M90 Race Car Engine Build (Now with more M54!)

E28 technical advice asked and given! Troubleshooting, modifications and more.
nik77356
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Location: Indianapolis, IN

M90 Race Car Engine Build (Now with more M54!)

Post by nik77356 »

This is somewhat of a resurrection of an old thread, but also a completely new build. Here is the old thread, of which this is a continuation: http://www.mye28.com/viewtopic.php?f=3&t=121538

I spun a bearing in the race car at the last race due to oil starvation in left hand turns. Here is what that sounds like: https://youtu.be/XgT3XwVLMGg

Now I am building a new motor for the race car, using an M90 bottom end as a base.

Some issues I discovered after switching to slicks, is that oil pools up in the cylinder head in those same left hand turns. This causes the oil to get sucked through the intake and burned, causing a massive smoke screen for the people behind you. After discussing this with several members here, the solution is to tap the oiling holes in the block that go to the cylinder head and install set screws that are drilled all the way through as a restrictor. This will help in two ways; It will keep oil in the sump, as well as keep oil from pooling in the cylinder head.

My planned components are as follows:

- Bottom End:
  • * M90 Block and Rotating Assembly
    * Oil Passage Restrictors installed in the block to help prevent Oil pooling in the Cylinder Head
    * M30B35 Oil Pan and Pump, with custom baffles in the Pan
- Cylinder Head:
  • * M30B34 Cylinder Head ported to match a B35 Intake Manifold (running vacuum brakes)
    * HD Rockers
    * Dual Valve Springs
    * 47mm Intake Valves
    * 39mm Exhaust Valves
    * Schrick 284 Camshaft
    * Headers (unknown brand, came with another engine I have laying around)
I will also be running M1.3 engine management.

I'm hoping to have roughly 210-220whp out of this engine. This should put me right in the sweet spot for the P/W ratio required for my race class (NASA ST5, for those that are curious).

One question I did have; I know the B35 comes with dual valve springs, but the B34 does not. Are the "Racing Dual Valve Spring Kits" that everyone sells (Ireland, VAC, Bimmerheads, etc) the same as stock B35 dual valve springs, or are they different (Spring Kits are stiffer than B35)?

My goal with this thread is to not only document my engine build, but to also put as much information related to tracking M30 engines in one place. Currently, all this information is scattered about the internet, and can be VERY difficult and time consuming to track down.
Last edited by nik77356 on Mar 14, 2021 10:25 AM, edited 2 times in total.
WVe28
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Re: M90 Race Car Engine Build

Post by WVe28 »

I used the Ireland dual valve spring setup in my M90 and it's my understanding they are the same spring rate as the B35 stock springs, but I did not compare side by side with my B35 head or anything.
nik77356
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Re: M90 Race Car Engine Build

Post by nik77356 »

WVe28 wrote:I used the Ireland dual valve spring setup in my M90 and it's my understanding they are the same spring rate as the B35 stock springs, but I did not compare side by side with my B35 head or anything.
Good to know, thanks! I will keep that in mind. Maybe I will order the set and measure.
tschultz
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Re: M90 Race Car Engine Build

Post by tschultz »

Are you sticking with M1.0a or M1.3?
nik77356
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Re: M90 Race Car Engine Build

Post by nik77356 »

tschultz wrote:Are you sticking with M1.0a or M1.3?
Thanks for the reminder! I will be running M1.3, and have edited the original post to include that.
Tiit
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Re: M90 Race Car Engine Build

Post by Tiit »

Following.
Shawn D.
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Beamter
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Re: M90 Race Car Engine Build

Post by Shawn D. »

nik77356 wrote:Some issues I discovered after switching to slicks, is that oil pools up in the cylinder head in those same left hand turns.
The oil drains are on the right side of the head, so the forces in left-hand turns would push the oil to the right towards the drains. Did you mean it happens in right-hand turns?
nik77356
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Location: Indianapolis, IN

Re: M90 Race Car Engine Build

Post by nik77356 »

Shawn D. wrote:
nik77356 wrote:Some issues I discovered after switching to slicks, is that oil pools up in the cylinder head in those same left hand turns.
The oil drains are on the right side of the head, so the forces in left-hand turns would push the oil to the right towards the drains. Did you mean it happens in right-hand turns?

