m20 cam

[MrMorda]

hello,

sorry to make another topic about a stroked m20 cam. It was easy for me to decide wich cam i wanted till the schrick 288 is n/a.
i'm in the proces of getting the parts together for an m20b29.
looking to for a cr of 11 to 1
got rhd itb in my possesion already.
car is gonna be a track day car but would like to keep the power band under 7k preferably even under 6.5k rpm.
it's not an E30 but an E34 since the platform here in europe was so much cheaper for me to go. already have en E30 325i touring with a 2.7 stroker in it.
i have searched high and low on the internet and still can't figure out wich camshaft i would take best.
hopefully some of you wizards can help me out

[daruma3gakoronda]

You could try one of the Ireland Engineering cams.

https://www.iemotorsport.com/product...shaft-m20-272/ I'm happy with my 272. You could have them make you a 288, too.

[MrMorda]

You could try one of the Ireland Engineering cams.

https://www.iemotorsport.com/product...shaft-m20-272/ I'm happy with my 272. You could have them make you a 288, too.

a 272 cam is way to mild for what i have in mind with the car, got a 284/272 in my e30 touring 2.7 stroker and it is good for a daily imo. but a 272 would be way to mild for my track toy.
thx for the respons anyway

[82eye]

a 272 cam is way to mild for what i have in mind with the car, got a 284/272 in my e30 touring 2.7 stroker and it is good for a daily imo. but a 272 would be way to mild for my track toy.
thx for the respons anyway

bimmerheads has aggressive grinds in 284 - 292

[AWDBOB]

a 272 cam is way to mild for what i have in mind with the car, got a 284/272 in my e30 touring 2.7 stroker and it is good for a daily imo. but a 272 would be way to mild for my track toy.
thx for the respons anyway

He was showing you that page link, as there is a dropdown for grind option which includes a 284/280, 292, and 304. I have used their 284/280 on a 3.1L build with good success.

Also, it's worth noting that the Schrick 288 shows in stock on several sites still, such as Bimmerworld and VAC.

Catcams also has a 291

https://5150autosport.com/products/cat-cams-camshaft-bmw-m20-b20?variant=45630575313203

[MrMorda]

He was showing you that page link, as there is a dropdown for grind option which includes a 284/280, 292, and 304. I have used their 284/280 on a 3.1L build with good success.

Also, it's worth noting that the Schrick 288 shows in stock on several sites still, such as Bimmerworld and VAC.

Catcams also has a 291

https://5150autosport.com/products/c...45630575313203

might be worth mentioning that i am living in belguim, on this side of the pond the are n/a. with the 288 i kinda knew what is was getting based on a previous m20b28 with an 288 cam. I am just afraid if i go to agressive with the cam angle i push up the powerband to high.
Catcams has several cams that are pretty close to each other. but then some have a more agressive up angle on the slope of the lobe. Or longer duration with less lift. that's where i'm getting confused.

[hasa]

Schrick or dBilas 288-304

[digger]

a 2.8/2.9 with RHD 40mm itb and schrick 272 peaks at 6300-6500rpm and makes around 210-230whp with mild port job. if for some strange reason you want a low peak hp rpm then you dont want much duration

[MrMorda]

a 2.8/2.9 with RHD 40mm itb and schrick 272 peaks at 6300-6500rpm and makes around 210-230whp with mild port job. if for some strange reason you want a low peak hp rpm then you dont want much duration

not looking for peak hp, just an overall powerband wich isn't to narrow. i kinda got a feeling with a 288 schrick it comes on just before 4k and nothing much gained past 6.5k that is my but dyno thou. was looking for something similar from a different brand. but kinda get overwhelmed with the numbers of them all. And i'm feeling limited by my own knowledge.

[hasa]

headers & exhaust has effect too how the powerband looks like

[digger]

not looking for peak hp, just an overall powerband wich isn't to narrow. i kinda got a feeling with a 288 schrick it comes on just before 4k and nothing much gained past 6.5k that is my but dyno thou. was looking for something similar from a different brand. but kinda get overwhelmed with the numbers of them all. And i'm feeling limited by my own knowledge.

i am confused, you implied in the first post that you wanted a 288 but that it was NA, but now a 288 is too narrow a powerband?

The RHD intake is going to tune in at higher rpm and behave differently to the stock manifold with the same cam. The engine will benefit more with the 288 having the RHD iitb

A smaller duration cam will make more torque below 3500rpm but is this relevant for your track car?

Also the wrong exhaust can cause a big torque loss at lower rpm even with a modest cam duration. Bigger cams also produce a narrow powerband with the stock intake manifold so dont blame the cam for a narrow powerband as is the combiation of cam, intake and exhaust as they "tune in" at different rpm depending on the parts so you need to choose them to work together so they tune in at similar rpm.

