'72 240Z Rebuild

[bartsscooterservice]

bumped the topic up nothing to do with the pistons.

Usually piston rings have a few letters on them, the letters always point to the top ( head )

[siteunseen]

I'll have to share this with you guys and see what you all think.

 

I'd thought I found a L series machine shop in North Georgia.  The late John Williams had his shop located behind theirs, or vice versa, they built a shop in front of Mr Williams's place.  It's all up around Road Atlanta race track.  Two guys but only one talks on the phone, he says you need to talk to the other guy but he's never there or in the bathroom or on the roof, blah blah blah.  I called Monday to ask if they would notch my block for me.  The phone guy says that sounds crazy as hell but he'd ask the other guy and call me back.  When he called back the other guy had said that I shouldn't have put larger valves into my E head, I told him it was a very common mod and that I had bought it that way.  Then I remembered reading the 2.6 blocks were notched from the factory so that bothered me too.  Then he say's I'll need .150" lash pads for proper geometry.  Schneider told me that I would get .175" with my cam kit because they REMOVE material resulting in the need for thicker pads.  So that's 3 things that got me to wondering how many L heads they do.

 

I called my Dad for some reassurance, he's a simple kind of guy in the best way, love that man.  He say's that getting the geometry right isn't as hard as I think and his favorite machinist could do it easily.  I read where Madkaw notched his own block and looked at tons of pictures, I can do it myself.  So the question is, I have chosen the cam and the cam company myself, they'll send everything I need, the head has new valves and stems already.  I can get a local guy to take it apart and lube everything up (it's been in a bag for 5 years at least) put it back together with the new springs and retainers that are coming with the cam.  New valve stem seals most likely, they've not had oil on them.  Center the wipe pattern and give it a try.  15 minute drive compared to 2 1/2 hour drive.  Telling my local shop what I want or having the out of state shop tell me what they want?  If you read this THANK YOU for your time and your opinion.  Cliff 

[madkaw]

If the machinist doesn't want to do the work, find someone else. You need and want to notch the bores. Datsun motors aren't the only motors that practiced this notching. I notched my bores right to the limit of the HG fire ring, but you don't need to go that far. If you are careful and take your time you can do this yourself. Just don't go to deep or wide.

Sounds like the machine work is all done and you just need better valve seals and a wipe pattern checked? I would think any competant machine shop could do this. I handed my machinist the "how to modify" book for a references. I just told him that I know he doesn't see these motors everyday and just thought he might want the book to look at.

 

[madkaw]

I would also express a concern about rocker geometry an quality of the rocker arms. Whoever winds up doing the wipe patterns, make sure the wear is square on both the cam surface and the lash pad surface. 

[rossiz]

go with your gut - if something feels off, it probably is.

i've burned myself more than a few times letting my brain tell me to go down a certain path when i had vague misgivings... 

 

now that i'm working on my third head, i'm learning that setting the valve geometry is not that complicated - but it's really important.

[Zed Head]

Seems like one of the reasons that people like to work with Rebello or DatsunSpirit is because the owners share what they know and the customer learns something when it's all done.  Your guys seem more like the old, classic, "leave it there and we'll call you when we're done" kind of guys.  Guys that always come in at the top end of the quote range and call you with "problems" found requiring more work.  I think the descriptive word is sketchy.

 

On notching the block, a general trick that I learned from a machinist is to turn the block upside down.  The grinding or filing chips will fall away from the cylinders.  That's if you're planning to leave the block assembled.

[siteunseen]

Good news!  I went to my Dad's machinist and he knew exactly what I was talking about.  He told me I may need tower shims to get the wipe perfect.  I have an extra 2.4 block that I'll do the notching to and keep the numbers matching motor OE, rebuild it later on.  When I walked in he slid his glasses down on his nose and says "well I'll be damn, there's Marvelous Jr." my Dad's name is Marvin, I haven't seen that man in at least 20 years. 

 

Another funny thing he said was "I thought all those old L heads were scrapped by now".  One more thing Steve"madkaw" brought up that he knew about was notching blocks.  He said he makes templates out of cardboard with the HG when he notches blocks so he doesn't ruin the HG.  So YES, other blocks need notching too, thank you Steve.  Looks like I'm following in your footsteps

 

I feel so much better now I'm going to have a couple of beers and run over the dog poo and onions in my yard, with my mower of course.  I'll get back to the motor removal tomorrow, the weather is going to turn cold again.

 

Thanks again guys, y'all are the best!

[siteunseen]

Boy this is a lot easier than before, I'm learning something I guess.  It'd be hard not to when I check in with you all everyday.

The head has been off before for sure, I guess for the steel valve seats? and a newer style spray bar.  It has big phillips head screws in the bottom holes so I guess it's a multi car type.  It looks good too.  The head gasket has overly large fire rings so I guess it's for a 86mm bore, it has a copper coating on both sides too.

 

The only 2 bolts I broke were the 2 holding the exhaust manifold to the exhaust pipe.  I drained the radiator and only got a little over a gallon last Sunday.  Today I removed that plug at the back of the block and got a GUSHER of coolant, at least a gallon maybe more, I'll have a catch pan next time.

 

Cylinder walls are as slick as glass, so standard size rings will work fine hopefully.

 

280Z, 1st rebuild worried me sick and took 6 months.  This 240Z will be done in a third of that time and done right, blue block not bar-b-q grill black paint.

 

All the topside is done, tomorrow will be the exhaust pipe then the transmission.  Saturday the blocks coming out and apart.  Then clean, clean and some more cleaning.

[rossiz]

great to hear your progress - and excitement! i'll be borrowing your enthusiasm when i start re-building my f54/p79.

[siteunseen]

I'm on schedule but will be as sore as ever.  I decided to drop the transmission onto a motorcycle jack I've used before for holding it to roll around while I pressure washed it.  BAD idea for my 50 plus years old cracked up to hell garage floor.  

 

Getting my Dad's cherry picker tomorrow to pull the block out.  I can't believe I wouldn't wait and get them both together.  Stupid mistake I'll never repeat.

 

This time I'm making a pile throughout the day then going back and bagging and boxing up everything in the evenings.  Seems to be a lot less worrisome.

 

RossiZ I have my console out so if I can take some measurements or pictures just let me know.

 

[djwarner]

Love the idea of the rubber pipe cap over the transmission output. Do you know what size it is?

[siteunseen]

Love the idea of the rubber pipe cap over the transmission output. Do you know what size it is?

It's a 2" or something, I'll make sure in the morning and post the size.  That works way better than a baggie and tape.  Even Carl Beck noticed that a few years ago when I rebuilt my 1st Z.  He told someone that was hauling their car on a U-Haul type that holds the front tires only to remove the drive shaft and use that cap on the transmission for a long trip.

 

In the morning, I promise, I'm not about to go back down there now that I'm clean.  It was a couple of dollars at Lowes.