'73 240z - Project Build

[demo243]

41 minutes ago, datzenmike said:

Yes 1/16 is better. My 710 is just a couple of mm. Tires aren't perfectly symmetrical so I used the outer edge of the mag rims front and back. Also on my lowered car it's hard to measure across between the 9 and 3 o'clock positions on the rims. One goes through the transmission bell housing the other through the oil pan. 

 

 

Yea… driveway alignment consists of a couple piece of angle aluminum on top of two 2 2x4s all shoved up against the tire. I marked center and equal distance on either side, slightly wider then the tires, and two tape measures

 

it was enough to get it close 

[datzenmike]

Oh yeah, close enough is good enough. I also reset my 'apparatus' and was able to repeat the measurement which is a good check on the work.

[demo243]

7 minutes ago, datzenmike said:

Oh yeah, close enough is good enough. I also reset my 'apparatus' and was able to repeat the measurement which is a good check on the work.

I recall setting it around 1/8th last time I did it so the difference could just be in where it was measured 

[demo243]

A bit of reading and maybe it is my toe in that is causing the shake. Being so far in could be causing the wheels to fight each other - amplified by the road grooves. Would also make sense why it goes away if you hug one side or the other. 

 

I am hoping for a big drive next weekend to join the local Z club so maybe Ill try and adjust the toe a touch tomorrow. 

[datsunfreak]

On 8/13/2023 at 2:26 PM, demo243 said:

The 510 tends to wander in them, but never shook that I recall.

 

This is a common 510 problem if you swap to 280ZX struts. They really want a slightly more aggressive offset than most people run, in order to get the right scrub radius.

 

FWIW, I saw this on a lot of my 510s, then the first one I put a 15x7 +0 wheel on, it went away. Always ran more aggressive offsets after that and it seemed to fix the issue. 

[datzenmike]

[demo243]

Got the front end aligned today. Helped a bit and drives a bit “looser” but it was toes in too far. Still had a bit of a shake, but that could be anywhere else in the 50 year old steering setup. 
 

I’ll do tie rods and the rest later at some point.

[demo243]

21 minutes ago, datzenmike said:

What hubs are those?

[datsunfreak]

14 hours ago, demo243 said:

What hubs are those?

 

Looks like a comparison of 280ZX to 300ZX, but I could be wrong...  😁

[demo243]

Took the car out for a good shake down run this weekend. 175 miles round trip to Thompson Motor Speedway to meet up with the CT Z Club. Z did great down and back. Cruises at 75-80 with no problem and plenty left to give. Still a bit of a intermittent shake in the wheel, but its definitely steering component related is my guess. As mentioned before, if you stick to one side or the other of the lane it goes away, so in my mind you are slightly loading the steering then which keeps it calm. 

 

 

 

Got a few "parade laps" in as well. Definitely not a track day... but we still go up to 80 on the front straight. 

 

 

 

The car is definitely not as confident as the 510... and I think the 510 is faster... but that makes sense since there is a lot more done to that car both engine and suspension wise. 

 

I definitely need to tear the brake master apart, as the residual valve is definitely still in there, even with the rear disc conversion. I could feel them dragging pushing the car around, but you can feel the rear wheels are warm after driving it, so the brakes are definitely dragging.

Narrowing plans for the future... got most of a set of donor struts, and located the last, so BC Coils. Then I think Ill do front and rear control arms, tc rods, and tie rods. Will probably replace the rack with either T3 or APEX depending on which suspension components I decide to go with. Thinking I may go with an MSA roll bar, mostly for looks ... I don't think Im going to run harnesses in the Z but TBD. Also got my eye on some drift style "bash bars" instead of bumpers - they are shaped pretty close to the stock bumper lines... but TBD

[datsunfreak]

19 hours ago, demo243 said:

Also got my eye on some drift style "bash bars" instead of bumpers - they are shaped pretty close to the stock bumper lines... but TBD

 

Have you looked at the Skillard aluminum bumper? Kinda spendy, but very light weight. I really dig the bash bar idea. 

 

FWIW, I am planning to use an MSA fiberglass front bumper/air dam with a bash bar hidden inside. 

[demo243]

4 hours ago, datsunfreak said:

 

Have you looked at the Skillard aluminum bumper? Kinda spendy, but very light weight. I really dig the bash bar idea. 

 

FWIW, I am planning to use an MSA fiberglass front bumper/air dam with a bash bar hidden inside. 

I have looked at Skillards and they are an option - although pricey... and I feel like their edges are kinda sharp?

 

I thought about fiberglass ones too, but after getting a fiberglass spoiler from MSA and how terrible the gel goat was... I definitely don't want to deal with that.

 

Street Faction made the bash bars. I don't know if they still do... need to message them.

 

https://streetfaction.net/collections/bash-bars/products/rear-bash-bars-datsun-infiniti-nissan?variant=39701430534232

 

My only fear is that a bash bar is too strong and directs all the impact into the chassis and then destroys the chassis instead of a "replaceable" bumper... I have no plans on using them, just a thought. 

Edited August 22, 2023 by demo243

[datsunfreak]

11 hours ago, demo243 said:

I thought about fiberglass ones too, but after getting a fiberglass spoiler from MSA and how terrible the gel goat was... I definitely don't want to deal with that.

 

There's a reason their stuff is cheaper than everyone else's.  😁

 

11 hours ago, demo243 said:

Street Faction made the bash bars.

My only fear is that a bash bar is too strong and directs all the impact into the chassis and then destroys the chassis instead of a "replaceable" bumper... 

 

I have a similar concern, but moreso at the rear. I was thinking nothing at the rear (because that sounds safe 😋) and the bash bar, air dam combo up front. That rear bar seems like it would only protect you in a very low speed impact. 

 

Since the front pokes out at the middle, that and the fiberglass bumper should buy me a little bit of "crumple zone" before the chassis gets bent. 

 

Everyone is a little different, but I have been rear-ended multiple times and as such I have been very careful to protect myself from that happening again. I'm a lot less worried about someone hitting me than I am me bumping something with the front end from driving like a hoon...  😄

[demo243]

Another successful Labor Day in the books. Took the Z car out this year and it ran great! Coolant and oil temps stayed rock solid the whole trip. Cruised slightly lean on the wideband gauge, but once you put your foot down it fattens up and pulls great. Ran 80 down the highway all the way home. I’ve put about 600 miles on the car now.
 

 

4 240z were running this year and put up a good fight with the Porches in the big bore class. One was holding of one of the fast Donavon E-type jags. I’ll check back and see if I snagged any decent shots of them.

[demo243]

Took the Z out for a cruise this morning. Didn’t stop… so no pics. Was a nice fall drive.

 

Did notice a slight fuel issue. Had it once before on the way back from Lime Rock too. Seems like I am running out of fuel after a long pull- ie 2nd, 3rd, hit 4th gear pull (highway merge) once I hit 4th it has a stutter… feels just like fuel cut. Throw it in 5th and let it cruise a sec and it’s fine. Drop to 4th and do a big pull and it’s fine. Leads me to believe the float bowl is running low. I guess that would be the needle, or fuel pressure…. 

[datsunfreak]

On 9/17/2023 at 9:32 AM, demo243 said:

Leads me to believe the float bowl is running low. I guess that would be the needle, or fuel pressure…. 

 

SUs like fairly low pressure, like 2psi or less. I ran mine at 1.5 and they worked great. Maybe a restriction somewhere? Or possibly a low float?

 

Stock fuel pump? 

[demo243]

11 hours ago, datsunfreak said:

 

SUs like fairly low pressure, like 2psi or less. I ran mine at 1.5 and they worked great. Maybe a restriction somewhere? Or possibly a low float?

 

Stock fuel pump? 

I believe it’s the stock electric fuel pump- 73s had an electric one I think.

 

yea fuel pressure is probably not the culprit, but it feels just like it’s running out of fuel.

 

Probably a float or needle as you suggested.

[demo243]

Got out to the Larz Anderson museum for the Japanese Car Day. Good turn out as usual. 
 

Car ran great down and back. One weird issue with the flasher unit… it would come on over 3k rpm…. Maybe a bad unit? The signals are all on relays, so no issue with them coming on un-intended.
 

 

 

This Z was pretty Rad- definitely after a similar stance.

 

 

Then my old truck showed up! New owner is up in NH not far away, so look forward to seeing more of it. He already cleaned up the frame and refreshed the rear axle. Excited to see what he does with it.

 

 

[demo243]

Then tried to take it for a cruise today…

 

And she almost left me stranded…

 

 

Did great on the on-ramp… and then lost it… went super lean and lost a lot of power. Got it off the highway at the next exit and pulled off on the side. It died on me and didn’t want to idle… got it fired back up and a little further down the road to a better spot to pull off. Tried a few more times but was still real down on power and didn’t want to idle.

 

Popped the air cleaner off to check the carbs since I had the synch tool. Got it idling and checked both carbs were sync’ed and pulling to same vacuum. Hoped back in and drove it home- no issue…

 

I think it’s a fuel issue- seems very similar to the time my needle valve was sticking on my old webers on the 510.

 

I’m not into the SUs so I think it’s time for a change.

 

The current value of the Yen makes OERs a quite affordable - and likely the “correct” answer being tried and true… but I’ve read mixed reviews… and need to figure out the “baseline” jetting… I do worry that maybe they will disappear one day to making parts hard to come by.

 

Would love a set of Mikuni PHHs , but they are out of my budget- that’s where the possibility of Moto carbs comes in. I know I can run 2 Mikuni HSRs on the SU manifold, but where’s the fun in that!

 

I’d love to run 6 bike carbs. They come with their own issues, and there isn’t a ton of info out there, but thinking about it- they are in current production, with a lot of support (Particularly the Mikuni HSRs with the Harley crowd) and readily available jets and parts.

Here’s some inspiration- stolen from the intrawebs.

 

 

The big question is what size? HSR42 could be a good option but with a 42mm bore and no chokes I fear they may be too big, they are also expensive. The next option would be Mikuni RS carbs. They come in 34, 36, 38, and 40mm bores. The RS carbs come in racks of 4 so I would need two, but can potentially be found second hand and are a little more reasonable.

 

Of course by the time I do all that and build an engine… maybe I should just RB swap it

 

 

Edited October 25, 2023 by demo243

[demo243]

On 8/21/2023 at 9:19 PM, demo243 said:

 

Street Faction made the bash bars. I don't know if they still do... need to message them.

 

Also Street Faction does not produce these anymore… but the more I look at em the more I dig em. 
 

@Crashtd420 got a tube bender?

 

They actually look pretty simple so should be able to find a local fab shop to make something.

[datsunfreak]

13 hours ago, demo243 said:

Question is what size? HSR42 could be a good option but with a 42mm bore and no chokes I fear they may be too big, they are also expensive. The next option would be Mikuni RS carbs. They come in 34, 36, 38, and 40mm bores. The RS carbs come in racks of 4 so I would need two, but can potentially be found second hand and are a little more reasonable.

 

IMO, the smaller the better. Usually means better throttle response and torque.

 

13 hours ago, demo243 said:

Of course by the time I do all that and build an engine… maybe I should just RB swap it

 

Then there's that.  😄

 

13 hours ago, demo243 said:

Did great on the on-ramp… and then lost it… went super lean and lost a lot of power. Got it off the highway at the next exit and pulled off on the side. It died on me and didn’t want to idle… got it fired back up and a little further down the road to a better spot to pull off. Tried a few more times but was still real down on power and didn’t want to idle.

 

Popped the air cleaner off to check the carbs since I had the synch tool. Got it idling and checked both carbs were sync’ed and pulling to same vacuum. Hoped back in and drove it home- no issue…

 

I think it’s a fuel issue- seems very similar to the time my needle valve was sticking on my old webers on the 510.

 

How long since you last changed the fuel filter? If there's trash in the tank, it can do this. Clogs the filter, then after it sits for a little while it goes again. 

 

13 hours ago, demo243 said:

I’m not into the SUs so I think it’s time for a change.

 

I can understand that, but they have always been super reliable and easy to tune for me. For the sake of reliability, I wouldn't run anything else.  That being said, they are the least sexy option out there...  😋

 

Except maybe a single downdraft...

[Crashtd420]

10 hours ago, demo243 said:

Also Street Faction does not produce these anymore… but the more I look at em the more I dig em. 
 

@Crashtd420 got a tube bender?

 

They actually look pretty simple so should be able to find a local fab shop to make something.

I wish..... 

[demo243]

56 minutes ago, datsunfreak said:

 

How long since you last changed the fuel filter? If there's trash in the tank, it can do this. Clogs the filter, then after it sits for a little while it goes again. 

That is going to be the first thing I do. The one right after the pump has definitely seen better days. The one up in the engine bay is pretty fresh.

 

Probably going to replace the fuel pump too with a Carter low pressure pump while I’m at it

[demo243]

16 minutes ago, Crashtd420 said:

I wish..... 

bummer 

 

I’ll have to check with some local shops, but depending on estimates maybe a trip to Harbor Freight is in order!

[Crashtd420]

13 minutes ago, demo243 said:

bummer 

 

I’ll have to check with some local shops, but depending on estimates maybe a trip to Harbor Freight is in order!

There are so many tools I'd love to have... I could have used a bender a few times but I took the idea a different way....

I have a few ideas kicking around in my head for future projects,  I'd even love to make some small parts for people here but I'm just not setup to do it.... I think I have the neccessary skills but not the tooling to support it... I'm unfortunately not able to use my work machines for personal use..