emccallum

I have a box of old jacks. Most arent in great condition, but I will check and see if I have anything close to 6/71.

FWIW, when I replaced the valve seals (which were fine) I used compressed air to hold the valves in place. On several cylinders I could hear air escaping somewhere at a pretty good rate. It wasnt coming up through the valves. I couldn't feel it through the dipstick but I didnt close off the PCV hose, so it may have been coming through there. At that point I knew swapping seals was a waste and the motor needed to come out. Pretty sure the issue is going to be rings, but I will know for sure pretty soon. Thanks for all the comments and support. @Patcon has offered to drive down and help me pull the motor. Great group here.

Thanks, I am past that. I leaned it out until it was starving for fuel with the carb floats and mixture. Zero change in smoke. The smoke is even more impressive in person.

I had just started it up and had it idled up to check fuel pressure at different rpms. Smells of oil

Good points. PCV is clear, and oil was 5qts and to the full mark. Like a dumb*ss I threw away the old rings and boxes, so I dont know what they were. I bought rings, rod/crank bearings. No pistons or head stuff. Spoke the the engine guy at length today. He did some homework on the SU's and asked me to check the fuel pressure. 2psi. He said pull the motor. I checked the dipstick for any fuel and noticed its about a qt low. I think the missing quart is all over my shop and concrete! I will post up what I find. May pull it on Friday if I can find a spotter. Bad video attached.Enjoy my pain 🙂 20230424_181138.mp4

all look black. None of them look good.

Its a tough situation. The builder has been a family friend for many years. He has rebuilt numerous motors (BMW, toyota, Ford, Z's) for me over the years. I had a problem with a 351 (marine motor) he built and he gladly tore it back down and we discovered the problem was me. I installed a different flex plate from the original and it took up all the crank end play. He is laser focused on the fuel and assures me the bottom end is fine. He admits he doesnt know SU carbs and says that everyone he knew that messed with them are dead. It is hard for me to question someone with way more experience than me, especially someone that has bailed me out more than a few times. I think when I get him back over and he sees it run, he may change his tune. At the time I ordered the parts for the rebuild, it was hard to get stuff due to the supply chain issues. I wont mention where I got some stuff as they are not the most popular vendor on here! Who knows, its all speculation until we look inside. It will work out, just not sure exactly how right now!

@Patcon, yesterday I adjusted the valves as they were set a little loose for the initial start. Several were very loose. Fired it up and of course it still smoked. I raised the idle and turned the mixture knobs all the way lean until it wouldn't run, and there was zero change in smoke. If I start the carbs at 2.5 turns, I can go to 3 turns and get the highest, smoothest idle. Sounds great. Carbs seem to be doing what they are supposed to do. It has to be in the rings and there is only one way to find out. I can have the motor out and on a stand in an afternoon. I am thinking of tearing it down myself to see if I can see anything amiss.

A good video? That made me laugh! Its a real bad smoker. I will get a video, but it won't be good. Its not going to get better. I would rather pull the motor, get it right, then move on to finish. Sucks, but this car has fought me every step of the way.

I think its time to bite the bullet, pull the motor and take it to another shop. I am in the upstate of SC if anyone knows a reputable shop within driving distance I am all ears.

Replaced the valve seals which looked perfectly fine. Adjusted the valves and still have about the same smoke. Spoke with the engine builder. He is very confident in the head and bottom end. He really thinks it is too rich. We talked over several things. I understand where he is coming from. Good compression, all plugs look about the same. I have triple checked the floats, even rigged up a float sync type tube. Ztherapy used .100 nozzles and SM needles. I always thought SM needles were for l28 stroker type builds? Anyone else running SM needles with a stock L24. I had some old carb pistons that probably had stock needles. I swapped them and no difference. Engine runs strong and adjusting the mixture changes the way it runs, but has zero affect on the smoke. If it was rings, then it would show on compression, right? Are .100 nozzles stock? Are SM needles ok with a stock L24? I have never had a good or bad z smoke this bad! Argghh

Played with the float levels tonight. Removing the lid is stupid easy when you rotate it properly as @siteunseen described. Instead of going by just measuring the float, I checked it against the fuel level in the nozzle when 2.5 turns down. From my reading the fuel level should be 1/16 below the nozzle when they are 2.5 turns down. Thats where I tried to get it.

Good idea, I have a scope. The head was done a year ago. I am sure they will tell me everything was perfect. I tried to contact them today, and will keep trying. I think what I need to do is figure out what is wrong, then figure out how best to fix it. Since last year I found another machine shop that I think might be good for a second opinion. Bottom end was honing, rings, and bearings. Plugs all look very similar, black. #1 looks a little more normal. Whatever it is, it doesnt seem to be just one or two cylinders. I am open minded, maybe it could be fuel, but my nose smells oil. IMO, too much fuel would be more of a black smoke. This is blue, constant and gets worse the more it revs. Whatever it is, its a consistent leak that will be apparent when found.

