1970 rebuild

Peter loveday

Club Member
Hi all,

I posted some pics up a while ago of the project I’m just about to start on. I thought I’d share my latest thoughts on the project direction and my intentions for the build.

The shell is a strange mix of perfect and terrible- great front end, no serious body damage but rotted out floors and boot. I’ll be keeping the body standard except for a little cleaning up of a few details ( side markers and repeaters removed.

Interior will be kept mostly stock with some modern gauges and perhaps some subtle period style buckets, also considering a rear cage.

I’m thinking of leaving it lhd as I want to keep the shell as original as possible but I’d like to hear some thoughts on that.

Engine will be a high reving l28 running itb’s etc, with some detail orientated customisation. I’m going to try and mate it up to a rx8 6 speed and a suitable rear diff mounted in a custom cradle.

Suspension will be lowered 2” with a lot of custom fabrication. Tubular front cross member with optimised geomery to correct roll centres, remove bump steer and add some rigidity to the front. I’ll be creating a custom bolt in rear end, retaining the chapman struts but again correcting the roll centre, optimising geometry and generally re engineering things a bit to improve stiffness and alignment. The ultimate goal here is to keep the shell unmolested.

In general I’m after a few points of view, am I going too far on a potentially valuable low vin number car or am I being too precious and I should just go all out?

It’s a long term project and progress is likely to be slow until I get a new house/garage etc so I have plenty of time to stockpile some parts and work on the modification designs.
 

Woody928

Events Officer
Staff member
Club Member
Sounds like an awesome plan to me! Really curious to hear more about your plans for the RX8 gearbox and diff, not heard of that being done before.

Low vin number cars are a much bigger deal in the US and particularly so if they're stock, it seems less so over here. Given that you already don't have the original engine I'd say do what you want, you'd never get it to the state that would really make a collector really swoon over it without that. I have an early US car with a non original engine which I'm fine with as I can swap another L series and do what I want should I choose. I just liked the earlier details... If you're happy with it then I'd leave it LHD, it's not easy or cheap to source all of the conversion parts and you really don't gain that much imo.

In a lot of respects your build sounds similar to mine, stock looking with modern and uprated running gear where appropriate with a little bit extra :coolgleam:

https://zclub.net/community/index.php?threads/just-bought-our-first-z-240z.21463/page-13
 

Albrecht

Well-Known Forum User
I’m thinking of leaving it lhd as I want to keep the shell as original as possible but I’d like to hear some thoughts on that.

Suspension will be lowered 2” with a lot of custom fabrication. Tubular front cross member with optimised geomery to correct roll centres, remove bump steer and add some rigidity to the front. I’ll be creating a custom bolt in rear end, retaining the chapman struts but again correcting the roll centre, optimising geometry and generally re engineering things a bit to improve stiffness and alignment. The ultimate goal here is to keep the shell unmolested.

In general I’m after a few points of view, am I going too far on a potentially valuable low vin number car or am I being too precious and I should just go all out?

(my bold highlights).

It sounds interesting, but one thing I'd point out with your intention to keep the 'shell as original as possible is that it's going to be a weak link in your quest for suspension rigidity and stiffness. You might just be making the bodyshell reveal its built-in tendency to be the 'fifth spring' in the equation, even with a half cage in the back.

Can I be Devil's Advocate here? I'm not sure how far it's worth taking a quest to improve geometry, alignment and stiffness if it will ultimately conflict with your desire to keep a high level of 'period correct' in the rest of the build, and in the 'shell in particular. With a relatively modest amount of changes to the stock drivetrain, steering and suspension you can have a much improved 'old' car which punches well above its weight. Some of the on-paper 'faults' contribute greatly to its charm and feel. We would frown on somebody who installs UPVC windows on a Georgian townhouse, but installing modern triple-glazed wood framed sash windows which look period-correct whilst working better than the originals will get a pat on the back. If you can avoid the UPVC type scenario with your build then you'll be going in the right direction.

I have a 4/70 production dated HLS30U myself, and it will not be staying stock. I'll keep it LHD, but I'll move the handbrake lever over to the left side of the tunnel (LHD works rally car style) for better ergonomics and - honestly! - to make a point that few will care about. It will be far from stock, but it will be as 'period correct' modified as I can manage. As I've got older - and I've owned S30-series Zs since the early 1990s - I've learned that what I *like* best isn't necessarily what *works* best, if 'best' is even a thing. I advise staying away from modern-style modifications that you might grow to dislike a few years down the line, or even before the car is on the road.

Yes, 'early' cars are fetching more money these days and there's a general 'earlier the better' theme for so-called collectors, but once you get into four figure body serial numbers that effect is lessened somewhat. In short, there are still PLENTY of HLS30-prefixed 1970 build cars around so you won't be defacing a Faberge egg. Go for it.

Sounds like you have good fabrication skills, so I'm 'subcribed'. Good luck!
 

jonbills

Membership Secretary
Site Administrator
I believe the S15 gearbox bellhousing is integral with the gearbox front case, so where its been mated to an L engine before they've cut the front of the gearbox off and tigged an old L engine bellhousing to it. I think there's a thread on it on viczcar.
 

Peter loveday

Club Member
Thanks for all the input, it’s great to have some real world experiences of these cars and their character discussed before making any decisions and I really appreciate any input particularly from people who have been around these cars for some time.

Ultimately this projects intention is to end up with a car that is enjoyable to drive in a spirited manor as a road car whilst keeping as much of the charm as possible. It won’t be built for resale and doesn’t need to be the fastest car on the road, it just needs to put a smile on my face.

