M20 Stroker Build: Take 2

[digger]

printout a cam degree on paper or cardboard and photocopy with rescale function to the szie to suit the cam gear an attach with double sidetape or temporary glue. then use a dial indicator on the retainer measure the following (ensure lash is correct). will likely need to remove upper timing cover which is a pita. You can also count cam teeth and kind of interpolate with a nice steel rule. IIRC each cam tooth (8mm) is like 15 crank degrees equivalent

0 open and close
0.1mm open and close
1.0mm open and close

record the degrees for the open and close at each increment and apply the correct transfer function (likely just an offset and x2 or x0.5 mulitplier) to get the printed cam degree to give crank degrees

can also tighten up lash a bit afterwards to test how the engine behaves.

[Nader393]

Maybe just get calipers and measure the cam lobe lift vs. base circle. That quick and dirty measurement with the valve cover off would be your first clue if the cam is stock or not, without removing the cam for further inspection.

[Lugnuts]

Maybe just get calipers and measure the cam lobe lift vs. base circle. That quick and dirty measurement with the valve cover off would be your first clue if the cam is stock or not, without removing the cam for further inspection.

Yeah, I'm going to also do that when I measure the duration using Digger's procedure.

Useful degree wheel website:

https://www.blocklayer.com/degree-wheel.aspx

Turning over the engine with all the coolant pipes installed is going to be...a challenge.

Concocting a plan to video call my dial gauge using my phone, from my laptop while lying under the car ...

Edit: on second thought, poking a hole in the middle of the degree wheel and turning the engine over using the cam bolt (spark plugs removed), would be easier. Only concern is chewing up that bloody Torx bolt turning over the engine 50+ times. Might be fine. Think I'll temporarily swap for either a meaty hex head or a socket cap...

[Lugnuts]

Finding ferrous surfaces to mount a magnetic base on can cause you to fill a swear jar...

Managed to slip a cardboard timing wheel inside the hole of the front cover (120mm in diameter), mounted to the gear with 3 double-sided 9mm velcro pads. 17mm hole in the middle, and a large flanged hex head bolt to replace the stock Torx. Worked well.

The lifting hook on the front is steel, which helped measure #1 In + Ex. The stock exhaust manifold also provides something to work with. No 6 intake was a balancing act. Unfortunately the intake manifold makes it impossible to measure 2-5 intake. I didn't fancy going to the effort of removing it.

It's also damn near impossible to measure the cam lobes with all the rockers/retainers/shafts installed. My attempts with a depth gauge on the tiny end of a lobe were unreliable.

Here's what I was able to measure, eyeballing the timing numbers using a handy casting "nub" on the inside of the upper cover as my reference point.

Lash was set to 0.007"/0.1778mm for all valves:

Valve    0-0                0.1-0.1            1-1              
#1 In.   315-101 (146)      319-94 (135)       330-80 (110)  
#1 Ex.                                         221-328 (107)
#2 Ex.   83-227 (144)       87-221 (134)       100-209 (109)  
#3 Ex.   328-105 (137)      326-100 (134)      339-88 (109)  
#4 Ex.                                         160-268 (108)  
#6 In.   132-278 (146)      138-271 (133)      150-260 (110)

Fairly consistent, give or take a bit.

Looking at Digger's M20 camshaft profiles, I can't arrive at a definitive conclusion. The 1-1mm durations seem a tad on the short side, but the total duration seems in the right ballpark?

Are IE/Schrick cam durations from 0-0 lift?

[digger]

i dont think it is a stock cam but it is certainly very mild based on the 1mm numbers

A schrick 284/272 is around 236/230 at 1mm

schrick advertised durations are based on the end of the ramp which is fairly meaningless as we dont know how high the ramp is but id estimate it would be somewhere between 0 and 0.1mm (i.e a ramp of 0.25 to 0.35mm based on specified lash being 0.25mm)

[Lugnuts]

Alright. Seems the evidence is hinting that my engine would benefit from moar cam.

SkiFree stated he built the Mahle stroker pistons around a 284/280, something I only recently discovered:

https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/m20/373131-pistons-for-m20-stroker?p=6873564#post6873564

Considering the dbilas 284/284, barring any comment against, or recommendation for a better suited alternative.

https://dbilas-shop.com/en/engine-valve-train/performance-camshafts/bmw/2-0-2-7-6-zyl.-12v-m20/new-camshaft/1196/bmw-2-0-2-7-6-cyl.-12v-m20/performance-camshaft?c=12007

Picked up my spare 885 from the shop on Friday. Clean and flat and awaiting a new cam.

Head swap incoming :D

[digger]

Dbilas 284 looks ok on paper, 284/272 Schrick is a commonly used cam. I would ask IE/BH for a cam card of 284 and 284/280 new billet cams

what are the longer term plans, e.g. any plans for itb or other mods ?

[Lugnuts]

what are the longer term plans, e.g. any plans for itb or other mods ?

I may revisit RHDs ITB kit. Currently sat in a box in the garage. Ran out of time during my first install attempt. A combination of product issues (that Rama was prompt to address) and a noisy TPS when I finally got it all balanced meant I shelved the idea. My E30 isn't a DD, but from memory the car had been off the road for 4 weeks. The noisy TPS was almost certainly a grounding issue with either the TPS or my Megasquirt. I have a P&G TPS somewhere that I was going to try...

