S1 rebuild....not one for the purist

[mk1fan]

As a follow on, what radiator did you use?

If you haven't decided yet can I suggest you check out the Subaru Impreza STi (1997-01 iirc) rads which can be had for a lot less than replacement TVR models. The alloy versions are plentiful thanks to the popularity of the car for motorsport.

[Alan 1209]

Car is fully stripped right now so no picture available. I used the rover 75 tank because of its shape, and 15 psi cap. Be careful with the VAG as some run at 21psi.

[mk1fan]

Thanks for the heads up. I'm not set on the VAG one.

[Alan 1209]

Iv'e used an ally Sierra RS500 30% uprated. The porting is a reversed but not an issue.

[Alan 1209]

Just sticking this in because it explains me.......https://www.youtube.com/watch?v=WprXJE1fgwc

[Alan 1209]

Just got round to pulling the rear hubs and trailing arms apart to replace bearings, CV's and trailing arm bushes. Confusing to find left hand threaded nut on the right hand shaft, and right hand on the left shaft. Presumably messed up when the trailing arms were changed. I'm converting to discs and i've seen a number of posts re this so here's my short take on it. Iv'e bought a couple of adaptor plates from ML, £30 for the pair, and they put the caliper at the top, which puts the handbrake cable and bleed nipple where they should be. I'm also using a pair of 1275 midget front flexible brake pipes, these have 7/16" UNF banjo's at one end so you can point the pipe where you want it, that seems to take care of most of the issues iv'e seen with this conversion. I'll post pictures when I start the reassembly.

[phillpot]

Alan 1209 said:

Confusing to find left hand threaded nut on the right hand shaft, and right hand on the left shaft. Presumably messed up when the trailing arms were changed.

Yeah, should be LH thread on LH side at rear and LH thread on RH side at front.

Alan 1209 said:

I'm also using a pair of 1275 midget front flexible brake pipes, these have 7/16" UNF banjo's at one end

Will they seal ok? banjo bolts will be M10 into calipers.

[Alan 1209]

nope. the calipers I have are 7/16 unf, but if you have 10mm then you can use 10 x 1 banjo bolts. The banjo eye is the same. As a simple check if a 7/16 unf pipe fittings screws in its 7/16, if a 10mm screws in it could be either.

[greymrj]

Alan 1209 said:

The gearbox is an RX8 5 speed from a 232 bhp model.

I like this Alan, just a few more thoughts that I guess you have already had.
I believe the ratio spread on this gearbox is better? The S is great for acceleration but the revs at 70+mph are too high for comfortable high speed cruising, this is a torque rather than rev strong engine. I am modding the new 2.8 with Burton Power advice to take the safe rev limit up but better gearing spread would be fundamentally a better option.
I presume the remote lever will have to be moved forward? Is that going to be a big job? The linkage looks like it would be fairly easy to extend but I presume the remote couldnt readily be chassis/body mounted instead? Mounted properly the torque reaction angular displacement of the engine is quite limited. Common these days to mount the remote to the body but modern linkages are often quite long.
As the gearbox is longer the prop shaft will be shorter, by quite a significant proportion. That makes it significantly more important to get the alignment of the gearbox end drive flange and the diff flange in line. You might have to tip the engine ever so slightly to achieve this?
Not even sure how the RX8 clutch is activated? Presume it will have to be hydraulic operation in the S. There is a problem with the design of the hydraulic slave set up on the S as it doesnt exert force at the right angle and the wear on the end of the clutch arm is also an issue. Be interesting to see how you rig the slave to get the correct displacement and a good connection between slave and clutch actuating lever.
Good engineering stuff!

A weakness on the rear drive system on the S is the location of the UJ's to the drive flanges. They are not dowelled and rely only on the bolts for location. There have been many incidents of these bolts coming loose and any damage to the bolt holes or flange threads then makes matters worse. We have found the 12 point star bolts a pain, OK for quick machine installation during manufacture but not easy to get right with hand tools. 12.9 hexs heads are worth sourcing instead. Mine are now paint marked to pick up any movement but next time mine will be drilled (24 bolts...how many drills!) and wired in place.

[phillpot]

Alan 1209 said:

nope. the calipers I have are 7/16 unf

Strange? By the eighties Ford were "all metric", mine are definitely M10 x 1, which can be confused with 3/8 unf (24tpi).



