M20 B3x Naturally Aspirated Stroker build past, present and future

[skitzy777]

thats a pretty aggressive cam (lots of overlap) for a daily driver, especially if the ITB arent until down the road. with standard manifold thats going to idle like a pushrod drag car. what valve springs and rockers are you planning on using?

http://www.catcams.com/products/camshafts/datasheet.aspx?ENGINE_id=111&CAMSETUP_id=269

i contemplated using it with mine but thought id start quite mild to begin with but the pistons will be designed with a big overlap cam similar to this

Oh, yeah I thought it would have been to much of an aggressive cam for daily use, but I wanted the highest compression motor I could use on aus 98 octane.

I would be using the catcams springs they provide, and either the MM inspected rockers or IE.

What piston manufacturer are you going with? I might just end up doing the same compression and piston design as you as well as the same camshaft but instead using a different crank. I’m still not sure yet I feel planning is essential.

Where are you sourcing your crankshaft from?

[digger]

Is the 11.5CR pistons the highest compression you could go coupled with the 292 cams?

I've been in thought putting the pieces together for a 3L stroker (s50 86mm crank, s50 135mm rods, catcams 1300530 camshaft, CP 85mm 12:1 pistons, supporting valvetrain mods, ITB's down the road)

Not sure if the cams ive selected would be too big for my car being a daily.

Your build is coming along nice though. Cant wait to see how it turns out

thats a pretty aggressive cam (lots of overlap) for a daily driver, especially if the ITB arent until down the road. with standard manifold thats going to idle like a pushrod drag car. what valve springs and rockers are you planning on using?

http://www.catcams.com/products/camshafts/datasheet.aspx?ENGINE_id=111&CAMSETUP_id=269

i contemplated using it with mine but thought id start quite mild to begin with but the pistons will be designed with a big overlap cam similar to this

[digger]

I have schrick 288 degrees in the car.

Do you guys have E85 fuel accessible down under? We have it on basically every fuel station, so im running E85.

There are a few places, I did think about running flex fuel but seems like more hassle than it's worth.

[digger]

It's a street engine so I'm not looking to push it too high as it gets quite hot here in Summer and a heat soaked engine is significantly more prone to knock . It's diminishing returns with compression anyway doesn't make much sense to be on the ragged edge. I might even go a bit lower than 11.5

[lindskrot]

thanks

what cam are you going to be running?

I have schrick 288 degrees in the car.

Do you guys have E85 fuel accessible down under? We have it on basically every fuel station, so im running E85.

[skitzy777]

I'll be ordering some custom Pistons shortly around 11.5:1 CR

Cam will be the RHD roller cam. 292 advertised duration 110 LSA 13mm lift

Is the 11.5CR pistons the highest compression you could go coupled with the 292 cams?

I've been in thought putting the pieces together for a 3L stroker (s50 86mm crank, s50 135mm rods, catcams 1300530 camshaft, CP 85mm 12:1 pistons, supporting valvetrain mods, ITB's down the road)

Not sure if the cams ive selected would be too big for my car being a daily.

Your build is coming along nice though. Cant wait to see how it turns out

[digger]

The stroke is 93.80mm and bore is 86.00mm so its 3,269 cc (199 CI)

[2mAn]

I'll be ordering some custom Pistons shortly around 11.5:1 CR

Cam will be the RHD roller cam. 292 advertised duration 110 LSA 13mm lift

You're using a S52 crank (89.6mm Stroke) , correct ?

If thats true, what Bore is the 11.5:1 piston? Are you running thin on the cylinder walls yet?

[digger]

I'll be ordering some custom Pistons shortly around 11.5:1 CR

Cam will be the RHD roller cam. 292 advertised duration 110 LSA 13mm lift

[skitzy777]

What pistons/cam combo are you using for the b33

[digger]

thanks

what cam are you going to be running?

[lindskrot]

Impressive

Just looked through your build.
Deeply impressed with all your knowledge. And perfect for me to study.

I have a 1987 325is with m20b30 running E85 and RHD itb’s.

Bought it with the engine built, but the former owner was not able to finish it.
Working with the tune, fuel delivery and installing vacuum system and proper air box intake.


I will study this thread closely.

Unfortunately I live slightly farther away from Rama than you, since I am located in Sweden.
Possibly the only e30 running RHD itb in the country.

Keep up the amazing work!

[Bimmer_man]

Epic. Good to know thanks

[digger]

fits no problem, just need a modified intermediate shaft. im getting a custom one as the stock one gets weak when you machine too much off the depth so not looking to risk it

[Bimmer_man]

I’m still dying to see if the 3.3 crank will fit in the m20.