What did you do to your Z this week?

[Mr Ex Jnr]

Drove mine for the last time on Sunday car is now sold. Been fun for 13 years now a new chapter starts, thanks to all who have helped over the years, especially Pmac, Paul (status) Mr F RIP and everyone else who chipped in. Take care all of you and drive safe

Awww was hoping to.bump.into.u again.matey

We spoke last at Donny quite a few years ago now

Hope all is well.mate

 

[Mr Ex Jnr]

Painted a Rocker today at work rising.sun theme happy with it

 

[johnymd]

With the failure of the isky cam in my freshly built engine, I’ve been rummaging through the parts I’ve accumulated over the years. I was looking for good used rockers (suspect the new ITM items contributed to the cam ware) and came across a bag full of new unused Nissan rockers among lots of other interesting stuff. Found these 133mm rods which I know nothing about. I’m assuming they are modified Nissan ones.

 

[Pilot1002010]

Started my other 260z 2+2 has not been started for at least six months, poured some fresh petrol in the tank turned the key and after a few attempts the engine burst into life. Now I need to get it ready for a respray and finish the interior.

 

[SacCyclone]

With the failure of the isky cam in my freshly built engine, I’ve been rummaging through the parts I’ve accumulated over the years. I was looking for good used rockers (suspect the new ITM items contributed to the cam ware) and came across a bag full of new unused Nissan rockers among lots of other interesting stuff. Found these 133mm rods which I know nothing about. I’m assuming they are modified Nissan ones.

Great find John!!!

 

[Alphabettispaghetti]

With the failure of the isky cam in my freshly built engine, I’ve been rummaging through the parts I’ve accumulated over the years. I was looking for good used rockers (suspect the new ITM items contributed to the cam ware) and came across a bag full of new unused Nissan rockers among lots of other interesting stuff. Found these 133mm rods which I know nothing about. I’m assuming they are modified Nissan ones.

it didn't damage my crank did it?

what was the cause of the failure?

 

[jonbills]

With the failure of the isky cam in my freshly built engine, I’ve been rummaging through the parts I’ve accumulated over the years. I was looking for good used rockers (suspect the new ITM items contributed to the cam ware) and came across a bag full of new unused Nissan rockers among lots of other interesting stuff. Found these 133mm rods which I know nothing about. I’m assuming they are modified Nissan ones.

They don't look like Nissan L24 rods to me - mine have maybe 8 character part number on one side and nothing on the other. Also the squirt hole isn't flush like that and generally that looks much tidier.

what do they all weigh?

 

[johnymd]

Reason for failure is unknown so I'm asking peoples opinions and assuming feasible answers.

Cam had plenty of oil up top before starting. It did take a good 30 seconds of cranking without plugs to get the oil up there. Plenty of assembly lube was used. Cheap rockers could be a factor. Uprated springs could be a factor(seen recommendations of just using thew outer spring for run in period which seams a real faff). I will never know for certain so I'm trying to make the right choices the second time around which are:
1. Use new nissan rockers.
2. Use original nissan cam (reground by kent cams).
3. Plenty of cam lube.
4. Run the engine up on an engine dyno by people that know what they are doing.

The rods have the same basic dimensions as l24 rods but have been heavily worked on by the looks of it. They are ex big sam parts.

 

[Mr.G]

Sounds like your spring pressure may have been too hard especially if the recommendation is just one spring. There's a real science to getting it all right, even down to the height of the retainers and washers used all playing a part.

I will be fitting a turbo cam in due course and I believe that it is supposed to be used with just one spring but i dont know the spring poundage, so I will be in the dark too. I like the idea of putting it on an engine dyno, do you need to supply your own ECU if EFI, I dont fancy having to bring all this stuff along with my intercooler and piping....

 

[Albrecht]

The rods have the same basic dimensions as l24 rods but have been heavily worked on by the looks of it. They are ex big sam parts.

"Ex Big Sam parts" have a similar status to 'Used To Be in The Sugababes'. There's a lot of them knocking around.

Are we talking Rob Grant-era, Gordon Allen-era, Tim Riley-era or JD Classics-era Big Sam?