Show greymrj your rather neat gear linkage

[Alan 1209]

Hi Phillpot, i'll check but the banjo is a good fit so may be m10 x 1.
As for the gearbox stuff, its a complex job but basic details are :-
Bellhousing shortened by 8.5mm to get proper spline engagement and clutch release geometry,
[/url]|http://thumbsnap.com/MrrgX7lm
adaptor made to bring spigot bearing out, rather than extending g'box input shaft


this takes its registration off the 21mm bore in the crankshaft.
I'm using the mazda slave cylinder, moved forward 12mm on the same alignment and all the standard clutch release setup.
The prop will be approx 50mm shorter so alignment is critical, this will be taken care of with the new g'box mount.
The remote shift is my own manufacture, it moves the shift 60mm forward of the standard S position which was to far back for comfort, so 135 mm rather than TVRs rather crude 3" crank.
|http://thumbsnap.com/kGC8daq7[/url]
I'll post more pics as I go forward. (no pun intended)[url]

[Alan 1209]

Added to all this, due to the gain in torque I have gone for a 3.36:1 LSD,

This is the gearing comparison

RX8 G’box 3.36 LS Diff
Gear Mph per 1000 RPM Mph @5500 RPM
----------------------------------------
1 6.97 38
2 11.58 64
3 16.44 90
4 21.86 120
5 26.86 148

T9 G’box 3.63 open Diff
Gear Mph per 1000 RPM Mph @5500 RPM
----------------------------------------
1 6.02 33
2 11.18 61
3 16.06 88
4 20.23 111
5 24.53 135

Which means that French motorway cruising comes in at just under2.9k rpm rather than the current 3.3k

[mk1fan]

Looking at your photos you've just given me an idea for improving the T9 set up. Cheers.

I agree with philpot, very odd your calipers are imperial.

Any reason why you didn't go braided hoses? Would enable you to delete the short flexis 'on to' the trailing arm.

[Alan 1209]

Mea Culpa. Caliper and banjo are 10mm. I didn't go for braided as all the brake plumbing is new right up to the rear cylinder.
A little anecdote from my time in the early 80's working part-time in a cars spares shop ( this kept the cost of my first restoration project down) A customer returned a set of rear pads for a newish Granada as 2 fitted and 2 didn't, a close inspection of the car showed that it had 3 ATE calipers and 1 Girling! Ford were still holding a lot of stock in those days so there was a lot of mix and not quite match going on.

I made a remote for my old T9 box, It looked like this, I have drawings but not all the parts though i could put it back together.

[Alan 1209]

greymrj said:

A weakness on the rear drive system on the S is the location of the UJ's to the drive flanges. They are not dowelled and rely only on the bolts for location. There have been many incidents of these bolts coming loose and any damage to the bolt holes or flange threads then makes matters worse. We have found the 12 point star bolts a pain, OK for quick machine installation during manufacture but not easy to get right with hand tools. 12.9 hexs heads are worth sourcing instead. Mine are now paint marked to pick up any movement but next time mine will be drilled (24 bolts...how many drills!) and wired in place.

I've already sourced a set of 12.9 capheads, or do you mean hex head bolts? if using bolts you could lift the corners of the tabs. I had to cut the heads off the old torx bolts after breaking 3 drivers.

[greymrj]

Alan 1209 said:

I've already sourced a set of 12.9 capheads, or do you mean hex head bolts? if using bolts you could lift the corners of the tabs. I had to cut the heads off the old torx bolts after breaking 3 drivers.

Very interesting indeed Alan. Nice to see some re-engineering rather than bodging!! I look forward to seeing more of your work.

I have gone for 12.9 hex head cap screws (Allen) from a reputable company. Members have found some dodgy ones on ebay listed as suitable but clearly not of adequate standard.
Not sure if bolts would be accessible? I certainly havent tried bolts.
The existing plates under each pair of screw heads rather puzzle me. They are too thick to be used as tabs. There doesnt appear to be a need for load spreaders and they do not tie pairs of bolts together in any way. They are harder than the CV body so they might prevent the screw heads digging in?

[magpies]

Alan 1209 said:

I made a remote for my old T9 box, It looked like this, I have drawings but not all the parts though i could put it back together.

A properly engineered solution



unlike my version

Edited by magpies on Friday 6th January 18:43

[phillpot]

Alan 1209 said:

I made a remote for my old T9 box, It looked like this

Ingenious, sorting out the push down for reverse must have taken a bit of working out?

my way round it............





Very interesting to see how you got round issues like first motion shaft length etc.

[TVRees]

What a great thread ! An S1 with a 2.9 engine and a Mazda gearbox
Excellent work Alan, very much looking forward to the next updates.

[Alan 1209]

phillpot said:

Very interesting to see how you got round issues like first motion shaft length etc.

see above for issues around first motion shaft. The spline is the same so you can use the standard 2.9 clutch, though I have the lighter 2.8 flywheel.
I changed to the RX8 box because the t9 is already at its limit on the basic 2.9 engine, even ford didn't use it hence the mt75, the shortened remote is a really neat fix. I must learn to weld ally.

Edited by Alan 1209 on Friday 6th January 23:57