V12 conversion for 740 shorty

[blackknight530i]

I see. I think I knew the torque rating would be more but wasn't aware of the bellhousing pattern as I thought both the V12 and the V8 are the same.

If they had the same bellhousings, there would be a lot more 750il 6-speeds out there.

[auaq]

True.

[xlr8tin]

My budget it however much money I can make of the parts car that I have. Right now it's stored at a friends house. I'm trying to get it towed back next month. I have a transmission to swap in, but I don't like to do things twice. I don't have the resources/tools to swap drivetrains out. Now that I have been told of the common transmission failure of the 5hp24, how long can I expect the other one to last? That's why I've been researching the parts it needs and videos on how to rebuild it.

The V12 swap started because I wondered how much more reliable the 5hp30 if at all, which no one has commented on. Because if I can get a 750 for the price of a complete M62tu drivetrain (because that's what I will need if I keep this car running) than obviously the V12 is a no brainer. I don't care that I have to swap it all over and move a couple things to make it fit. It comes down to cost. and right now the $1500-2000 is too much until I start selling parts.

I still want the S62, but price is the issue. Plus I'm still not sure about this car to be the right one. It still needs body work for dents and a whole respray, which that cost is a lot.

[Kurt C]

After all that's been written here, it still seems to me if you want a 750i, cutting a 750iL in half and removing the required amount of body is a better option. You can do all the interior removal and wire loom disconnecting and tying off to each half of the car as necessary. And if you talk to a body shop that specializes in limo conversions about it you'll see it's not all that impractical. If I had the Huevos to do this conversion that's the route I'd go.

If it's power you want and a 6-speed go the S62, and if it's power and an automatic consider the M62TUB46 route.

[kulgan]

After all that's been written here, it still seems to me if you want a 750i, cutting a 750iL in half and removing the required amount of body is a better option. You can do all the interior removal and wire loom disconnecting and tying off to each half of the car as necessary. And if you talk to a body shop that specializes in limo conversions about it you'll see it's not all that impractical. If I had the Huevos to do this conversion that's the route I'd go.

If it's power you want and a 6-speed go the S62, and if it's power and an automatic consider the M62TUB46 route.

Having seen the aftermath of crashed vehicles that have been joined together as your suggesting I wouldn't go down this route in good conscience. Adding length to a car to create a limo is fine when your adding strength to the sub frame/chassis. Simply cutting a car in half as you suggest and removing a section to join it back together will leave the vehicle severely weakened and dangerous. In NZ this is now illegal and I was sure it was illegal in the States too.
And the OP has already said a few times that the S62 is not financially an option and that it's not entirely about more power. Cool factor is what he's after.
Technically the M73 conversion shouldn't be too difficult if sticking with the right years body and motor so why not build a shorty 750i?

[Chris V]

Having seen the aftermath of crashed vehicles that have been joined together as your suggesting I wouldn't go down this route in good conscience. Simply cutting a car in half as you suggest and removing a section to join it back together will leave the vehicle severely weakened and dangerous.

Not true, and it's not illegal and has been done successfully thousands of times to make shorty vehicles, like this VW Bus:





Same with other cars (also not photoshops):















That Mercedes is a prime example of it done well, turning a Pullman into a shorter coupe. Most are disproportionate, but all are safe. A good weld is a good weld and will be stronger than the surrounding metal, so it'll be no less safe than a stock example. Tack welds and bono are bad, and some, yes, are done that way. But a correctly welded car will be no different than a modded street rod or full custom. Or a car with a shortened or stepped frame or a body dropped truck.

[auaq]

Hmm ... so a two door E38?

[clarkitect]

Just as an out-there idea, how about a shorty 750i COUPE? I've wanted to build one for years... The only hard part for me would be the side glass. Did a pshop of what that might look like:

Hmm ... so a two door E38?

Yes! Someone needs to do this too.

But xlr8in is going to whip us back on task in a minute!

I think the 750i conversion is a winner. It may be some work but we all know that's half the fun. Don't do it just to get rid of the 5hp24 transmission, or as a way to save money. Do it because it is cool and would make you feel good.

[kulgan]

Not true, and it's not illegal and has been done successfully thousands of times to make shorty vehicles, like this VW Bus:





Same with other cars (also not photoshops):















That Mercedes is a prime example of it done well, turning a Pullman into a shorter coupe. Most are disproportionate, but all are safe. A good weld is a good weld and will be stronger than the surrounding metal, so it'll be no less safe than a stock example. Tack welds and bono are bad, and some, yes, are done that way. But a correctly welded car will be no different than a modded street rod or full custom. Or a car with a shortened or stepped frame or a body dropped truck.

Showing me pictures on the internet wont make me believe any of them are safe. As I said, I've on more than one occasion seen the aftermath(in a professional capacity) of one of these that's been wrecked and it's not pretty.. And they are illegal in NZ unless certified which in itself is a lengthy and cost prohibitive procedure.

In any case. To have this done professionally would still cost a hell of a lot more than to transplant a motor and trans from a donor car.

[psjr]

I don't think anyone has addressed the 5HP30 reliability question.

Most evidence will be anecdotal, but I believe that in 750s, I have seen more issues with them at lower miles (~120k) than the 5HP24s.
The earlier version pre-facelift also had a few issues such as the valve body check balls and pistons.

That said, I don't think that they are that bad either, and I certainly wouldn't be scared away from them. It is a very nice and smooth transmission when in good shape.

I don't think the wiring for the swap is as bad as it is being made out to be in here; there are not a whole lot of lines of communication between the engine bay and the interior electronics.

[xlr8tin]

Yes! Someone needs to do this too.

But xlr8in is going to whip us back on task in a minute!

I think the 750i conversion is a winner. It may be some work but we all know that's half the fun. Don't do it just to get rid of the 5hp24 transmission, or as a way to save money. Do it because it is cool and would make you feel good.

Someone has to. Too many getting carried away, which I admit is usually me

And yes, it would most likely be for the WOW factor. I wouldn't get it to replace the trans, I was mostly asking to make sure I wouldn't be swapping in a trans that was even worse. Yes, I would want to do it because it would be cool to have and no one else around me has one. Although, most everyone wouldn't even realize the rarity of it, but hey, so what.

I'm pretty interested in making this happen, but I see that it will take a while to source one that isn't already $5k. But this will give me time to save up. It would be nice to find one that is loaded so I can swap everything over that fits.

- - - Updated - - -

I don't think anyone has addressed the 5HP30 reliability question.

Most evidence will be anecdotal, but I believe that in 750s, I have seen more issues with them at lower miles (~120k) than the 5HP24s.
The earlier version pre-facelift also had a few issues such as the valve body check balls and pistons.

That said, I don't think that they are that bad either, and I certainly wouldn't be scared away from them. It is a very nice and smooth transmission when in good shape.

I don't think the wiring for the swap is as bad as it is being made out to be in here; there are not a whole lot of lines of communication between the engine bay and the interior electronics.

Thank you, no one has just yet.

Isn't the 5hp30's also in the E34 540i? Because I have had to rebuild the valve body in a couple. No where near like rebuilding the whole trans like the 5hp24.

So do you think even trying it with a pre facelift 750 and swapping the wire run would be possible, even for someone that hasn't done it yet? Is most everything else the same between the 750 and 740s? like fuel pump, lights, seats, etc..? I really don't want to get into it and realize there is a huge issue that makes me scrap the whole thing.

[xboss]

A ton of work to reduce by six measly inches. By the time you get it running we will be able to import 750i's from Europe.

[xlr8tin]

Ok, here is the biggest issue between the iL and i (in my eyes) I like lowering the car so the wheel well it right above the tires. I absolutely hate the 4x4 look of the stock suspension.

I had an iL that was lowered the way I like it, and it bottomed out over every speed bump no matter how big. Now with the i I have it lowered to practically the same height and I never bottom out. It's ultimately why I sold the iL.

So yes...6 measly inches is huge in my eyes which to me is what matters. Pretty soon this car will be my project car once I get my wife a car, and the amount of work it takes to complete it will be irrelevant.

Besides, think how much fun it will be when done!

[Kurt C]

Amen!

Ok, here is the biggest issue between the iL and i (in my eyes) I like lowering the car so the wheel well it right above the tires. I absolutely hate the 4x4 look of the stock suspension.

I had an iL that was lowered the way I like it, and it bottomed out over every speed bump no matter how big. Now with the i I have it lowered to practically the same height and I never bottom out. It's ultimately why I sold the iL.

So yes...6 measly inches is huge in my eyes which to me is what matters. Pretty soon this car will be my project car once I get my wife a car, and the amount of work it takes to complete it will be irrelevant.

Besides, think how much fun it will be when done!

[clarkitect]

You had me at OK.

[Jamos]

I'd take the 5HP30 over the 24 1000x a day.

[xlr8tin]

Good to know!

Thanks Kurt and Clark!

Now I need to start a gofundme page;-)

[xboss]

Heh, GL, I'd like to see it happen. Would def be cool and rare in the USA

[pavrom]

Copart.com
Iaai.com

[kulgan]

Copart.com
Iaai.com

Way to go Pavrom.
Found 5 on these sites.

[oooeemrlee]

Orient Blue will have to do for now.

I might have to sell the sport seats out of my other parts car first before I buy the 750il. Who wants them? Biege

I'm interested in your seats.

Sounds like a wonderful project, too cool.
Absolutely for fun, enjoyment and sharing

Honeeey! What happened to the car? "Oh, it was running poorly dear, the shop said maybe the engine was undersized, so we shoehorned in, ah sorry, replaced it with the biggest engine they make, you know, the one that goes in the Rolls-Royce Silver Seraph?" It should run fine now.

My 5HP30 is original and has 263K on it. It's recommended that the valve body be rebuilt at the first fluid change (100K). Most people don't get the message about this including me till recently. Check ball degrades evidently and they improve some other bits. I've not done mine, but those who have say it makes a big difference in smoothness.

[xlr8tin]

Copart.com
Iaai.com

This is awesome, Thanks!

Way to go Pavrom.
Found 5 on these sites.

Shoot, I'll have to look again, because I didn't see anything

I'm interested in your seats.

Sounds like a wonderful project, too cool.
Absolutely for fun, enjoyment and sharing

Honeeey! What happened to the car? "Oh, it was running poorly dear, the shop said maybe the engine was undersized, so we shoehorned in, ah sorry, replaced it with the biggest engine they make, you know, the one that goes in the Rolls-Royce Silver Seraph?" It should run fine now.

My 5HP30 is original and has 263K on it. It's recommended that the valve body be rebuilt at the first fluid change (100K). Most people don't get the message about this including me till recently. Check ball degrades evidently and they improve some other bits. I've not done mine, but those who have say it makes a big difference in smoothness.

LMAO! I love it. It went a little different, but if I typed the conversation would be equally funny I assure you.

As far as the seats, I'm not really sure how to ship them so I don't pay a fortune and lose money. Would you happen to have an account with a company or an easy way to do it?

[kulgan]

I'm at work so cant look up laai.com. I think there where 4 on that site and only this one on Copart.com.

http://www.copart.com/us/Lot/3509848...chId=914256979

[xlr8tin]

See, that one didn't even show up so I must be searching wrong. I found a few all 1996 or 1995. Is the 1998 one late enough though? Everyone keeps saying 99-01 is best so I'm not real sure which to get. Makes sense to go with a newer one, but finding one is tough

psjr has one, and may know of another, but he won't get back on to reply to my PM...so we wait. I asked if he wanted to trade parts cars;-)

[clarkitect]

Here it is!:

https://newhaven.craigslist.org/cto/5347171231.html