requirement will never be met, and I certianly hope it gets revised downward. I like innovation and moving forward, but not at the expense of fun and exciting vehicles to drive. It is only a matter of time before the green nazi's target the S30's as pollution and planet killers and are banned. You have to be cautious of what these guys are doing in the 'name of the planet'. How many freedoms are we losing in the name of 'green'.

Due to my overwhelming hatred of this government picking its winners, I will refrain from getting to involved with this. But I will say that Propping up an immature industry to appease the call for 'green' technologies is a misguided waste of taxpayer money. The whole green movement nothing more than the most successful marketing campaign in the history of the world to charge people more money for an inferior product. The Green movement has nothing to do with saving the planet, and everything to do with making green for the companies that slap 'green' onto everything from flooring products to home health insurance.

That will certainly get you out of a jam! Great thinking When you put the engine back in, you may have to remove the front bumper to get the engine far back enough. I would remove it now to save yourself the trouble.