R16 internals in R8 Casing

Firstly I need to give credit to Frans for all his hard work, machining and ideas in putting this together. Thanks Frans.

We initially talked about this gearbox and diff after the first targa (2002). It was obvious that we needed more top end in those long fast stages. With current gearing and 13" rims the car is getting 24km/1000rpm in 4th which equates to 168kph at 7000rpm red line. With this upgrade I was hoping for a 10% increase in top speed (185kph). I think we started work on it about mid 2003 so it has taken a while.

It is a standard R16ts gearbox and diff inside a R8/10 housing. Nothing new about that but what is different to others I have heard of on this site is that we have used equal thickness spacers on each side. That required much machining of the diff and the cups that hold the diff bearings.

The second biggest problem was the universals. I ended up having the standard yokes re cut with a new internal spline to match the R16 out-put shafts. I then fitted BMW crosses which are much stonger than the originals but because of their size do restrict up and down movement a bit (no problem on my car due to the stiff springs)

Other wise this was a fairly straight forward project. Total cost was only about $150 for the spline machining and about $200 for the crosses.

I hope to install it over the next week or 2, I will let you know how it goes.

Photos attached hopefully

Ross

Ross,

Frans has done a great job with that symmetric R16 diff, the extra effort makes for a nice looking install.

Does he want to make conversion kits????

How much axle articulation is available with the stronger universals?

Tony

That really does look like a neat conversion! Well done!

I love that sort of innovation. These types of postings are the most interesting on this forum. Cheers.

Ross, if you've got the time, could you post a few pics of your car? There's a tantalising bit in one of those shots, you tease... :wink2:

Thanks

Stuey

750sport said:

Ross,

Frans has done a great job with that symmetric R16 diff, the extra effort makes for a nice looking install.

Does he want to make conversion kits????

How much axle articulation is available with the stronger universals?

Tony

Click to expand...

We need to do some testing before recommending this as the "way to go" but I am sure that we can post measurements and plans if things go well.

I didnt actually measure the amount of movement available but I think it would just about work with standard suspension travel.

Ross

Stuey said:

I love that sort of innovation. These types of postings are the most interesting on this forum. Cheers.

Ross, if you've got the time, could you post a few pics of your car? There's a tantalising bit in one of those shots, you tease... :wink2:

Thanks

Stuey

Click to expand...

Some photos of the engine bay attached just for you Stuey

If you want others of the car go to http://www.groundsky.co.nz/ and look under events - Dunlop Targa NZ 2003 - car number 220

Ross

Thanks Ross. Great photos of the Targa...

Rear engine Renos.......

For those who haven't yet guessed Ross and Frans are the "original nice guys" with a passion for the regie. Haven't yet ( to my knowledge) met Ross in person but a number of phone calls have ALWAYS been helpful. His car is stunning to look at at goes like sh1 t off a stick. Innovators of the best kind! If there is an award for the enthusiasts of the year, here are a couple of candidates!
Ross, I thought Targa was on again?

Ross said:

Some photos of the engine bay attached just for you Stuey

If you want others of the car go to http://www.groundsky.co.nz/ and look under events - Dunlop Targa NZ 2003 - car number 220

Ross

Click to expand...

Thanks Ross and congratulations - what a great bit of work! You could almost go into business making those transmissions.

JohnW

Thanks Guys

I will update the post once I have done a few racing miles with it.

Rhys - yes targa is on again and no I am not competing this year. Combination of lack of funds and very busy at work. Its been a bit hard this week watching the results and wishing I was there.

I doubt I will do it next year either as I have started building another Dauphine so hopefully by 2006 it should be all on again.

Ross

Thanx as well

Thanks for the compliments guys.
Can anyone with the off center gearbox conversion comment on the wheel to arch clearance. With equal spacing that adds up to 6mm either side Ross encountered a very tight fit between the tyre and body. We were discussing the matter and wondered with the 12 mm on 1 side only if you would have to roll the arch out on one side and leave it standard on the other? Keeping in mind that whoever does this conversion will have wide wheels.
Frans.

As promised here is an update on the gearbox now I have done a few race miles.

Firstly the issues - it started leaking oil fairly seriously about a week after fitting. It turned out to be the inner half of the universal joints. I had them resplined to take the R16 output shafts and I recapped them with some 1mm sheet steel but the oil found a way past. Some good quality silicone sorted that one.

