Albi Blue 200 >> BMW E46 Track Car

[tombate911]

Sent the spare block off for machining, same company that did the last one, with the mind set of copying exactly the same progress and engine I built last time

I also bought a donor M54B30 as I was a few parts missing to build a full engine. I had a look through the spare parts shelf... Choice of heads...

Looked into the costs to repair the CNC head, safe to say they're out of my budget now, also looked into getting one of my heads CNC'd but again the costs didn't seam to be worth the gains.
I started making some templates and taking lots of measurements around the ports and looking at the port shape. Much easier when you have a standard head the ported head side by side

Stripped the valves out of the spare head

Spent a few evenings going at the head, constantly referring back to the damaged one.

Finished exhaust ports

Finished inlet ports

Fresh head and valves lapped in

Checked the rings in the bores, same as last time, right at the top of the BMW recommendations but right in the middle of Mahle recommendations.

Bearing clearances checked for the mains and big ends, will notice I have also drilled and tapped the block for the additional tensioner for the oil pump.

Stripped and rebuilt the Hopwood Motorsport oil pump, pulled out the pressure relief valve as it was little bit noisy on the previous engine, gave it all a good clean and reassembled

ARP Head studs

Freshly painted block in bright silver. It's nice to start fresh anyway.

Schrick 272/256 camshafts refitted

Noticed that the helical gears have slipped at some point, probably during the contact when the engine failed, I have reset these using the steel ruler at 12 o'clock technique.

Final timing up, decided to retard the inlet cam by 2 degrees just to create a little more clearance between the valve and piston at max inlet cam advance

14th September, the engine went back into the engine bay. Only 2 months after it all went wrong... So much for a winter rebuild.

Following my original comment earlier, keeping with the same process I did back in 2021, opted to run in the engine on proper running in oil while on the dyno, shame it only gets used for an hour or two but it worked last time.

Engine bay all boxed up ready for starting...

 

[Helpimonfire]

Always love reading your updates Tom. It was a massive shame when the engine let go at Cadwell, you and Foxy were absolutely flying!

I've been following the build on Insta (as most of us probably do now), I knew the moment you pulled this engine that we'd see it rebuilt before Christmas

 

[tombate911]

Final update to bring the thread up to current.
Had the car back to the dyno once again, spent 40-50 minutes running the engine in with progressive increase of revs and load on the engine, trying to create cylinder pressure as well as vacuum on overrun to bed the rings in with the bores and checked over the logs and the engine. Everything so far was looking pretty good with the exception of the calibration of the coolant temp sensor.

Finished with 4/5 power runs, few changes to the VE table but not a lot of difference from the previous engine. Few points to note, Torque the same through the mid range, I had brought the rev limiter down slightly for the dyno runs so it starts to cut cylinders at 6900 to a 7100 limit, I tend to run it slightly higher on track so I don't actually use the limiter on circuit, looking at the shape of the power curve how it continues to make power at the start of the limiter I wish I'd left it at 7200 just to see what it looked light beyond 7k to see if it maintained the power, the previous engine didn't with the other head it ran into a little bit of resonance at 6900 and the power dropped off. Picked up 5bhp peak at the higher RPM's so happy with that! Turns out the hand porting was as good if not better than the CNC for my application anyway, my set up obviously not being optimal cams and ITBS for the CNC porting, but it was nice to have.
Really happy with how it's all turned out so far, but this is only the start.

Dyno graph from one of the runs, there's a few other runs with slightly more torque mid range up to 255ftlbs but you get the idea.

Oulton Park booked for the 21st November for a test, looking forward to getting behind the wheel again hopefully before the end of the year.