260z 2+2 RB20DET The Frankenstein rebuild

I wasn't going to go to this section till i completed the car but got so much stuff i though i better start slowly.

The Start

I was bored nothing to do on a HOT summer weekend.Just sold one of my cars so had bit of $$ to spend. Started thinking what car would be cool unique and wont depricate much over the years. Also that can accept an import engine and that its faster than my current car an S14 S2 200sx.

First to mind came a 2 door mazda 929 or Rx4. Had to be 2 doors and had to be the pointy nose one.being a nissan freak the dream mazda was going to have an sr20det with few mods. being lighter than s14 should be faster.

Grabbed the trading post and to my disapointment none available. being of the type  I WANT IT NOW. i started thiniking what Dato i like that has the same qualities as the rx4 did.

Not being a big fan of 1600 frankly they look ugly to me same as any other datsun in that era besides the early Z car. 240z or 260z. SR20det will fit with ease same as any RB or VG.

got the trader Again and fair enough found two for sale. one was defected so it was scraped and other siezed engine for $1100.grabbed the address and i was off to check it out.

Being around automotive industry for a while i knew where and how to look for problem cars. in my head it had to be complete not defected so its registrable and all the outer chrome bits present.

when i arrived wasnt that good but after a while wasnt that bad for what intensions i had for the car. it was a 76 2+2 with sunroof and auto tranny with 1cm of rust in the bores and top of the pistons.

no way i was gona pay $1000. after negotiating got it down to $500 with owner to pay for half the rego and transfer.

went home and grabbed the trailer to bring my new beast home.

here some pics of the day.

When it was parked under the carport the planning started.

In my head everything out just the dash and body is to retain its originalty. had to have a later model engine with big brakes. rear drums to be deleted. needed more info so turn to the internet. Found hybridZ and few other known Z forums but i wasnt interested what USA was upto but more what AUS was.

Thats when i stumbled accross VicZcar and theZgarage being the local one.

didnt register or anything like that just kept reading the info. did all the homework regarding RTA rules and talked to few engineers to see what im allowed and what not.

after i  was set on what to do i joined the forums.

not much had changed from original plan which was to build a fast and comfortable every day car with all the gadgets.

Import engine SR or RB turbo

5 stud conversion

Rear disks brakes

4 spot front vented brakes

LSD diff

Power mirrors and windows

boost controller

Alarm

normal stereo (not 200kg of crap in the boot)

Power steering

Digital climate control and A/C

All the wiring to be replaced with the engine donour half cut

Front original seats modded and retrimmed while rear retrimmed to match

Custom door trim to match the seats.

Custom Gauges to be white facia with digital trip meter.

I tried sticking to the plan as much as i could but as most of us know some things we do not forsee and do end up changing.

All the work was to be done by myself to save the capital outlay unless i was forced to contract other people cause of lack of expensive tools.

i wanted a clean street car that is faster than my other car but not more expensive. initial budget set was between 7k for basic to 11K for full optioned car.

When the project started i was doing realy good with the budget. most of the major stuff was purchased and only took 3.5K still 3.5k to go and couldnt find any mayor things to spend it on i was in reallly good shape.

cost cut down

car $500 + 90 for rego and transfer. Yep she was registered and on my name 

front cut R32 GTST $1300 with bigger turbo and brakes nardi steering wheel with boss,turbo timer and something else i cannot remember now. Bargain!!!helps to know well some importers

diff $750 lsd 4.4 with cv shafts

power steer rack the Mazda one that got scraped at later date $250

big intercooler and apexi boost controller thanks to ebay $500

And other bits and pieces that i was missing from the car. chrome strips and mouldings etc...

so the striping and....................

the rebuild started

when things were stripped to my supprise i didnt find many hiding gremlins. the car was repaired at some stage with all the major trouble spots replaced with rust repair sections. some things they took shortcuts which i ended up cleaning and fixing with metal and not with fiberglass.

At the time i didnt pay to much notice to other cars and details 240z vs 260z . to me it was the engine size and 2+2 had the extra back seat but the cars were identical) but i kept noticing that my 2+2 definetly has different lines.

thats when the trouble started.

I always wanted the 2+2 for practical reason of a daily driver but the 240z had something different about it and sure did some 30cm less of it and different 1/4 window.

half way through my project i was thinking i wish it was a 2 seater. but i still pressed on. though searching for some parts for the 2+2 i ended up buying the first advertised defected one for parts car for mere $85 with complete good rear bar. at the same time i stumbled accross some RX4 which i still couldnt get out of my head. i still wanted it.

but i was determined to finish my 260z the stretch version no matter what. i was too far into it to back out.

THE Frankenstein BITS

In the list also came the electric metal sunroof that was borrowed from a 84 celica. at the time couldnt find a replacement roof to get rid of the ugly pop top. (till about 3month later the parts car was purchased with perfect roof)

to be continued..............

few more bits

the car was always going to have a power steer. so hunting i went. a Mazda rack was purchased and later discarded as being too wide. so the path of the Subaru rack has emerged.

sold the Rx7 rack at a loss on ebay and purchased a reconditioned Subaru liberty/Leone.

