labrat

I have an 81 zx and was in just your position two weeks ago, and here's what i did... i have the power non rack n pinion steering, so it may differ from your situation. i don't have pics, but this description may help. On the drivers side, i just put 3" of aluminum plate between the block and the motor mount (from a 69 chevy truck) and used longer bolts. Frame hole lined up perfectly. On passenger side, same thing only used 2.5" of spacer. This left my carb very close to the hood (there is also a 1" spacer under carb to adapt my squarebore carb to my spreadbore manifold). For the exhaust, i had clearance problems with my steering gearbox, so instead of headers i used stock manifolds. The drivers side is a rear exit type manifold from a chevy truck, the passenger side is a center dump ram's horn manifold from a 69 caprice. I hope this helps... Bill

Ditto on the bolt thing. I almost went broke buying grade 8 bolts!

From what I understand, the higher rod/stroke ratio increases piston dwell at TDC after ignition, increasing cylinder pressure, and increasing horsepower while reducing detonation. I'm kinda fuzzy too about specific effects on horsepower/torque, but long rod + short stroke = good thing.

Well, it seems i have the uncommon power paralellogram type steering in my 81 ZX, and it has made mounting the 350 and finding headers VERY difficult. I finally had to go with 3" of spacers on the drivers side, and 2.25" on the passenger side with no set back plates to get everything to fit right. Bell housing bolts are easy to get to from the top, though. Headers were definitely not an option, had to go with cast iron manifolds. Center dump rams horn type on passenger side to clear starter, and rear dump chevy truck manifold on driver's side to clear steering gear box. What a PITA! Now the only thing i really have to worry about is the driveline angles from mounting the motor so high (shouldn't have to raise the back of the diff, though), and cutting a hole in my hood for the f$@#$&g carb. well, the carb would fit, but not an air cleaner. Has anyone else done this swap, and if so, did you have these problems? Sorry, just venting some frustration, and trying to document this for posterity! Bill

Okay, tore down the motor this weekend and resolved the dilemma. Cam had no bumps. Ok, well, about half as many as it should. Few of the exhaust valve lobes had any lift to speak of, and a couple of the intakes as well. Midnight run to autozone for a wolverine/blue racer with lifters and lube, and 5 hours of swearing later my friend has one bad-ass 72 240Z! Took it up and down the street his neighborhood, and left paralell 14" wide rubber streaks for 50 ft.! All we have to do now is get the vacuum secondaries working... Bill

damn man, that sucks!

Thanks Ross, that was exactly what I was looking for! I'm gonna try 2 1/4 on drivers side and 2" on the pass. side to start, and work from there. Is there any danger to "dimpling" the oilpan all the way across, like oil not returning to sump? Just wanna make sure and not blow something up... Bill ps already got the mounts made, but finding bolts is a pain!

Well, to be more specific, i used a 1" thick spacer on the pass. side and a 1.25" on the drivers side, and the motor mounts come about 1" from the crossmember when the motor is centered. I went out and bought some more aluminum stock, 1" thick, and made yet another spacer. I hope when i get the longer bolts that it will be enough. Ellobo, please send me those pics! If this doesn't work, i will need an alternative method! I might just use your way if I don't like the looks of all those spacers. 2" on each side is more bolt than i really want...

That holley tuning guide was great! I have a holley and an edelbrock, and there is no comparison as to which is easier to tune!

Well, I had a set of motor mounts made up just like the JTR manual says, except for the setback plates. 60 bucks at the local machine shop. For some reason, they don't fit. In my test fit yesterday, the oilpan hits the crossmember long before the mounts line up. Has anyone gotten this to work, and if so, what thickness spacers did you use with your mounts? Thanks a bunch!

i'm using a set for a 69 chev truck. $6.50 each from autozone... they look hard as a rock though, and will probably transmit lots of vibrations into the passenger compartment. They will get my car running, though. you can always swap to OEM once the vibration issue reaches the top of the priority list.

well, I think this is a carb problem anyway... The car sat around for a few years, then my buddy bought it last weekend. It is a 72 240 with a 327/th350 combo that tubbed and narrowed with a for 9 inch and 4 link in the back. Problem is, he just rebuilt the Holley carb, and now it does strange stuff (well, still does strange stuff...). In park or neutral, the motor screams. Revs to 5k and back smooth as silk. WOT sounds great with no hesitation or bog at all. When you put it in drive, however, it starts running like crap. Bogs completely at anything over 1/4 throttle, and backfires out the exhaust. I'm in austin and he's in dallas, and i m trying to give him tech support over the phone. Is this more likely a timing issue or carb? I'm thinking retarded timing, can the timing chain cause this? he says he's tried timing it, i really don't know though. Just looking for some places to look! Thanks guys! Bill

Well, I figured it out today. As I was checking timing for the 10th time and readjusting the carb yet again, it ran out of gas. Put in 3 gals of premium, and it runs like a top! No hesitation or bog at all, and no more fireballs! It was either leaning out because it was running out of gas or it was the old gas that had been sitting in the tank. Finally got all the timing numbers and idle speed from the 68 vette 327 haynes manual. Thanks for all the help! Bill [ November 01, 2001: Message edited by: labrat ]

Well, figured out the correct timing mark, and made sure it was to to 8* btdc @ 1000 rpm. backfires through carb still. changed it to every position through 12* initial timing @ 1000, still happens. Tried readjusting carb. No dice. Are these numbers correct for the timing? Thanks

Well, without the vacum advance hooked up and the port blocked, it came out to 4 btdc with the harmonic balance white out mark. There are many marks on the balancer, and i don't know if this is the true tdc mark. I know it should be around 8~12, but i was unsure of the timing marks...

