lemonade

so....custom mounting for the engine and transmission, custom driveshaft. you'd most likely have to move the radiator up. (do all engines use oilcoolers?) you'd need the complete bmw engine, engine harness, and ecu. im confused about the body harness. would you need to splice the two? could you use the rx7 gauge cluster? what would you need from the bmw? would this be a wise investment, i really like the bmw I6.

christaylor

No. It's expensive to put a BMW engine in a BMW car, I can't even fathom putting a BMW engine into a Mazda. Pretty much everything would have to be custom, from radiator back. I'm not even sure you could use much or any of the stock harness, I'm not familiar with my BMW's wiring setup (other than it's screwed up).

Put a 1.8L Miata engine into an RX7, much easier to engineer (though still no picnic). Unless you've got fab skills out your ears, I wouldn't even think about an exotic engine swap.

Elysian

bmw I6?? ****... i wouldn't want to touch that... i've looked under the hood of my roommate's M Roadster... its no picnic... kind of intimidating, its packed in so much...

Dan H

Which BMW I6?

I'm willing to bet the front part of the hood will need to be cut out or modified so the front part of the engine doesn't hit it. Some of the old ones are iron block so your handling won't be as good anymore (if you care about that.)

Its probably easier and cheaper installing a smallblock Ford or Chevy V8.

Rx-7Doctor

iTrader: (13)

talking about putting in a bmw inline 6. German engineering is a whole different ball game. It would be pretty difficult to put in a 6 cylinder Bmw motor because of the lenght. Do you actually want to adjust the valves every 15k? All Bmw's up until
91 required this adjustment. Yes they can produce alot of Hp and are very fuel efficent motors.
However my humble opinion is "If you want a BMW motor,Buy a BMW"!You can pick up 528e's or 525i's at at resonable price. Leave the rx7 alone. It would cost you more money and time to do the swap than picking up a used BMW. rx7doctor

rotarygod

iTrader: (1)

If you really want an inline 6 cylinder, get a turbo Supra engine. Those things are damn near indestructible.

peejay

Judging from the German cars I've worked on (oh, especially BMW), German engineering WASN'T. As least as far as designing things so that they would last any reasonably expected length of time without intensive maintenance at a minimum.

rx7doctor mentions adjusting the valves. That's not so unusual. What *is* unusual is the way BMW did it... with little eccentric cams that you would rotate, instead of a screw adjuster. The little eccentrics wouldn't like to actually *hold* an adjustment. It must have been October when they thought up that little idea. But hell, the exhaust manifolds on some of those engines have four bolts around *each* exhaust port. (So an inline six would have a total of 24 bolts holding the manifold to the head... yep, double rows between each port!) I guess they couldn't figure out how to engineer a manifold that would stay put with the traditional one between each port and one at each end?

BMW engines need injections of large amounts of money to make decent power, unless you start with something that already made large amounts of power, in which case the spending of the money goes to the seller instead of to the parts manufacturers.

But at least they're cheap. (Oh wait...)

Rx-7Doctor

iTrader: (13)

I worked for 5 years as a Service Manager for a Bosch Authorized Service Center.
Bmw's are not high maintenance vehicles. They have standard schedules as do all
vehicles. The problems is that most people that would buy them never were educated on the proper schedule. So by the time they hit a shop they had alot of wrong things.
We had customers with anywhere from 100k to 450k on their cars. This is without the engine having any major problems. As with most automobiles its the way that they are serviced. Granted there are alot of manufactures that no matter how you
take care of them, they fail.
the injection systems on a Bmw are highly efficent. that is why you could take a full size 525i and still get 24-26mpg with it.
The o'2 sensors really have a critical function on the cars unlike ours.
The main things that fail on a Bmw is suspension components and brake rotors.
That is because the vehicles suspension was designed to feel the road and be very responsive. The brake rotrs were designed for maximum absorbtion of heat dissapation to keep from brake fade at all times.
Note, i am not stating this because i want to own one but as fact.
And most regular replacement items such as chassis and brakes are very inexpensive. it's when you get into the siver tipped plugs and the cap,rotor and wire sets that get pricey. rx7doctor

peejay

I also speak in terms of regular repairs that need done because of crappy engineering, like the suspension components made apparently out of old lawn chairs (tap a curb or hit a pothole = massive suspension damage) or electric motors and mechanism with poor weatherproofing if present at all.

