745i engine head fit on stock m30 block?

chaste420 · Post by **chaste420** » Apr 20, 2006 11:53 AM

found one for a good price

wanted to know if it is worth adding if i am going for a turbo. Also, will it fit or does the block need to be bored larger to fit this head. Thanks.

Tjn182 · Post by **Tjn182** » Apr 20, 2006 12:16 PM

will fit just fine - the only difference between heads are the size of the exhaust studs, the normal M30 head has m8x1.25 threads and the M106 head has m10x1.25(?) threads

otherwise they're exactly the same.

gol10dr1 · Post by **gol10dr1** » Apr 20, 2006 12:35 PM

won't that combo yield a compression ratio of like 7.5:1?

russc · Post by **russc** » Apr 20, 2006 12:59 PM

No, the M106 combustion chamber is the same as the M30b34. If the pistons are the same, then the CR is the same.

Even thought the M102/106 has "turbo" stamped on the head, no one to date has determined what the differences are from the b34.

RussC

Velocewest · Post by **Velocewest** » Apr 20, 2006 7:30 PM

russc wrote:Even thought the M102/106 has "turbo" stamped on the head, no one to date has determined what the differences are from the b34.

Sodium filled exhaust valves is one. Not much else that I can see. I've got one of both on the bench now.

russc · Post by **russc** » Apr 20, 2006 7:48 PM

Ive not seen one or heard of one M102/6 head with the sodium valves, not one. Why, do you? If so, your the fist.

RussC

Tjn182 · Post by **Tjn182** » Apr 20, 2006 8:15 PM

Velocewest wrote:
russc wrote:Even thought the M102/106 has "turbo" stamped on the head, no one to date has determined what the differences are from the b34.
Sodium filled exhaust valves is one. Not much else that I can see. I've got one of both on the bench now.

That was a myth that was disproved, the valves are exactly the same as the normal M30 valves.

Duke · Post by **Duke** » Apr 20, 2006 11:13 PM

Ceramic coat the exhaust ports and CC's, then it will be different.

Jimmie G · Post by **Jimmie G** » Apr 20, 2006 11:22 PM

Has anyone taken a exhaust valve from a m106 and cut them in half too find out? I was told that the price of the valves was in the $250 to 300 range is this a myth also.

Jimbeaux

russc · Post by **russc** » Apr 22, 2006 2:32 AM

Yes,
There have been many cut open, none to date have been the filled type.

RussC

Bert-Ola · Post by **Bert-Ola** » Apr 22, 2006 3:40 AM

Jimmie G wrote:Has anyone taken a exhaust valve from a m106 and cut them in half too find out? I was told that the price of the valves was in the $250 to 300 range is this a myth also.

Jimbeaux

Some difference should it be.

M30B25->M30B34 (E3,E9,E12,E23,E24,E28) ø 38 mm
Partnumber: 11 34 1 250 129 .............................$ 50.22

M102 / M106 (E23) ø 38 mm
Partnumber: 11 34 1 269 419 .............................$129.46

DMNaskale · Post by **DMNaskale** » Apr 22, 2006 7:48 AM

Just to muddy the issue with more rumors and hearsay, I had thought that the valves were not filled, but an upgraded material. Possibly Stellite coated or or an inconel head.

Or made of pure Ultranium, the special alloy that NASA invented to make space shuttles out of. Actually a guy I know used to use that line in his job as an above ground pool salesman to describe the galvanized steel pool walls.

Damon in STL · Post by **Damon in STL** » Apr 22, 2006 9:33 AM

The exhaust valves are made from a nimonic alloy for better heat dissipation.

Damon in STL

Velocewest · Post by **Velocewest** » Apr 22, 2006 1:01 PM

Damon in STL wrote:The exhaust valves are made from a nimonic alloy for better heat dissipation.

Damon in STL

My bad, you're right. I did some more digging, here's a rundown from a BMW Tech document:

3.4-liter fuel injected turbo charged engine, model 745i

The 3.4 l motor replaces the preceding 3.2 l fuel injected, turbo charged model.
The turbo concept was redesigned based on the 3.4 l suction motor, which resulted in distinctive improvements in fuel efficiency and response.

