Ownallday

Thank you, just confirmed today that the itbs will bolt right up to the canon manifold no problem. Wanted to use this manifold since the manifold grabs vacuum from from every port so I can get a better MAP reading for tuning.

Good idea, I will send get in contact with them. Thanks!

Hello, I have triple Weber dcoe 40 at the moment. I plan on going fuel injection itb setup. My question is will the triple webers canon intake manifold bolt up and work with Jenvey ITBs (40s) or ITBs in general or is another manifold required?

Sounds like the 3.9 is the way to go then. my 280z typically ran at 3k rpm at 65 mph and it did not bother me at that rpm.

Thanks for the response, so a 3.9 would be a good option?

Hey guys, I recently sold my 1978 Datsun 280z and picked up a 1973 Datsun 240z. I plan on doing a manual swap with a 280z wide ratio 5 speed as I have a rebuilt one. Down the road I plan on doing a NA L28 build and push at least 250hp+ from it with an ITB setup but for now the L24 will have to do for the next two years. I live in California and the car will mostly see city driving, freeway driving but will also see the canyons pretty often in spirited driving and maybe a track day once every year. I am wondering what would be the best differential to pair with the type of driving I will do and my engine goals. I also plan on doing an LSD conversion for whatever diff I get. (Also if anyone can specify if they know what gearing a stock automatic 1973 240z came with would be appreciated).

Will do, I think it'll be fine I barely tightened the bearings about a quarter turn and used really good bearing grease. Just to be safe however you wouldn't happen to know what the max temp the bearings should be at?

We can finally celebrate! My steering wheel shaking is gone! I re-checked every single bolt in the front suspension (for the third time), removed the steering knuckles even and tightened the bolts for the bolt joints. Removed my wheels and removed all the rust on the hubs and backside of my wheels. However I think the fix was the front bearings! Even though I followed Nissans procedure for the wheel bearings I think they might be too loose for my suspension setup with hind joints and poly bushings. I tightened the nuts for the front bearings just a little more making sure the hub can still spin nicely obviously. All this and steering is solid! Crazy to think I went though two sets of bearings following Nissans procedure only for it to be the problem haha. To everyone with modified suspension and getting wheel shake, tighten the bearings! Thank you to everyone for helping! appreciate all of your for the help!

My lug nuts are tapered. I'm using the same lug nuts my friend used when he was running these wheels and he had no shake.

Quick update. Adjusting the tire pressure had no change or effect any where between 25 psi and 35psi with the steering shake. I finally got my wheel spacers that are also hub centric and no change to the vibration either. I went to double check for play and noise when moving the hub and even with the tire off I get a small clunk/thump sound when moving up and down. My wheel bearings and ball joints (Part of the TTT control arm) are maybe only two years old at best with less than 15k miles on both. You guys think the hubs could be bad? I am almost at the point now where I am just going to order TTT hubs with new bearings. Two videos of the noise below. Yes I know the surface rust on the rotor looks bad btw. Going to fix that soon. 20240409_100445.mp4 20240409_100418.mp4

I've tried anywhere between 30psi to 35psi and no difference. To the eye and feeling with my hand there are no noticeable flat spots. And I've already tried balancing the tires at work at least 10 times. One thing I will say is on the driver side I can here a slight click or tap noise when moving the tire in the same manner if you were to check for wheel bearings. However I cannot get that noise with the wheel off the car. This might be leading me to believe that the wheel studs might be ever so slightly too long and the lug nuts aren't 100% pressed against the wheel to the hub. The car has extended studs and were cut slightly but maybe they weren't cut enough for the wheels I have. I have a 5mm spacer coming so I can check when that gets here.

Thank you, yes I have psi right around 32 psi. I'll try an reduce tire pressure and see what results I get with that. I run a 225/45r15 and I have the technotoytuning control arms and tension rods. Maybe the combination with higher tire pressure and my hankook Rs4 the tire tread catches into the road surface aggressively? Anyways I'll reduce it to 25psi and see what the results are next week. Thanks for the tip.

Noted, going to be removing the wheels and looking into everything sometime next week. My wheels look like the lug holes have been repair sometime in the past I'll have to post some pictures of that. The only thing I have yet to replace in the front at this point is the wheels and tires (going to swap wheels and tires with a friend in two weeks if it's still isn't resolved), the steering rack, and the wheel hubs. Still haven't got rid of the vibration to this day. Also even though I replaced my struts and have lowering springs, not sure if it can still be that because if the road is perfectly smooth the wheel doesn't vibrate at all, but if there is any very minor road imperfections is when it vibrates at nearly any speed so it varies with road surface.

I know Z cars are lug centric and not hub centric. If the wheel is less than 73mm then in that case means the wheels wont sit completely flush against the hub? Or am I missing something.

Thought I would give a continuation and update to what I have found. I may have found the solution to my problem! Years ago my friend gave me his Enkei 92 Wheels from his Datsun 240z and this is what I have been running since then. I have just discovered the 280z hub bore size is 73mm while the Enkei 92 wheel bore size is 72.6mm!!! My wheels are not 100% flush against the hubs is what it looks like I am seeing here! After replacing nearly everything I think this might be it, but what is confusing is other people have used these wheels without problems apparently like my friend. Can someone give any insight? I might buy a hub centric wheel spacer to make sure this is the problem before buying other wheels as I just bought Watanabe wheels but they don't fit currently over my brake calipers and even then it shows Watanabe wheels are 63mm or 70mm so that's saying these wont fit either?

I actually contacted a couple of other people. Got my question answered. Wildwood micro kit on TTT and silvermine will work in the front and rear but the rear e-brake cable hits the wheels and requires a spacer or no e-brake) The guy I talked to has a 12mm spacer not sure if anything smaller will work to clear the cable. The S12+8 front brakes (stage 3 on silvermine) fit and require only a 2mm spacer or 2mm to be shaved but someone else got away without shaving so it's 50/50 direct fit. And the rear disc brake conversion from Z car depot or the stage 4 rear brakes from silvermine will work with no spacer. Writing this Incase anyone needs an answer.

Doesn't need to be the most expensive brakes out there though, I'm obviously not going to go back to stock brakes either. I'm willing to get Wildwood brakes (especially the smaller 4 piston brakes that TTT or silver mine sell) but I need to know if it'll work with my Watanabes first.

I read the ZCG kit works but the price is what keeps me away

Its hitting the entire caliper, the caliper sticks past the hub portion by a pretty big margin like 6-9mm past it. I think I would only be okay with only running a 1-5mm spacer currently since I still don't have coilovers and the 15x8 is apparently the max size before running into rubbing problems with rolled fenders too. I personally don't feel comfortable grinding down that much of the caliper too and essentially making it more unsafe and look uglier lol.

Hello, I recently got a set of 15x8 0 offset Gold Watanabe Type R wheels. I currently have the front Toyota 4X4 SW13 brake calipers installed on my car which does not fit with the Watanabe wheels. My question is does anyone know what front and rear brake kits will work with my new wheels excluding the ZCG kit. My fenders are rolled/cut so I may also be able to run some spacer if needed but nothing too crazy. Any input would be appreciated thanks.

As you can read from the title, I wanted to make a quick write up on how I got my Z to pass smog with flying colors and something that can help anyone diagnose why their car isn't. There is not a lot of write up on this either. I have a 1978 Datsun 280z. I ended up buying a second L28 with N42 block and N47 head (proper block and head for 78 280z). I performed a full rebuild on the engine along with restoring or replacing everything I can on the intake manifold. When it came time to smog the car, It failed due to high CO (Measured 1.84 on 25mph, max is 1.16) and HC was really close to being above the max also and NOx was practically 0 indicating my chambers are running very cold. It surprised me considering it was basically a new engine with new parts. Aside from the engine rebuild, I had new injectors, new AFM, all new sensors on the thermostat, new fuel filter, new hoses and lines, new fuel pump. new air filter, new Spark plugs, new cap and rotor, new spark plug wires, new egr valve and new Carb compliant catalytic converter from magnaflow and fresh 91 octane gas. Timing set at 10 BTDC with idle ~800rpm. Almost all the wiring has been redone with new connectors or cleaned connectors. The steps I took in diagnosing why the car didn't pass started first with making sure my valves were properly adjusted again, these damn valves like to go out of spec pretty quickly from my experience. Minor improvement was saw after doing a valve adjustment again but it was very minor. I checked all my spark plugs and saw a near perfect brown color that you want to see from spark plugs. My results indicate my car is running rich but the spark plugs say otherwise. California has very little wiggle room for cars running rich even if just slightly rich. Tested water temp switch resistance and resistance came back indicating my water temp was fine with ~290 ohms at 280 degrees. Inspected my Cold start injector to see for leaks when the fuel system was pressurized and also checked to see if it was firing when the engine was warm and saw that the cold start valve was working properly. Inspected all my injectors for leaks even though they were new. With a boroscope and the fuel system pressurized i stuck the camera into each cylinder and looked for fuel seeping. All my new injectors checked out and were good with no leaks. Ordered a fuel pressure gauge and found my pressure was right at 30-32psi at idle, a little low from the fsm 36 psi but imo was not a big deal since the car is supposedly getting too much fuel anyways. I saw PSI rise to 36 psi when revving the engine which is normal. To check if the fuel pressure regulator is working I removed the vacuum hose going to the fpr and saw a jump from 32psi to ~38-40psi indicating the fpr is good. THE SOLUTION FOR MY Z: Fuel was out of the question for me at this point and decided it was time to tinker with the AFM. I recommend doing this as the last step if all else fails. There are other things you can test such as the tps, afm itself, the ecu and so on! I removed my new AFM and reinstalled an old afm I already had that has already had the box open (didn't want to tinker with my new one). There is a good write up online about how to adjust the afm. There is a white gear (could be a different color depending on your afm) that has a spring on the inside. If your AFM has not been tampered with or has no adjustment marks, I would put some markings so you remember where the teeth originally were incase something gets messed up. This gear can be moved in one direction or another that essentially makes the car run richer or leaner. Do not mess with this without reading up on how to properly adjust it, there is tension on the spring! I WOULD HIGHLY RECOMMEND that you find a smog shop that has a smog tech that is willing to constantly run the car on the dyno and get emission results while constantly adjusting the afm at the same time. This is essentially what we did. We got a baseline results on the dyno, after seeing the results were still rich, we turned the car off and I adjusted the afm a couple teeth leaner, tightened the adjustment screw and re-ran the dyno until it was eventually good and passed with flying colors! You may also need to adjust your idle depending how much afm adjustment you do. After you pass, drive the car for a about 50 miles or so and recheck your spark plugs and make sure you are not running too lean! My spark plugs were still a nice brown indicating everything is where it should be for California emissions and the car itself but I will still be swapping back to my new AFM since these cars like to run slightly richer. Heres my results. Didn't think a Z could have such low CO and HC. Something I noticed after passing this test was my measured 15mph NOx jumped to 862 (before was at nearly 0) which means that running leaner and reducing the CO and HC will most likely in return cause higher NOx (essentially hot polluted air). You will have to find a fine line when adjusting the AFM so everything is equal. If you choose to adjust the AFM, I think it would be beneficial to have an older one for adjusting just for smog reasons and swapping back to a newer one for daily driving which is what I did, otherwise make your markings so you know where to readjust after smog. Extra things to test and look out for: Some other things that you can also check on is the overall state of the engine by doing a compression test. Low compression usually causes an engine to run rich. If you have dying cylinders there is only so much adjusting the afm and everything else can do. You can add the option of putting a rheostat inline with the water temp switch and essentially trick to water temp switch to run leaner sooner or vise versa depending on the condition of your results. I am not sure if California smog techs will question this or not though during visual inspection. Change your catalytic converter. Depending on how old your catalytic converter is and how many miles have been put on it, it's possible that it is not performing at it's peak. You can test the Cat by using a temp gun and making sure the cat is hotter than the pipe before and after the cat, would indicate the cat is working properly. However, overtime a catalytic converter does slowly deteriorate and become worse at doing what it's suppose to do. Spark plug gaps can also play a roll in NOx emissions as the wider the gap the more NOx emissions produced. The smaller the gap can lead to unburnt fuel and cause a richer condition. Next thing you can check for is the TPS. There are multiple write ups on how to properly adjust the TPS. While it can make a difference to your emissions results, I don't think adjustment will make much of a difference unless yours is severely out of spec. You can test the EGR valve. There is a write up on how to properly test it. Change your oil is another thing that gets looked over. Fresh oil usually makes a pretty small change to the results depending how old the oil is. Hopefully for those you struggling, this write up gave you some insight on what you can do to hopefully pass your smog test. Some guys will tell you not to mess with the AFM and I do agree that it should be a last resort. If you have two working AFM's do what I said above and use one just for smog and use the other for daily driving. If most things are working as they should the AFM has the biggest impact on how the car does emissions wise but will also drastically change how the car drives if your car actually is not in good running condition to begin with! Good luck!

Alright, I'll remove it after 500 miles since I'll have to go back in at that time to retorque the arp head bolts and probably do a valve adjustment again during break in.

That hole is already sealed from factory. It's an N47 head which only came on fuel injected cars.

She's ready to fire up this week! Been a 8 month process! That's pretty much what the engine came with when I picked it up and tore down, had it on my last engine with no issues and electric fuel pump so just threw it on, wasn't actually sure you can just remove it.

100% positive, the timing chain is covering the timing mark on the crank gear but I made sure it was on the mark with the darker link in this timingchains case. For the most part to my knowledge too, the crank gear dimple can only be in one general area with the engine at tdc which is where the darker link is in combination with the cam gear.