 

[jonbills]

Reason for failure is unknown so I'm asking peoples opinions and assuming feasible answers.

Cam had plenty of oil up top before starting. It did take a good 30 seconds of cranking without plugs to get the oil up there. Plenty of assembly lube was used. Cheap rockers could be a factor. Uprated springs could be a factor(seen recommendations of just using thew outer spring for run in period which seams a real faff). I will never know for certain so I'm trying to make the right choices the second time around which are:
1. Use new nissan rockers.
2. Use original nissan cam (reground by kent cams).
3. Plenty of cam lube.
4. Run the engine up on an engine dyno by people that know what they are doing.

The rods have the same basic dimensions as l24 rods but have been heavily worked on by the looks of it. They are ex big sam parts.

What was the nature of the failure? did I miss it?
I've only heard of rapid failure of cams on non Nissan cores, so that might seem key.
When my cam started to show some wear last year, here's the advice I got on Hybridz https://forums.hybridz.org/topic/130549-valve-spring-seat-pressure/
I think the point about keeping revs above 1000 rpm is important.

(and for completeness, when I swapped the springs out we found they only had 85 lb seat pressure - so that wasn't the problem)

 

[johnymd]

Alan - the parts came with the purchase from jd last year.

Jon - I read through your hybrid thread last week and have taken what was said onboard. I notice you didn’t run a spray bar. Is that still the case?

I am intending to take extra precautions this time and cross my finger on both hands.

 

[Albrecht]

Alan - the parts came with the purchase from jd last year.

In which case they are very likely to have been part of the short stroke engine that Tim Riley built for Nick Howell, and which one of JD's rentadrivers over-revved. As far as I'm aware JD took that engine apart and built their own long stroke race engine for the car. There would have been quite a few parts left over.

 

[jonbills]

Alan - the parts came with the purchase from jd last year.

Jon - I read through your hybrid thread last week and have taken what was said onboard. I notice you didn’t run a spray bar. Is that still the case?

I am intending to take extra precautions this time and cross my finger on both hands.

That's right, no spray bar - I did enlarge the oil jet in the block to 2.5mm and I did change my EMS to keep the RPM above 1000.

 

[TimFZ]

This week I managed to get around to a compression check. I did it cold and "dry" in the hope of maximising differences between cylinders. I have the L20(A) engine I believe with the twin Hitachi FT carbs so I assume it is a 9:1 compression ratio.

I got the following figures:
1- 151 psi
2- 150 psi
3 - 154 psi
4 - 160 psi
5 - 159 psi
6 - 152 psi

I think these appear not too bad but what does everyone else think? The car claims to have 47k Miles on it and there is no visible smoke. I will repeat them at some point and do a dry/wet comparison for ring condition and also cold to hot.

I also ordered a "colourtune" plug this week so I can start getting somewhere closer to tuning the car. It is still running rich but appears more so on the front 3 cyls and only slightly rich on the rear 3 according to plug condition. The hitachi carbs only have 1 mixture screw I think for both so may need new needles at some point to help balance things out.

 

[jonbills]

those compression figures look ok to me too.
There's an idle mixture adjuster under each carb.

 

[Rob Gaskin]

The main jet mixture screw/nut is indeed under the carbs so they can be adjusted separately. Haynes Manual?

Compressions ok.

 

[TimFZ]

Thanks will look under - I thought the flat tops only had the one screw between the them but I guess thats not for idle then!

Of course nothings ever easy on an old car.... having completed the compression tests, I had to gently move the coolant pipe out of the way. On a test drive today, it has started leaking (the horizontal one between heater matrix and goes under no 6 plug). Should be an easy enough swap out though!

 

[Rob Gaskin]

Thanks will look under - I thought the flat tops only had the one screw between the them but I guess thats not for idle then! ......................

Sorry didn't realise you were working on the Flat-tops. I'll look in my manual.

 

[TimFZ]

Very interesting - took off the little hose between heater matrix and the angled one next to the block and found what looks like a short section of brass bottle brush inside. Did someone break one off and forget about it or is it supposed to be there to prevent rust moving in to the heater matrix?