Changes with respect to the 3.2 l turbo engine:

Block of 3.4 l engine has bores for knock sensors
Pistons have concave head for 8.0:1 compression
Bottom of piston is cooled by stream of oil from nozzles in main journal at 1.8 bar
Exhaust driven turbocharger K27 with additional oil hole to cool turbine shaft
Turbocharger is thermally separated from compressor (point contact only)
Standard cylinder head 3.4 l
Crank shaft is the same as in the 3.4 l suction motor
Digital-Motor-Electronic II (Motronic) unit with integrated overload and over heating protection
Compression regulation
Knock regulation
Pistons with concave bottoms and altered ring configuration
Exhaust manifold studs are high temperature resistant
Nimonic exhaust valves
Cam shaft has mounting feature for Motronic high voltage distributor finger
Improved water flow in cylinder head
Water pump with larger diameter

M635CSi · Post by **M635CSi** » Apr 22, 2006 2:02 PM

"made from a nimonic alloy for better heat dissipation"

And I thought they were made of unobtainium...

chaste420 · Post by **chaste420** » Apr 23, 2006 1:24 PM

thanks for the help guys. The 745i head is on ebay right now for like 100 bucks (reserve not met), it also includes a wastgate and exhaust manifold, which are the two parts im most interested in. I just want to know if the head is an actual improvement over what ive got now if i go turbo.

Thanks.

Heres the link for those of you with similar dreaming habits.

http://cgi.ebay.com/ebaymotors/ws/eBayI ... %3AIT&rd=1

russc · Post by **russc** » Apr 23, 2006 3:14 PM

You can be tthe reserve is very close to the Buy it Now.

RussC

M635CSi · Post by **M635CSi** » Apr 23, 2006 7:18 PM

chaste420 wrote: I just want to know if the head is an actual improvement over what ive got now if i go turbo.

Well, if you go 745 turbo you'll have to either use the "turbo" head, or drill out what you have for the larger studs, buy the studs, and have the head fitted with the larger studs.

If you're going BMW authorized parts, then this is your only option. You'll still need the Motronic unit, intercooler, all connecting pipes, and oil filter mounting flange for the turbo oil supply, oil cooler and some other bits and pieces.

Once you’ve collected all the pieces you need, you may want to take them apart and refurbish them to factory or near factor specs so you start with a good base.

Saving money and turbocharging don't go together. If you're on a tight budget, don't kid yourself; the project won't get done anytime soon.

Jesse · Post by **Jesse** » Apr 26, 2006 11:42 AM

Bert-Ola wrote:
Jimmie G wrote:Has anyone taken a exhaust valve from a m106 and cut them in half too find out? I was told that the price of the valves was in the $250 to 300 range is this a myth also.

Jimbeaux
Some difference should it be.

M30B25->M30B34 (E3,E9,E12,E23,E24,E28) ø 38 mm
Partnumber: 11 34 1 250 129 .............................$ 50.22

M102 / M106 (E23) ø 38 mm
Partnumber: 11 34 1 269 419 .............................$129.46

The P/N for the valve guide is different too because the diameter of the valve stem is considerably larger for these special valves.

I think it's all a bit of overkill myself.

Tjn182 · Post by **Tjn182** » Apr 26, 2006 7:24 PM

M635CSi wrote:
chaste420 wrote: I just want to know if the head is an actual improvement over what ive got now if i go turbo.
Well, if you go 745 turbo you'll have to either use the "turbo" head, or drill out what you have for the larger studs, buy the studs, and have the head fitted with the larger studs.

No that is the most expensive way to do things.
Just go to mcmastercarr.com and order some 110 - 140 (and cut em) 8mmx110-140x1.25 studs and just replace your stock studs with longer ones. Gah... I tell people this all the time.

It'll save yourself a good chunk of change.

M635CSi · Post by **M635CSi** » Apr 26, 2006 8:25 PM

Tjn182 wrote:
M635CSi wrote:
chaste420 wrote: I just want to know if the head is an actual improvement over what ive got now if i go turbo.
Well, if you go 745 turbo you'll have to either use the "turbo" head, or drill out what you have for the larger studs, buy the studs, and have the head fitted with the larger studs.
No that is the most expensive way to do things.
Just go to mcmastercarr.com and order some 110 - 140 (and cut em) 8mmx110-140x1.25 studs and just replace your stock studs with longer ones. Gah... I tell people this all the time. It'll save yourself a good chunk of change.

That sounds like a good way to save some money and a lot of work changing the cylinder head.

jimbixjr · Post by **jimbixjr** » May 28, 2006 10:45 PM

No that is the most expensive way to do things.
Just go to mcmastercarr.com and order some 110 - 140 (and cut em) 8mmx110-140x1.25 studs and just replace your stock studs with longer ones. Gah... I tell people this all the time. It'll save yourself a good chunk of change.

Thats what im doing. Is the size you said the exact size? Which material should I get?

Tjn182 · Post by **Tjn182** » May 28, 2006 11:14 PM

They only do 110 and 140 now... i think you'd be safe with 110 if I'm not mistaken. If you want to play it safe, get 140s and just cut them to size. I know that I had to trim 2 down pretty short to clear the "S" intake pipe to the turbo

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