On the other side, I've had these sat on a different shelf for a couple years now:



I know you've done a fair bit of testing wrt different exhaust configurations and their respective performance gains/losses. I'm interested to hear your thoughts! :)

[digger]

if you will realistically implement ITB at some point then a schrick 288 would be worth considering as it will better match the ITB kit.

what headers are those? there are not many options for RHD vehicles

[Lugnuts]

Dug out the email. I bought them in 2016. Sold on ebay by "ems-europeanmotorsports" in Wiley Park NSW. Advertised as "direct copies from a genuine set of hartge H23/H26 headers". Seemed like a better quality alternative to some of the dodgy "ebay headers" available at the time.

The original ebay ad is NLA. Found a link with the details:

Brand New Bmw RHD E30 M20 320i 323i 325i 325is Hartge Alpina Extractors Headers. BMW E30 M20 extractors/headers, these are direct copies from a genuine set of hartge H23/H26 headers. They're made from highest quality steel and are sold with 12 months warranty, ceramic coating also available, ports are matched to standard 731/885 head. Piping from flange to collector is 1.5inch and 2 in from collector. No fabrication to extractors needed, direct factory fit RIGHT HAND DRIVE, beware of poor quality copies. Please call Warren on 0420 206 206 for more info. We also supply headers for most M30 vehicles (E28/E24) We can source most parts, email us today with an enquiry Condition: Brand New, Returns Accepted: ReturnsNotAccepted, Modified Item: No, Custom Bundle: No,

[digger]

Dug out the email. I bought them in 2016. Sold on ebay by "ems-europeanmotorsports" in Wiley Park NSW. Advertised as "direct copies from a genuine set of hartge H23/H26 headers". Seemed like a better quality alternative to some of the dodgy "ebay headers" available at the time.

The original ebay ad is NLA. Found a link with the details:

I remember seeing them on eBay. Can’t be worse than factory iron stuff unless they don’t fit

[Lugnuts]

Cleaned the head today and installed the dbilas 284/284. I wanted to make enough progress to measure the duration numbers, for comparison.



Actually bothering to check this time...



Discovered the end plugs on the Genuine BMW rocker shafts thread in far enough to really recess the plug. When tightened all the way in (like in the picture), the inside face of the plug sits flush with the side of the oil feed hole(s).

I haven't made a decision on which way to install the plugs - tighten them down like in the picture, or back them out so they're flush with the end of the shaft. In both cases I'll likely need to use a thread locker/sealant. Unsure which yet..




I can see how having the plugs all the way in would prevent a static "pool" of oil from sitting in end of the shafts:



On a related note, check your shafts for debris! Couple of the holes had some nice shards of metal hanging off them from manufacturing.

Bought a couple of checking springs to make measurements easier.



The numbers (a helluva lot easier with the head out of the car!):

#1 base circle: 28.222mm
#1 lobe: 35.326mm
#1 valve lift: 11.5mm

Durations:

Valve    0-0                0.1-0.1            1-1              
#1 In.   157-317 (160)      163-307 (144)      174-294 (120)

Happy with that!

[digger]

That seems about as expected. Will be interested to see how much timing will be acceptable and impact on the power curve. Will you be doing the exhaust at the same time?

[Lugnuts]

Will be interested to see how much timing will be acceptable and impact on the power curve.

You and me both. I'm looking forward to finally seeing the back of this knock issue.

Head probably won't be installed for a couple weeks. Dyno will follow very shortly after!

Will you be doing the exhaust at the same time?

I'd certainly like to. Only hurdle is getting a handle on what to install.

Based on your comments from 2014, it sounds like some careful considerations need to be factored in - eg, cross pipe location.

Right now all I have is the stock exhaust manifold, a couple of offset hi-flow cats and a Remus cat-back. I stupidly installed the hi-flow cats with very little forethought (something I've become quite adept at... )

And of course those Hartge H23/H26 headers sitting on the shelf. Assuming they're not a terrible option, I'll be most likely using them as the basis for whatever gets installed.

Need to spend some time documenting a plan for the exhaust...suggestions welcome.

[digger]

You and me both. I'm looking forward to finally seeing the back of this knock issue.

Head probably won't be installed for a couple weeks. Dyno will follow very shortly after!



I'd certainly like to. Only hurdle is getting a handle on what to install.

Based on your comments from 2014, it sounds like some careful considerations need to be factored in - eg, cross pipe location.

Right now all I have is the stock exhaust manifold, a couple of offset hi-flow cats and a Remus cat-back. I stupidly installed the hi-flow cats with very little forethought (something I've become quite adept at... )

And of course those Hartge H23/H26 headers sitting on the shelf. Assuming they're not a terrible option, I'll be most likely using them as the basis for whatever gets installed.

Need to spend some time documenting a plan for the exhaust...suggestions welcome.

6-2-x-twin pipe or if your muffler is a single 6-2-y-single

twin 2" is fine, single 2.5" is also fine

X or Y around the fuel tank area if you want to boost torque in the 2000-3000 rpm range otherwise just behind gearbox

generic metal cats

a small muffler as resonator works better than hot dogs

muffler with biggest volume that fits