Jeff G 78

Z train, forgive my ignorance again, but what exactly does the MSD replace? The '75 dizzy + MSD 6AL and I'm all set, or do I need other components? I know Z cars rather well, but I've never messed with distributors much.

I couldn't *feel* any shaft play, but it doesn't mean it doesn't have some. There is nothing in the rules stopping me from swapping to a GM HEI, but I just haven't done it before so I'm a bit ignorant. Could I use my spare '75 distributor for the GM swap? I always hear people talking about ZX distributors with GM HEI. I have no access to a ZX distributor unless I have one shipped from someone with a spare. I have a spare '75 dizzy and the dizzy in my '78 "good" Z. The '75 dizzy could be a permanent solution if I can make it work, but that engine last ran 17+ years ago, so ??? My '78 is in good working order with a newish pickup coil, but it can only be borrowed so I can drive that car after the race is over.

I've talked to a few more people and I might have gotten some good advice. My buddy who is a powertrain engineer at Ford listened to my tale and he's pretty sure the problem is ignition. Specifically, the distributor. He thinks that something is getting hot and I'm getting weak/no spark under load. Since the plugs look sooty after I come in from the track, he thinks that I have plenty of fuel, but a lack of spark causing the plugs to read rich. In reality, they just don't have the spark to fire. Also, since the bowls always look to be the proper level and the filters stay full, we shouldn't be experiencing the stumble when we first accelerate out of the pits. We should have gotten at least one straightaway of good running before the bowls got low. Instead, it coughed right from the very start of acceleration. Now, assuming he is correct, what are my options? I have a '74 260 in Michigan and I need to be fully repaired in 5 days before leaving for the race. Getting a 260 distributor will not be easy or cheap. I have a '75 distributor, but no transistor ignition unit from a '75. I'm not sure if they are functionally different, but the P/Ns don't match. My other option is my '78 280Z. In it, I have a perfectly working stock ignition system. I can steal the distributor and transistor ignition unit from the '78 for the 260, but what else do I need? Will my '75 tach work? I assume I'll have to make a new harness between the distributor and the TIU, but what else am I missing? I REALLY don't want to have to cut any connectors off my '78, but I will if I have to. I have a lot of money and time tied up in this race and I cannot fail now. I'd rather rewire my '78 after the race than throw all this prep time and money away if the 260 doesn't run right. Ideas?

We are running the stock fuel rail with return that has the small orifice in the outlet to regulate pressure. We plan to add a pressure plumbed to a gage mounted on the hood.

Yes, we are running NGK BR-6ES-11, I think. I'm going from memory. They are the normal Z plugs everybody runs.

I am out of spit and I only have a few days to figure out and fix the problem with my 260Z LeMons car or I will have a very long, frustrating race next weekend. I'm asking for thoughts you have. The biggest issue we have is that it's a track-only car and we cannot prove out anything we try until we are in the race next weekend. Here's the story: Car setup: '74 260Z with 3 screw SUs on a 260 intake and stock exhaust manifold Fuel tank was cleaned and POR15 treated and has two fuel filters that stay clean Engine has good compression SUs were cleaned/rebuilt and SM needles installed. Floats set to spec and they synched at idle and 1500 RPM Pistons drop at same rate and needles move smoothly up and down in choke seats New mechanical fuel pump - electric pump removed New fuel hoses and vent lines All hard lines flushed and checked for blockages Stock magnetic pickup distributor with working vac and mechanical advance Extra heat shielding between exhaust and intake and fuel rail well insulated Performance coil running at full 12+V (no ballast resistor) No EGR or water lines to intake manifolds New MSA radiator with gutted thermostat The sympoms: Car starts immediately and idles perfect as low as 700 rpm Free revs smoothly to 5k+ rpm Runs great on roadcourses for 10-20 minutes with zero issues After 10-20 minutes (depending on air temp), car begins to stumble at 4k rpm. Within a few turns, the car hits a brick wall at 4k and will not rev higher Backfires through exhaust 2-3 times on decel after a stumble Runs worse and worse and within a few turns, car will not accelerate at all Continues to free-rev to 5k+ without missing Sometimes after car cools for 30 minutes or more, it will run well again for 10-20 minutes and other times, it continues to have issue Car always free-revs fine and always restarts immediately and idles smoothly What we've tried: Checked fuel inlets at carbs, checked/replaced filters, floats, etc Symptoms did not change with/without SM needles Plugs are all the same and rather black after a stumble incident Replaced Transistor Ignition Unit immediately following stumble Removed gas cap to rule out tank vent issue Ran car without hood to aid airflow to fuel lines in case of vapor lock Replaced coil, spark plugs, plug wires Our thoughts: We are fairly certain the problem is heat related as is is worse when ambient temp is higher and only happens after car gets fully up to temp We *think* the problem is fuel related since it's only under load. If ignition, would the car free rev OK? We think the problem is in fuel delivery and not in the carbs since the plugs all look alike Our next steps: Install an electric fuel pump in addition to mechanical pump Add fuel pressure gage so we can monitor pressure Recheck mechanical advance in distributor Like I said earlier, the car free-revs fine and it only happens under load, so we have no way of knowing if a fix works or not until we are on a track for 10-20 minutes. Our next opportunity will be DURING our race next weekend. We plan on trying anything and everything we can do in one week, so I'm open to suggestions!

I run 195/60R14 Falken RT-615 tires on my LeMons 260Z and they fit and look great. The rims are 6" wide and the car is lowered about two inches. If anything, they would look better on wider rims. They might look really small on a stock height Z.