Not quite. What happens, is it gets sucked up into the intake through the PCV (or whatever they deem it on these engines), and then gets burned in the combustion chamber. Several other members that also drive their cars on track have had similar issues. The forces are so great in that direction that the oil is actually climbing the walls of the cylinder head instead of draining.

Hopefully that makes sense.
Mike W.
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Re: M90 Race Car Engine Build

Post by Mike W. »

nik77356 wrote:One question I did have; I know the B35 comes with dual valve springs, but the B34 does not. Are the "Racing Dual Valve Spring Kits" that everyone sells (Ireland, VAC, Bimmerheads, etc) the same as stock B35 dual valve springs, or are they different (Spring Kits are stiffer than B35)?
Later B34s, 87+? came with dual valve springs. I don't know if the ones you mentioned are the same or not.
Last edited by Mike W. on Apr 13, 2019 10:03 PM, edited 1 time in total.
Shawn D.
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Re: M90 Race Car Engine Build

Post by Shawn D. »

nik77356 wrote:
Shawn D. wrote:
nik77356 wrote:Some issues I discovered after switching to slicks, is that oil pools up in the cylinder head in those same left hand turns.
The oil drains are on the right side of the head, so the forces in left-hand turns would push the oil to the right towards the drains. Did you mean it happens in right-hand turns?
Not quite. What happens, is it gets sucked up into the intake through the PCV (or whatever they deem it on these engines), and then gets burned in the combustion chamber. Several other members that also drive their cars on track have had similar issues. The forces are so great in that direction that the oil is actually climbing the walls of the cylinder head instead of draining.

Hopefully that makes sense.
Yeah, that makes sense -- thanks for the explanation!
VintageRacer
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Re: M90 Race Car Engine Build

Post by VintageRacer »

I would also suggest running a catch can breather instead of routing to the intake to prevent oil burning.

I’m just finishing up my group A Alpina clone engine. I went a little bigger on the cam and pistons and should make 330hp at the crank.

Here are my specs:
Started from M30B35
Cam custom grind from Top End around 316 duration and huge lift
Crower dual valve springs
Intake and Exhaust valves +2mm
Ported intake and exhaust with extensive chamber work
13.5:1 Forged Pistons w/total seal rings
Billet 144mm rods
Stock crank but polished and lightened
Balanced and Blueprinted

External stuff:
Dinan Stage 3 intake (extrude honed)
Mustang 70mm TB with IAC
36lb/hr Buick 3.8L injectors
Nuke fuel rail
Team2Fast Stainless Headers
1 range colder plugs
Stock coil
Ireland 8mm wires
No air box
Mega squirt PnP ECU
adam_poll
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Re: M90 Race Car Engine Build

Post by adam_poll »

Those Team2Fast Stainless Headers look identical to the Schmiedmann ones - https://www.schmiedmann.com/en/bmw-E28/ ... uct=SCMM30

Maybe you can save $150 on your race motor. I'm hoping at some point to do a mild build on an M30B35 so I'll be following this thread with interest.

Adam
euroclassicmotors
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Re: M90 Race Car Engine Build

Post by euroclassicmotors »

nik77356 wrote:Some issues I discovered after switching to slicks, is that oil pools up in the cylinder head in those same left hand turns. This causes the oil to get sucked through the intake and burned, causing a massive smoke screen for the people behind you. After discussing this with several members here, the solution is to tap the oiling holes in the block that go to the cylinder head and install set screws that are drilled all the way through as a restrictor. This will help in two ways; It will keep oil in the sump, as well as keep oil from pooling in the cylinder head.

Hi,

By reducing and draining the oil from your valve train you are
reducing the oil lubrication with potential of making the valve
train to run dry. To my understanding you are trying to drill holes
on the exhaust side so that way the oil will drop in the back
of the block and then back to the pan, absolute no.

I would suggest something, think of S38. The S38 valve train has
even more oil than the M30 because of extra cam and also extra
12 friction pieces which needs lubrication, so how come S38 does
not have such a problem ?

Study the M30 ventilation system, flip your valve cover and note
from were the oil is getting sucked via the valve cover pipe and
then direct to the Intake, the screen is very very very very small
and not insulated to prevent the oil from getting to the intake
valve cover pipe.

Compare the M30 valve cover to S38. Note how on S38 you have
a very very long solid screen/wall and this prevents the oil to
splash and hit the valve cover vent hole. Second, note how the
valve cover casting is looped even with harshest race conditions
the oil will never ever reach the valve cover vent hole, unless you
put the car on the roof and have the engine to operate then the
oil will get into the intake via the valve cover vent pipe for sure,
but in this case we have a lot bigger problems than puff of smoke...

So what you can try is measure the plate that is on the OEM,
get 2 more plates from another M30 valve covers and put them next
to each other TIG welded so to get rid of absolute any holes of were
the oil will get near by the valve cover vent pipe to Intake.

Block any side access which the oil will have a slim chance to
get inside. Remember the vent opening hole is about 20mm so take
that ~20mm and measure total opening area and complete close the
rest and box that area.

With higher springs pressure and more aggressive camshaft you
need oil in your valve train. Also remember on the track under
hard braking with slicks as you do have the oil is splashing like a
tsunami towards the front of the engine were massive amount of
oil is pushed down from the front timing chain cover. So imagine every
corner how much oil you drain via the front. Reducing the oil in
the valve train you are making it for the worst. Open the oil cap
on S38 and see the exhaust cam nearly dipped in oil, and that's on
Idle speed of 850+/-,imagine at 7500-8000rpm and ~ 4-Bar oil pressure
how much oil is splashing the valve train up there...and no issues with
puffing smoke.

Note your path, you never had issues up until you put slick because
now the oil is reaching the valve cover pipe and dumps oil inside
of the intake which pollutes the cyl chamber.

try to you will see how easy is to fix this problem. Hopefully, you
don't have biow by from worn out piston rings ?, also your guides
should be tight and nice without any play, then no problems.

Regarding the oil in the pan during race ? what you can test is
on the morning when the engine is cold start and the oil pressure is
very very hi run the motor and rev it to say 3-4k rpm then while under
revs check the oil level and see how much oil is missing form the oil
pan, take notes. I assume the valve train would not take much more
than 500ml meaning half a liter. Add that 500ml on top of the the max
level of your dipstick and you are good to go.

On my E24M6 race car I do have a mechanical pressure gauge and no
matter how many G's I pull my oil pressure is frozen at 4.2Bars on
hot day, but I have modified the oil pan which holds 9 liters of oil
but the same time does not interfere my knife edge crankshaft at all.

Hope this helps a bit.

Regards,
Anri
Last edited by euroclassicmotors on Apr 15, 2019 9:42 AM, edited 1 time in total.
VintageRacer
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Location: Waco, TX

Re: M90 Race Car Engine Build

Post by VintageRacer »

Well said.

Also remember that PCV and plumbing on these cars are meant for emissions regulations and NOT racing.

Our TWR V12 XJS has the breathers running to catch cans which are designed to allow the air out but not the oil. After a race weekend we typically see about 1/4 qt of oil in there.

As for the headers I already bought them. Quality is good. I am not impressed by the fitment. On the B35 block there is an extra casting nub that I had to trim at the back of the block and the headers have some clearance issues with themselves. Overall I’ll run em till I find something better.
nik77356
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Re: M90 Race Car Engine Build

Post by nik77356 »

I'm not going to use an S38 because I don't need that much power, and I don't want to spend that much money building and maintaining an engine. I'm estimating about $4000 max in my current build, and I'd spend more than that just acquiring an S38, plus another $5,000-$10,000 to go through it. That's not what I'm after.
euroclassicmotors
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Re: M90 Race Car Engine Build

Post by euroclassicmotors »

nik77356 wrote:I'm not going to use an S38 because I don't need that much power, and I don't want to spend that much money building and maintaining an engine. I'm estimating about $4000 max in my current build, and I'd spend more than that just acquiring an S38, plus another $5,000-$10,000 to go through it. That's not what I'm after.

Hi nik77356,

Your post reply clearly demonstrates you absolutely
did not get my point on how to fix your "oil puff" issue
on your M30 engine.

Regards,
Anri
nik77356
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Re: M90 Race Car Engine Build

Post by nik77356 »

euroclassicmotors wrote:
nik77356 wrote:I'm not going to use an S38 because I don't need that much power, and I don't want to spend that much money building and maintaining an engine. I'm estimating about $4000 max in my current build, and I'd spend more than that just acquiring an S38, plus another $5,000-$10,000 to go through it. That's not what I'm after.

Hi nik77356,

Your post reply clearly demonstrates you absolutely
did not get my point on how to fix your "oil puff" issue
on your M30 engine.

Regards,
Anri
Your post reply clearly demonstrates that you do not understand M30s. They also have a plate that covers the area in front of the valve cover vent hole. In addition, 2002 guys have been running oil restrictors in their M10s for years without issue. It would be nice if you would stop being condescending to others, as you have done in multiple threads. Thank you.
nik77356
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Re: M90 Race Car Engine Build

Post by nik77356 »

As I have previously stated in the original post, I would like to run a B35 Oil Pan and Pump. I want to do this for multiple reasons. The B35 Oil Pan seems a bit more conducive to adding baffles, as well as the B35 Oil Pump providing more pressure due to the smaller drive gear diameter. The biggest issue I see, is that the block I am using does not have provisions for the oil pump chain tensioner. Based on this thread: http://www.mye28.com/viewtopic.php?t=119354 I should be able to run the B35 Oil Pump using part number 11 41 7 577 655, as this chain has 44 links, along with the correct number of shims to get chain tension correct (part number 11 41 1 250 562).

I don't believe there are any differences in the way oil gets from the pump into the engine between older M30/M90s and the M30B35. Has anyone experienced anything different? I will likely mock this up later this week.
VintageRacer
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Re: M90 Race Car Engine Build

Post by VintageRacer »

I think you'll be fine with the B35 pump and pan. I also think the B35 front sump pan will be better for racing as it's deeper and the sump is towards the front (E34).
VintageRacer
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Re: M90 Race Car Engine Build

Post by VintageRacer »

Also, i'm not a fan of oil restrictions to an OHC valve train but you're right that other engine types including the M10 have been using them for years. I would seriously consider just a re-route of the breather lines instead of using them though.

What oil are you using? Perhaps running a slightly thinner oil may help with the drain back. I'm running Redline 40wt race oil (which is 10w40) and it works very well in the S38. Once the M30 is broke in I'll be running this in that engine as well. A lot of folks run 20w50 but I don't see the need, now the Jaguar V12, that's another story.

You're estimate on building a race S38 is a wee bit low too :rofl: I think I have more than triple that into my 4.0L S38 but oh is it fun to hear it pull all the way to 7,000 RPM.
euroclassicmotors
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Re: M90 Race Car Engine Build

Post by euroclassicmotors »

nik77356 wrote:Your post reply clearly demonstrates that you do not understand M30s. They also have a plate that covers the area in front of the valve cover vent hole. In addition, 2002 guys have been running oil restrictors in their M10s for years without issue. It would be nice if you would stop being condescending to others, as you have done in multiple threads. Thank you.
nik77356 wrote:As I have previously stated in the original post, I would like to run a B35 Oil Pan and Pump. I want to do this for multiple reasons. The B35 Oil Pan seems a bit more conducive to adding baffles, as well as the B35 Oil Pump providing more pressure due to the smaller drive gear diameter. The biggest issue I see, is that the block I am using does not have provisions for the oil pump chain tensioner. Based on this thread: viewtopic.php?t=119354 I should be able to run the B35 Oil Pump using part number 11 41 7 577 655, as this chain has 44 links, along with the correct number of shims to get chain tension correct (part number 11 41 1 250 562).

