clutchdust

ya, ya, going to take pics soon. she's nothing to get too excited about yet. i guess that's what separates us "gearhead" types fromnormal people. my wife sees it as a $100 POS that doesn't run and i see it as a future 300hp, 1g street car with great styling. btw, she's already jealous. she thinks she's third in line behind the vette and the dog!

good to hear. hopefully, someone knows the site your talking about. it's very common to mill the block .010"-.020" to clean up any warpage on most American iron. is this not an issue with the nissan? i don't have any experience with aluminum heads but my experience would make me more comfortable milling the block. i'll go with this forum's more experienced opinion though. is there more meat on the head to mill? how much mill do you recommend and what does that give you for compression? my first thought was to bore out to 2.8 but some people have said this is a bit too much for the stock L24 block to handle. if this works, i'd rather do that. what i figure is pull the engine, new oil pump, fresh bearings, reuse crank and rods (barring significan wear or damage), bore cylinders, new chain and tensioner, check the head/valves/guides, minor porting, and new cam and springs. externally, i'm thinking pertronix, home-built cold air intake, the aforementioned headers w/2.5" exhaust and aluminum radiator. not looking to blow the doors off any vettes, vipers or porsches but i would like to show tail lights to the rice boys in their slammed civics and preludes.

sweet! that should make life alot easier when i start looking for some new wheels. BTW, anybody have opinions? i'm going flared so i'm thinking a 17"x7" or 17"x8" with a 245/40-17. i'll probably go with something like a centerline or weld wheel but haven't decided on style yet.

thanks. that's the kind of input i'm looking for. give you a little backround on what i have in mind, i just want to bump the power a bit without a great deal of $$$. later on in life, the little L6 will give way to a 4.3 chevy v-6/t-5, so i don't want to inject a great deal of cash in this engine. what about milling the block? is there enough meat on the deck for any noticeable bump? what about a thinner head gasket? if i mill the deck or head or both, what will that require about the chain? different chain or some type of tensioner mod? i like the idea of a high-winding engine so a little longer stroke (ala 2.6) is not really what i wanted to do. not to mention, like i said above, i should be able to get a good price on pistons, but not so much the rest of the go-fast goodies. i do want to go with a set of 3-2 headers and a cam but i will be sticking with the factory intake and the round-tops for the time being. i'm not afraid of a little port work so i can bump up intake and exhaust efficiency that way. i just need to bump the compression to take advantage of that.

thanks guys. ed: came retro-fitted round tops. how sweet is that?! started last night draining the bad gas. :sick: crap is caustic! i put about 2 gallons of fresh gas in there to try and help dissolve the sludge and i'll drain that too. i just spent some quality time getting to know the car a little yesterday. i'm thinking this is going to be fun. the only thing i've noticed is it's actually a tighter cockpit (shoulder and hip width) than my vette. never thought i would say that!

any issues i should be aware of when taking the factory block out to 2.6L? '73 block, all original to my knowledge. i want to take it out to 2.6 just to clean it up and a slight bump in compression and displacement. could this engine be taken out any further? if so, what's the max? could the block handle 85.0mm? has anyone ever tried the L18 pistons in a bored 2.4L block? a company i buy alot from for my work also sells speed pro so i can get a good deal on a set. my speed pro catalog lists one set of pistons for the L6. this is the information they show: L6: 2565cc 2.6L 83.0mm (3.2677) <---no idea what this spec means 1972-75 car (non-USA) recessed head 1.20mm deep x 71.5mm dia. 8.3:1 C.R. (available sizes) standard, .50, .75. 1.00, 1.50mm rings: 2-2.00mm, 1-4.00mm <---don't know what this means comp. dist: 38.2mm <--- ? pin diameter: 21.0mm there are a couple specs there i don't know what they mean. if you have any ideas, let me know. i think i want a bit more compression than that, though. i was thinking with an aluminum head, decent ignition and headers, i should have no problems with 9 to 9.5:1CR. these are also cast, and i wanted to get them in hyper. i'll see if that's available but i want your input first so i only have to ask questions once. one question is, do these engines only utilize two rings? the other question above was about the L18 engine. I show a nearly identical piston (only difference in the specs being the dish is 1.3mm instead of 1.2mm) but it's an 85.0mm piston. it's also available in hyper with moly rings whereas the 2.6 L6 is cast with iron rings. maybe i'll do some experimenting with this unless anyone has tried this before.