As a profession I’m a design engineer and I really enjoy the challenge of design improvements so a lot of the enjoyment I will get from the build will be in the subtle integration of modern parts and designs in a sensitive way.

I’m sure my intentions may change along the way and I’ll struck a ballence of how far to go on the chassis front. My tastes have already since I started looking into these cars- over fenders and headlight covers have already been dropped from the plan so I’ll see where the road goes on this one. I have read through all of the infamous 260 2+2 thread and cringed in many places, I can assure people this won’t be following that path!

@ woody. Looks like a great car you have there, looking forward to reading through your journey in full. Are you moving out to Singapore? I am literally in the middle of relocating back to the U.K. from a 5 year stint in Hong Kong. Life in Asia is very different but has treated me well.

@ albrecht I’m sure I’m going to be bouncing some ideas off you in the future, seems like you have a wealth of knowledge on a lot of the period touches and modifications. Feel free to sling any ideas my way. If you are still likely to have that spare wheel well up for sale in the near future please let me know.

@ mark n. Yes the rx8 transmission is the same unit as the s15 with a different bell housing and input shaft and isn’t a Nissan transmission unlike the s14 5 speed that can be easily swapped in. It looks to have great ratios for a revvy engine and is a bargain to pick up second hand. Should fit the stock transmission tunnel and put the shifter in almost original position. There is a blog about someone fitting one up to a 510 somewhere, it’s a bit involved as you have to splice the bellhousings together but should work out if I can brush up on my tig.

Out of interest, what’s the general consensus on the mzr cars?
 

Woody928

Events Officer
Staff member
Club Member
@ woody. Looks like a great car you have there, looking forward to reading through your journey in full. Are you moving out to Singapore? I am literally in the middle of relocating back to the U.K. from a 5 year stint in Hong Kong. Life in Asia is very different but has treated me well.

Thanks, it's getting there now. Unsure right now, I'm having permit issues which has halted current plans. Assuming the permit gets approved then the plan is to go for a couple of months as a trial and assuming all good then a one or two year contract to start and go from there.... Small world, I've heard nothing but positive things about the region and travel posibilities!
 

Peter loveday

Club Member
Hi all

a bit of an update on my build, i did write quite a long update but seemed to have lost it.

ill add some more later but ill start off with a few pictures- a virtual pint to anyone who guesses what engine I'm dropping in and the inspiration- there is quite a big clue there.


 

Peter loveday

Club Member
Well done. The chocolate followers were one of the reasons I got it for a good price. Thankfully a new set come in at about the same price as l series items and resolve the issue:cheers:
 

atomman

Club Member
Funny enough I have just been designing some trumpets for a speed 6 engine a friend who's sticking in an old Jag
 

Peter loveday

Club Member
Funny enough I have just been designing some trumpets for a speed 6 engine a friend who's sticking in an old Jag

What a small world. If you need any cad for the throttle bodies etc let me know. The trumpets I’m using are from an e46 m3. Basically a perfect fit and work well in the space I have. I would be really interested to hear some more information on the swap. I know it’s quite a similar layout to the jag engine
 

atomman

Club Member
Thanks for the kind offer of the CAD Peter, Thought I recognised the M3 trumpets , I have done some custom trumpets for a few of them so have them in CAD, good to know they fit ,

he's just got it placed in for now , but it fits nice in there
128597761_1329803760687557_471823543269919667_n.jpg
 

Peter loveday

Club Member
That looks great, a mk2 I assume? Seems to be a good bit of space in there for it.

mine thing to pass on that he might not have considered, the tvr engine runs at about a 20 degree angle and only has oil drains on the lower side in the head. I’d be a bit concerned that under hard cornering to the left oil could build up in the head. I’m running mine at 8 degrees and still a little concerned. Might be fine though.
Is he running the tvr t5 box? I’m just working on that myself. I will be using an adaptor plate to clock the gearbox back to vertical.

I might be after a set of your trumpets in the future, what are you making them from?
 

atomman

Club Member
I will have a chat about the angle to him, just in case he hasn't realised , think he is running the TVR box to , trumpet wise I usally make them from 6082 ally but have made titanium ones for my Z . coz i had some
 

Peter loveday

Club Member
A bit more information on my engine build.

it is my intention to recreate the nissan S20 engine with the TVR engine. They are remarkably similar in layout (exhaust/intake on correct sides, low profile cam chain, engine inclination to passenger side even the cam cover bolts are in a similar position) the TVR is just a bit bigger, however being a dry sump i am able to mount the engine lower so bonnet clearance is not an issue. The TVR engine also comes with bespoke ITBs which mount direct to the head. The engine is also significantly lighter than the L series so there is a little bonus there. I've added some images to compare. My cad is still work in progress but as you can imagine, it takes some time.

Nissan s20 cam cover

Yokohama-Car-Shopping-Nissan-Skyline-GT-R-KPGC10-S20.jpg

Standard tvr cover- rather ugly and will look out of place

tvr cover.JPG


My redesigned tvr cover- designed to fit in with the datsun- im still working on the plug lead solution, i may follow the s20 design
cam cover.JPG


s20 induction side


OIP.jpg


tvr induction side- even oil filter is in the same location

upload_2021-1-8_9-43-13.png

tvr exhaust side
speed6.JPG

s20 exhaust side

s-l300.jpg
 

Attachments

  • speed62.JPG
    speed62.JPG
    138.6 KB · Views: 3
Top