P65 Conversion kit!

I just stumbled across a P65 conversion kit Sold by M24, a race team out of Germany. They make a whole slew of mods for our cars.

Theres a Crankshaft to take it up to 9k rpm too.

But the more interesting thing is the S65/P65 4.4l stroker it. It comes with the Z4 GT3 (P65) rotating assembly. I believe you can also buy just the Crankshaft on its own, but I’m not sure that’s just a “drop in” thing.

This seems quite Interesting, I know there was someone on here who was trying to P65 swap his E9X. This almost seems just as “easy” as any other stroker kit. But I’d imagine a Vanos delete would be needed. Let’s hope someone is ballsy enough to do this!!!

Having a P65 and its sound would be awesome. Only problem with most stroker builds is the relatively low mileage between rebuilds. I suppose limiting max RPM and pure street use will net you a longer rebuild interval but reducing max rpm defeats one of the best reasons for building such an amazing engine - the sound!

I still think the interval will be longer for a street car vs a full blown track car that’s seeing sustained high rpm pulls lap after lap. I know someone with a dinan 4.6 and he has 96k miles on the motor and has never been rebuilt.

gh0stE92M3 wrote

I still think the interval will be longer for a street car vs a full blown track car that’s seeing sustained high rpm pulls lap after lap. I know someone with a dinan 4.6 and he has 96k miles on the motor and has never been rebuilt.

But why build a BMW M P65 race engine and then just drive it on the street? That’s the job of a standard s65 stroker build. I’d be curious to see a dyno comparison of the stroker at 1k miles vs. 96k miles. Rebuild times can be stretched if you’re not looking to maintain max rpm, hp and torque.

Here’s why you build a S65 stroker:
https://www.m3post.com/forums/showpost.php?p=25012711&postcount=3

M3SQRD wrote

But why build a BMW M P65 race engine and then just drive it on the street? That’s the job of a standard s65 stroker build. I’d be curious to see a dyno comparison of the stroker at 1k miles vs. 96k miles. Rebuild times can be stretched if you’re not looking to maintain max rpm, hp and torque.

Here’s why you build a S65 stroker:
https://www.m3post.com/forums/showpost.php?p=25012711&postcount=3

It’s not a p65 it’s an s65 4.6 dinan stroker. I’m curious to as how much power from new and after a few thousand miles.

gh0stE92M3 wrote

It’s not a p65 it’s an s65 4.6 dinan stroker. I’m curious to as how much power from new and after a few thousand miles.

I know. I’m talking about the kit that uses a flat plane crank to build a P65. There’s a couple P65s being built/converted from a S65 to a P65. The link I included is for a s65 4.6 L Carbshn stroker with 292 cams that makes almost 500 whp and originally used in a dedicated track car but the point was to show why you’d build a P65 in the first place - an ultimate track weapon. Building a P65 and then limiting max rpm to increase longevity and using it on the street seems like a huge waste. P motors are true M Motorsport race engines so an original S65 rebuilt into a P65 should spend its life on the track making the glorious sounds only a flat plane crank motor can make! If it’s for street use, just build a S65 cross plane stroker.

M3SQRD wrote

I know. I’m talking about the kit that uses a flat plane crank to build a P65. There’s a couple P65s being built/converted from a S65 to a P65. The link I included is for a s65 4.6 L Carbshn stroker with 292 cams that makes almost 500 whp and originally used in a dedicated track car but the point was to show why you’d build a P65 in the first place - an ultimate track weapon. Building a P65 and then limiting max rpm to increase longevity and using it on the street seems like a huge waste. P motors are true M Motorsport race engines so an original S65 rebuilt into a P65 should spend its life on the track making the glorious sounds only a flat plane crank motor can make! If it’s for street use, just build a S65 cross plane stroker.