just wondering if the ford 4 bolt pattern is the same as the early 4 bolt datsun/nissan pattern. from what i read, the stud spacing is the same. has anybody verified this? what about center hub issues? wheel stud size?

hey guys. some of you probably might remember me. i've been posting off-and-on for about a year now. the saga started with a friend who had a '72 that she let sit for about 5 years before she decided to get it running again. she asked me for help, which of course, i accepted (just because i'm the stunningly nice guy that i am! ). anyway, we got the car running but she ended up using it as a trade-in on a new hyundai. oh well. so a couple months ago i went out to her parents house one day after a track event and her dad was very interested in the whole race track experience. so the next day i go out at lunch time and pick him up, take him to the track and get him all dizzy. but i'm just like that! apparently, i made a bit of an impression on him so he offers to sell me one of his other two Z cars he has sitting there, for $100! i ask, "how can i pass that up?" well, obviously, i can't. finally, yesterday i take my fresh, crisp five $20 bills and my trailer out there (about 60 miles away) and come back with one very straight, very original '73 240. it's very straight, with some minor rust. the engine hasn't run in a few years but that (rust) shouldn't be a big issue out here in nevada. i need to replace all the fuel line, rebuild the carbs, clean the fuel tank, secure the exhaust pipe (the back 3 hangers are broken) and replace the tires and it will actually be drivable. well, obviously there will be more to it than that but still, i figure that for about $500, i'll have a running z-car. just damn!

hi all. i don't have much to add to this, i just thought i would check in since this is such an interesting topic to me. i spent a year in okinawa about 10 years ago, with a brief deployment to the mainland, while i was USMC. i understand Katz impression of the island. the US military has something like a dozen different bases in okinawa between the four forces so it almost seems like the entire island is a military base. it's not, of course, but it would be impossible to walk in any direction for a day and not run into a westerner. it was a fun time and i didn't take the opportunity to do all the things there i now wish i had. the same for my time on the mainland. wish i could go back, it's a beautiful country and culture. as for the fairlady, i wish i could tell you anything at all about them but, as anyone who's ever been there will tell you, not many cars live past about 10-15 years before the rust eats them. i'm not surprised the manual actually outlasted the car! i think the oldest car i saw was a late 70's 280 2+2 that was just about rusted away. i never drove while i was there but many of the guys i knew bought these cars that were just eaten away by the rust for $50-100, drive them for a year and sell them for whatever the GCR (mandatory insurance and licensing fee) was or just abandon them all together. sorry for the fluff. just thought i would share that little experience, it was definately a memorable time in my life. BTW, Katz, some of those girls.....

thanks for the input. is .030" the max you can go with the head before you run the risk of getting too thin around a water jacket or the chambers? if you can go deeper, can you either remove a link or get a smaller chain to take out that slack? what about bore? can the 2.4L be punched out to 2.6 or 2.8? if i have it torn down that far, i could just as well bore it and fit larger pistons. milled head and increase in displacement should give a pretty good bump in CR. what is the CR in stock form anyway? i'm just looking to massage this little engine enough to make decent power until i can find a suitable 4.3L v-6/T-5 combination to drop in.

thanks for the reply guys. as i figured, alot of this is just personal taste. the one comment about introducing the japanese manufacturers to the world was kind of telling. i never really thought about that but when i read that, i tried to think of any other japanese car that was taken seriously and i couldn't, at least not here. sure there were some imports prior to that but they were commonly referred to as throw away cars. i love my vette and expect to grow to love the Z as much. i'm sure they're very similar in those certain "intangable" qualities that car people seem to be the only ones to understand. and i'm sure they are very different in many ways and i trust they will complement each other. the one thing that they both share are timeless good looks. since i first started looking at my friends last year, i really began to take notice of those lines. it really is a fine looking car. will let you know as it grows on me!

