1981 S3 V8 conversion

[hilly]

hope to post up some pics in next few weeks guys..

That's what I like to hear

Hilly - was the linkage an easy enough process to develop - what are the main considerations - ???

Errrrrr...... well it wasn't trivial, I spent quite a few hours scratching my head in front of a computer drawing the assembly out on CAD to make sure it worked and all the moving parts missed each other at all limits of movement.

The main thing to take into account is reducing the amount of backlash in the linkage.

Not sure about the Stevens cable system, but the 'G'car cross gate cable has only got 20mm of travel from one side to the other. Having now fitted a 6 speed box that is just 6mm from reverse to 1st/2nd to 3rd/4th and so on. You only need 2mm of slack in the whole assembly (which isn't difficult) and you have instantly converted 33% of your gear leaver movment between gears into wobble and that makes for a pretty crappy gear change.

There will always be some backlash, it is just a matter of trying design it out to a minimum. This means using rose joints and decent bearings where ever possible which isn't cheap. Just the rose joints and bearings in my set-up cost over

Edited January 31, 2007 by hilly

[hilly]

Seeing as there is now sooooooooo much competition on this section, I'll try and do a weekly update to avoid getting left behind, so here is this weeks efforts.

Got around to finishing off the drive shaft adapters.

The bolts for the gearbox flange need counterboring to ensure they don't interfere with the back of the CV joint, which meant I had to get a bigger milling cutter.

With the holes counterbored and the back face machined to the required shape it was time to test fit the whole lot onto the gearbox. Phew.... it all fits.

As the new gearbox doesn't have a mechanical speedo drive on it, I need to add some metal to one of the adapters to make a trigger wheel for the new electronic speedo I am fitting. Once that is finished I'll get them anodised.

Now that the paint has had a week to harden on the sump pan I can now fit it back onto the good engine before the dirt and water can get in. Unfortunately as I have hacked a big section off, the sump gasket is not use, so I had to make my own. A handy sheet of synthetic rubber will do nicely for that. Here is the sheet layed out on the now spare alloy sump section ready for the profile to be cut and the bolt holes punched out.

When all done it looks like this....

Now that it is finished I can bolt the modified sump pan to the bottom of the modified engine, ta daa !!!

Just need to make the mounting adapter for the 60-2 trigger wheel and VR sensor and the gearbox can go back on permanently.

Talking of which, I have finally decided to go with VEMS for the ECU so I have been messing around with it on the bench (the VEMS PCB is the blue board in the bottom right hand corner) over the last few weeks getting a decent base configuration before trying to start the engine with it.

I have been simulating all the sensor inputs using a PIC microprocessor and then adjusting the configuration files for the ECU until it kinda does what it is supposed to. At the moment it is running the 60-2 crank trigger, coolant sensor, air temp sensor, throttle sensor, air pressure sensor and the idle valve appears to be functioning. Next on the list to simulate is the cam position sensor and then get the knock sensors working, when that is done I can box up the PCB and set about wiring it up.

Hilly

[bigsi]

see now i love all this technical stuff, from pcb's to cnc milling;) more sexy machining pics please hilly

[punky]

Excellent work Hilly

I wish I had that kind of machinery available,but then I don't need quite so much machine work doing so its not to bad.

Its all hacksaws and files for me

keep the pics coming.

[hilly]

see now i love all this technical stuff, from pcb's to cnc milling;) more sexy machining pics please hilly

Errrrrr I wish it was a CNC mill as it would make my life easier.

It is 40 year old mill, the CNC bit is my brain telling my hands to twiddle the knobs and handles in the right order (sometimes!!!!)

I'll keep the pics coming as fast as I do the work.

Hilly

[M Blur]

You also need to make sure the engine/gearbox movement during acceleration and braking doesn't cause the car to jump out of gear.

I am not familiar with the gear selector on the G50, but if you give me some info on how it works along with some dimensions of selector and cable travel I'll have a think about it and see if my system can be adapted to fit yours.

Hilly

That's be great Hilly - the Honda tech guys are pretty switched on but may not have the CAD-angle to get the initial design working. Any help much appreciated.. can you PM me your email addy for the all importance consultancy... Could you also fab me some shafts and adaptors (for a price of course..) as yours look superb.. the stock shafts will probably twist even if the new billet adaptors held up>? any suggestions on what grade to use for the shafts?

can you start with any 5-speed cable shift arrangement or is it better to start with a specific type.>? A stock G50 shifter used rods not cables - not sure what to use in its place. There are a cpl of firms offering conversions but all for big mone - Bobby Hart racign offers a cable conversion linkage but can't find a pic..

These guys also purport to be able to do conversion but am I right in thinking that the simplest part is finding a usable shifter..?

www.renegadehybrids.com

I'd love to be able to use a Hurst shift action ... http://cgi.ebay.com/ebaymotors/ws/eBayISAP...mMakeTrack=true The thing with that would be to convert the forward-back Hurst movement into a cross-gate - is that jst making matters even harder Hilly... if we could pull it off it'd in effect make a semi-sequential or even a sequential if I later used dog gears and became versed in timing shifts to rpm.. even with a clutch it'd reduce shift time and missed shifts.. downside being I have to make sequential shifts even on the down-changes but even that suits the G50. May drop this one as it'd be a headache to make I'm sure. Re Ameniya did sth similar for the RX7 but it was a bit gimmicky - I guess it must use some sort of toothed wheel - perhaps the lever goes progressively forward as it goes up the gears.. if throw wasn't too long and it's close enough reach wouldn't be an issue. Otherwise I'm sure the Phonix guys would prb tend towards a Honda shifter tho most of them are fwd layouts...

First big thig Phoenix have to do is modify the G50's spray bar, filter etc to work upside down and add in a pump and cooler arrangement/. They redrill the adapter plate and position assembly to work out mounts/clearance. Once they've staretd that I'll start my own thread and get some pics posted.

Edited February 5, 2007 by M Blur

[hilly]

I've sent you a PM

Hilly

[M Blur]

I've sent you a PM

Hilly

PM back - tks again Hilly B)

I compared the Bobby Hart linkage for the Porsche trans and it looks way more basic than the lovwely stuff you put together m8 [butter, butter] Have sent pics over...

Not sure whether to start with a Porsche shifter or not - hopefully Bobby Hart will confirm - if we can go any 5-speed shifter then makes sense to maybe use either a) Stevens 5 speed or B) Audi to match yours..

The whole CAD thing is very cool.. without some guys could take weeks of trial and error.. what I could do with seeing is the linkage John Hazzard made up for his 3.5>G50 but Mike sold it off along with the trans...

[hilly]

The competition is hotting up in here so time for some more news about progress.

Got the manky welded bits of metal back from the powder coaters, all nice and shiny now, mmmmmmmmmmmm...........

So time to start fitting parts to the working engine.

A few people had asked for a picture of the left hand engine/alternator mount so here it is with added tensioner and gear change bracketry goodness..

I bolted on the flywheel/clutch/gearbox a few weeks ago (you can see it fitted on the engine in one of the photos in the last update) and we patted ourselves on the back for another job done. However, when it came time to take off the front crank pulley to fit the 60-2 trigger wheel, we suddenly realised that there was no way to lock the crank to get the big nut un-done.

D'oh!!!! school boy error

So off came the gearbox again so we could use the ring gear to stop the crank turning.

With the big bolt un-done and the crank pulley off, time to go about fitting the 7 1/4" trigger wheel.

First job, machine a nice flat surface to mount an adapter plate onto.

With that done, a couple of M5 tapped holes were added.

Then an adapter plate with a spigot for the trigger wheel was machined to be a nice snug fit in the modified pulley and bolted in place with offset screws to make sure it only goes back on one position.

With that done the pulley went back on the engine so I could see how it all fits together and fathom out a bracket for the VR sensor.

The VR bracket now sussed, time to put the gearbox back on.

If anyone is interested in getting a feel for the engine/gearbox shape and size, here a a couple of shots of the assembly (spot neighbours wobbly fence!).

I hope that patch of oil comes off my patio ..........................

Also re-fitted the gear change rods back onto the shifter, but not much to take photos there.

Hilly

Edited February 19, 2007 by hilly

[Simon350S]

Nice one Hilly.....

Makes my little project look like a little school boy lego set.......

Never mind hey...... one day I'll do something special!!!!!

Got ideas for a daily driver Esprit for work, 30k+miles per year........ gotta be extremely economical, modern refinements, power steering, roomy etc.....!!!!

One day.... who me?? dreamer???