The other issue is the noise. I obviously havent got something right as it is quite noisy but only on light throttle. As soon as I apply power or brake the noise goes away.

But now for the good news. Ive done 2 hillclimbs using this box.

The first hillclimb I have done twice before. First year time 1.32, second year time 1.32, this years time with the new box 1.27.
The second hillclimb was new to me but I did well getting 5th fastest out of about 35 cars.

I cant attribute all the improvement to the box as I have made some other changes as well (details on another post soon) but it is definitely a step in the right direction. I really didnt expect such an improvement especially in hillclimbs where top speed is not an issue but I think what is happening is I am carrying more corner speed due to the higher gearing.

Whatever the reason Im just glad it works.

Big block conversion with R16 trans internals into R8

Ross said:

As promised here is an update on the gearbox now I have done a few race miles.

Firstly the issues - it started leaking oil fairly seriously about a week after fitting. It turned out to be the inner half of the universal joints. I had them resplined to take the R16 output shafts and I recapped them with some 1mm sheet steel but the oil found a way past. Some good quality silicone sorted that one.

The other issue is the noise. I obviously havent got something right as it is quite noisy but only on light throttle. As soon as I apply power or brake the noise goes away.

But now for the good news. Ive done 2 hillclimbs using this box.

The first hillclimb I have done twice before. First year time 1.32, second year time 1.32, this years time with the new box 1.27.
The second hillclimb was new to me but I did well getting 5th fastest out of about 35 cars.

I cant attribute all the improvement to the box as I have made some other changes as well (details on another post soon) but it is definitely a step in the right direction. I really didnt expect such an improvement especially in hillclimbs where top speed is not an issue but I think what is happening is I am carrying more corner speed due to the higher gearing.

Whatever the reason Im just glad it works.

Click to expand...

Yo namesake,
I last checked the site a year ago and my timing couldn’t be better. I intend to do a similar conversion but have a few questions. What do you mean you capped the R16 output shafts with 1mm sheet metal? Would you explain this little more? Isn't there an oil seal that the R16 splined shaft goes thru or where the inner yoke rotates against?

I assume you are using a small block in the R8 racer. How do you accommodate the difference in diameter of the R16 mainshaft splines and the diameter of the splines on the driven clutch plate of an R8 ? Will a R16 clutch fit in the R8 bellhousing?

I plan on using a big block R17 1600 cc crossflow engine in my Alpine GT4 (also R8 based). When I bolt it up to the R8 transaxle it doesn’t bolt up flush to the bellhousing as I believe the R8 mainshaft is too long or the bushing hole in crank is not deep enough) although it may even be that the locating dowel pins may be buggered up preventing complete bolt up.(it was within 3-4 mm of closing the gap on one side) I did one trial fit up and did not wish to force it before it was retired to the back room knowing that the engine will basically fit in the engine compartment. But the R8 shaft is smaller in diameter than the clutch splines of the big block. I assumed I would have to modify the shaft to fix the issues. If that was resolved then there is the issue of lots more power being put to the spider gears. I understand that the spider gears on the R8 are the weak link when putting more power to it than intended. However since you have found a way to use R16 internals in the R8 case it seems my problems are solved. The R17 bellhousing bolts up to the R8 case nicely although there are a couple of extra holes in the top of that bellhousing that could be drilled thru the R8 trans flange to provide more purchase but I’m not sure this is even necessary. However the reverse is not true, the R8 bellhousing will not bolt up to the R16/17 engine flange, this not an issue since I have the matching bellhousing. The question is, is there an difference in length between the 2 shafts as they stick out of the trans case? Will I have any problems here? Were you able to compare the two as you would have to check this also even though you are using the small block? How many spider gears does a R16 differential have as opposed to a R8 differential? (4 vs.2 or are there just 2 but they are beefier?) Is this why you went to the R16 internals in addition to the gearing change?
We also determined that we would come up short on revs with the 4 speed trans and want to go with a R5 Alpine - 5 speed trans for more flexibility. It uses the only other 5 speed trans from a small block ? mid engine front wheel drive configuration that works in an R8 based rear engine rear wheel drive but it was imported only to Mexico correction Guatamala. I now understand the car was also available in France, talk about hard to get. Gearsets with different ratios can always be made. I'm not positive but I believe the trans mounts are similar to the R8 style trans mounts this may not be correct. There is another R5 speed trans isn't there? a R16TX ? (another thread, R16TX 5 speed individually imported to Land of Oz) but the R16 case does not have the trans mounts on the side of the case similar to the R8?

