[F30_Adler]

Anyone know of someone who blew their N20 engine and rebuilt it with forged internals? or just rebuilt their N20 in order to have better reliability under higher hp?

[Stubok]

Originally Posted by F30_Adler

Anyone know of someone who blew their N20 engine and rebuilt it with forged internals? or just rebuilt their N20 in order to have better reliability under higher hp?

Bought the CP Carrillo Pistons and Rods (with hardened Carr bolts), but I bought a house and that put the kybosh on my build.

Apparently the cylinders can not be honed and will need to be dry sleeved, and also notched/relieved at the bottom of the cylinder to accommodate the bigger rod.

My plan is to send the block for the rod relief, dry sleeves, ARP head studs and maybe closing the deck.

Then I can really push the stage 2 turbo. Should be able to get to close to 380Hp to wheels.

eventually I will build a custom exhaust manifold for a big Turbo (60mm), port the head, change cams and valve springs and make big big power... I reckon 600.

[Domotron]

Originally Posted by Stubok

Bought the CP Carrillo Pistons and Rods (with hardened Carr bolts), but I bought a house and that put the kybosh on my build.

Apparently the cylinders can not be honed and will need to be dry sleeved, and also notched/relieved at the bottom of the cylinder to accommodate the bigger rod.

My plan is to send the block for the rod relief, dry sleeves, ARP head studs and maybe closing the deck.

Then I can really push the stage 2 turbo. Should be able to get to close to 380Hp to wheels.

eventually I will build a custom exhaust manifold for a big Turbo (60mm), port the head, change cams and valve springs and make big big power... I reckon 600.

I'm also wondering this... I've looked everywhere and cant seem to find where to get pistons and rods for N20/26 engines

[F30_Adler]

Please keep us updated as you do your build.

[Diegov209]

Originally Posted by Stubok

Bought the CP Carrillo Pistons and Rods (with hardened Carr bolts), but I bought a house and that put the kybosh on my build.

Apparently the cylinders can not be honed and will need to be dry sleeved, and also notched/relieved at the bottom of the cylinder to accommodate the bigger rod.

My plan is to send the block for the rod relief, dry sleeves, ARP head studs and maybe closing the deck.

Then I can really push the stage 2 turbo. Should be able to get to close to 380Hp to wheels.

eventually I will build a custom exhaust manifold for a big Turbo (60mm), port the head, change cams and valve springs and make big big power... I reckon 600.

Can't wait man can't wait I will be doing the same soon just takes time patience lol I got to have patience and not go broke entierely lol.

[Stubok]

Originally Posted by Domotron

I'm also wondering this... I've looked everywhere and cant seem to find where to get pistons and rods for N20/26 engines

There are a couple different options. I went for Stock bore (84mm) and compression (10:1), but there is also a 9.5:1 CR from a slight over bore piston (84.5mm).

I bought my set off these guys:

https://www.monkeysracing.com

[Domotron]

Originally Posted by Stubok

There are a couple different options. I went for Stock bore (84mm) and compression (10:1), but there is also a 9.5:1 CR from a slight over bore piston (84.5mm).

I bought my set off these guys:

https://www.monkeysracing.com

they look good ! very beafy ! do you know anything about the crank ? is it forged ?

[D041987]

Our crank is forged ;-) Anything above 400-450 is recommended to close the desk or the cylinders will crack/ turn egg shape and you will have blow-by. I am having a hard time finding anyone in my city/state that even wants to touch the motor let alone have any prior knowledge of rebuilding it ;-( Ill still be looking as well but might consider the machine shop that did the HPF builds in Oregon and hope for the best and will also see about doing an oil baffle at the same time as I was quoted around $200 to 300 ish for that. Will probably be taking this on next summer as I myself am looking for a house, haha.

[Diegov209]

Originally Posted by Stubok

There are a couple different options. I went for Stock bore (84mm) and compression (10:1), but there is also a 9.5:1 CR from a slight over bore piston (84.5mm).

I bought my set off these guys:

https://www.monkeysracing.com

Wow that price is really not that bad honestly seeing the price I might be able to speed up the process wow pretty cool man thanks for the info.