Well, this 327 motor has been sitting for about a year and we finally get the car running, but it's running REALLY rich on the Holley 4 bbl. Try to adjust the carb, get kinda close, but backfires out the carb (Big Fireballs!) when slamming pedal from idle, and still blows huge black smoke clouds. Off comes the Holley, on goes brand new 600 cfm Edelbrock 1406. Adjusted carb per manufacturer's specs. Idles good, runs good, but on "Slamming" the gas from idle, still huge fireballs! Is this a carb problem or in the ignition timing? This is a new carb, it was supposed to make the problem go away! Thanks Bill

This is a swap you really need to think long and hard about, as there is not a lot of info covering it (yet) on this forum. Most of the swaps done here are to the older model Z cars, not ZX's. I am in the middle of such a swap myself, and have to rely on my own intuition more than documentation here. It's good for ideas, but you will have to work out some particulars for yourself. I don't want to discourage you in any way, but be aware that you will be blazing a trail, so to speak. I will try to add my experiences to the vast amount of knowledge on this forum, just to give a little more voice to the minority of ZX owners out there. You may even want to buy a 240 or 260 instead, since you haven't purchased the car yet. I didn't have that luxury, and a motor swap was definitely in order (threw my main pulley and it "remachined" my crank), so this was the cheapest and easiest way for me to even have a running car again. Hopefully it will all be worth it in the end though. A few things to watch out for in the meantime: Verify which steering configuration the car has and make sure you find headers to fit. There are three different versions, power rack n pinion, non power rack n pinion, and power parallelogram. Each one is mounted a little differently and the header has to miss whichever you got. You can't use the JTR method to set back the motor with the setback plates. The crossmember is 3 inches closer to the firewall in a ZX, so the motor mounts go right over the frame horns in front. This shouldn't affect handling too badly, however, as the ZX's are heavier overall anyway. The strut towers are slightly farther apart in a ZX, but that room is offset by the greater number of options that these cars had. Cruise control, power steering, A/C, all of this has to be factored in. I'm not trying to dissuade you from this, just trying to give you some of the information that I didn't have when i made my decision! Bill

If you decide to go auto, i have a TH350 newly rebuilt with a shift kit i'd be willing to swap even for the 6 speed...

Has anyone used a driveshaft from an older model (`69) truck in the conversion? The truck driveshaft I have looks quite a bit larger in diameter than a car driveshaft ~ 6 in. in diameter or so. Will the "flywheel" effect of the larger driveshaft cause any problems? Will there be clearance problems with the exhaust? And finally, will the neapco adapter fit the u-joint on this driveshaft? Sorry for all the questions, but its zero-hour, my ZX is sans engine, and the new one goes in next weekend (Hopefully!). Thanks for all the input, and as always, HybridZ RulZ! Bill [ October 21, 2001: Message edited by: labrat ]

I have an 81 280ZX (One of the few ZX conversions i've heard of...) with a freshly removed l28 trying to wedge in an: early (lh dipstick) 350 block flat tops .030 over dart iron eagle heads edelbrock performer RPM intake edelbrock 600 cfm carb 4106 edelbrock cam (don't have specs with me) HEI Ignition with accell coil and module TH-350 tranny with B&M Shift kit Hurst Pro-Matic ratchet shifter all of this put to the ground through crappy 235 60 14 yokohama's

I know I have to plug/unplug my head temp sensor every oil change several times to keep my 81 NA running right. 20 years of corrosion has really done a number on those connections...

It also depends on what you are willing to "settle" with as far as parts and such go. The route i'm going, i bought a wrecked 69 chevy truck my neighbor has been restoring with a new motor and transmission for less than $500, and i'm hoping i can keep the rest of the cost below $800 or so, not including brake and suspension work, which i will handle slowly as budget permits.

Well, i don't know if it's easy enough for a five year old, but if you know what all the parts are and what they do, then you shouldn't have too much trouble. At least you have everyone here to help you out if it gets too hairy!

Well, I just got the flowtech's from autozone. The price was very reasonable, 79.19 tax and all. I Just hope they fit! The tubes are kinda long, and they are listed for chevy trucks and blazer, but I think they just might work with my setup, as long as they are tight enough to the block. They have a good return policy and are right across the street if they don't... Thanks for all the input! Bill

Well, the swap is rapidly approaching, and I have a serious problem... Headers. The clutch went out on my stock 81 280ZX (na) on the way to work this morning, and my donor truck will be here friday, so the swap will start this weekend. My problem is I have a $500 budget for the exhaust and driveshaft and other incidentals, and i can't afford $300+ for headers alone. Does anyone know of a pair of relatively inexpensive (under $150) headers that will clear the power steering gearbox on my 81? It's parallelogram, not rack and pinion. Would it be acceptable for the exhaust shop to modify the long tubes that are on the truck now? Or should i just hit the boneyard for some stock manifolds and have them machined to fit tighter? This is the only hitch in my plan so far. I was originally gonna go with the cheapo block huggers from summit ($79) and wrap them, but according to the sales people at summit, they hit the motor mounts on both sides. They won't even fit a stock application! Since this is a ZX, it will be a Scarab type mount... Thanks for any and all input. HybridZ's Rule! Bill