How will you determine cause of noise (difficult I imagine?) It’s not likely you will put enough miles on the racer to fail the trans to discover the problem that way. What’s a poor mother to do?

Also would you email me digital photos of higher resolution of the engine mounted in the race car (yellow?). I down loaded them from the site and they are quite small and when one enlarges them they immediately pixelate and go fuzzy losing all detail . I finally downloaded them properly and I have them now thanks The trans shots are okay but could use more megapixels to really see the detail as you enlarge them.

Hi Ross

I will try and answer all your questions.

Firstly the capping issue. If you can picture the inner end of the universal joint, the outside surface runs on a rubber oil seal and the inside is splined to take the output shaft from the diff. Because we were using the R16 diff with bigger output shafts we had to have the universals re splined. To do this I pushed out the factory fitted cap at the end of the spline, had the joint re splined and then fitted a new cap. This was were the oil was leaking from.

The spigot shaft (you called it mainshaft) is interchangable on all these boxes. There is a splined collar just above the diff which joins the primary shaft to the spigot shaft using roll pins. We simply took off the R16 spigot and replaced it with a R10 spigot. I am using a R11 clutch plate, pressure plate and modified flywheel. It is the largest clutch available for the seirra block (I think the last of the R12s used this clutch as well) sorry cant remember the diameter.

I cannot give you definite answers regarding mating the R8/R10 transaxle to a R17 motor as I havent done that yet(wont be far away though). However in the articles I have translated I believe the correct protusion of the spigot shaft past the bell housing is 42mm.

R16 diff has only 2 spider gears but everything is beefier so should be stronger.

To be honest Ross I'm not really worried about the noise. There is so much noise inside that car as it is a bit more is not really here nor there.

I hope this all makes sense and good luck with the conversion. Any other queries and I will try and help.

Ross said:

Hi Ross

I will try and answer all your questions.

Firstly the capping issue. If you can picture the inner end of the universal joint, the outside surface runs on a rubber oil seal and the inside is splined to take the output shaft from the diff. Because we were using the R16 diff with bigger output shafts we had to have the universals re splined. To do this I pushed out the factory fitted cap at the end of the spline, had the joint re splined and then fitted a new cap. This was were the oil was leaking from.

The spigot shaft (you called it mainshaft) is interchangable on all these boxes. There is a splined collar just above the diff which joins the primary shaft to the spigot shaft using roll pins. We simply took off the R16 spigot and replaced it with a R10 spigot. I am using a R11 clutch plate, pressure plate and modified flywheel. It is the largest clutch available for the seirra block (I think the last of the R12s used this clutch as well) sorry cant remember the diameter.

I cannot give you definite answers regarding mating the R8/R10 transaxle to a R17 motor as I havent done that yet(wont be far away though). However in the articles I have translated I believe the correct protusion of the spigot shaft past the bell housing is 42mm.

R16 diff has only 2 spider gears but everything is beefier so should be stronger.

To be honest Ross I'm not really worried about the noise. There is so much noise inside that car as it is a bit more is not really here nor there.

I hope this all makes sense and good luck with the conversion. Any other queries and I will try and help.

Click to expand...

Ross,
Thank you this explains a lot. Its been awhile since I looked at it . I do remember that the spigot shaft is collared and roll pinned now that you mention it,I forgot so I should be able to use the one from the R16 and 42mm is the majic number to remember. As for mating the big block I think it's easy (for you) as the dowel pins which aren't dowel pins but open roll pins were buggered and knowing that the spigot shaft is easily adjusted for length if required. Your biggest issue is the physical size of the engine will it fit in the small engine bay of the dauphine? Please check your old reply to the R16 Tx thread, I had trans question there! Do you think noise is actual fault (you alluded to) or just noisier because it has been converted or is the R16 trans just noisier also but because its up front (in a R16) you don/t hear it?