I have run out of easy stuff to check. PCV and carbs seem ok. I ordered some valve seals and I am going to check and replace them as a first step. If that doesnt do it, then I guess my only option is to pull the head and bring it to a different machine shop for evaluation. I will keep you guys posted. Thanks.

smells of oil to me. I just need to find out where its coming from....bottom or top. Hoping the top.

Yep, and it is getting harder and harder to find people with integrity. I have restored several cars over the years, and the last couple of years has been the hardest ever to get work and parts. I am thinking this is my last restoration.........until this pain is forgotten and another project drops into my lap!! 🤣🤣 I looked at the valve train and didnt see anything but it may be worthy to look again more closely. Felpro valve cover gaskets suck. I am running it with nothing on the valve cover breather port and no smoke is coming from there. I did remove the oil cap while it was running to make sure I could seeing oil spalshing around and didnt note any smoke. Could it possibly be water from the manifold heater getting into the intake? I bought new carb insulators to make sure everything had fresh gaskets. I assume the new OEM insulators have gaskets on them?? They appeared to have a gasket, and it isnt leaking water. The carbs are the style that have water jackets in them.

That is my thought as well. Kind of grasping at straws with that one. As for new seals, I would certainly hope so, but i dont know for sure. That is something that could be done without removing the head. I am thinking of doing a leak down, I know that wont cover the seals, but it may give me some more info.

This may sound crazy, but I have used the yellow 3M weatherstrip glue for gaskets. An old stock car engine builder showed me that a long time ago. That is all he uses. Works great to hold gaskets in place but work to remove later.

Thanks for the pics. That is just what I needed to know. The pic I posted was just one I got from online and it looks like someone "modified" that one. Mine actually look just like the pictures you posted. I turned it 90 degrees but didnt think try to get it in the notch. Makes sense now. It might be useful to glue the gasket to the lid. Thanks!!

Smoke is blue/white. Smells like an oil burner. After sitting not much smoke at first, then it gets worse as it runs. As you rev the smoke increases. Like its injecting oil into the cylinder, or sucking it in. When I lean out the carbs with the knob, it starts to fall off. Best running at 2 3/4 turns. Motor really runs very well. Valves might be a bit loose. Just smokes. Oil level is stable and oil looks good. It reminds me of an air cooled Porsche that has oil dripping into the heat exchangers. I wonder if my garage find exhaust might have been filled with oil or burning off old deposits? I would think that would all burn off pretty fast.

Complete engine overhaul. Stock build L24/e88. First start this weekend. 10w30 dino oil, engine fired up, held revs 1500-2k for about 30 min shut down and let cool. Noted a small amount of blue smoke. Restarted fine tuned timing, carbs etc. and blue smoke continued and got worse. Called engine guy. He thought the rings weren't seated. Said to run hotter 180-200 for an hour then shutdown, let cool. Lots of smoke. Engine seems to run well and no noises. Just smokes. Coolant is fine, engine runs with gauge right in the middle. Builder came by today checked plugs, compression and valve train. He isnt an SU guy, but really thinks the issue is too much fuel. Wet black plugs. Compression #'s were all 175-180. All immediately jumped to 90 at first rotation. Warm engine, throttle wide open, all plugs removed. Carbs are fresh from ztherapy. SM needles. I just dont see how they could dump that much fuel to cause the amount of smoke I am seeing. I am thinking valve guides. Is there any way the ATF fluid in the carbs could be getting sucked into the intake? I told the engine builder I would check out the carbs. The engine builder did the block and a machine shop did the head. Thinking the head is going to come off. Just wanted to get some input from the forum. Fun, fun. I often wonder what people who dont work on cars do with all their free time and money 🙂

Yes, the only way I was able to remove the lid was by loosening the float bowl from the carb. That gave me enough play to get the lid on/off. Kind of a pain, as that nut isnt very accessible. Hoping there was a secret trick if I have to do it again.

Thanks Mark. I tried the twist and I guess my twist wasn't quite right. I was concerned about compressing the float too much trying to get it in and screwing up the level.

What is the easiest way to remove the float to check the level on 3 screw carbs? There is a machined ledge that the cap hits after removing the four screws. I circled the area in red in the photo. I loosened the nut that holds the float chamber to the carb to give me enough room but I was just wondering if there is an easier way. Thanks

No just a minor pattern. Here is a close up of the Banzai headliner: