Just bought our first Z (240Z)

Rob Gaskin

Treasurer
Staff member
Site Administrator
Looking at Woody's picture, i notice there is no overflow pipes fitted on the top of the float bowl lids, what do others do?
I have pipes on mine that meet in Y joint and then hang down just below the exhaust, near the bottom of the inner wing.

IIRC the factory setup has pipes feeding into the back of the standard air filter case.

and are those throttle return springs wired to the exhaust? :D

I have seen short pipes just going up and over - over the exhaust! I did express my concern.
 

Paul_S

Club Member
I just read this thread from start to end. Thanks for sharing your experiences :)

I'm staying tuned for more!
 

Woody928

Events Officer
Staff member
Club Member
Looking at Woody's picture, i notice there is no overflow pipes fitted on the top of the float bowl lids, what do others do?
I have pipes on mine that meet in Y joint and then hang down just below the exhaust, near the bottom of the inner wing.

IIRC the factory setup has pipes feeding into the back of the standard air filter case.

and are those throttle return springs wired to the exhaust? :D

Having had floats stick in the past, you really should run those overflows somewhere. Often into the back of the filters. Just drill a whole the same size as the rubber overflow pipes and poke them in.

Thanks for the comments guys, having almost no experience with carbs are you able to enlighten me as to the potential concern? (I'm presuming the concern is there is a fuel overflow that would vent over potentially hot carbs and exhaust headers/manifold leading to a fire risk?)

Lol the throttle return springs were attached to the exhaust when the car came from the US however that has since been remedied. That being said the spring is awful, the throttle is very much on or off so to speak :( Any ideas where to obtain new replacements? and where they were mounted onto from factory?

I just read this thread from start to end. Thanks for sharing your experiences :)

I'm staying tuned for more!

Enjoying the thread as well.

Look forward to some new pics with mirrors installed.

:thumbs:

Glad your enjoying it gents, its good to know people are reading! The plan is to keep the thread posted as our ownership continues and we upgrade and use the car. I'm pleased to report that despite not being an extensive list it is by far the funnest car I've had the pleasure of owning :D I've always been interested in classic cars however this has really opened up my eyes to them.

The Hella mirrors are unfortunately looking to be a non starter and when trial positioning the passenger side door mirror I couldn't adjust them to a position where they would actually be beneficial... :( Drivers is spot on though.

I'll post up some pics when I can in case anyone has any ideas however now considering vitaloni californian mirrors as we want door fitment that is functional first while still being aesthetically easy on the eyes.
 

toopy

Club Member
presuming the concern is there is a fuel overflow that would vent over potentially hot carbs and exhaust headers/manifold leading to a fire risk?)

You presume correctly :)


Lol the throttle return springs were attached to the exhaust when the car came from the US however that has since been remedied. That being said the spring is awful, the throttle is very much on or off so to speak :( Any ideas where to obtain new replacements? and where they were mounted onto from factory?

There should be a heatshield under the carbs, i think bolted to the inlet manilfold, the springs attach to the bottom of it, image courtesy of Ztherapy

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Woody928

Events Officer
Staff member
Club Member
You presume correctly :)




There should be a heatshield under the carbs, i think bolted to the inlet manilfold, the springs attach to the bottom of it, image courtesy of Ztherapy

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Should I be concerned? (i.e. is it normal practice?)

Ahhh that would now explain my issue, another item to add onto the list thank you. Any reason you can think of why one wouldn't be fitted? (exhaust manifold clearance?) Also if I could source one then could it be retrofitted without the carbs? The throttle spring setup at the moment is pretty **** to say the least and could really do with replacement... :(
 

toopy

Club Member
Should I be concerned? (i.e. is it normal practice?)

Well, when i first got my 240z carbs to replace the 260z 'anchors' they did have pipes on the overflows but as someone else mentioned earlier,
they were simply an upside down U shape. One of my carbs initially had an issue and was slowly dripping fuel from the over flow on to the exhaust!
since then i have the arrangement i described earlier in the thread.
I also have K&N filters fitted so running the piping into the back of the metal OEM filter box isnt an option for me, i didnt want to do that with the K&N's because any petrol would strip the oil off the filter element, and the oil needs to be there for filtration purposes

Ahhh that would now explain my issue, another item to add onto the list thank you. Any reason you can think of why one wouldn't be fitted? (exhaust manifold clearance?) Also if I could source one then could it be retrofitted without the carbs? The throttle spring setup at the moment is pretty **** to say the least and could really do with replacement...

IONA on the forum has lots of spares for sale at the moment, he may have a suitable one and may even have some springs
 

Woody928

Events Officer
Staff member
Club Member
Well, when i first got my 240z carbs to replace the 260z 'anchors' they did have pipes on the overflows but as someone else mentioned earlier,
they were simply an upside down U shape. One of my carbs initially had an issue and was slowly dripping fuel from the over flow on to the exhaust!
since then i have the arrangement i described earlier in the thread.
I also have K&N filters fitted so running the piping into the back of the metal OEM filter box isnt an option for me, i didnt want to do that with the K&N's because any petrol would strip the oil off the filter element, and the oil needs to be there for filtration purposes

IONA on the forum has lots of spares for sale at the moment, he may have a suitable one and may even have some springs

Lol sounds like as usual a lot of these things get bodged somwewhere down the line, regrettably somewhat inevitable given the age and number of owners in some cases. Thanks you for the advise, I like your idea however I don’t have the necessary bits at the moment and have gone with John’s suggestion as a solutionin for now rather than leaving it as it was.

I will try IONA and see if he/she has one, if not and anyone who’s reading see’s this then I’m looking for a the heat shield that sits below the carbs, mounting bolts and throttle springs . Show me what you’ve got as I’d love to get rid of the shocking throttle spring return currently fitted!

Well in other news I had a very productive weekend with some servicing and general maintenance which in some cases was well overdue. First ssue to confront was ground clearance to get enough access to the car, having no access to a ramp or pit and having owned a couple of cars that are too low for ramps I’ve never bothered until now (Off to Halfords). With the front of the car now up on newly purchased ramps at the front we jacked up the rear off the diff and had axel stands placed under the rear sills to give 5 strong points to hold the car up. Access sorted and onto the essentials.

After all of the debate over coolant we ended up with some standard IAT blue anti freeze from Eurocarparts on reccomendation. In light of the unknown mix from the heater matrix refurb with the rad requiring a topup it seemed prudent to flush and clean the system so that the mix was consistent. We drained the system on both the rad and engine block (which needed the asistance of a pry bar to release the engine block drain bolt) before fully flushing the system and refilling with a 50/50 mix. Onto fresh oil and after some recent advice we’ve also gone with Millers 20w-50 Semi Synthetic oil for the engine and chucked a new OEM Nissan oil filter on before refilling the system for good measure given its age was unknown.

Next onto the carbs and air filters, being K&N’s it was all straightforward to strip down and fully clean (persil washing powder in warm water works wonders) before re-oiling. While at it, it also seemed prudent to strip the carbs down for a clean and to change out the oil. This was an interesting expirience having never touched carbs before and this being my first car with them, 10 minutes of Youtube viewing later and off I went. Not knowing the usual state of wear I’ve no idea what I should have expected however it seemed well worth doing. Both were covered in gunk which got sorted out with some carb cleaner (thanks halfords), all cleaned up I decided to give the dome tops some tlc given their dull apearance. Now I’m hardly into bling however out came the power drill and polishing wheels. Whilst not perfect they now look a darn sight nicer and have a nice patina to them so as to not look off the shelf new.

Here’s where the plain sailing gave way to a shocking discovery particularly in light of recent conversations of fuel overflows. Whilst removing the coolant drain plug from the engine block previously I came into contact with the fuel line running below the carb, next thing I know fuel was ******* all over my hands while I tried to stop it. Having clamped off the fuel supply we went about removing the culprit fuel hose. On removal it suddenly became clear what’s horrors lurked beneath, the rubber hose (which was completely unfit for its purpose and too small) had gone completely rigid from the fuel and age cuasing it to split from the pressure of the clamps holiding it in place. It was quite clear that for the last few months we’ve been driving around with a ticking time bomb waiting to go off which could have potentially covered burning hot headers/manifold in fuel which would have been an engine fire and game over.

Back off to Halfords again and some new replacement fuel hose sourced and we were back to refit and crack on with (had to return on Sunday to get a bigger hose to accommodate the fact the perished pipe was too small and had been bodged). With safety in mind we decided to replace both as a precaution. It turns out that the other hose with in a similar state and well past its sell by date, albeit wasn’t hanging on by a thread in quite the same way. Crisis averted we put the carbs back together and whilst reassembling the K&N’s noted that someone had previously drilled a hole in the back of both which was the perfect size for more fuel hose, fuel overflows now routed more safely in the air filters and fully reassembled another job was tackled.

New dizzy cap and rotor arm also fitted as part of the ignition system refresh. Spark plugs are currently awaiting the arrival of our new HT leads for the US which will hopefully refresh the whole ignition system and tidy up some of the some of cables currently all over the engine bay. A few more bits and pieces also coming from the states to make some improvements which I’ll update later.

After a few attempts to start up and having resolved a few random bits she fired back up, but was running a bit rough and even more in need of a tune up than before. Out of time for the day that problem was left for Sunday to deal with following a run down to the SE with the MR2OC in my MR2 Turbo to strech our legs in the early hours of Sunday before a full english. Having revisited Youtube again my attempts at tryinng to tune up the car ended in disaster, despite my efforts the car was running terribly struggling to idle before being brought back to a more respectable level albeit in need of some professional attention. Accepting I was way out of my depth I left the car until later that evening well aware that I was planning on sending the car off the BD engineering to be properly tuned and inspected in the coming weeks before its next major journey.

To my surpise late on Sunday evening having told my dad about my completely failed attmepts to tune the car we went to return the car to the lock up where it is stored, at which point to my complete surpise it seemed to be running relativly smoothly and was a completely unrecognisable car from the state I had left it in earlier! God knows if everything had just settled down after everything that had been altered or I genuinely by fluke managed to improve our situation by the time I left it is a mystery to me. Either way I’m going to try and book the car in for some professional help on the Tuesday after the Easter bank holiday before I head up to the Highlands on a driving holiday in the MR2 and in preperation for the run up to the Donnington Historic.

There will be more to follow as things continue to develop however here are some pics as that’s the bit your all really interested in!

All the bits ready for servicing
IMG_1240 by Mark Woodrow, on Flickr

Starting point for the day
IMG_1242 by Mark Woodrow, on Flickr

Dirty looking carbs
IMG_1244 by Mark Woodrow, on Flickr

Clean up has begun
FullSizeRender by Mark Woodrow, on Flickr

Some TLC underway
IMG_1254 by Mark Woodrow, on Flickr

Comparison after some clean up!
IMG_1255 by Mark Woodrow, on Flickr

Tired looking fuel line
IMG_1316 by Mark Woodrow, on Flickr

All freshened up
IMG_1308 by Mark Woodrow, on Flickr

Period correct nos Hella 4004 GT mirrors which we picked up a while back, the drivers side will work perfectly however I've currently not worked out whether the passenger side will ever be able to be made functional :(
IMG_1306 by Mark Woodrow, on Flickr
 

datsfun

Club Member
From my experience on Hitachi carbs that were fitted to the L16 and L18 engines, I would recommend that the fuel line that you have replaced needs to be as supple as possible. This allows the choke mechanism to work effortlessly. The common rubber hoses don't flex that easily. The correct pipes cost a small fortune as they have a high nitrile content IIRC. I used motorbike fuel pipes as their ID was compatible and pipes were supple as well.

Don't know if same applies to s30 carbs?
 

toopy

Club Member
From my experience on Hitachi carbs that were fitted to the L16 and L18 engines, I would recommend that the fuel line that you have replaced needs to be as supple as possible. This allows the choke mechanism to work effortlessly. The common rubber hoses don't flex that easily. The correct pipes cost a small fortune as they have a high nitrile content IIRC. I used motorbike fuel pipes as their ID was compatible and pipes were supple as well.

Don't know if same applies to s30 carbs?

That's exactly what i did a couple of years ago, works a treat :driving:
 

samuri-240

Well-Known Forum User
Period correct nos Hella 4004 GT mirrors which we picked up a while back, the drivers side will work perfectly however I've currently not worked out whether the passenger side will ever be able to be made functional :(
IMG_1306 by Mark Woodrow, on Flickr

I have a black pair of 4004 GT's, paid quite abit for them but not as much as the pair on ebay £470 !! :eek:
 

Woody928

Events Officer
Staff member
Club Member
From my experience on Hitachi carbs that were fitted to the L16 and L18 engines, I would recommend that the fuel line that you have replaced needs to be as supple as possible. This allows the choke mechanism to work effortlessly. The common rubber hoses don't flex that easily. The correct pipes cost a small fortune as they have a high nitrile content IIRC. I used motorbike fuel pipes as their ID was compatible and pipes were supple as well.

Don't know if same applies to s30 carbs?

Thanks for the advise, the line's we've used seemed pretty supple and are designed for fuel albeit I'm not 100% satisfied with the fit quite yet. I may do some more tinkering and will research this further. Thanks for the input as I hadn't even heard of nitrile before now, makes more sense now :thumbs:

I have a black pair of 4004 GT's, paid quite abit for them but not as much as the pair on ebay £470 !! :eek:

Have you fitted yours? and if so have you got any pics you could share? I'd be really curious to see them.

They do seem to go for crazy money from what I've seen being only available as nos or second hand items. I'd be lying if I said ours were cheap but hadn't realized they'd got quite that expensive! :eek:
 

samuri-240

Well-Known Forum User
Have you fitted yours? and if so have you got any pics you could share? I'd be really curious to see them.

They do seem to go for crazy money from what I've seen being only available as nos or second hand items. I'd be lying if I said ours were cheap but hadn't realized they'd got quite that expensive! :eek:[/QUOTE]

No they are still in the boxes, not done anything much with my Z for the last 10 years ! :eek: apart from buy certain parts to improve it.

As for the mirrors I think if you mount them as far forward as possible they will be good to use & look the dogs.
 

Woody928

Events Officer
Staff member
Club Member
No they are still in the boxes, not done anything much with my Z for the last 10 years ! :eek: apart from buy certain parts to improve it.

As for the mirrors I think if you mount them as far forward as possible they will be good to use & look the dogs.

Haha sounds like its well overdue some attention, its hard to resist nice period parts though!

Are you talking about door mounting though? I'd going to have another play with ours and see if we think they could work or not but I'm currently not convinced unfortunately as I agree they look fantastic :thumbs:
 

Woody928

Events Officer
Staff member
Club Member
Well I've had various parts arrive over the past couple of weeks with some last minute necessary tweets before my upcoming trip to BD engineering next Tuesday for tuning.

Firstly I've got to give a big shout out to Albrect who kindly donated me a heat shield in order that I could fit some proper throttle springs rather than the completely bodged setup that was in place from the states! In my haste I sent this off to the local powder coaters to be finished in a rush to have it fitted, stupidly having not tired to trial fit it :(

So it turns out when I came to fitting that there are not in fact two different heat shields over the generations but three different ones, with the second and third looking very similar with subtle differences as pictured below :eek: Unfortunately to my disappointment it therefore wouldn't fit, while the purists will cringe out came the dremel to remedy the fitment issues so that following some tinkering it now sits perfectly in place (albeit I need to touch up a couple of areas and its not quite the same shape). Finally the car now has proper throttle springs fitted giving the pedal a much more progressive feel and the rather shambolic bit of wire has been well and truly removed from the subframe!

IMG_1458 by Mark Woodrow, on Flickr

After powder coating and before some modification :unsure:
IMG_1428 by Mark Woodrow, on Flickr

With that now fitted and fully functional it was time for some new new spark plugs and HT leads to change out some of the more unknown components as part of the service. Spark plugs looked well in need of a change and I now have peace of mind knowing the current state of the usual consumable items. Big thanks to Mike F on that front. On the subject of HT leads we decided to splash out and rather than modify a new set or buy some off the shelf items we purchased some from Datsun Spirit in the states. In place of the traditional layout over the top of the head they are now neatly routed around it giving a much cleaner appearance. There's still a myriad of cables and pipework in the engine bay to confront however its at least a start. I think its fair to say the results speak for themselves, and should put us in good stead given the unknown age of most of the original components.

IMG_1437 by Mark Woodrow, on Flickr

IMG_1453 by Mark Woodrow, on Flickr

IMG_1456 by Mark Woodrow, on Flickr

Some other small details have been altered that make a big difference imo with the replacement of the worn out foot rest, and the replacement of the OEM door lock pulls. One was broken on purchase and was letting down the overall aesthetic, I'm sure again it will be to the purists disgust however we've gone with some nicely detailed Z finished replacements to modernise and detail the car further. I'm really pleased overall and think the finish speaks for itself :)

IMG_1438 by Mark Woodrow, on Flickr

IMG_1440 by Mark Woodrow, on Flickr

IMG_1443 by Mark Woodrow, on Flickr

IMG_1445 by Mark Woodrow, on Flickr

That's all for now, however I'm hoping that the car will be running spot on for the upcoming Donnington Historic following its trip to BD engineering on Tuesday. Hopefully there will be some dyno print outs to follow in due course. Will be interesting to see what figures its producing come the hour.
 

Paul_S

Club Member
Wow - those HT leads really make the engine bay a lot tidier! Not OEM I know, but a real improvement IMHO.

Other than to save costs, does anyone know of a reason why Datsun chose to route the HT leads over the top of the head?
 
Wow - those HT leads really make the engine bay a lot tidier! Not OEM I know, but a real improvement IMHO.

Other than to save costs, does anyone know of a reason why Datsun chose to route the HT leads over the top of the head?

I don't know how it'll save costs? think about the brackets etc that were used on the valve cover? The clips, extra casting efforts? I'm sure a shorter length would offer more performance from the wires(back in the day!). Keeps them nicely separated also, which might have been a key point with noisy leads. A few years back when we use to do the tv coverage for goodwood we could get interference off some of the more original cars and their ignition systems.

What are you going to do with the clips/brackets/holes on the valve cover?
 
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