I totally agree man, Steve dinan has some p65 blocks stored away somewhere and at the price they yield i feel it’s more like look what I have, the s65 stock trim is already a great motor for the track. Having it stroked to a 4.6 I still feel is overkill. Cause at some point you’re gonna have to get it rebuilt. I’m sure there’s a limit on how much you can hone the cylinders until the space between cylinders becomes to thin. I think the way to go is 4.4L with 292 cams and since you’re doing all that might as well get a dry sump setup cause what’s another 7k lol

gh0stE92M3 wrote

I totally agree man, Steve dinan has some p65 blocks stored away somewhere and at the price they yield i feel it’s more like look what I have, the s65 stock trim is already a great motor for the track. Having it stroked to a 4.6 I still feel is overkill. Cause at some point you’re gonna have to get it rebuilt. I’m sure there’s a limit on how much you can hone the cylinders until the space between cylinders becomes to thin. I think the way to go is 4.4L with 292 cams and since you’re doing all that might as well get a dry sump setup cause what’s another 7k lol

I agree. Makes wayyyy more sense to just get a Dinan stroker than build a P65. But I find it cool you still could technically convert your car to a flat plane crank if you wanted

I believe the Z4 GT3 uses a crossplane crank. The e92 GT2 is the one with a flat plane crank.

Cool that it is possible to buy this stuff if your pockets are deep enough though!

I really want a rich guy to build one of these and daily the shit out of it.

iamtrashman wrote

I believe the Z4 GT3 uses a crossplane crank. The e92 GT2 is the one with a flat plane crank.

Cool that it is possible to buy this stuff if your pockets are deep enough though!

Both are flat plane, P65!!!!

M3MATT wrote

Both are flat plane, P65!!!!

YES. Here’s the awesome sound…

Listen to the e92 m3 GT2. They sound completely different. The Z4 sounds similar to an s65 with a crossplane crank. I believe the GT3 crossplane p65 has a different firing order than the road going s65 but it is still a crossplane crank. The flat plane p65 in the e92 GT2 sounds more like a Ferrari (think 458).

iamtrashman wrote

Listen to the e92 m3 GT2. They sound completely different. The Z4 sounds similar to an s65 with a crossplane crank. I believe the GT3 crossplane p65 has a different firing order than the road going s65 but it is still a crossplane crank. The flat plane p65 in the e92 GT2 sounds more like a Ferrari (think 458).

Listen for yourself.

Yes it’s interesting. Due to that because of the side exit m3 vs merging on the z6
One crosses exhaust banks while the other doesn’t

Similar to how different the side exit RSR sounds compared to the normal RSR. A lot more “Gnatty”

M3MATT wrote

Yes it’s interesting. Due to that because of the side exit m3 vs merging on the z6
One crosses exhaust banks while the other doesn’t

Similar to how different the side exit RSR sounds compared to the normal RSR. A lot more “Gnatty”

iamtrashman is correct. The P65B44 is based on the S65B44 from the M3 GTS and it uses a cross-plane crankshaft. Scroll down the attached document until you reach the Z4 GT3.

https://www.m3post.com/forums/showthread.php?t=1065981

M3SQRD wrote

iamtrashman is correct. The P65B44 is based on the S65B44 from the M3 GTS and it uses a cross-plane crankshaft. Scroll down the attached document until you reach the Z4 GT3.

https://www.m3post.com/forums/showthread.php?t=1065981

Yes, both the M3 GT2 and Z4 GT3 have P65b4X’s
But they both sound so different due to exhaust setups. Same engine, different exhaust = different sound.

M3MATT wrote

Yes, both the M3 GT2 and Z4 GT3 have P65b4X’s
But they both sound so different due to exhaust setups. Same engine, different exhaust = different sound.

I agree the difference in header stepped equal/non-equal length collector designs and exhaust geometry can completely change the sound of an engine. It’s easy to screw up the sound of an engine with badly designed headers. Flat vs cross plane changes the sound even more. Firing order also affects sound. I remember hearing the Honda (Acura badged) IndyCar engines from the early-mid 90s and they were playing around with firing order to maximize torque - it sounded as if it was a new clean-sheet engine design. They may have tweaked header designs as well but it was known they were changing the firing order.