1981 S3 V8 conversion

[hilly]

Cheers Andy - us V8 boys got to stick together..

Had some rough workings - motor looks ok but my worry is the tranny + adaptor plate but then I look at that audi tranny and it's pretty long. Main thing is there's enough room to line-up the driveshafts. Appreciate you looking.

Before I started this project I spent a lot of time researching the measurements to ensure it would fit, a lot of head scratching and internet research.......

OK, just been out in the dark with a tape measure and here are the measurements :-

Total length (Audi ABZ engine + 01X gearbox) = 1200mm

Length of engine (front pulley to bellhousing face) = 490mm

Length of 01X gearbox (bellhousing to rear casing) =710mm

Max width of engine (across exhaust manifolds) = 760mm

Max height of engine (sump to idle air valve) = 660mm

Drive shaft position (front pulley to drive flange) =690mm (or from gearbox rear casing = 510mm)

Now when I had the assembly in the car the there was still a couple of inches left to move the engine further foward. I chose it's current position due to the fact that the drive shaft flanges on the gearbox are now 2 inches ahead of the rear wheels (instead of about an inch behind with the 912/Citreon gearbox) and it is also in the middle of the engine covers.

Now I am not sure how long the block is on the Chevy 350, but I bet it is longer as the ABZ is very short for a V8. Now as I said there is still room ahead of the engine and there is room behind the gearbox so I reckon it should fit length wise. An adaptor plate shouldn't add more than about 20mm to the total length.

What would be worth checking out though is the exhaust manifolds, the Audi ones (very nice double walled stainless efforts) are very compact and sweep upwards as they leave the heads which fits round the chassis rails a treat. Not sure about the Chevy 350.

Yes the Audi gearbox is long-ish, but not any longer that the UN1 which looks long in photos. Never compared the 2 side by side, but I reckon if the UN1 will go then the Audi unit will. The 5 speed Audi boxes are shorter, but not quite as strong (I think), it would be worth checking out. The other fly in the ointment with the 5 speeders is that the gear change linkage is at the back of the unit and not on the side like mine so fabbing up a decent linkage will be more difficult.

Phew...... I think that is it........

If you want me to take some measurements of the Esprit engine bay whilst it is empty (my S3 is the same as yours) then let me know and I'll do them tomorrow.

Andy

[M Blur]

thanks Andy - engine already out of mine and gave the workshop the critical measurements for the 358 and all looks good.. as you say headers are suck n see so we didn't have them cermaic coated in texas in case I need to get Meercat to make up custom jobbies.

as you say the Audi is a small bore - long stroke motor. My 358 is the other way round tho big in all dimensions relatively - bores are about 4.75" in diameter.. it uses a 348 crank to square it as much as poss for the high revs.

all. now down to the size of of the G50

ultimately we can move the firewall to accomodate so headers probably the biggest thing jst now. Engine arriving in about 2-3 wks.

[hilly]

Time for an update....

What I will start doing is putting the full project story on this site as well to keep everyonne happy.

So here is last weeks update.

So I take the sump off the wrecked engine to see what is in the section that is hitting the frame.

The bit that is causing the problem is at the top in the picture.

Well there is nothing in there that can't be hacked off as the oil pump, pick-up and baffle are on the other side, so out comes the saw.

Now I will obviously have to weld a section back in to stop the oil peeing out, but for the time being I need to put it back on the wrecked engine to check that it will now fit and the project is still do-able.

Back on the engine with a section cut off the pan to match.

Put the gearbox back on then throw it back into the car.

Phew!!! it now fits, with plenty of clearance on both sides, result

Now it is time to get on with the new engine and gearbox mounts.

Centered up the engine and put it on wooden spacers to get it to the final height.

Knocked up some cardboard templates which I can then take measurements from and draw in CAD.

Engine passanger side (in the UK that is)

Engine drivers side

Gearbox passanger side

Gearbox drivers side

Now I would of liked to make the mounts out of alloy, I can't or don't have the equipment to weld that stuff so I would have to get someone else to make them.

If I do that, I have a nasty feeling they won't fit right when I get them back.

Which means I will have make them out of steel.

I'll cut out the required shapes and then tack them together in situ and then weld them properly off the car.

That way they will defo fit, just a bit heavier that I would like.

Off to the metal shop...........

And this weeks.........