[Stubok]

Originally Posted by D041987

Our crank is not forged ;-( Anything above 400-450 is recommended to close the desk or the cylinders will crack/ turn egg shape and you will have blow-by. I am having a hard time finding anyone in my city/state that even wants to touch the motor let alone have any prior knowledge of rebuilding it ;-( Ill still be looking as well but might consider the machine shop that did the HPF builds in Oregon and hope for the best and will also see about doing an oil baffle at the same time as I was quoted around $200 to 300 ish for that. Will probably be taking this on next summer as I myself am looking for a house, haha.

It's is forged...

[D041987]

Sorry I corrected my post above to not give false info on the crank being forged. I was under the impression from reading up that BMW used a new Aluminum alloy designed from 2013 and on to last no more than 4.5 years and/or 55,000 miles and after that it would sheer metals from the rods etc. This is not the case for F30 platform upon further research. So I stand corrected. After further document review and crank is Forged ;-)

[Stubok]

One thing to note on the crank is that it probably has the same crank hub issue that all the n55 and s55 guys are running into.

They're well above 500HP, so hopefully getting our little 4bangers up to 500HP we will avoid that problem. Otherwise I guess we will need to Key the hub the same way they have.

[Domotron]

Originally Posted by Stubok

One thing to note on the crank is that it probably has the same crank hub issue that all the n55 and s55 guys are running into.

They're well above 500HP, so hopefully getting our little 4bangers up to 500HP we will avoid that problem. Otherwise I guess we will need to Key the hub the same way they have.

i guess the question now is .. can the tranny handle 500hp

[D041987]

Yeah that's what I am concerned about with adding a heavier 6puck clutch to the 6 speed. Can the tranny withhold the power without breaking the gears. As for the AT, it will hold at 500HP No problem as it's the same one the 335i guys use and have plenty of cars in that area. For safe measure you can always have your tranny ECU flashed and or just have the valve body rebuilt to handle more power so around $800 for the rebuilt valve body. Still not bad if you run into the issue. But just the re-flash will be needed above 550 i think if you want to have a safer option as it changes the fluid pressure in the lines etc. But some run stock and have no issues as well. Just depends on your driving style I guess.

[D041987]

So just as I was going to drop a email to a shop to see if they can do an oil pan baffle I find this: http://e89.zpost.com/forums/showthread.php?t=1023546

Seems the boys already found out that we cannot get an oil baffle made in the plastic pan as it's molded around the pickup tube. So options:

1. Get a custom aluminum oil pan with baffle made
2. Get dry sump system (Not allowed in some classes of racing)

[Domotron]

Originally Posted by D041987

So just as I was going to drop a email to a shop to see if they can do an oil pan baffle I find this: http://e89.zpost.com/forums/showthread.php?t=1023546

Seems the boys already found out that we cannot get an oil baffle made in the plastic pan as it's molded around the pickup tube. So options:

1. Get a custom aluminum oil pan with baffle made
2. Get dry sump system (Not allowed in some classes of racing)

Good info ! thanks man

[nemobanks]

So how's is this build looking?

[Stubok]

Originally Posted by nemobanks

So how's is this build looking?

Mines is getting closer. Every month I buy a few more parts/gaskets/seals etc. Just splurged on a maxjax lift for May garage, so making progress. Hoping to get installed soon so I get really stuck in!

[M2_MEDUSA]

Originally Posted by Stubok

Mines is getting closer. Every month I buy a few more parts/gaskets/seals etc. Just splurged on a maxjax lift for May garage, so making progress. Hoping to get installed soon so I get really stuck in!

We're waiting patiently man

[CandyRedRC46]

No one seems to be addressing the only half counter weighted crankshaft yet. It really surprised me that BMW cheaped out here, though I suppose a fully counter weighted crank is kind of unnecessary for an engine with a 1200-5500 rpm power band. I couldn't imagine the stock crank being able to reliably spin at much over 7000 RPM or even continuously at the 7000 RPM limit.

I think that reliably raising the maximum RPMs of these motors would make it much easier to get bigger HP power numbers and allow a much more usable power band with a big turbo. Then again, I am not sure if the N20 valvetrain/oil pump/etc would be up to the task or if the head flow could keep up either.

Top pic is a fully counter-weighted crankshaft
Bottom pic is the factory n20 crank shaft