By the time they started making suspensions that did not require table-smooth roads to maintain proper function (I don't think they have yet to formulate rubber that doesn't biodegrade-in-place) they started using large wheels that were made out of horribly soft aluminum that would bend if you looked at it funny.

I consider keeping up with repairs like that as "maintenance" - maintaining the condition of the vehicle.

the injection systems on a Bmw are highly efficent. that is why you could take a full size 525i and still get 24-26mpg with it.
[/QUOTE]

As opposed to, say, a Ford Crown Vic (about 7-series sized) which also gets about 24-26mpg. Only it actually accelerates when you depress the throttle, unlike a 525i.

797

pretty sure the inline 6's in bimmers are great motors. they do last forever and dont require much maintance. This is just coming from someone whos had several in his family throughout his life so what do i know.... I had a 540 but that had a v8 and with unrestrictive exhaust it sounded so sweet- http://home.earthlink.net/~twc952835...les/reving.wav What would be cooler than doing the inline 6 would be to take the 4.4 dohc v8 and 6 speed manual from the 96+ 540i's and putting that in an old 3 series or possibly your rx7. Check out- http://www.akgmotorsport.com/ click on engine swaps and then click 4.4 v8 into e30. Just looking at the v8 crammed into that little 3 series is awesome. I wanted to do this project but decided it involved to much custom fab. That and the motor and tranny together cost 3500-4000 which was too much $$ for my budget..

Rx-7Doctor

iTrader: (13)

As opposed to, say, a Ford Crown Vic (about 7-series sized) which also gets about 24-26mpg. Only it actually accelerates when you depress the throttle, unlike a 525i.[/QUOTE]Yes and the crown victoria handles like a boat. Also you are talking about a obd2 system on the Crown verus an old antiquated system with an AFM.
Meaning early model years. And the motor in the BMW will still be going strong long after that Vic motor dies. No comparison in engineering. rx7doctor

steve84GS TII

I second the Supra inline 6 swap.Its availible,reliable,powerful and its of the same era/country as the RX-7.(assuming you go with a MarkIII, turbo or N/A.......(go turbo!)
Nearly all inline 6's are long,heavy iron beasts,they do tend to be powerful and make beautiful music,not to mention being silky smooth due to good balancing.Id stay away from a BMW engine,just asking for an expensive headache there.I see MarkIII Supras in the wrecking yards on a daily basis.Cheap and simple, and still some originallity to boot.There is a guy on TeamFC that put a Supra 6 into a 2nd gen,supposedly its a screamer.

peejay

You must not have any experience with the police package 'Vics, which are readily available with only 80k on them for a song. They do not handle like boats. The engines never seem to quit, either.

Not all Vics are OBD-II, but if you're talking older BMWs, then the Vics are automatically better because they haven't rusted themselves down to worthlessness, at which point they fall into the hands of the likes of people who don't put anything into their cars but gasoline, until it quits running or fails emissions. Admittedly, most 5-series from that era got scrapped because of rearend bearing failure before bodyshell rust got to be too much of an issue.

797

why all the hate for bimmers? And saying bmw's dont handle well, thats just ignorant..

Rx-7Doctor

iTrader: (13)

there is no comparison between handling of a BMW and a ford vic or otherwise.
As far as rearend bearing failure. The diff's were easily rebuilt and the only time i saw a need for this was up in the 200k mark. And rust, well sorry i am in CA, don't get must rust here. As far as emmisions go, a correctly tuned BMW could pass the CA emmision test without a Catalytic converter. Your talking to a person that worked for the elite of the elite. Meaning Bosch certified Service center. rx7doctor

Kory_yahi

I wouldn't doubt him either.

Kentetsu

I once picked up a '79 (I think) 320i that was on its last legs. The body was perfect (in Michigan no less, go figure) but the motor was going. The ride was cushy soft on the freeway but it still handled like a dream in tight parking lots and back roads. Handling was simply unbelievable.

When the motor finally blew I took it to a shop and put a $1,200 deposit down for a V8 swap. A week later the bastard closed his shop and split with my money!!!