Simon

[M Blur]

nice stuff Hilly - will tap you for those adaptor plates hopefully but also speaking with a cpl of firms re shafts as I need shafts that can take 600bft eventually... thankfully engine set-up for good spool and avoid silly traction shattering torque with the power up with good top-end.

Your headers are way more compact that mine... very envious m8..

[hilly]

I have got a spare pair of those headers, trouble is it is pretty unlikely they will even remotely fit your block ........

Hilly

Edited February 20, 2007 by hilly

[M Blur]

I think they may be a bit small Hilly.. not to boast about one's manhood (cough)..lol

more's the pity... however the Stahl headers will work well - jst need a raised engine cover design and lots of heat wrap.. !

Edited February 20, 2007 by M Blur

[punky]

Looking good dude

I'm still waiting for the engineering company to start on my adapter plate

Its been three bl##dy weeks now and they told me two.

[silverfrost]

Andy,

looks very tidy chap, glad to see you have all your newly painted bits back,

very impressed qwith the mounting of your 60-2 trigger wheel will need

your advise on getting mine sorted,

Keep up the good work and it may just get me to pull my finger out

cant wait for next update

regards danny

[hilly]

This weeks stuff

Having got the 60-2 crank trigger wheel fitted to the pulley I can now position the VR sensor. As I won't be using the fan on the front of the engine, I took off the bearing and used the mounting point to secure the VR sensor bracket to the cam belt cover.

I know the bracket looks a bit overkill, but it needs to stay put, it is also adjustable to allow me to fine tune the gap between the sensor and the trigger wheel. All I need to do now is get the final few issues with the VEMS ECU sorted and I can then set about splicing it to the Audi loom.

Next job is to re-fit the engine/gearbox into the car so I can measure the required drive shaft lengths so they can be sent off to be modified. As this update is a bit light, here are a few gratuitous big engine in little car shots to pad things out a bit.

Phew!!!! It fits in the engine covers...................

Here you can see the position of the gearbox at the back of the car.

Now that the gearbox is in it's final position I can now modify the rear cross brace to clear the casing.

Having measured the amount to cut off, set about the cross brace with the grinders. Unfortunately my little grinder decided to curl it's toes up when I got 90% through finishing off, so I am a bit stuck till I go to the shop and buy another one.

It also started to pee down , and not having a garage to keep the wet stuff off meant that rain stopped play.

Hopefully if things work out how I want this week I should be able post a bumper update next week, hmmmmmmmmmm, probably jinxed it now...............

Hilly

[fenton]

That V8 looks like it belongs in there!!!!!!!! TOP JOB

[silverfrost]

Looks great Andy keep up the good work,

Cannot wait to hear the beast run

regards danny

[Simon350S]

Very nice.....

Cant help thinking i'm lacking a few pistons in my engine bay!!!!

Simon

[Goose]

Looks great! Nice work! Great to see it taking shape!

[M Blur]

Hilly - you should leave the rear bumper off and keep the exposed racer look and dress up the rear with a couple of bump stops etc..

[hilly]

More efforts.......................

To finish where I left off last week when my angle grinder died, I bought a new one and now the cutout in the rear cross brace to clear the gearbox is finished.

I now need to add more metal to put a bit of strength back into the brace. A section of 3mm steel was cut and bent to fit into the gap.

Out with the MiG welder and then fit it back onto the car.

That should do the trick.

Just need to send it of with the next batch of parts for powder coating before bolting it to the car.

Now to the major part of this update, brakes

[hilly]

Then onto the mill for machining

I got about 95% of the way through the machining process and then hit a snag.

The lathe and mill I have access to are not big enough to allow the brackets to fit during machining of the hub cut-outs. I scratched my head about how to do this final machining step for nearly 2 months until a friend came to my rescue.

At this point I want to thank Kurt and the guys in the machine shop for taking my chunks of alloy and doing a fantastic job of machining out the final holes. Also while I am at it I should also thank my father as well for helping out with the whole car so far (they are his feet you occasionally see in the photos) as without him I would have got nowhere with this project.

Anyhow, here are the finished brackets

I need to do a couple more things to get the brackets to fit, so I

[M Blur]

we are not worthy.... !

[silverfrost]

Very nice work Andy,

looks fantastic, looking forward to seeing your callipers fitted

you have yourself an order for the rear end machine work

regards danny.