Searched on forums to see what people did with the mods. didn't like what i was seeing. Chunks taken bit here bit there. didn't think RTA would be happy to see that. so got all the bits together and started experimenting.

the aim was as less mods to the subframe as possible.

my power steering guy told me that the Subaru power head can be rotated 180 and work perfectly. obviously the new lines had to be made. the help of Phil from Kent Automotive got that sorted out really well.

in the equation also fell 5 stud front conversion and 4 spot brakes and vented rotors. had R32 items but to adapt to the stock shocks proved bit of a nightmare and again RTA wouldn't really like it.

(RTA in SA rule book, if things are welded need engineering checks and to be welded by a accredited welder (big $$$$$) other option is to use parts of other cars. can drill and bolt things up without special licence but the bolts obviously had to be high tensile with locks which can be easily checked and verified by engineer and RTA)

so to avoid using a licenced welder i went down the path of finding alternative parts that can be bolted up.

the trick was to find a car that has a strut assembly that can bolt to hub assembly that has 4 spot brakes and front mount rack. could have used rear mounted and swap left to right. but the issue i came across is the struts themselves. it had to have a smaller diameter spring seat.

to remove spring seats on a gas strut was difficult and expensive. (welding issue pops up)

S13 and S14 Silvia/200sx had most of the benefits but being hard to get and very expensive i looked further down the chain.

Visiting a Mazda rotary specialist to try find my first obsession the Rx4 coupe i told him about my dilemma. than he pointed out that s4 Rx7 has the same properties what i wanted but even more. the front struts had a small diameter seat.

a quick measurement here and there seemed like a good alternative. especially having lower ball joints that are removable with 2 bolts.

a swap with him for s4 Rx7 hubs and lower ball joints for my R32 gets front brake setup. found 2 crappy struts and home i went to put the puzzle together.

the lower controll arms mods were necessary and some none structural welding was required.redrill 4 new holes and weld the old ones up was pretty straight forward job.

at the same time stabiliser pick up points were borrowed from Rx7 as well. so still stock stabilisator bar can be used.

the whole thing was than brought to the subframe. marked where "dents" had to be put in to clear the power steer lines.also the right engine mount  bracket had to be slotted to pass the rack spindle.

bit of heat and few hits with the hammer got my shape. few cuts with grinder i got my basic setup sitting quite nicely.

to reinforce the slightly slotted right engine mount bracket. 1.5mm thick plate has been shaped and double welded to the bracket. that reinforced the right engine bracket.

at the same time the engine mount holes have been slotted as per R32 skyline frame. R32 engine mount have been used as well.

while at modding i thought ill install a slight adjustment on the lower controll arms. so lower controll arms holes on the subframe were slotted and guide welded in. thanks to Nick 240ZR for the idea as i seen his rack with similar mod.

new lower ball joints have been purchased as well as new Rx7 struts. so i had sorted out the lower part of the bolt up. with subi rack shortened and tie rods from n12  pulsar were used to connect the rack to the Rx7 hubs which had 4spot calipers vented rotors and 5 stud hub. so far so good.

the next issue was the strut tops. this was easily done by using stock z top hats that had the hole slightly enlarged and "D" shaped to accommodate the RX7 strut. fairly easy mod. now in between we are missing a spring. Mazda had a conical shape spring small diameter at the bottom with large at the top. Z had smaller top by almost a half than the RX7. so stock springs are out.

A trip to universal springs or Aurora springs with my strut and hat setup. the guys were helpfull and made a custom spring to suit. didn't cost a fortune. bit more than lowered springs. all was put together and looked like it just came out of the factory.

so that sorted out the power steer, 5 stud, and 4spot vented brakes conversion.

the above setup was my work and its the only Z around at this time with that setup. not sure how Nick ended up with his but he was looking at doing the same thing.

the beauty of the above setup is that i can use Mazda Rx7 coilovers ( tein,hks,mazdasped etc...) with slightly modded cap with camber adjustments which are in abundance.

next on the agenda was rear which ill explain bit later. at this time probably anyone reading this is half asleep. sorry peeps.

more pics (take 2)

At this stage the obsession of trying to find a Rx4 was huge and luck has it i found one and really wanted it...... but wait it was on ebay.

the car was in Melbourne and was genuine RX4 with a piston engine fitted. price was good but it also reflected on the car. it needed bit of work. work no biggie i wanted the car with good rust free chassis.

while negotiating the price for the rx4 and doing all the relevant check to see if the car is in the clear a local defected 72 240z also popped up on thezgarage.com. dilema dilema. the 240z was local but the price was 3 times more than the Rx4. 