like i have said in the previous post, i'm new to the Z thing. since i've been on this forum, i've noticed quite a few of you that are very dedicated to this car. i can admire that. my first (car) love is the corvette. they're great cars. unfortunately, they're too heavy and expensive to go out and just enjoy a track day. so mine will get restored and the Z will become my track car. from what i've seen so far, it looks like a platform with alot of potential. already, though, i can feel the same type of division with the rest of the Z owners, just like the corvette community. there seems to be two or three sub-groups in each group of car enthusiasts. one says restore it, anything else is destroying it. another says, race it, that's what they were meant for. and yet another group says, modify it and drive it. just don't junk it. so what's the big deal with the Z? i can tell it has a much more international appeal than my corvettes do. been imported all around the world so they have a world wide reputation. but yet, they're still somewhat of a novelty even so. give me a little history of the Z and what it means to you.

again, the car is a '73 with roundtops. i was on MSA snooping around and what i'm thinking of is the stage 2 or stage 3 cam kit and the 3-2 coated headers. i will be doing a little port work on the head myself and have it milled to increase CR too. when i have it milled, do i have to shim the cam towers? i noticed they listed a separate header for the '73 from the '70-72. why? will the SU's support this if they are rejetted? (sorry, i don't really know what is going on with them. more of a quadrajet kind of guy). pertronix with a hot coil and new pipe with something like a flowmaster will likely round out the engine mods. any other suggestions? BTW, this will not be a daily driver. maybe a little weekend driving but mostly track.

well, since you guys brought it up.... the 240 i'm picking up is still mostly stock except for the (apparent) retrofit of roundtops. i'm pretty mechanical by nature and fully intend to tweak this little dude. i'm currently thinking of new cam with a fresh head re-work, including a fair amount of porting, maybe a slight mill to bump compression and full exhaust. will the pair of roundtops support this? top end sounds good to me, i have no qualms about rapping an engine to 6000 all day long!

wow, quite the busy little thread we have going here!:classic: since i know next to nothing about these carburators, bruce can you explain to me what the biggest advantages and disadvantages are to them in stock form. and then tell me what you do to fix that (and an idea of how much that costs). at this point, i just want to get it running well enough and focus on the suspension and brakes. then, once that stuff is done and i have a few bucks to spare, i'm finding a chevy 4.3 v-6!:devious: love my chevy power!

thanks guys. sounds like either way, i'm golden! right?

o.k. guys, this is pretty much wide open. i'm really new to the Z-car thing so i don't have alot of experience with what mods these cars like and what to watch out for. what i can tell you right now is the car is a nearly stock '73. it will be modified for track events so cornering/braking will be of utmost importance. i'm planning on running a DOT 'R' compound tire like the kuhmo v700 or g-force KD, about a 245-45-17-ish. find some front disc in the 11-12" range and maybe run some wilwoods. i have no idea what to do about struts and anti-sway bars though. have at it.

forgive me if this sounds like a rookie question, since i am, after all, a rookie. my experience with the Z consists of a little work i did on a friends '72 earlier this year. well, the good news is i'm picking up a nearly identical '73. apparently, the hitachis:cross-eye have been replaced with SU's. i am slightly confused though because although they look very much like the SU's on the '72, i noticed these have 4 bolts holding the 'dome' on where the other ones had 3. at least i think the other ones had 3. am i imagining things? were there two (or more) different types of SU's? anything i need to know about these carbs?

man, sorry to hear about your cam but at least it's warning to others like me who are new to the Z thing. as long as we're on this subject though, i was about to start a thread asking where to get performance parts for the L6, like a new cam. who is MSA? what other companies/catalogs should i look for? and most importantly, who should i stay away from?

some of you may remember the saga of my friend's '72. i spent quite alot of time asking questions and getting advice. well, i have bad news and good news. first the bad news. said friend traded the Z as partial down payment on a new tiburon. not really a bad deal because she really needed something reliable. now for the good news. her dad still has another '72 and a '73. he is saving the '72 for her, well, because he loves her and all that 'parent' stuff. but i've helped her out alot and he appreciates that, so that has gotten me "in there like swim wear" and he has offered to sell me the '73 for, get this, $100! now granted, it doesn't run (yet) but that's just because it's sat for the last 11 years since they moved from colorado. the car is straight and clean, with no rust. and it appears the only thing that would need to be done to get the car in good operational shape would be replacement of all the rubber lines and cleaning out the bad gas. he's even replaced the square top carbs with the "good" round tops! how cool is that?! so because of the costs associated, i will be retiring the corvette from track duty and performing a 'resto-mod' on that and the Z will become my track car. should be alot easier and cheaper to make go really fast. WHOO HOO!