Sent my old man to a metal yard and he came back with a lump of 6mm sheet steel 1 foot x 3 foot which should be plenty to knock up some mounts..

So in a few days with the help of a grinder, a drill and a welder, I managed to turn this

into 2 engine mounts

and 2 gearbox mounts

These should do a better job of holding up the engine than the cardboard jobbies.

Then had to put the assembly back in to check it was still in the right position. Everything still fits a treat, here you can see the clearance for the exhaust manifolds past the chassis rails.

Plenty of room and that also goes for between the bulkhead and the front of the engine.

So now that the engine/transaxle has got mounts and is the correct position time to crack on with some of the other tricky stuff.

The alternator is never going to fit in it's original position which means it has got to move and space up the front is tight. Now this is where the offset sump does me a favor. The Lotus does not have air con or power steering so I can junk the pumps for those and put the alternator in their place. As the sump is offset this means that the large-ish alternator will fit in the small space available. So a few bits of metal tacked onto the left-hand engine mount and we now have an alternator.......

Now onto the next problem.

The belt tensioner is now on the wrong side. I spent many hours scratching my head with bits of string trying to figure out a way to route the belt so as the tensioner would work. I failed miserably........

Then while looking on eBay I found a brand new tensioner for an Audi TT which looked like I could possibly do something with and for only a tenner it was worth a go.

So another bit of metal welded to the left-hand engine mount resulted in a working tensioner, I love it when a plan comes together

Right..... next problem, the gear linkage.

The Lotus uses a rod and a cable to attach to the gearbox linkage to the gear lever. The old gearbox connection is on the right-hand side where as the 01X is on the left, also the rod action needs to be reversed to work the gearbox properly. I should be able to use of most of the old lotus assembly, just cut and re-weld it. So where am I going to put this translator, yeap...... you guessed it, on my friend the left-hand engine mount (damn this lump of metal is getting complicated). The mount is whipped off the engine and bolted to the chassis so I can modify the rod linkage (the red bit) and fit the translator (the black bit on the left hand of the picture).

That all seems to work, now to connect the translator to the gearbox.

Again I should be able to re-use the Lotus stuff. A new temporary translator is made up out of alloy as well as the lever for the 01X so I can fiddle with the lengths to get the lever throw correct. The bath tub shape is to get around the drive shafts.

Back on the car the adjusted rod assembly works a treat, so now I need to concentrate on the cross gate cable, but that will have to wait till next weekend...............

Andy

[JRTurbo909]

great work... look forward to see more...

shah

[andyblackman777]

hi,

that looks like a very exciting conversion . cant wait to see it done and how it drives!

cheers Andy

[silverfrost]

Fantastic

A clear methodic aproach thats what i like to see Looking great and those mounts look

strong enough to do the job too!

keep going

regards danny

[hilly]

Update time.................

Got a bit more done on the gear change linkage.

Having made a mock up of the translator to get the lever throw correct I then machined a new one with a bearing to improve the feel a bit.

Now onto the hard part, the cross gate mechanism........

As the gearbox is now in a completely different position (ie at the very back of the car) the Audi cross gate linkage wasn't going to work, which is just as well as I didn't get that bit with the gearbox.

If I thought I spent a lot of time scratching my head over the alternator tensioner then I must have rubbed right through to my brain over this thing.

The tricky bit was coming up with something with minimal play as the cross gate cable has only 20mm of travel from one side to the other. Any slack in the linkage would make the gear change feel terrible.

So this is what I came up with after many hours on the mill and lathe........

Here you can see where the cross gate cable has to bend around the alternator.

It still works OK, but, the extra friction added by the bend combined with the fact that linkage is 3 or 4 times longer than original Audi unit means that the spring return on the lever to 3rd/4th position is pretty poor. Now I am not sure if the Audi gear lever has any springs in it or it just relys on those within the gearbox but I am going to have to add something to my set-up to get the feel right. More on that in the next update.

Moving onto the oil filter.

The ABZ differs from the PT/ABH as it uses a combined oil filter housing and oil-water cooler. Trouble is this thing is huge and sits just behing the alternator.

From my previous posts most of you will be aware that space in that area for me is zero, so the oil filter/cooler had to go.

The Lotus already had a oil-air cooler fitted so I can use that with a bit of new pipework. A remote oil filter housing solved the other problem. Drilling out and tapping the oil feed holes to accept 1/2 BSP hose fittings and a bit of copper pipe, the new oil system seems to fit around the starter motor, ta daaaa !!!

Hmmmmmm, looking at this update it looks like I haven't done much over the last 2 weeks, I think I need to get my finger out a bit............

Hilly

[M Blur]

really nice work on the shift locator - I'll need somethign similar to make my current gate work with the G50..

[silverfrost]

Great bit of engineering Andy,

looks extremely proffesional, miles behind you on the project and 500cc

short of yours but at least its audi keep up the good work and you are coming up with some great ideas of getting around problems!

Cant wait to see it running,

regards danny

[Jonathan]

God I wish I had the tools to do that kinda stuff - still look back at all the stuff I made when I was 16, tool making, and wonder if I could ever get those skills back.

Looks superb, I for one really appreciate nice mechanics and quality engieering

[diver_dylan]

OUT OF SIGHT! Ive been around and done quite a bit of fab work and reengineering, and yours is very creative and well executed! Cant wait for your next update/pics.

Regards,

Dylan

[M Blur]

I may have to recruit you as a technical consultant if my workshop run into any problems..

[hilly]

I may have to recruit you as a technical consultant if my workshop run into any problems..

Recruit away...........

[JRTurbo909]

hows the project coming?

shah

[hilly]

It has been nearly a month since I last posted something, so I thought I had better do an update. It's kinda light this time as there is not a lot to take pics of

Plus I spent a lot of time sitting in the car testing the gear change action and making broom broom noises..........

Well to finish off the stuff about the gear change I needed to do something about the lever spring return, It was OK from 3rd/4th to 5th/6th, it was the other side that was a bit sticky. Bit of metal and a spring fixed that......

Also had to had to make a mod to selector coupling as I over tightened the clamp bolts and broke it

Moving on, after talking to a guy in the USA, I now have a nice spangley alloy flywheel and pilot bearing adaptor.

All was not good when I went to fit it onto the engine though as it would not go on. It was then that I noticed that there was a guide for the torque converter were the pilot bearing adaptor fitted. This thing proved to be a nightmare to get out as pliers, grips etc would not budge it. I ended up having to use a large tap to push the thing out.

With the guide out the pilot bearing adaptor and flywheel went on a treat.

I even tested that the engine turned over with the starter motor until I then spotted that I hadn't put an oil filter on and covered my patio in about a pint of used engine oil, D'oh!

Unfortunatly that is all I have got photos of at the moment, lots going on to post soon though...............

[M Blur]

Recruit away...........

good good - consider yourself on standby .. ever thought about visiting bonnie Scotland?

Trans will be here in about 10-14 days. Then can work out what shifter arrangement to use - both our trannies are essential Getrag (right?) so should share some similarities - such as the darn tricky path from tunnel to linkage.. ]

Worth it tho for a bullet proof reliability B) and this one coming is rated to 850bhp and has a fancy race diff and cr ratios.

[hilly]

Trans will be here in about 10-14 days. Then can work out what shifter arrangement to use - both our trannies are essential Getrag (right?) so should share some similarities - such as the darn tricky path from tunnel to linkage.. ]

I haven't done a lot of research into it, but from pictures I have seen the Audi and Getrag look very similar so the linkage will work the same, possibly.

What car is your gearbox sourced from????

If it is a six speeder then it should be OK, if it's only a 5 the there is a strong chance the gear change linkage will poke out the back.......

Andy

[Simon350S]

Hey dude.....

Dead impressed.... how have I missed this up till now???

Makes what I'm doing look like a very simple job!!!!

Update it so I can read more!!!!

When is the estimated completion time??

Simon

[hilly]

Seeing as Bibs has gone to all the effort to create a new section the least I can do is add an update.

I have been busy working away on the car over the Christmas break and New Year and was hoping to be able to post a load of completed stuff, but as always it never works out like that. There is loads of stuff going on in parallel, getting everything finished off is proving difficult.

As it has been over 2 months since I last updated the page, so I thought I had better put something on (even if is isn't finished yet) to prove that the project is still on-going.

OK first the sump.

As you may remember the ABZ sump is too wide to fit the Lotus chassis requiring a lump to be chopped out of it.

I cut a piece of 15mm thick alloy plate to cover up the hole and that has been welded in place on the lower alloy block section.

