1970 Z Refresh...biting the bullet

[motorman7]

Pull the steering rack bushing caps and replace the steering rack bushings.....while you're at it, clean and paint the caps and replace the nuts with new cad nuts. We love to find new projects for you! !

Thanks for the input Guy. I will definitely get that cleaned up. Easier to do it now before the motor goes in.

Rich

[kats]

Hello Rich,your car is very nice and original car and fantastic job!!

I really love to see these updates,because my 240Z is also 03/70.Please tell us as much as you can,then I can see what is original for my 03/70 U.S. 240Z.

My 240Z has a very close VIN and engine number to yours.It is interesting My Z's VIN is earlier than yours but enigne number is later than yours.

kats

Edited July 2, 2009 by kats
add little bit

[motorman7]

Hi Kats,

I like your web site. Those are some sweet cars you have. Yes, odd thing about the engine numbers. It would be interesting to track the pairing of engine S/N with body S/N. I wonder if there is a sequence (backwards in some cases) or it is just random. Also, it is very educational taking these cars apart. The 'non-standard' items are very cool.

I lucked out today; looks like Les has the bushings (Rack and T/C) I need. That means I should be able to drop the engine in tomorrow. I have a 3 day weekend so should be able to get a lot done.

Best Regards,

Rich

[jeff81]

I have to say that the attention to detail and the large amount of work is truly special. Great Job.

[Mike B]

It would be interesting to track the pairing of engine S/N with body S/N. I wonder if there is a sequence (backwards in some cases) or it is just random.

Engine numbers weren't sequential with VIN numbers, but engines do generally fall within a certain range for each specific VIN. Car data, including VIN and engine number, are tracked in a couple of places. There is an online spreadsheet that MikeW put together and is linked in this thread http://www.classiczcars.com/forums/showthread.php?t=27519&highlight=vin+spreadsheet. There are also Z car registers on Zhome.com

-Mike

[26th-Z]

Ok, something doesn't make sense. Maybe I got it wrong - it wouldn't be the first time.

Rich, you said your engine serial number was 005353? That can't be. Your engine serial number should be L24-xxxx and 5353 would be way too high for the reinforced oil pan. I believe that starting with engine # L24-3607, the eight counterweight crankshaft was used replacing the six counterweight crankshaft in August, 1970. That's when the oil pan should have changed. Didn't you mention that you had three lengths of cylinder head bolts? That changed in April 1970 with engine number L24-04257. And now that I'm reading the service bulletins, I see that one bulletin lists the engine number with five digits and the other lists four. WTF?

Her Majesty the 26th is fitted with engine number L24-2338 and Princess Ziesta the 27th is fitted with engine number L24- 2162.

[Carl Beck]

I lucked out today; looks like Les has the bushings (Rack and T/C) I need. That means I should be able to drop the engine in tomorrow. I have a 3 day weekend so should be able to get a lot done.

Hi Rich:

When you drop the steering rack to replace the bushings I'd suggest that you add a strip of lead stick-on wheel weights - across the top rubber bushing. This will tighten up grip that the clamps have on the steering rack. This really should not be considered an "up-grade" so much as a bit of reinforcement to the OEM bushings - they were too soft and too weak right from the beginning. Either do that, or use steering rack bushings made from more modern materials.

You will also notice what looks like a muffler clamp - around your steering rack. That clamp has a rubber nose on it that presses against the front cross member. Normal by now the glue that held the rubber nose on the clamp drys out and the rubber nose falls of. Make sure you glue it back on if that is the case and reinstall it.

Nissan added these clamps to help keep the steering racks from walking around in the soft rubber rack bushings - which puts unnecessary stress on the tie-rod ball joints.

FWIW,

Carl B.

[Carl Beck]

Ok, something doesn't make sense. Maybe I got it wrong - it wouldn't be the first time.

Rich, you said your engine serial number was 005353? That can't be. Your engine serial number should be L24-xxxx and 5353 would be way too high for the reinforced oil pan.

Hi Chris:

On my listings I have L24-2476 as the lowest engine number used in March 70, and L24-005562 as the highest reported.

So that I could sort numbers - my list eliminates Zero's to the left of the first significant whole number. Nonetheless - as reported by the owners - several report L24 0055xx, several others report L24 055xx... So it would at least seem that for some reason, some engines got four digit numbers, some got five digit numbers and some got six digit numbers - if the owners reported them correctly.

I believe that starting with engine # L24-3607, the eight counterweight crankshaft was used replacing the six counterweight crankshaft in August, 1970. That's when the oil pan should have changed.

With the exception of #2476 & #2497 which were reported as being in cars produced in March 70 - - all engine numbers below #3606 were installed in 69 Production units and 01/70 units. So by Feb 70 all the engines had eight counterweighted cranks. You may have got "August" as the date that the TSO was published.

Didn't you mention that you had three lengths of cylinder head bolts? That changed in April 1970 with engine number L24-04257.

I don't recall Rich saying that - but I do recall someone else mentioning that it might be possible his engine had the three different lengths.

And now that I'm reading the service bulletins, I see that one bulletin lists the engine number with five digits and the other lists four. WTF?

As mentioned above - owners report numbers with four, five and six digits... but all have only four siginificant digits. Could have been a way for the foundry to keep track of different lots produced... Who knows?

FWIW,

Carl B.

[26th-Z]

Thanks,

Yes, the service bulletin date is August and I was the one who asked if there were three different head bolt lengths.

(Edit) Oh, and yes I have seen the blue and white tape on the steering rack - presume it is "factory".

Edited July 3, 2009 by 26th-Z

[motorman7]

Hi All,

Just thought I'd post the tags and numbers since they were easily accessible (and look cool of course).

The head had 2 different size bolts. 5 long that were on the cam towers, the rest were short.

Got the T/C bushings replaced. Got the new rack bushings but will need to find a shim material. May send my son down to the tire shop to get the tire weights. It's not to far away.

So, back to work here. Should have the motor in today. Will show pics later.

Rich

[Montezuma]

Did you get my PM about the my offer of a set of free brand new tie rod ends? The wife and I might do Crusin Grand Escondido tonight, I will let you know.

[motorman7]

Did you get my PM about the my offer of a set of free brand new tie rod ends? The wife and I might do Crusin Grand Escondido tonight, I will let you know.

Thanks David, I'd like to get those from you when I do the front and rear bushings, after the engine refresh.

Best Regards,

Rich