The cap you write of , I was not aware of it so I'll try to check it out. Is the cap pressed in from the exterior side once the innner yoke is put on similar to a freeze plug (core plug) in an engine block or from the interior side?, is it an actual cup or flat disc? is the yoke stepped to accept the cap in a smooth bore since the innermost part of yoke would be splined?
Ross

Ross said:

Hi Ross

I will try and answer all your questions.

Firstly the capping issue. If you can picture the inner end of the universal joint, the outside surface runs on a rubber oil seal and the inside is splined to take the output shaft from the diff. Because we were using the R16 diff with bigger output shafts we had to have the universals re splined. To do this I pushed out the factory fitted cap at the end of the spline, had the joint re splined and then fitted a new cap. This was were the oil was leaking from.

The spigot shaft (you called it mainshaft) is interchangable on all these boxes. There is a splined collar just above the diff which joins the primary shaft to the spigot shaft using roll pins. We simply took off the R16 spigot and replaced it with a R10 spigot. I am using a R11 clutch plate, pressure plate and modified flywheel. It is the largest clutch available for the seirra block (I think the last of the R12s used this clutch as well) sorry cant remember the diameter.

I cannot give you definite answers regarding mating the R8/R10 transaxle to a R17 motor as I havent done that yet(wont be far away though). However in the articles I have translated I believe the correct protusion of the spigot shaft past the bell housing is 42mm.

R16 diff has only 2 spider gears but everything is beefier so should be stronger.

To be honest Ross I'm not really worried about the noise. There is so much noise inside that car as it is a bit more is not really here nor there.

I hope this all makes sense and good luck with the conversion. Any other queries and I will try and help.

Click to expand...

Ross
would you send me a shot of the inner axle mounted on the trans (The universal joint in place ) or is it covered by a rubber boot and the axle tube ?

Hi Ross

The cap I made is a flat disc, Frans machined a step in the outer end of the spline for the cap to sit in and I simply spiked it into place.

I dont have the photos you are after however I have attached a couple of photos which may help you, one is of the universal after the BMW cross was fitted and the other is of the end of the driveshaft with the rubber button fitted. They are not great shots but it may help you.

I am fairly confident that the 1600 crossflow will fit as it has been done many times in France. Go to a site called "Dauphstock" and check out the protos and you will see what I mean.

I think the noise is either a crook bearing or I havent got the diff meshing properly. I used the special Renault tools but I may have made a mistake with the measurements engraved on the crownwheel and pinion.

Frans and Ross you are here to pump me up!

Ross said:

Hi Ross

The cap I made is a flat disc, in and I simply spiked it into place.

I dont have the photos you are after however I have attached a couple of photos which may help you, one is of the universal after the BMW cross was fitted and the other is of the end of the driveshaft with the rubber button fitted. They are not great shots but it may help you.

I am fairly confident that the 1600 crossflow will fit as it has been done many times in France. Go to a site called "Dauphstock" and check out the protos and you will see what I mean.

I think the noise is either a crook bearing or I havent got the diff meshing properly. I used the special Renault tools but I may have made a mistake with the measurements engraved on the crownwheel and pinion.

Click to expand...

Ross,
title is reference to a"Saturday Night Live" skit you wont get!

You have outdone yourself. I have a spare R8 engine, transaxle, crossmember and wheels unit. I looked at it and of course the axle tubes have the rubber gaiters in place. But I understand how the tube swivels in the bolt on carrier. It's what's inside I have yet to see even on the car itself since I haven't taken it down that far yet. I've been reluctant to tear into it with out a definite plan for a conversion.

Well, my friend, your 2 photos have allowed me to completely understand how this all goes together with one small exception.
Your photo of the end of the tube exposing the spline end of the drive shaft is exactly what I was asking for not realising that the rubber gaiter covers this up.
Exception is: "Frans machined a step in the outer (Do you really mean the inner end of spline closet to the cross?) end of the spline for the cap to sit. I think I get it ! The outer circumference of one end of the ujoint rides against the oil seal (did you machine this OD to fit the oil seal?) and oil gets by the splines themselves but comes up against the disc and can't leak into the cross part of the ujoint right? Since the R16 spline shaft coming out of the trans has a cross drilled thru hole for the roll pin which normally secures the u joint of a R16 axle to the R16 shaft. In the conversion I assume that the roll pin hole is not used (I don't see any noles in the ujoint itself) because the axle is captured within the axle tube between the pivot carrier on the trans and the backing plate of the wheel ass'y unlike the R16 axles which are not carried in a separate axle tube ? Have I got that right? :banana:

I have an R17 ('78)transmission, IS there any reason why I can't do the conversion with it and does anyone know the gear ratios of it.