I just need to dill and tap a number of M6 hole to hold on the steel pan.

Talking of which, that has to be modified as well.

Here it is before I set about it with the saw, Mmmmmmmmmm nice and straight

I cut off the excess part and then used a section off the old bent pan from the wrecked engine to fill the gap.

This new section was then hammered and bent to fit.

The 2 sections were then spot welded together to stop them moving about during MiG welding.

Next the joints were MiG welded, ground to shape and a lick of paint added. Apart from my crappy paint finish it almost looks like the real thing, that will do

All that needs to be done is let the paint harden then I can cut a new gasket and bolt it in place.

Next the radiator.

I had an up-rated triple core radiator fitted a couple of years back and that did a real good job of keeping the car cool. However I am now doubling the capacity of the engine so it is probably a good idea to up the size of the radiator as well.

The current radiator only fills 2/3 of the front of the car, the rest being reserved for the air-con radiator. As my car hasn't got air-con the gap was filled with a blanking plate, guess what is going to happen with that blanking plate............

I didn't want to chop up a perfectly good radiator, so after a bit of searching I managed to buy a completely rotten one off eBay. Here you can see it with the old radiator.

I was only interested in the end sections of the knackered radiator as I would have a new core fitted, oh look at that, it has already been done.

3 Spal 11" fans and some mounting brackets later and here is a completed radiator assembly ready to go back on. I just had to test them on the floor to make sure it all worked before crawling under the car.

Finally for this update the drive shafts.

The plan is to use the old Lotus outer CV joints and mount them to Audi inner joints and shafts. I picked up a pair of brand new A4 TDi drive shafts on Flea-bay. Unfortunately when the shafts turned up they didn't fit the gearbox flange, arse!!!!!!

It turns out that the shafts sent are 113mm units and the flanges on the 01X gearbox are 104mm. After a lot of digging about it looks like they changed the size in 2003 to a new size. As the inner joints have less movement they hence wear out more slowly than the outer joints and nobody has got any of the 104mm inner joints, not good.

The only answer is to make up some adapters as getting hold of the correct shafts is proving to be a right pain.

2 chunks of 7075 hi-tensile alloy ready for the lathe and mill treatment.

The mounting holes are printed on paper and then stuck on with spray mount so I can mark the position of the holes.

Machined the drive shaft side of the adapters, just need to finish off the back and then they can be added to the massive pile of parts ready for anodising.

That will do for today, next update, brakes.........................

Hilly

[Bibs]

Amazing work, some lovely engineering there! Well done, you've done the new section proud

[M Blur]

I def may need you for some consultancy work Hilly.. suspect there mey be a few bits we need machined so if we hits walls I'll drop you a PM for advice. Needless to say I'll be telling the workshop to check this thread.

Have you done anything for cooling, oil lube, spray bar inside the box..??

Cheers Jon

[silverfrost]

Andy , very nice work,

love the radiator looks very smart, glad to see you got your sump sorted at last aswell, looks like everythings going together nicely

Good luck with the project regards danny

[Guy W Johnson]

M_Blur when are we going to see Your V8 conversion?

Guy

[hilly]

Have you done anything for cooling, oil lube, spray bar inside the box..??

Cheers Jon

No, I haven't done anything to the gearbox yet, I was going to hook up some thermcouples to it once I had it running to monitor the oil temps before going to the effort of adding pumps and spray bars.

PS Yeah, about time we saw some pictures of yours................

Andy , very nice work,

love the radiator looks very smart, glad to see you got your sump sorted at last aswell, looks like everythings going together nicely

Good luck with the project regards danny

Danny

Seeing as there is now an area for this stuff, it's about time you started a thread on your car as well, me thinks.

Hilly

Edited January 31, 2007 by hilly

[M Blur]

hope to post up some pics in next few weeks guys.. I'm well behind schedule for this season.. trans arrived today (at last) so first winch in prb next week... then mlunts marked up, shafts checked for alignment and see what height we're getting in the engine bay. Then mod trans, check over engine, locate and starrt plumbing..

The G50 needs to be flipped for our cars, then spray bar modded to work upside down, filter, pump, cooler and last but not least - developing a linkage without spending $$$$ for one of the conversions like Bobby Hart's.

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

Edited January 31, 2007 by M Blur