Mounting UN1 upside down

Question...

Do or have people installed a Renault UN1 upside down thus having the outputs above the input shaft aka like a ZF 5ds-25?

I know the UN1 can have the crown wheel flipped so it could be possible to mount upside down and thus having a setup similar to the ZF box and inverted G50 boxes with the outputs above the input shaft.

If someone has done this before what mods were required? Also if you have done this do you have any pictures showing the drive shaft angles etc.

If I should forget this idea and mounting the UN1 the standard way up can other shares pictures of the drive shafts and the angle they are on ie Flat...or lower at the transaxle or higher at transaxle

Cheers
Mike
 
Hi I mounted my un1 upside down when I built my 40 back in the late 1980s. It still works fine on the rare days it goes out. Others have copied the idea probably. I did magazine articles on how I did it way back then. I originally did it to get the driveshaft angles less steep as my engine is as low as the original cars.
 
Hi I mounted my un1 upside down when I built my 40 back in the late 1980s. It still works fine on the rare days it goes out. Others have copied the idea probably. I did magazine articles on how I did it way back then. I originally did it to get the driveshaft angles less steep as my engine is as low as the original cars.
That is exactly why I am thinking of do it. Soni can have the engine lower/more original location. Also if I ever decide to upgrade to ZF later on I don't have to locate the engine.
 

Kevin Box

Supporter
Mike

I've looked at this myself and been in touch with Kev Farrington also
I have the following combo
Canton road race oil pan approx 7.5 inches (190 mm) deep
Wheels / tyres 335 35 17
Inverted this gives me about 12 degree downward half-shaft angle with ground clearance 125mm less with 100mm clearance and this just gets better under bump as the chassis goes down

Non-inverted is approx 15 degrees upward and gets progressively worse as you get into more bump

For my money inverted looks a whole lot better for me but is a lot of work to get there.
Firstly changing the crown-wheel side to side is a little mucking around but the bell-housing is the next issue as follows and depends on what flywheel you are running - l chose 157 tooth Ford so only options 2,3&4 are OK for me.

Option 1
From memory Kev F had an adapter plate from the back of the Ford Block to the Renault bell-housing/transaxle which was inverted. there was also a bit of playing around for the starter. Correct me if i"m wrong Kev

Option 2
Start with an aluminium Ford bell-housing either C4 or Manual and add an adapter plate to back of it approx 30 mm thick. you also need to get a longer input shaft made to match up. This is not optimal option as it shifts the half-shafts back and creates another angle issue. (UN1 ends up about 38 mm further back)

Option 3
Start with a Ford C4 or Manual bell-housing and cut the back off it and weld an adapter to the back of it. Not too hard but would need to be finish machined after the welding

Option 4
Fabricate a bell housing from scratch either from steel or Aluminium. A bit of shagging around but you can get exactly what you want.
I found an interesting article on the web where a Chev block was mated to a Ford Toploader. If you look at the principle it was quite nicely done and could be fabricated in steel or my preference aluminium. Web address below

I have mocked up option 2 with customwood adapter on a C4 bell-housing just to see if it works and ended up with the 38 mm mentioned above.

The current non-inverted bellhousing I have is 139 mm from the block face to the UN1 face. The C4 is 147 mm so by the time you add the 30 mm required to cover the crown wheel 38 mm is where you end up.

I would have to say I quite like the idea of fabricating a custom one in a similar manner to the one on this web site but instead out of aluminium.

I hope this helps ???

regards

KevinB
 
Thank you KevinB for the info. I was looking at pictures of the ZF 5DS-25 bellhousing and this looks short and the mounting for the ZF is large round mounting face. So was thinking of an adaptor where the UN1 bellhousing mounts thus going from UN1 to a ZF bellhousing with the un1 inverted.

I don't know how long/thick a ZF bellhousing is but it might work out such that the standard ford type GTO Racing single input (quaife) will work.
 

Kevin Box

Supporter
Mike
I assume you mean this one
157t Kennedy belhsng.jpg

The depth is 4.5 inches (114.3 mm) so you could easily make an adapter for the back of it. Either a piece of 30 mm Aluminium plate and some time on the mill or make a plug and get something cast to the right shape. PCD is 11.654" (296 mm)

Excellent suggestion Mike

regards

KevinB
 
Mike
I assume you mean this one
View attachment 105327
The depth is 4.5 inches (114.3 mm) so you could easily make an adapter for the back of it. Either a piece of 30 mm Aluminium plate and some time on the mill or make a plug and get something cast to the right shape. PCD is 11.654" (296 mm)

Excellent suggestion Mike

regards

KevinB
You have one already :) nice I need to get me one of those :)
 
Need this Covid-19 lock downs to pass so business can get back to normal so I can import a ZF 5DS-25 bellhousing and I think I know were you can get an adaptor plate already - after some emails. Will check again. To confirm.
 

Kevin Box

Supporter
Mike
That is not mine - I will have to buy one
I sent a note to Kennedy for pricing and freight cost along with confirmation it will work with my 157 tooth alloy flywheel and clutch.
 
Right I can get one custom made locally here in NZ - cost will vary depending on if a single unit for just my self or if I get a mold made up so I can get 5 sand cast up = more upfront cost for me but I could sell 4 others if there was enough interest - to offset the cost and they would be 1/2 has much as just the one off item.

I will have to wait until after the Covid-19 lockdown is over here in NZ so I can get parts shipped to my contact down in the South Island.
 
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