A good balanced design with nice powerband with RHD itb will be the 288 with headers ~650-750mm primary and secondaries ~1600mm, you cant really go wrong for a track car. Alternatively the ENEM Z45 naturally aspirated verson (BMW M20: Z45: 280/108/11.0/2.5) may be a happy medium between the 272 and 288 and it has tighter lobe centres which should build a bit more torque in the midrange but its not going to make the same power as a 288.

you dont want anything bigger than 288 unless you have a proper ported head

[MrMorda]

i am confused, you implied in the first post that you wanted a 288 but that it was NA, but now a 288 is too narrow a powerband?

The RHD intake is going to tune in at higher rpm and behave differently to the stock manifold with the same cam. The engine will benefit more with the 288 having the RHD iitb

A smaller duration cam will make more torque below 3500rpm but is this relevant for your track car?

Also the wrong exhaust can cause a big torque loss at lower rpm even with a modest cam duration. Bigger cams also produce a narrow powerband with the stock intake manifold so dont blame the cam for a narrow powerband as is the combiation of cam, intake and exhaust as they "tune in" at different rpm depending on the parts so you need to choose them to work together so they tune in at similar rpm.

A good balanced design with nice powerband with RHD itb will be the 288 with headers ~650-750mm primary and secondaries ~1600mm, you cant really go wrong for a track car. Alternatively the ENEM Z45 naturally aspirated verson (BMW M20: Z45: 280/108/11.0/2.5) may be a happy medium between the 272 and 288 and it has tighter lobe centres which should build a bit more torque in the midrange but its not going to make the same power as a 288.

you dont want anything bigger than 288 unless you have a proper ported head

sorry to come across so messy. not really my strong point. communication let alone writing.
what i meant was that a 288 powerband is roughly what i am after. i am just afraid of going to wild in cam that the powerband will be pushed up way to high for what i want. i know that the rhd itb set is best for high end. but i"m basicly looking for a cam that has a propper power band just up untill 7k rpm. preferably a bit lower drop off point. like with catcams they have camshafts with a roughly similar duration, but with sometimes less lift or sometimes more. and that's where im getting confused at atm
we had a m20b31 in the shop with a 3xx cam but that thing kept going even well after 7.5k. that costumer had deep pocketsm something i don't have. (we didn't build the engine, just serviced the car)

[digger]

sorry to come across so messy. not really my strong point. communication let alone writing.
what i meant was that a 288 powerband is roughly what i am after. i am just afraid of going to wild in cam that the powerband will be pushed up way to high for what i want. i know that the rhd itb set is best for high end. but i"m basicly looking for a cam that has a propper power band just up untill 7k rpm. preferably a bit lower drop off point. like with catcams they have camshafts with a roughly similar duration, but with sometimes less lift or sometimes more. and that's where im getting confused at atm
we had a m20b31 in the shop with a 3xx cam but that thing kept going even well after 7.5k. that costumer had deep pocketsm something i don't have. (we didn't build the engine, just serviced the car)

IMO you dont want a catcams in that case, they feature quite a "lazy" (gentle) ramp/flank profile that makes the engine fairly cammy as it actually has much more duration than what most people without experince would interpet from the advertised numbers.

Unforunately you can't compare catcams and schrick catalogue values as the rating system is so different it is pointless without actual valve lift measurements in the head.

The catcams advertised numbers are rated at 0.10mm lift (and 1.00mm is also provided) whereas schrick is rating at the clearance ramp thus schrick is actually much closer to the seat duration i.e. a rating of 0.00mm (not 0.1mm). What ths means is for the same seat to seat duration the schrick has much more lobe area which is better. Or looking at another way for a given lobe area the schrick achieves this with measureable less duration which is pretty much always better.

for example the schrick 288 is approx 276@0.1mm and 245@1mm.

[MrMorda]

IMO you dont want a catcams in that case, they feature quite a "lazy" (gentle) ramp/flank profile that makes the engine fairly cammy as it actually has much more duration than what most people without experince would interpet from the advertised numbers.

Unforunately you can't compare catcams and schrick catalogue values as the rating system is so different it is pointless without actual valve lift measurements in the head.

The catcams advertised numbers are rated at 0.10mm lift (and 1.00mm is also provided) whereas schrick is rating at the clearance ramp thus schrick is actually much closer to the seat duration i.e. a rating of 0.00mm (not 0.1mm). What ths means is for the same seat to seat duration the schrick has much more lobe area which is better. Or looking at another way for a given lobe area the schrick achieves this with measureable less duration which is pretty much always better.

for example the schrick 288 is approx 276@0.1mm and 245@1mm.

aha, great thx for the info. back to doing some more research.
even schrick doesn't have them in stock anymore. that's why i'm frustrated. looking for the next best thing then
thx again

[digger]

aha, great thx for the info. back to doing some more research.
even schrick doesn't have them in stock anymore. that's why i'm frustrated. looking for the next best thing then
thx again

when i looked some places still say hey have them in stock but sometimes you cant trust them

dbilas do have what appears to be a similar cam though

https://www.dbilas.com/en/Engine-Valve-train/Performance-camshafts/BMW/2-0-2-7-6-Zyl.-12V-M20/New-camshaft/1197/BMW-2-0-2-7-6-Cyl.-12V-M20/Performance-camshaft