Went to check out the 240z before settling on the RX4. It was in Adelaide hills so bit of a drive out of suburbia.to make things easier my workmate llives in the same town. so of we went after work to check it out and drop him home.

the price for the 240 was 3K on initial glance it looked good but it had few big badies. like 2 defect stickers, blown head gasket on the l28 and some butchered work on left chassis rail. nothing that cant be fixed but the price was bit too high. i offered 2k but owner said no. so i said to him offer stands for a week otherwise not interested as i got another car lined up.

never got the call so i proceded with the RX4.

few days later i got my yellow 74 Rx4 coupe. now i had another toy to think about and play with. bad move on the 260z which had few weeks delay because of the mazda. findign info on how to do things and what to avoid. Also was hunting to find my first Rotary engine. it had to be turbo and 5spd.

Originaly the car came with 13b so naturaly was going to replace it with 13B plus efi and a huffer on the side.

the SR20 went to drain for the RX4 beacuse now i was a firm believer in non cross breading (at least engine wise)

eventualy found a S5 rx7 13b turbo engine with 5spd and all the electrics for price that was a steal sub 1K  . so i have my first rotary engine and my heart was set.

so got my arse in gear and started to concentrate back on the 260z. at this time i forgot all about the 240z.

some more pics

PS some pics are shown while the mods have been made and than assembled to the car when all got painted and detailed. so there would be some early shots going to final shots and than back to early shot again. i thought ill do section by section from start to finish.

Been a while since ive done an update on this.

bit bored so thought i kill some time.

Rear Setup:

The LSD Diff  i got come with cv driveshafts. The 4bolt turbo ones. Even thought the original uni shafts will just plug in i still had an issue with 4stud hub that needed to be converted to 5 to match the front.

internet bashing i came up with solution. i needed Z31 turbo Hubs as their companion flange matches the CV shafts i had.

Also Z31 300zx turbo had 5 stud and largish disc brakes.

after few fone calls to local wreckers i found a pair of complete trailing arms hubs with disk brakes calipers and companion flange. all for the grand sum of $220.

the trick was to remove the stub axle, get new bearings that match the shaft and the 260z hub. than just bolt it all together. yeah RIGHT......

after having both 260z and Z31 hubs appart there were few mayor differences.

biggest problem being that 260z used imperial sized bearings while the Z31 used metric.

finding such bearing was impossible.

conclusion was made that i needed the axle turned down to accomodate the imperial bearings or make the hole slightly larger on the hub to accomodate metric bearing.

i decided to go for the second option as i didnt want to weaken the axle.

finding a place to enlarge the diameter by approx 1mm was very difficult.

But luck has it that i was given a number of a retired machinist and mech engineer that ended up doing the job for small amount of $ with quick turn around.

got brand new bearings and that was it.

at the time ive noticed the spacing on the brake caliper bracket and 260z hub were identical

got the old guy to chop the brackets clean them up and the whole thing bolted together.

there u have it. CV conversion with 5stud hub and disk brake conversion in one.

but not the case. there was a small isue of driveshaft lenght that i knew about but just wasnt enough.

issue with drive shafts was they were tad long when wheels were fully pressed under load.

this wil cause the cv to bind up. big no no...

after tiresome searchin i couldnt find off the shelf replacement shaft.

back on the net and found out from our yankie friends about little trick called CV race reversal.

this means simply to remove the cv race and install it the other way around. this magicaly reduces the overall lenght ov the driveshaft.... but was it enough...... simple answear NO....

it reduced it by about 15mm now they didnt bind up but there was only slight freeplay.

rule of thumb from my suspension steering expert was that it needs at leas 10-15mm of free play.

he suggested to me to cut a new the circlip  grove slightly further down the spline on both ends. by doing this he managed to shorten the drive shafts by further 15mm..

new cv joints with heavy duty cv grease and back on the car. Finally the rear setup was complete.

need to find pics of this and i post it as soon as i find them.

next in the line is the engine bay and master cyclinders for brakes and clutch.

now with brakes present the stock master cylinder wasnt up to the job.

since i still had the front cut i utilised as much as possible from it.

quick check on the R32 master seem to be a good fit. small problem. the bolt spacing between the s30 and r32 were different. nothing a drill and grinder welder cant fix.

original s30 holes welded and new spacing redrilled. brake master in.

even though the manual Z came with hydraulic clutch mine being an auto didnt come with it. finding an original clutch master seemed to be too hard. another quick check at the r32.

yep should fit but again the hole spacing was different. no biggie weld, grind drill and the clutch slave was in.

but one of the holes was slightly outside of the pedal box. slight pedal box mod plate extension and welded an nut on both holes so the master can be bolted up with ease.

that seemed to sort that out.

while i was drilling, grinding and welding in the engine bay started removing brackets that were no longer needed.the same faith headed to the exess holes.

The r32 engine compartment fuse box needed some mounting were the original relay fuse box lived.

I bent up a bracket, welded the nuts for mounting  and that ticked off another annoying job.

the fun bit is next the engine.