70 Cam Guy

Hey all, I have tried searching but I decided to ask everyone's experience. The background: my 73 240 with round tops and ZX dizzy. I installed a used exhaust fitted with a 40 series flowmaster. With the stock exhaust manifold, it sounded great, not too loud. Recently I installed my Clifford header and cleaned up the engine bay a bit. The new situation is the exhaust is considerably louder and now I get a persistent drone on the freeway. (it also revs significantly faster ) I have read many many threads with people adding a resonator in the middle to cut the drone. What I can't decide on is the style of resonator or glass pack to install in the middle section. I am looking at 2 styles of glass pack: perforated internal tube & traditional glass pack style with internal louvers traditional glass pack http://www.summitracing.com/parts/BIG-50252FLT/ perforated tube style bullet muffler http://www.summitracing.com/parts/WLK-24215/ Those of you that have a resonator, which style are you using? I know the perforated internal tube is ideal for flow, but can anyone say if it cut a significant amount of the noise/drone? Did the benefit of the resonator fade as it broke in (ie burned out the fiberglass)? Perhaps it wasn't enough of a difference to be a bother? Did adding a resonator cure the drone to your liking? I'm just looking for impressions/experience, I know exhaust noise is VERY subjective, thanks!

Welcome! Does it look like this? http://www2.zhome.com:81/History/10thAnniv.htm Carl Beck's very useful site on Z cars http://www2.zhome.com:81/ If it it lost oil pressure or your friend over-revved it at 90mph, anything can happen. Impossible to say without checking it out really. Quick and dirty review of US spec Z cars 70-73 = 240Z [L24 inline 6 2.4L] 74 = 260Z (somewhat larger bumpers) [L26 inline 6 2.6L] 75 = 280Z and 1st year for FI (big square bumpers if stock) [L28] 79-83 = 280ZX 73-74 come stock with the undesirable "flat top" carbs, many replace/replaced with the earlier "round tops"

If you have a week or 2 it's worth reading the Weber thread on HybridZ. I read the entire thing at lunch time over the course of a week at work. I just checked, it looks like you're posting there too (I would too) My gut tells me your air correctors are too big for your mains. Do you already have the 175 airs? It's probably worth it to see if changing them makes a difference. The Haynes Weber book I have recommends 130 mains and 175 airs with the 40 DCOE, likely for a stock L24. Maybe the 180-185 is closer to what you need with the 140 main How do your plugs look when you pull them? An Air/Fuel gauge would tell the whole story here. As a note to the hybridZ thread, I have seen pistons come out of Toys/Honda 4 cylinders looking black, but not loaded up with carbon. ...Or they have holes in the pistons :eek:

I just checked the factory manual for the 73 and it says the cap controls pressure ~12.8 psi. If you have a 13 psi cap, that sounds right to me. I would say if you pressurize the cooling system to 15-17 psi, you should see no real pressure drop. The manual actually says pressurize the system with the cap removed to 23 psi to detect any leakage. No problem on the delay, I am just getting back home after camping at my Grandma's house since last week. We were having the floors refinished and couldn't walk inside for a good 5 days

It might be worth trying a cooling system pressure test. The cap is rated for the correct pressure? If you run the engine stone cold, with the radiator cap removed, are there bubbles in the coolant? If your cap is working at the correct pressure, it sounds like you have a small head gasket leak to me too.

My coworker has Hagerty for his muscle cars I believe and he's been happy with their coverage. He bought a 72 Cuda with a Mopar performance 426 hemi that was side swiped while it was briefly parked on the street. He said his agent sounded horrified when he told him but they fixed it no problem. The guys asked.. is it bad?

The attention to detail and workmanship on Eiji's car is fantastic! Still, that muffler is not really the style I like to see on Z cars. Can't please everyone though right? I have to appreciate your 73. I might still have my bumper protectors on still but one of them is a little tweaked. I actually like the look of the 73 bumper without the bumperettes. The twin vertical exhaust looks great, a very clean look. Seeing some truly well done Z's gives us all something to work toward.

If I recall, you had the old pins pressed out by the machine shop. Do you, by chance have the old one to compare? I have yet to do my spindle pins (coming this month) but can you slip out the new one to see how far the lock bolt fits through before bottoming? it's a tapered hole right? Is the taper facing the right direction?

I understand why you're looking for a place, sounds the leak has grown a good amount. Keep an eye on your oil level until you can get it worked on!

I love the slide carbs! You knew this one was coming. Are those motorcycle carbs or something else? Do you know which model? Great pictures!

I've seen a few Z's at my friend's shop in Oakland. They will work on new and old but old school stuff is what they enjoy Performance Options in Oakland, couple blocks down from the West Oakland Bart station. http://performanceoptions.net/ Can you tell where the oil leak is?

