The 15 Y/O Turbo M42 Build Thread (Now Holley EFI Terminator X Controlled)

[2mAn]

Dang, thats a legit number! Nice... Would love to see the graph

[ccsdo5]

Hell yeah! still one of my favorite cars to this day looks and engine. Glad to see a 3 as the starting number haha!

[Dj Buttchug]

[Dj Buttchug]

Turned out well overall. I was very conservative on the redline just to be easier on my engine. There is more hp there if I add some more boost and pull a little more time. It was also a bit warmer, so on cooler days I anticipate a little better numbers. As of now I am content with the results and will likely leave it alone. The car is a blast to drive and I am still using a G240 trans. Reliability has always been a big concern so I think leaving the engine as it sits now is a good balance between power output and longevity. Yes the internals can take more. In my mind its not really worth it. The car rips as it is. We did do a final 4th gear pull and I managed to munch a spark plug. Melted a strap and blew the insulator off the electrode. Misfire started at around 4k on cylinder three. Here is the result.


Swapped out the whole set of plugs and luckily things are ok. I was worried the pieces of insulator could have damaged my engine but after a borescope was done no damage was found. Butt pucker scenario for sure.

Now time to focus on the M50 engine for my E34. If anyone has questions about Holley EFI or the process in doing this let me know. For now its time to put some miles on the car and enjoy it.

[econti]

Greasy torque curve. How many pisseye?

[Dj Buttchug]

Greasy torque curve. How many pisseye?

17.4 pisseyes

[Northern]

I would've shit a brick at the sight of that plug

[econti]

17.4 pisseyes

Barely even breathing. Nice result

[zwill23]

I really think 300whp is the perfect amount for this chassis, with the right setup everything is well balanced and it's not a burnout machine. I've opted to not push the pisseyes as well and I think it's the only reason the engine is still together 30k miles later. M20 but same philosophy.

[Dj Buttchug]

Do you see it.

[econti]

Shit go. What from?

[Dj Buttchug]

Shit go. What from?

A while back I dyno tuned the engine and cylinder 3 spark plug failed at about 5k rpm under 15psi. The insulator broke off inside the combustion chamber. The gouges in the cylinder head outer area are the result of that. I was unable to see this when I borescoped the cylinder. I cannot confirm this same event caused the cylinder head to crack but it is possible.

My #3 piston is also a bit beat up.


New OEM old stock m42 cylinder head from Germany via Turner Motorsport. $2,900.00
New CP piston set at a discounted rate due to the sales rep feeling bad for my situation $800 shipped.
85mm ball hone to revive the cross hatching in all cylinders after 10 years of incorrect overfueling/megasquirt love and care $116

Expensive Lesson.
Only use REAL (not fake chinese copies) NGK spark plugs. Failed plugs were DENSO brand. The only real surprising thing here was the cylinder HG and cracked head has lasted almost 2500 miles of everyday driving until it finally gave up resulting in a constant misfire on #3 due to coolant intrusion and cylinder head crack between valves.



The 318 is gonna be down for about a month or so until the parts arrive.


Fun right?

[econti]

I would doubt the crack is from that. I think most likely from high exhaust temps, or over tightened head studs but I wouldn't expect that mistake.
Could also just be one of those things on an old motor, maybe it was overheated before your time.
Such is the game for more than doubling the power out of old engines. Doesn't make it any cheaper however.

[Northern]

I think the same crack issue happens on the 24v stuff. Not common but not super rare. Seems mostly random

[2mAn]

No luck on the WTB here? Bummer...