who haves done a bmw s38 engine swap?

[bmwmtechnike]

hello

I need some info about the engine swap (S38)

i have mailed M5dCS but i recieved no answer

are there more people with knowledge about that.

thank you

best regards

ruben

 

[E9Wayne]

S38 swap

There's plenty of information here if you try some different searches. Here is one good thread. I've never seen an E9 with an S38 engine in person but I prefer the stock single overhead cam look that my B34 high compression engine provides and the power output with some simple mods isn't far below the S38...plus it is far cheaper to find and probably install.

http://www.e9coupe.com/forum/showthread.php?t=4086

 

[bmwmtechnike]

s38 swap

hello sir

thank you for the answer.
before I asked here on the forum I have checked the net first this forum under s38,M88,M5,M6

and I found out that

M5dCS,spartacuscsin,corsachili have experiance or see some thing about the build,I have send mails to them but i recieved now answer,maybey holyday

I only need to know some little things

best regards

ruben

 

[x_atlas0]

What do you need to know?

 

[bmwmtechnike]

s38 swap

hello

I need to know if the engine can go in the car with original struts.


that the S38 needs other oilpan,or oil pump or that the orginal must be cut out a little

that you must use a belhouse gearbox
or work the tunnel floor

other way for speed mesurements



my plan is to use a lot e30 m3 parts(the belhouse(e30 M3) and a gearbox(sport version) m3 or m5 drive shaft,weld the e30 mount for diff on the e9 rear axle,to use the 3.91 limited slip diff,brakes are 3.6 m5 with adapter plates,complete brake system from e34(without abs)

I am going to try to take the rpm and speedsensors from the e30

I want to learn from other s38 engine swaps,thing to look out for

i want to use ass much as possible bmw parts,and not break to car?only when its needed

greatings

ruben and thank you

I am sure I forgot something,but I will take a lot of pics of the builld

 

[x_atlas0]

I don't know about the oil pans off the top of my head, but I do know about the transmissions.

The S38/M88 use the standard M30 bellhousing bolt pattern, so any M30 transmission can be bolted up. As such, rather than trying to use the Getrag 280, most people use the Getrag 265. (either flavor, but the close ratio box is significantly weaker than the overdrive version and is more expensive)

Using the 265 lets you drive the speedo just like the original transmission, although units from an E30 M3 lack the mechanical speedo drive. Most people just use an older one, which does have the drive. It ends up making things much easier. However, since you are also doing some diff work, that may not be the best option, as the stock speedo mechanism has no provision for altering the differential ratio.

Speaking of the diff, the easiest setup is to transplant the entire rear subframe from an E28 535. It bolts up and lets you use the much cheaper (and arguably more robust) front-loader diffs used in BMWs from the E28 on. That should significantly decrease the amount of welding required for that work. Also, if you use the later diff, it will have the speed sensor in the housing.

If you want to convert the speedo to an electronic unit, so you can use the stock BMW diff speed sensor used in later diffs, a good instrumentation shop should be able to do it. I've seen good results on this board from Hollywood Speedometer. (http://www.nhspeedometer.com/)

As far as the tachometer signal, the S38B36 and the M88 use a single coil/distributor system, just like the original M30. There should be no problems with that. However, if you switch to the S38B38, that uses a coil-on-plug system, which would require some additional work. I know of no one using this engine, so I can't say too much about it.

You shouldn't need to use a different driveshaft, but any driveshaft you do use will need to be altered to fit the setup you described. It may need to be shortened, lengthened, or have different flanges welded on. Either way, you are not going to be able to use a stock, unaltered driveshaft for this project. The stock driveshaft is plenty strong, if that is what you are concerned about.

 

[rb1971]

I'm doing this swap right now, and just last week put the engine in the car.

A couple of points:

1. The oil pan does clear the front E9 subframe and there is sufficient ground clearance.
2. There is enough room to put the correct radiator in the original E9 radiator brackets, but you will need to do a little work on the bushings, etc., to make the fitment correct.
3. I'm using a 265 tranny both because I had one and it makes the speedo issue easier.
4. The E28 535 subframe may work, but I had an E28 M5 subframe that did NOT match up. The result of this is that we are moving forward with the E9 original subframe, with the original CSi diff; however, this will probably be rebuilt by a race shop that rebuilt my E39 M5 diff.
5. You do need to rebuild and shorten the driveshaft, but after 40 years most of these cars could use a refresh on a lot of the parts.
6. You might run into a problem with the 3.91 diff since there is less clearance on the old cars than the newer ones (i.e., the newer diffs are taller). This might require some cutting and welding. Measure first, cut once, as always.
7. We also welded a new crossmember to support the tranny between the frame rails, which provides substantial lateral support. I would recommend doing this.

Happy to discuss other points.

 

[bmwmtechnike]

thank you for the info

thank you thank you thank you

 

[M5dCS]

s38 conversion

Rubin, I just now discovered your PM's and this thread as I just haven't had time to check this site recently,my apologies. Yes I've been all through this and I'd love to help out and maybe we can get someone to build this into a technical archive for an easy place to look it up for future referances. I'll address each area in a seperate post so things won't get too confusing and it will give me time to think things over so that I don't delete anything. Maybe we can get others that have done this conversion to chime in and help us out also. If you have questions that need to be answered by phone contact me @ 208-347-3309 in the evenings, I'm in Idaho so it's mountain standard time here. Regards, Leroy

 

[M5dCS]

diff

If you are going to use an overdrive trans yes the 3.91 gearing is the best. The 3.91 diff with the overdrive works out to a 3.15 ratio in 5th. I used a dogleg 5speed trans and currently have a 3.07 sideloader diff out of a euro 635 that also hade the 3.07 side loader diff, maybe later I'll change to a 3.25, but remember that our cars are 500kg lighter than the M5. If you are more of a sporty driver I'd go with the 3.25 or for more highway work use the 3.07. Both of these diffs are readily available from the wrecking yards. Your other alternative is with the overdrive trans, Metric Mechanic in the US modified the e9 diff mount to accept the rear loader diffs you will also need their rear cover so that you can use your stock rear diff mount. Yes you will need the electric speedo pickup to send a signal to the computer or else you will be in the limp home mode and you will never see top RPM from your engine. You can use one of the chopper wheels out of a later diff and mount it on the diff output shaft on the drivers side, fabricate a bracket for the speed sensor, and you are in business.

 

[M5dCS]

trans

M5s,at least the s38b36, need a motrinic bellhousing to match up to the engine, I used an 85 bellhousing and mated it up to my dogleg close ratio trans, also use an 85 throwout bearing and slave cylinder. An e9 automatic driveshaft will fit right in, use the 528i crossmember and trans mount, or build one that supports both sides of the trans for more stability. Guibo's are controversial, but I like the ones that look like they were cut out of an old tire, they have steel wire laced thoughout, like a radial tire and are hell for strong.

 

[bmwmtechnike]

hello leroy

thank you for the answers.

so when I take a 3.45 diff limited slip that is very fast acceleration.

the 3.91 is to much.I am going to look for the parts,thank you for those super tips


do you still use the same brakes? or do you use a upgrade
did you use the same engine struts?(S38 engine)


best regards

ruben

 

[61porsche]

S38 weight, etc.

The difference in weight between an M30 and S38 is less than 10lbs. ( 7: I think) Your struts should be fine.

If your concern is over the elec. speedo sensor and the mechanical speedo there is a convertor ( mechanical to electronic ) available now that is adjustable as an alternate. Roughly $300.