School Break - Rust, Rollover and Aesthetics. It's been a good holiday

[Tommo560]

I Finished my final year of high school in November last year, completed my TEE exams and achieved a Tertiary Entrance Rank of 98.00, putting me in the top 260 people in the state to sit the exams. I applied for University and had my application to study Chemical engineering at Curtin University of Technology accepted, as well as my application for an academic merit scholarship which covers all HECS fee's and provides $2000 a year in tax free dollars provided I can keep a course waited average of above 70.00%. So, well quite frankly, with a 4 month holiday ahead of me, and not much else to do but work, my dad and I got cracking on my zed. Here are the results so far with 2 weeks before the next event...

After coming fairly close to rolling the car at Wanneroo in November due to coming off into the sand at Colb sideways at about 100 kph my dad and I decided that we should have a little less conversation about putting a cage in, and a little more action :cheeky: . This is a fully cams approvable roll cage and we only need to complete the paperwork before we will receive our cams log book. We painted the cage flat black to match the interior colour so that it doesn’t stand out like a sore thumb when I drive the car on the road, and we will be trimming over those parts of the cage that we can; namely the bars across the roof and down the A pillar.

*** :disappoin which is a pain, so they wont appear as pics in the post, but as links instead***

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The accident also stressed the chassis so much that all the rust in the structural areas of the car has cracked and reared its ugly head . As a result the car is now, as I type, currently having the rust cut out of the rails and new rails being fabricated. Some rust has also been found in the strut towers at the front of the vehicle and where the seat mounts are welded to the floor so they are being sorted out at the same time.

With the car being silver we decided that all the chrome parts didn’t really look very aesthetically pleasing, and give the big "WOW" factor that they do on a darker coloured car. To rectify this situation and to make the car look all the more outstanding we decided that whilst the car was stripped for the cage and rust work that we would have all the chrome fittings, including the door handles and all locks, powder coated satin black :bandit: . I currently don’t have any pics but an alarm/immobiliser/central locking unit has also been fitted for safety and to add some creature comforts to the car.

We had to pull the motor out so that the panel beater could fix the rust in the rails, so this gave us the opportunity to do the valve grind to stop the compression leak past the valves that the car currently has. When we pulled the head off the whole combustion chamber, piston, exhaust ports, and to a lesser extent the inlet ports, were totally covered in a thick layer of soot because the motor has been running so rich in attempt to fix a flat spot.

We went to have the head skimmed today to put it back on the block and we found out that the head is actually already 1mm under thickness to increase the compression, so that couldn’t happen. We also managed to finally track down the man who originally built the motor several years ago and he said that this was something they did to get more grunt out of the motor.

When removing the valves from the head for the valve grind we also found a broken valve spring that we are trying to find a replacement for. With the motor not having stock springs, (2 pounds harder and having one less coil, 6 instead of the factory's 7) means that we are considerable having trouble trying to find someone with one spring in an attempt to not have to buy a complete set, and not having issues with the spring binding due to the huge lift on the cam. Although having said that we have found out from the man who built the engine that there are 3 other similar heads in storage in Osborne park, and we should be able to have a look and get a spring from one of these heads when we go to see them in a few days. Another man who has a head modification shop was also able to tell us that Crow Springs sell a spring that matches what we have, but this would be the expensive option and so hopefully we don’t have to resort to this.

The panel beater is also going to fix some of the very dodgy modifications that have been made to the cross member for racing applications, and so the cross member has been sandblasted so that he can see what he is working with.

As well as making all of the aforementioned modifications I have also spent days working with a wire brush to rid the car of rust on the floor and the boot, and we have repainted these area's body colour so that they look presentable when we take the carpet out when we race. I am also just working to make the car look more presentable in all areas and so we will be installing new carpet soon, repainting the engine bay, repainting the block blue, and I have already painted and polished the tappet cover.

The car should be back from the panel beater on Wednesday with any luck and so then dad and I can get stuck in to putting the car back together and take it to the tuner to get the webers dyno tuned for the first speed event series event on the 18th Feb.

Tom.

[mjfawke]

Full cage? Not street legal in the ACT - did you check the WA rules before fitting?

Hmmm... E88 Injection skyline head. Supposed to be one of the best combustion chamber shapes. Don't sweat on taking more off the head, as they are usually safe up to around 2mm anyway. The cam towers were shimmed, weren't they? You would have to change lash pads if adding more shims. As for springs - replace the entire set now. If one has fatigued and broken, more are on their way. I know someone who lost an engine this way when a second spring broke and the valve got taken out when it floated.

And what was the dodgy crossmember mod?

[kenz240z]

Wow, Tom, looks like a bit of work there, but you seem to be making good progress!

