madkaw

Plugs can verify what you think is a proper tune . I’ve been running programmable EFI for years - those plugs look bad . Something is not right . 17’s would be terrible for an engine that doesn’t have full spark control. I run my engines lean - even my stroker and 15.5-16 is a lean burn for these old engineered engines . I appreciate your effort to make these old Bosch systems tunable - but without any load readings( I assume you use standard dizzy) you are guessing . i would recommend a 123 dizzy if you don’t already run one .

Those plugs show lean and or hot - I would be concerned if my plugs looked like that . I haven’t read your complete thread , but those do not look good

I had issues with an AEM wideband myself . The O2 sensor was bad and the gauge would go full lean after running the engine for juts a minute . They send me another one and mad me cut the old one in half and send them a pic of it cut in half . Got another sensor - same freaking thing . This time they said they wouldn’t warranty it - only get one sensor . Googled all this and read of the many complaints of customers . Bought a different brand sensor and no issues

While you’re at it 🙂 - take your dremel tool with the biggest drum sander you have and clearance those areas I highlighted . Installing the larger exhaust valves will have a harder time breathing with the shrouding of the chamber . Etch a line from the HG and sand a nice radius to allow them valves to breathe . The engine will appreciate it .

Yes - you have tons of room away from the detonation holes . I would unshroud those chambers . That engine will breathe much better and it’s easy to do . 1” drum sander with 80 grit is about ideal. You can use that on the chambers and on the block to clearance everything. Just email me and we will work out a deal on the valves Sfinnerty1018@gmail.com

Upgrade valve size is no brainer if you already have to replace the seats and yes it might raise CR slightly . To mitigate that you could unshroud the valve areas which would help it breathe and slightly enlarge the combustion chamber. BUT - you will have to clearance the cylinder bores unless you have over sized the pistons. There is a chance the larger valve will catch the edge of the bore . There are plenty of threads addressing this . This will also decrease CR - but with added benefit of better breathing . I do have tons of used 35mm exhaust valves if you want to run Nissan stuff . They all in good shape and I would about give them away . They all came out of Maxima engines so maybe less abused than Z stuff . Not trying to increase your work - but the seats MUST be addressed or all your work will be in vain.

Might want to check how close those dings are to the fire ring on the HG - they look close

For a split second on start up . I had been welding dirty steel on my work bench and the head was also on the bench . One of those molten BB’s must have danced right into the port opening . Some more had burned themselves into the side of the port that I found later . That’s how I figured out what happened . It did take a while if scratching my head . What made it more strange was I had a rod bearing go on that engine . They issues were not related

If those are original seats I wouldn’t skip that step . I doubt they are steel . You’ll really have some dings if one of those let loose .

So was this head worked previously ? Are those steel seats ?

Here’s a pic of known FOD . This was done by a small bee bee of weld that found its way in the intake and got sucked in the engine - it’s a long story . That head is still in use on my 3.2 stroker Are you going to do anything to the head ? New seats , bigger exhaust valve, unshroud the valve areas.

That’s a crap shoot . Not sure if you’ll pass smog because that will probably change the way it runs . And be ready for a fight . One might have fell out , but I bet the others won’t 🙂 .

When I go to that link it shows the fenders being 400$

View Advert 280zxt 5 speed T5 transmission Looking for the T5 transmission used in the 82-82 ZXT models . This is the BorgWarner T5 transmission. PM me or email sfinnerty1018@gmail.com Advertiser madkaw Date 05/08/2023 Price $100 Category Parts Wanted Year 1982 Model 280ZXT

I believe they are hyper black . They have colors that are close to each other . I believe mine are hyper black . But when I ordered new caps in hyper black they looked darker . So maybe I’m no help - lol

Took the tires to get balanced . They said 3 of 4 wheels were not running true - bent .

Well this is a timely thread . Just had a customers car come back for an electric power steering install . Drove it 30 miles on the highway and the wheel shake was terrible. I think I replaced most of the suspension parts up front . I still have things to check , but it has the original steelies with newer 14” tires . My money is the wheels and tires . I’m going to swap the wheels on my car to his and see how that goes and go from there

Not apparent because you couldn’t tell from what direction ? Was it coming from the rear hatch area ? Have you sealed that hatch panel ? It can be tough to tell . Usually if you don’t see it right away it will make it hard to determine exactly where it comes from

Go buy a fog machine . I think I made a thread about this . Get your shop vac and tape seal around a window that is cracked open . Turn on the machine and get in the car with a flashlight . I suspect it the panel on the hatch . That vinyl panel needs to sealed with RTV is something . The low pressure will pull fumes through your hatch latch and around that panel . If you have had that panel off I bet that’s the source . The fog machine will tell all And I’ve been driving around in a Z with a Z story exhaust - it’s not the exhaust system

I’m running 350z seats in my car . I couldn’t do the stock seats for my back . I think they would fit about anyone . I’m almost 6’2 but very thin . Bolstering is more than a stock seat . Adaptation of seat rails is required

Not sure what advantage the MSD would be with the 123 - seems redundant . I wouldn’t waste time on porting the intake . There’s very little to port and the runners can handle 230hp as is 🙂 Advancing the cam can be done at anytime . I’d spring for a Kameari adjustable while the US dollar is strong . It makes adjustments so easy . Advancing can bump compression which will help torque .

The 123 ignition could help with performance and to help pass emissions - IMHO . A fully programmable ignition curve would allow a more aggressive power curve without giving too much vacuum advance . Your engine/ head combo is not the greatest for performance . Added compression would make a stronger case for adding a programmable dizzy . Cheap way to add a little power is to advance the cam to hole 2 or 3 . This would add noticeable power/ torque down low . Once again this would be better if you had full control of ignition . A cam and programmable ignition would be best bang for buck

Can you guys get away with a 123 dizzy ?

I don’t know guys - I’m not going to try and figure out Nissans engineering , but the larger capacity of the piston assembly in the BMC needs to go to the front brakes . My intention now is to get Classic Tube the correct info for when folks order lines . I made them aware that the early BMC’s are not readily available and most would be going to a later BMC - which means they need different lines than what’s in the early kit .