hey guys, i will be joining the ranks of a Z owner here shortly (new thread in general forum). but i do have a couple questions. baiscally, is the L6 block in the 240 the same block as the 280? in other words, if i have an original 240 block, can that be bored and factory sized 280 pistons installed? also, what cam/valve options are there for good performance? the plan with the new car is to just pull the motor from the beginning, have the block bored and honed, replace the cam, chain and oil pump and anything else that needs actual attention. anything else you guys suggest might need attention? i just want to get this running as strong as i can on a minimum budget until i can find a suitable v-6/5-speed for a swap. it will soon permanently take over track duty from the vette.

ahhhh. so i do have tha sprocket on backwards. i was wondering about that. the other thing is i never removed the lower cover so i couldn't see the crank sprocket at all. i started out in the hole, although it would have been nice if i had timed the motor before just tearing things out. one other thing. i never saw any obviously 'bright' links in the chain. there were several that appeared to be cleaner than the others but i'm unsure if these are the ones others were mentioning or what.

thanks, jeff. all information is good information. i don't remember seeing any numbers on the sprocket. the one thing i do remember is there are three notches on the ring. they are facing out, toward the front of the engine. i don't know if this is right or not but seemed to make sense as i think that raised hub would hit the plate if it were turned around. i also thought i saw a distinct line on the sprocket where the varnish staining had stopped where it's bolted to the sprocket (i dont' know if i'm making any sense here). additionally, since nothing was really replaced except the bad valve and related gaskets, alot of the internals are still as they came apart. this gave me some hint as to which location to use for the dowel. there are two dark varnish spots that correspond to the holes in the sprocket. i've just made sure the sprocket holes line up with the varnish stains to make sure the cam is timed correctly with the sprocket. that only works if i have the sprocket on correctly. thanks for your help!

hey guys, i got the cam timing thing figured out. looks like i was a tooth back on cam timing. so now the thing seems to run half way decent but for some reason the fuel pump eccentric is hitting the valve cover. i'm wondering if i put the sprocket on backwards. it seemed to be the only way to make sense to me but maybe i'm wrong. the way it is now, the shoulder is facing forward. there doesn't appear to be enough clearance for it to be turned around but since i didn't pay adequate attention, like i should have, during disassembly i don't know:o need help here, please! also, i don't know if this is related but it also seems as though the cam cover is hitting something on the back when i reinstall it. i've checked that all the cam towers are fully seated and inspected the cover for signs of contact but came up with nothing. still, when i put the cover on and just lay it in place, there seems to be a 1/8" gap between the cover and head sealing surface. any thoughts on that as well?

well, i got everything back together today. reset the lash to .006/intake and .008/exhaust. bolted everything back up. why is it you can put the exact same parts back on that you took off but yet nothing seems to want to line up quite right? is that some kind of assembly line voodoo or something? anyway. rolled the engine over a few times and didn't hear any clattering or othewise nasty noises so hooked up all the plugs, wires and hoses. after charging the battery a bit, i gave it a start. turns out i was 180* off on my ignition timing. for the time being i just rotated the plug wires, i'll redrop the distributor later. well, it kind of sort of runs, a little. <---been doing this alot today. but it won't stay running. it'll kind of lope along for 20 or 30 seconds and just die out. put my vacuum gauge on it to see what it reads. and i get just a couple inches of vacuum. i'm going to do a compression test tomorrow but my theory right now is, the most obvious, i have the cam timing off. i figure the cam timing is late, real late. at that low an idle (~400rpm), i would expect to be pulling at least 15", even if ignition timing is off and carbs are out of whack. needless to say, i checked everywhere for an external vacuum leak but could not find such a thing. that really only leaves the cam timing. as i figure it, the valve opening and closing events are occuring much closer to the center of the pistons stroke than at either TDC or BDC. that is the only way i can figure i haven't had valve contact and i dont' get any vacuum. so, any suggestions on what to do to fix this timing issue? i know the cam sprocket is on the same setting on the cam but i'm sure i'm off the correct tooth count. how the hell do i time this thing now? :ermm: