What is the head flow of the S65 engine?

[Tuner.Series M3]

I have just ordered a BMW s65 engine for my N/A project. There are just a few things i would like to know: too understand the real potential of this engine:

I would like to know how well the head can flow air into the chamber. Has anyone ever Flowbench the S65 cylinder head? What was the flow rate of the intake and exhaust ports independently?

Second of all I would like to know the S65 cylinder head stock valve angle(s) and size. Are there aftermarket oversize valves and larger individual throttle bodies available for the S65 engine?

What is the individual throttle body dimensions? (in diameter)

How well does the stock exhaust and intake manifold flow? What is the flow rates?

What other machine shops do port and polish? If possible to show me the flow graph before and after porting.

I have just moved on to the BMW Motorsport scene, which i have originally come from a Honda background and I understand the "method in madness" in going the N/A route . Spend loads of cash for minimal gains.

thank you Kyle

[Tuner.Series M3]

Thank you PencilGeek. I do believe that having a factory bottom end is the most reliable source for making power. I don't think I'll ever stroked a motor, even though the M3 GTS is factory stroked to 4.4

TrackRat well said. I plan on going custom camshaft with most effective duration and lift that the S65 engine can handle and ect...mods.

I can not equate BMW with Honda.
That being said , Honda k20a engine produces approximately 120-140 whp per liter with porting, cams , exhaust, intake on stock internals ( I understand that this is a fwd engine). The rwd f22c engine from the infamous s2000 has similar results with cams , exhaust ,intake and porting.

THESE RESULTS ARE JUST APPROXIMATIONS:

S2000 whp without porting, just cams intake and exhaust:
http://www.s2ki.com/forums/index.php...f=186&t=760409

Here are some links to how much flow they could get out of an f22c head
http://www.theoldone.com/components/...2000/s2000.htm

And the flywheel dyno results with similar mods:
http://www.s2ki.com/forums/index.php...ic=645353&st=0

Head flow aids supporting mod...it might seem like 2-5whp with no mods. As soon as you add bolt on you find you have a beast in you hands.

K20a from DC5:
http://www.k20a.org/forum/showthread.php?t=74977

http://www.honda-tech.com/showthread.php?t=1162191

I see similar results for the S65 engine...we just have to find the correct "code" to crack true potential of this beast..

Thank you for the replies.

[Tuner.Series M3]

Thanks once again for your insightful information PencilGeek. I do understand the the strucure to camshaft design and development. I have an extensive background with F1 development and research and there forth...

The threads were more than informing...thank you once again.

I would like to know do you perhaps have pictures of the oem camshafts of the S65 engine?

I would also like to know the the design structure of the camshaft, that allows the cams to take full advantage of the vanos system: full cam details and spec.
I build my custom modifications around flow of the engine....Im all about R&D myself. An expensive hobby that is most rewarding.
I would just like to add: factory engine are made to cost effective planning...so this S65 engine is far from its true potential

Thanks .

[Tuner.Series M3]

Pencilgeek i would like to know, what is the most whp and wtq produced by the s65 engine?

[Tuner.Series M3]

I will receive the motor within 1-2 months ...then I'm going too do some intensive R&D with my knowledge and the help of my friends from various motorsport enterprises. My goal is to reach the 450rwhp mark N/A. This is to help the S65 fanatics to reach dream potential. I'm not saying this is what my final result would be...but this is what I'm aiming for.

We never thought in the atlantic formula series that the 4age Toyota motor would make 250bhp...but yet we broke the "laws of physics" , and that is my plan for the S65 engine.

My plans are to keep the S65 to stock bottom end as possible. As we all know, power is all in the head.

PencilGeek it looks like you are the BMW guru from what I've read, and you have reason to be no doubt. I'll keep you posted

thanks...

[Tuner.Series M3]

Thank you PencilGeek...the photos of the engine was a great help, to further my research.
The S65 ports seem to be very well developed in factory trim. BMW did an excellent job. I do see improvement though.
I was trying to figure out where the valvetronic system is situated within the head, until I did some search and found BMW stop the production of their valvetronic. Is there a reason for this perhaps?

Has Schrick ever given information on their 292 cams for the S65?

What is the dimensions of your exhaust manifold on you stroked motor PencilGeek?
I have designed a new exhaust header for the S65 engine thus far. It will be a 4-2-1 with megaphone(taped) collector, tri-y manifold. The 4-1 race manifold is still under design.

I will be asking Jenvey & Hayward performance to help me on the itb/intake section of the project.

The camshaft is a completely different ball game at this moment in time. This resulting in many hours of R&D. This is my hobby and therefor I will only be working on it when there is time.

I will only be able to confirm designs and results once the S65 is delivered into my hands for R&D.

Is BMW developing a newer valvtronic system? If anyone has input to offer please feel free to do so. Variable camshaft profile is the way of the future.

thanks.

[Richbot]

The S65 is not equipped with valvetronic and never has been, and this engine will most likely die when production of the E9x M3 is discontinued, so a valvetronic version is unlikely. BMW didn't stop production of valvetronic as it is still available on many, if not most, of their other gasoline engines.

With just about every hot-rodding trick in the book thrown at it and some fancy cam timing devices to make it tractable at low rpm, the S65 is just a tiny, normal motor like any hot Honda engine. I do think 450whp on pump gas is asking a lot, 2.0l K20's making 225whp NA have a lot lower parasitic drag than a 4.0l S65 that has to sling around twice as many pistons, rods, valves, and so on. I bet the key to NA power (at least without changing displacement) on this motor is going to be getting it above 9,000rpm safely and camming it to match the flow at those rpm's. Most of the NA dyno charts seem to peak at or near the fuel cut, and plateau rather than drop dramatically. If supercharging weren't so cheap and easy I bet we could see some really cool builds but for now it just seems a little pointless unless you're crazy enough about NA engines to want to stay that way. I'm crazy enough but not interested in putting in the work, so keep us posted!

The Toyota Atlantics make incredible specific output for such an ancient design, but when the useful life of the engine is measured in hours, it's not so attractive anymore. I just got done shopping for racecars recently and the event-to-event cost on the atlantics is an eye-opener.


EDIT: Forgot, there is probably a way to use a set of factory cams to make a new grind. If you can find someone who can do a welded high-hardness overlayment (this is a technique used in everything from steel rolling machinery to Ford cylinder liners) sometimes called plasma arc metal deposition or other marketing-heavy terms, you could build up a few mm of material on the lobes and use that to machine from. For a one-off (well, two of each) it might be a good idea, especially for prototyping a cam which you may wish to change more than once.

[aus]

I believe BMW didn't do Valvtronic because of how high this motor revs.
It's used in most of the non-M engines... oh wait, all the other engines are now non-M engines since they're based on the N line with the boost turned up.

[gojcaj]

Bumping a very old thread since I'm interested. Anything ever come of this over the years?