[kenz240z]

Wow, Tom, looks like a bit of work there, but you seem to be making good progress!

[1 Bravo 6]

G'Day Tom,

Congratulations on achieving a TEE of 98.

As far as I'm concerned, it's far more important than what you're doing with the Zed.

To me, Education is the most important thing in a young man's life.

So, once again, congratulations. It wouldn't have been easy. I should imagine there was a lot of burning of the midnight oil to score a 98.

Rick.

:devious: :devious:

P.S. My son has recently been accepted to do his PHD, actually skipping the Masters, so I have a fair idea of the work you have put in.

[Tommo560]

Full cage? Not street legal in the ACT - did you check the WA rules before fitting?

Safety on the track has to come before some things we felt, so when i get defected for it we may have to modify the cage so that it bolts in at the front. would be a pitty but having the cage means we qualify for targa west, classic adelaide and targa tas, and we already do quite a few hillclimb events a year and when you are doing high speeds with trees on the verge of the road then you need some sort of protection, so this is what we have done.

Hmmm... E88 Injection skyline head. Supposed to be one of the best combustion chamber shapes. Don't sweat on taking more off the head, as they are usually safe up to around 2mm anyway. The cam towers were shimmed, weren't they? You would have to change lash pads if adding more shims. As for springs - replace the entire set now. If one has fatigued and broken, more are on their way. I know someone who lost an engine this way when a second spring broke and the valve got taken out when it floated.

And what was the dodgy crossmember mod?

Its actually a P90 head, not as high compression or power as the E88 but apparently the best compromise for a drivable, mild competition car, which just so happens to be exactly what this car is. For the head thickness, the issue is with the valves hitting the pistons because it is such a high lift cam. As for the springs i did have the same thought in my head, but have been told that its not too much of a problem just replacing the one spring. although having said that someone was telling us yesterday that he thinks the car has broken a spring before, so perhaps a new set is the way to go, although the springs dont seem to be fatiged, and still have the same height and compression strength as new... who knows.

The PO had the locating holes for the lower control arm moved out toward the edge of the crossmember to gove the car some negative camber, but the welds haven't been done properly (spot instead of seam) and the crossmember hasn't been adequately reinforced where the holes are now, so that has to be done.

Thanks 1 bravo 6, was defienately a hard year, and i almost didnt make it a few times, but i got there in the end, i achieved what a wanted (400 club. means an average school mark of 80% or more over all subjects) and now i am enjoying my well deserved break .

Tom.

[mjfawke]

Doh! Should have considered that it might be the P90. And you must be running one hell of a cam to be getting close to the pistons. Re. the springs - fatigue life is usually measured in cycles/hours of operation, and you would probably have to have regular X-Ray or penetrant die test to find the beginnings of the cracks - they do not sag just before they let go. What sort of springs are you running? I run an FIA 72 cam in my 260 2+2 (.490 lift), and the springs I used are supposed to be good up to around .550 lift. I can't remember the brand name, but they were purchased from SSS Automotive (now Stewart Wilkins Motorsport). Beyond .550 lift, the springs are supposed to be replaced regularly...

The PO had the locating holes for the lower control arm moved out toward the edge of the crossmember to gove the car some negative camber, but the welds haven't been done properly (spot instead of seam) and the crossmember hasn't been adequately reinforced where the holes are now, so that has to be done.

Both my cars have modded front crossmembers, with the original hole welded up and the original 'washer' spot welded on where the new hole is (has to look factory). But the mod should not be for neg camber - the hole should be moved up by 19-21mm to remove the front bump steer, and a about 6mm out for neg camber and clearance. The top inner edge of the control arm needs to be ground back to clear the crossmember when the suspension is compressed. Try this mod - best handling change I ever made (until the coil over mod was done ).

[Tommo560]

what has been done to the cross member is like you describe, except that our hole has been moved down. dont ask me i dont know why, but it seems to handle very well and would have been done for a reason. i had just presumed that moving the bolt hole out gave the car the camber and that that was the only reason for the mod. the problem lies in that they have only plated up the hole and drilled a new one, for starters using the wrong metal and so now the hole is elongated, the plate isn't welded properly, and they didnt put a new washer in place so the rubber things are all deformed.

[mjfawke]

Try jacking your car into the air and see where the wheels point. They are supposed to stay pointing ahead (when modified), but I think you will find they toe in quite a bit. You will get the opposite under brakes, with the wheels toeing out.

The stock geoemetry works O.K. with stock ride height - lowering the car moves it into a worse position on the bump-steer curve. The intention of Nissan was to get roll understeer, which normally comes from the rear suspension with live rear axle or semi-trailing arms. With the Z rear not providing any toe change, they built it into the front suspension instead.