Additionally, Frans mentioned something about the off center conversion 12 mm's offset and 6 mm on each side and wheel clearance issues with the fenders, in an earlier post, Please clarify this issue I am confused probably because I don't know the transmission well yet. I have dismantled R16's but not the R8 transaxle assembly.

I assume that because you have added a 6mm spacer plate to each side, it is to reduce the engaged length of the spline coming out of the trans so the ujoint and axle tube carrier will fit properly. This would increase the overall track width (to the CL of wheel) of the vehicle no matter the size of wheel used,wouldn't it?

Which BMW ujoint is used?
When you set up the ring and pinion did you do a dye check to see if it was meshing in the center of the gearteeth?
I'm so close I may just wet myself.
By the way, You two geniuses have done a great job with the conversion.
TIA

Hi Ross

Yes you have got it all right

Yes I do mean the inner end of the spline closest to the cross

No we didnt machine the OD to fit the oil seal, std joint is already machined

No we didnt use a roll pin, thats what the rubber button is for on the end of the driveshaft - to keep the universal joint in the right place.

No you cant use a R17 gearbox internals, the diff is way too big and will not fit inside the casings - I tried that.

The 2 x 6mm spaces are used because the R16 diff is wider and will not fit inside the R8/R10 casings

Frans was talking about the 2 methods of doing this job. The first method which is the most common is to use one 12mm spacer on one side of the gearbox only. This means the track is wider on one side. The second method which is the way we did it is to use 2 x 6mm spacers, one on each side. The first method is easier but the second method gives you equal track.

BMW cross is part number 902009. Not sure if this is a local part number or the genuine BMW number?? Anyway its used on a lot of models apperently so should be easy to get. Its not a perfect fit but with a bit of modification it does the job

Ross said:

Hi Ross

Yes you have got it all right

Yes I do mean the inner end of the spline closest to the cross

No we didnt machine the OD to fit the oil seal, std joint is already machined

No we didnt use a roll pin, thats what the rubber button is for on the end of the driveshaft - to keep the universal joint in the right place.

No you cant use a R17 gearbox internals, the diff is way too big and will not fit inside the casings - I tried that.

The 2 x 6mm spaces are used because the R16 diff is wider and will not fit inside the R8/R10 casings

Frans was talking about the 2 methods of doing this job. The first method which is the most common is to use one 12mm spacer on one side of the gearbox only. This means the track is wider on one side. The second method which is the way we did it is to use 2 x 6mm spacers, one on each side. The first method is easier but the second method gives you equal track.

BMW cross is part number 902009. Not sure if this is a local part number or the genuine BMW number?? Anyway its used on a lot of models apperently so should be easy to get. Its not a perfect fit but with a bit of modification it does the job

Click to expand...

Ross,
I cant see the other end of u joint in photo, I understand modification work on trans side. oil seal surfaced was already machined to correct size for the oil seal? Was axle side resplined also? what does rubber button bear against ,the bottom of a blind splined hole or thru hole and button bears against the cross itself? I'm concerned about rubber button in a greasy environment, would Delrin be a better choice?
Please explain some more about "The first method (easier one)which is the most common is to use one 12mm spacer on one side of the gearbox only".
I'm guessing the "ring" side since its the closet to the case? When you use the 2 -6mm spacers do the centerlines of the shafts and gear clusters need to be moved over. The spigot shaft can't move because it is centerline of bellhousing and engine correct? Are the case bores where the bearings of shafts and gear clusters ride need to be enlarged to accomodate larger diameter bearings of new internals. How do the axle tube carriers need to be machined on the back side to accept the outer race of the splined shaft bearing? in the 12mm method, no machining but then the other side would need an internal spacer"
How much machining of the case is required and what areas of the case are modified to make this all happen?
2-6mm spacers yes equal track both side but overall track is wider by 12mm?
Sorry to be a PITA