I don't believe there are any differences in the way oil gets from the pump into the engine between older M30/M90s and the M30B35. Has anyone experienced anything different? I will likely mock this up later this week.
Hi nik77356,

Many thanks for your reply

I am not sure what you are all about, but
I do apologize if you understood me
in any wrong way which I feel you did.
Your previous reply was very confused and
more out of the subject.

My reply to your issue is a suggestion you
either take or not, nik77356.

Many great solutions for all your questions on
your race M30 for easy on the wallet but you
are the builder, you are the pilot,I wish you
good luck with the project and happy times.

Kind Regards,
Anri
nik77356
Posts: 563
Joined: Oct 21, 2011 5:49 PM
Location: Indianapolis, IN

Re: M90 Race Car Engine Build

Post by nik77356 »

Hi nik77356,

Many thanks for your reply

I am not sure what you are all about, but
I do apologize if you understood me
in any wrong way which I feel you did.
Your previous reply was very confused and
more out of the subject.

My reply to your issue is a suggestion you
either take or not, nik77356.

Many great solutions for all your questions on
your race M30 for easy on the wallet but you
are the builder, you are the pilot,I wish you
good luck with the project and happy times.

Kind Regards,
Anri
I sent you a PM, Anri. Hopefully just a misunderstanding.
nik77356
Posts: 563
Joined: Oct 21, 2011 5:49 PM
Location: Indianapolis, IN

Re: M90 Race Car Engine Build

Post by nik77356 »

VintageRacer wrote:Also, i'm not a fan of oil restrictions to an OHC valve train but you're right that other engine types including the M10 have been using them for years. I would seriously consider just a re-route of the breather lines instead of using them though.

What oil are you using? Perhaps running a slightly thinner oil may help with the drain back. I'm running Redline 40wt race oil (which is 10w40) and it works very well in the S38. Once the M30 is broke in I'll be running this in that engine as well. A lot of folks run 20w50 but I don't see the need, now the Jaguar V12, that's another story.

You're estimate on building a race S38 is a wee bit low too :rofl: I think I have more than triple that into my 4.0L S38 but oh is it fun to hear it pull all the way to 7,000 RPM.
I have been running the 10w60 that BMW specs for the older M engines. My fear was that 15w40 or 20w50 would thin out excessively or break-down as the engine fully heat soaked under racing conditions. That said, I am no engineer, so if I am wrong, someone please tell me.

Do you have any pictures of your catch can setup on your M30?
LeiseyJr
Posts: 1345
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Re: M90 Race Car Engine Build

Post by LeiseyJr »

nik77356 wrote:
VintageRacer wrote:Also, i'm not a fan of oil restrictions to an OHC valve train but you're right that other engine types including the M10 have been using them for years. I would seriously consider just a re-route of the breather lines instead of using them though.

What oil are you using? Perhaps running a slightly thinner oil may help with the drain back. I'm running Redline 40wt race oil (which is 10w40) and it works very well in the S38. Once the M30 is broke in I'll be running this in that engine as well. A lot of folks run 20w50 but I don't see the need, now the Jaguar V12, that's another story.

You're estimate on building a race S38 is a wee bit low too :rofl: I think I have more than triple that into my 4.0L S38 but oh is it fun to hear it pull all the way to 7,000 RPM.
I have been running the 10w60 that BMW specs for the older M engines. My fear was that 15w40 or 20w50 would thin out excessively or break-down as the engine fully heat soaked under racing conditions. That said, I am no engineer, so if I am wrong, someone please tell me.

Do you have any pictures of your catch can setup on your M30?
What are your oil temps? It shouldn't thin out unless its getting too hot.
VintageRacer
Posts: 36
Joined: Oct 25, 2017 12:11 PM
Location: Waco, TX

Re: M90 Race Car Engine Build

Post by VintageRacer »

I haven't built it yet as the motor is still on the stand.

On the S38 we rarely see oil temps >200F. But then I have a HUGE Fluidyne cooler up front :D I often have to add tape if the OAT is less than 70F to keep the oil temps above 150F during a race.
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