Driveshaft/pot joint angles - lowered engine
Turbo Mini Forums

During the k1100 build I've decided to use an auto subframe to allow me to drop the engine down and gain bonnet clearance. I'm using a composite single skin bonnet so there is no gains to be had up top.

I've dropped the engine ~15mm which has solved the bonnet clearance issue. There is 5mm clearance from the cam cover to the underside of the bonnet now and I don't want to go any closer.

I haven't moved the engine forward or rearward from standard position and the driveshafts are currently parallel to the final drive axis in plan view.

After checking the driveshaft angles at full bump on the LH side (worst case, worst side because the shaft is short) I have found that the pot joints sit like this:

TOP VIEW



BOTTOM VIEW



I've canted the engine over on the adjustable top steady bar but even at the extreme this doesn't make a significant difference.

As they sit, I'm not happy with such a small amount of engagement. The centre of the balls at the bottom of the joint are only just within the pot itself so it really is on the limit.

What are people's thoughts? How do people manage to drop the engine down and make the driveshaft angles work?

Important to note that the joint is assembled correctly, ie not back to front.

Edited by adcyork on 8th Jul, 2015.

Doesn't someone make the ball joint spacers think it's the Welsh guy who races them ah what's his name. The BMW mini suffers with this when you lower it alot so spacing the ball joints help move the hub up akittle and the bottom arm down

cut the shaft, and sleeve it.

The ball joint spacers just change the angle of the lower arms to move the roll centre

I don't have that problem with Hardy spicers. It is now even easier to change to hardy spicers as Swiftune do output drive flanges that fit on pot joint splines. Clever!

http://www.swiftune.com/Product/593/swiftu...diffs-pair.aspx

Edited by Sprocket on 9th Jul, 2015.

Come to think about it, this is a similar problem to one that someone else posted recently and it was found that the cages were on back to font.

good call on both counts, i forgot about the spicer adaptors.

Spicer joints can be found for a lot less than that, my last set were £60. Just keep an eye out for them

Are they not available new?

They are dave but £100 each

you should be able to lower the car untill the sump sits on the floor and still drive it ( as far as driveshaft angles go,
that pot joint looks like its been disassembled and rebuild with the internal cage back to front

Yes i moved to the darkside

Instagram @jdm_brett

Ill agree that picture looks correct

Weird then

My previous comment was based on the fact ive done both lol
With masses of negative camber too and that would make the situation worse
I smashed a pot joint pulling onto a trailer thats how i found out they were 'inside out'

Edited by Brett on 11th Jul, 2015.

Yes i moved to the darkside

Instagram @jdm_brett

are you running metro hubs or anything like that?

I don't know what's involved in doing the automatic subframe swap and you haven't said what the other side looks like... Is there any chance your engine is now offset to the right?

Edited by PhilR on 11th Jul, 2015.

To run the auto frame i take it your running blocks to compensate the difference? Could that be throwing it out?

How is the engagement on the other shaft as a comparison? Just wondering if the others have picked up on the possibility the engine is offset

I'm running mini hubs so there's no trickery going on there.

To run the auto frame with the engine dropped I've got 4mm of spacing on each side so the engine is sat central in the frame.

I've confirmed the issue on the other side this morning which at full bump looks like this.

Top,



Bottom,



I also can't get full droop on the RHS as the shaft catches the bottom of the hole in the subframe, I'm confident there's enough meat for some local relief before it hits the bottom arm pin though.

Edited by adcyork on 12th Jul, 2015.

Did you solve this? I've got the same problem.. I didnt know if there was anything like a metro or whatever with slightly longer drive shafts?

I had similar issues when lowering my engine for my K build.
I found there is some gains in your rocker cover choice meaning a reduction in the required drop to allow clearance. the LT cover gives a height reduction of 5mm over the RS item, the 8V being the lowest (clearance issues were only discovered when making the transition from 8v to 16v).
I also fell foul of having the engine onset to the offside.
Shane

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Edited by shane on 27th Jul, 2020.

For me its more the fact the cars lowered too much. I haven't actually lowered the engine, as much as id like to.

I can make the whole problem go away by lifting the motor and that also gets rid of the disgusting drive shaft angles too. But I'm keen to experiment with this to try and keep the engine low, for COG purposes and also so i dont have to have a huge bonnet bulge.