Really? I didn't know that. I asked here once before if it was and I was told NO. At least now I know that I can buy the MSA exhaust and it will bolt up to my AZC header.

Arizona Z Car makes a good 6:1 as well. Nice thick flanges and well designed. Mine is a bit close to the TC rod bushing heat shield, but that is probably fairly typical of 6:1 headers.

I assume the smell is rather uh... strong? Been there, done that.

When I was searching for shank style lugnuts, EVERY parts store had the M12x1.5, but very few had the M12x1.25. Call around to good mom & pop wheel shops and you should find what you need. I think they even had them at Autozone and other chain parts stores.

Very cool Ron! Your Z looks fantastic on the track.

Shade133, there are a ton of Z guys and gals in Phoenix. Go to http://www.desertzassociation.com/ and ask for help. They are a great bunch. I was in Phoenix once on business and dropped them a post on their forum asking when they meet. Within a few hours, they scheduled a meet for the night I was in town and close to 20 Zs showed up! It was the middle of the week too if I remember correctly. I haven't seen a total of 20 S30s in Michigan since I moved here 16 years ago.

I have one car with each and they both have their places. The FI is great if everything is in perfect working order - same as the twin SUs. At least with the carbs, you can call Bruce Palmer and order a set of beautiful rebuilt SUs that will run great for years. With EFI, you will have to diagnose each component and connection yourself and might get frustrated trying to get it all working properly. Either will work fine if they are working properly and both suck if not.

If the car isn't rusty (which a CA car shouldn't be), the tank drops rather easily. Rusty cars are harder due to the long strap bolts which tend to be a pain. The hoses WILL be hard and tough to get off so you need to try very hard to salvage them unless you plan on replacing them. Once the tank is down, the cleaning and sealing process is a pain in the butt, but it can be done and does work. I have done two tanks with POR-15 and both came out great. To do it right, it takes about a week once the tank is down and costs about $80 if you do it yourself. If you go this route, you MUST follow the directions exactly and even go a step further if needed to preclean before starting the POR treatment.

Keep in mind that 14" tires are getting really hard to find in anything other than minivan grade grip. Go to TireRack.com and check out your options for a 195/70R14 before you spend any money on used rims.

Paintjob looks rather familiar, Check out my BRE LeMons racer... #46 was taken for that race, but we will be using #46 for our ChumpCar race in three weeks. What race are you entering? Let me know if you need any advice or setup info. Like d240zx2 said, Troy is another great source of info. EDIT: Was that you guys who rolled the S130 in LeMons after clipping another car? That was a sad ending for the ZX.

Looks like a perfect LeMons car to me!

I have no idea if it's still in business, but many years ago, while visiting my sister, I stumbled upon Z Car Atlanta. It was a Z-only JY that had at least 100 cars. Right across the street was a Porsche-only JY.

I lowered my LeMons late 260 by cutting two coils off each spring and then adding jounce bumpers from some new Nissan (Sentra maybe?) that are in contact at curb height. It's only a track car, but it rides much better than my 280 with Tokico springs and it handles great. Check out my Facebook page for pics of how it sits. It rides on 195/60R14 tires.

Based on the first line of the OP's question, there is NO WAY I'd recommend triples. They sound fantastic and can be made to run great, but they are magnitudes harder to tune than SUs even for the experts. Do yourself a favor and take Bruce up on his invitation to visit his shop. Spend the money and take home a set of his beautiful SUs. You'll be very happy.

I think POR-15 is as great as long as the instructions are followed EXACTLY. Cheat even the slightest bit and it will fail. I have done two Z tanks and both are doing fine so far. One was done a year ago and the other is going on four years. To do the job right, it takes about a week of back breaking labor. On both of my tanks, I had to add many pre-cleaning steps prior to even starting the POR process. I rinsed the tanks with water and lengths of chain at least 50 times first to get the majority of the rust out. After the water only rinse, I used water and muriatic acid to further prep the tanks for the actual POR treatment. I'm pretty sure I did a thread on it last fall. I'll look around and post the link to the thread when I find it. EDIT: I must not have posted pics. Here is my 260 tank before and after POR-15 This is the inside of the tank after the Z sat in a barn for 15 years or so After a few water rinses, this is what I got out After a week of cleaning, here is the same tank inside ready for the sealer step Finally, after sealing

Hee hee. Glad I could "help". I'm like the schoolyard crack dealer giving away free samples. Now that you have some spare parts, you're hooked like the rest of us.

Sounds right. The lugnuts for the steel wheels are cone seats and the alloy lugnuts are the shank style. Do NOT try to use the tapered cone lugnuts! With a small ruler, measure the thickness of the rim through a lug hole. Repeat for all four rims as they might not be a matching set. I have a set of rims that look identical, but the hubs are thicker on two, requiring different length nuts. After 35-40 years, you never know for sure that one or more wasn't replaced at some point. Once you measure the rims, compare the thickness to the various shank nuts available. Keep in mind that the nuts have a loose washer that must be used. The nut measurement must be taken with the washer in place. The shank from washer to the end of the nut MUST be shorter than the wheel hub thickness. 1/16" should be fine.

Thanks Michael. I'll check them out. I can buy the long length all day long for just over a buck each, but to get the mediums, I have to pay $4/ea. :tapemouth I could cut the longs down, but they are chromed and tapered, so it would be a pain.