Machining cylinder head for more compression?

[z shredder]

Pictures

Edited January 12, 2021 by z shredder
Forgot pictures

[siteunseen]

My '73 pistons aren't valve notched like your's. Maybe a European, N. America thing?

I would highly recommend new nuts for the TC rods. They're one use locking and I can tell you from experience and many other's experiences I've read, reuse of the old ones and they'll eventually come off. Small price for 2 new pinch nuts and peace of mind.

Looks good. 👍

[Jeff G 78]

34 minutes ago, siteunseen said:

I would highly recommend new nuts for the TC rods. They're one use locking and I can tell you from experience and many other's experiences I've read, reuse of the old ones and they'll eventually come off. Small price for 2 new pinch nuts and peace of mind.

Looks good. 👍

I reused and lost one once when I hit a bump on the highway.  Luckily I heard it come off and I was able to get home and replace it with no damage.  I did lose the poly bushing and the cup washer.

[Zed Head]

1 hour ago, z shredder said:

Pictures

 

If your front end groans and moans when you go over speed bumps and driveway ramps it's the rear poly bushings working the back of the TC rod.  Eventually it will break it off.  Most people use rubber on the back.  It doesn't really see much use when braking like the front one does.

[jonbill]

I don't think any original standard  Nissan pistons have cut outs like that.

on the compression rod, I have these, which are cheap and effective. 

https://www.thezstore.com/page/TZS/PROD/23-4190

I had poly bushes both sides before I fitted them, and I had a lot more roll after I fitted them which I think shows how much load they were taking. 

[Zed Head]

The piston thing just came up recently.

 

[dutchzcarguy]

13 hours ago, jonbill said:

I don't think any original standard  Nissan pistons have cut outs like that.

I agree, no L motor has that..  so this engine was already restored at one point.

16 hours ago, z shredder said:

well I think I am doing pretty ell for a 16 year old with a limided budget.

I'm surprised and very happy that a 16 year old is restoring a 240z!!  

Also ..  NICE pictures, i now think you did'nt bite off more than you can shew..   Most (very) young people start an resto but never finish it.  You'll get it finished i think!!

On the rubber and poly stuff..  I personal HATE the poly.. rubber is MUch more forgiving.. the poly makes it to stiff. I have seen broken suspension, just because the poly was to hard.. did not give.

I don't know where you live in NRW but i'm a few km of the city Goch/Kleve. Dld.   I think it's fantastic that you restore a Datsun when thought of "a cool car" 

I drive a 240z now for 20 years (restored myself.) and is ready for another restore haha.. and it's the small boys that walk on the hand of their mother that shout: OH MOM look at that BEAUTIFUL CAR!  👍  I had that more than once.  (These little boys grow up to restorers haha) 

Also people that start to video the drive by hahaha...   

With my just restored 280zx (on this site: 1979 slick roof 280zx) people spontaneously stop and say what a beauty!!  (It's almost impossible to drive that car without someone complement it or getting a thumbs up..  once a roadworker shouted realy loud: Nice DATSUN!  HAHA.. 

The most i'm excited about people who now are starting to put some thumbs up when they see me drive my almost as new 300zxtt !!   I drive that car now for 15 years (only in the summer) and the only thing i got was a jealous look!  People are clearly changing their opinion..

Show us your progress, we all love pictures!   AND.. if your not sure how to do something also let us know, we (all) are here to help.

Edited January 13, 2021 by dutchzcarguy

[z shredder]

I am probably going to buy this L26 because the price is good and it's not to far away. 

[dutchzcarguy]

That pulley (where the fan normally is on) is a bit out of line?  The belt looks a bit of a ghostbelt on that pic. haha.. it's there but not completly it looks like it disappears..

You know of course those carbs are not the original ones?  If it's a engine that was never apart it's time to take it apart completely and inspect every part. (install all new gaskets and oilseals!)  If it's a euro version block it probably has a E88 head and about 162 hp. (But with these carbs that could be a bit less or more..)  As it has a starter on it, you could do a compressiontest before you buy it, that should be around 10 Bar.  (155-160 psi) and best is that every cylinder has the same pressure.

Watch out the engine could get a bit jumpy when you get the starter running..  take out al the sparkplugs.. look if there was extra oil in the bores. it will influence your compr. data..

Bring a good flashlight and a full battery. 😉 

[bartsscooterservice]

On 1/10/2021 at 6:19 PM, z shredder said:

Thanks for the offer but I am not going to spent 1500€ on a cylinder head 😁

Do I really need new pistons? Until now I was planning on using L24 flattop pistons.

No problem. Just depends on what you want though. Maybe its better suited for someone who is doing an early 240 restoration and needs the correct E31 head for it.

It's not lying in my way anyhow. I intend to keep it as a spare because by that time in the future they are even harder to come by. I am willing to sell it to a fellow z enthusiast, but i'm not santa claus

[bartsscooterservice]

On 1/14/2021 at 11:24 AM, dutchzcarguy said:

That pulley (where the fan normally is on) is a bit out of line?  The belt looks a bit of a ghostbelt on that pic. haha.. it's there but not completly it looks like it disappears..

You know of course those carbs are not the original ones?  If it's a engine that was never apart it's time to take it apart completely and inspect every part. (install all new gaskets and oilseals!)  If it's a euro version block it probably has a E88 head and about 162 hp. (But with these carbs that could be a bit less or more..)  As it has a starter on it, you could do a compressiontest before you buy it, that should be around 10 Bar.  (155-160 psi) and best is that every cylinder has the same pressure.

Watch out the engine could get a bit jumpy when you get the starter running..  take out al the sparkplugs.. look if there was extra oil in the bores. it will influence your compr. data..

Bring a good flashlight and a full battery. 😉 

I would throw that carbs in the bin, they don't belong on a japanese car 😑

[bartsscooterservice]

On 1/13/2021 at 3:27 PM, z shredder said:

I am probably going to buy this L26 because the price is good and it's not to far away. 

I once went to Schut in Soest , the netherlands. He had some original datsun engines laying around. You could give them a call.

industrieweg 29, soest. tel +31 (0) 35 6010668