Welcome! Is Dr Migurski still in the ID dept? I was in Industrial tech while he was department head and he taught the mini curriculum with the other engineering and tech professors. Good times except for those horribly tight pants he always wore :sick: He may seem crazy but I learned a great deal from him. In all his joy of hearing himself talk, I learned a lot about rethinking your design and asking 'why not'. Part of the problem is that most people are not performance minded, they are much more practical. I remember a conversation with a (real) person and he was talking trash about people that would 'blow' 30-35 grand on some 'boring' sedan when they could buy a used Corvette or something like his STi instead. I said simply, not everyone needs that in a car, and most people need something more useful than either of those. I'm not kidding myself that my Civic coupe is some performance car, but it does get great gas mileage, doesn't look half bad, and is a hoot to flog around I do agree though, a gem of an engine combined with a light, sleek design, is a formula for success. The other unfortunate byproduct of great design is cost and difficulty in manufacturing. Still, someone has to think outside the box and push the design envelope and thought process

My friend that owns a shop and used to work for a Porsche shop where they used Swepco exclusively in their race cars. Do you have a good source for it? I assume it's local but I found it at Paragon products. I always heard it was really pricey but it doesn't seem any worse per quart than other synthetics. http://www.paragon-products.com/product_p/sw306.htm

Oil filters are also very important. I personally use OEM, WIX Premium, or NAPA Gold (wix premium). I think Car Quest premium are also Wix premium filters but they were twice what the napa filter cost me. I don't use Fram anymore.

Welcome to the site! Apparently this is a fairly common noise that our Z cars make. From what I understand it can be a couple things like diff mount bushings or u-joints. I am guessing you also hear going on and off throttle if it's an extreme enough change. The actual diff and gears are quite durable. If you search "differential clunk", you'll get tons of threads that will have ideas. As someone will surely ask, have any pictures of the car?

I always have to remind myself these distributors only go in 2 ways and have the little scale on the mounting plate. If the timing is too far off, it can cause hard starting or no start. I must have missed the part where you said nothing was coming out and thought you were trying to diagnose a crank-no start. Just a simple misunderstanding

I am assuming you're talking about the mechanical pump. When I was testing my fuel system, I took the flex hose from the hard line to the filter and submerged the end in a container of gas. The engine started and had fuel pressure within book specs but that was not the case when it was connected to the main feed line. The gas drained fairly quickly because I didn't re-route the return to my container... just something to remember. I had to blow out both hard lines. A totally dry fuel line from the tank takes a good amount of cranking to prime but mine did when the lines were cleared. You are certain the timing and/or points/ignition are good? hope this helps

Thanks Dave, I was out camping the last couple days. I agree, cheap insurance/peace of mind is to run a regulator from Spectre or Holley, both of which are under $30. For simplicity's sake I was hoping to avoid running a regulator. My friend has one he used on his (wrecked) drift car that he said I could have to run to have consistent pressure. FWIW, my stock mechanical fuel pump generates ~3.4 psi according to my fuel pressure gauge (Mac) to the carb inlet. That is, when the rpm's are high enough for the needle to stabilize. I think I'll shoot for ~3.5-4 psi regulated. 4.5 seems high for Webers but I have heard 4 is good for many conditions. Triple Webers are in my future, just a ways off

I've done a good amount of searching now and I haven't been able to come to a conclusion. I bought a Facet-Purolator electric fuel pump from ebay that was advertised at 2.75-4 psi. In my mind that was perfect for the Z car so I did a buy-it-now (at a killer price imo). Fast forward a couple days and the pump arrives only the packaging says 4-5.5 psi range. Still is brand new and made in the USA Ebay woes aside, would you feel compelled to run a pressure regulator with this pump? I have read 3-5 psi for our cars is ok (stock L24 with 4-screws). I understand it's not a bad idea to run an fpr but does anyone think it would be required in this case? Is half a psi rating anything to really be worried about?

Bigoak is correct, we need more on the year and model! Just a stab to take without knowing anything about the car... Crank-no start... I would look for spark and fuel (fuel pressure). Beyond that, it's hard to tell you more. My mysterious stalling problem turned out to be my points. The ZX distributor solved that!

Happy to help! I had to do some digging too. I love factory manuals but it always seems like the simplest things are the most difficult to find. I'll be doing my gasket as well in the next month and I was also happy to 're-find' the page

Hey that's Locktup's old rig right? I read the Trail Gear forums too That thing looks too clean to wheel but it is begging for trail time. Congrats on that purchase, that thing is worth a few perma-grins!!!

Thanks, while my car is in good condition, especially the interior, the paint is far from what I would consider show quality. It's not that it's bad, but it's certainly no 2 stage paint with 8 coats of clear like I've seen around here at local meets. It'll get a good wash and wax before the trip down, and I'll bring the Maguires touchup. Beyond that, the giant central valley moths, butterflies, and grasshoppers will add character to a 400 mile journey

5.8 - 8.7 is what I found in the 1973 fsm. It is in section EM - Engine Mechanical, page 33 (EM-33)

The Rubicon is awesome and is definitely a place I want to go when mine is done. If he's set up Fordyce is another great trail. People also come from states away to try their hands at the Hammers (Johnson Valley OHV) I just hope the trail associations can help keep these great trails open Looks like you've got some great projects and fun rides