Emma Watson and 2 E34's (Low Mount Turbo M50 Project)

[Dj Buttchug]

Update.


Severe engine misfire at idle...



There is coolant in cylinder 6....



Just let me die.

[Northern]

fingers crossed it's just head gasket...

[zwill23]

God damn it. Is this after street testing it or a second dyno session? The heat management is great, but man there has to be something majorly off with the tune settings. Maybe the motors timing is mechanically off? Not sure if it's easy to skip a tooth installing the timing chain on these motors...

Sorry dude, hopefully the head gasket was just your fuse like Northern said :(

[AWDBOB]

cars are pain

[moatilliatta]

I think a lot of tuners who do tune modern stuff don’t have enough fans for older cars. New stuff has 50a+ circuits for beefy fans that move a ton of air.

Duct work is just as important as cooling capacity, making sure the air doesn’t take the path of least resistance around the radiator cooling pack.

How big is your exhaust mid pipe?

Did the dyno log any pulls?

[Dj Buttchug]

We are fcked boys.


However


I am DJ Buttchug and I will not be defeated.

[Dj Buttchug]

Plugs from left to right cyl 6 on the left.




HG failure could be my fault. Improper install possibly causing this damage, not sure. No signs of detonation. No new visit to dyno. This happened under street driving, easy cruising no more than 9-10 PSI. Could also be caused by the previous over heating issue during the first dyno visit.




Warm compression test showed lower than expected. Four of the six holes had 120psi. Not good. Cylinder walls are pretty tired. I probably should have paid more attention. Bottom end does have 245k on it. Discoloration spots and the overall mirror finish on the cylinders (cross hatching is barely visible) leads me to believe the only way to do this is to continue further and build a short block.




Plan as of now:

Alien Engineering forged pistons 9.5:1 comp 84.5 MM overbore new rings, heavy duty wrist pins, the whole kit
Stock M50 Rods balanced
Stock M50 Crank balanced
ARP Mains
ARP Connecting rods
All new bearings
(possibly AMC high performance head with upgraded valve springs and hardware)

Total estimated additional cost +/- $4500

I suspect the block is not straight which could also have played a part in the failure. Obviously this will be addressed during the build.

What a shit show.



Let me know what you guys think.


I am also considering adding a ProMeth Direct Port injection kit. Idea would be to port each cylinder runners in the intake manifold and use an AEM meth pump and controller to manage the system. With these additional mods I think the engine could reliably support 450-500 hp BUT the turbo I have would be further than maxed out. I am hesitant to install a larger turbo due to fitment restrictions. I also do not really want to build a new exhaust.

Lots more thinking to do. I estimate this will keep the car down for the next 2-3 months.

[zwill23]

You say no sign of detonation, but that head gasket ring looks like its seen detonation. The ring looks pinged out to me in a few different places. Coming from someone who has played head gasket turbo games, I think you're jumping the gun on a rebuild. Those cylinder walls really don't look bad, they actually look pretty good from the photos.

Imo, I would hit the block and head with a straight edge and check for warpage, deck the head if needed and slap a new head gasket on it. With the overheating you experienced my money is that the head is warped a bit, but I bet the block is fine and perfectly straight. It is quite difficult to warp an iron block. Build an engine on the side if you want, but I'm sure this engine has life left in it to at least hone your turbo setup in and it's only a head gasket away from running again.

[varg]

That sucks, could be worse. The bores don't look that bad, just the usual old engine stuff. The fire ring looks pretty undamaged to me, it strikes me as the result of an overheat. Usually when you blow a head gasket with detonation it blows the fire ring out and/or takes chunks out of it. If you're going to do a fresh build, maybe do a 2.8? I decided against ARP mains for my build with higher power goals than yours. In the end what you spend on the line honing and ARP mains is money best spent elsewhere, like the head, if you want to rev higher. IMO, your intercooler will be a restriction before your turbo.

[Dj Buttchug]

You say no sign of detonation, but that head gasket ring looks like its seen detonation. The ring looks pinged out to me in a few different places. Coming from someone who has played head gasket turbo games, I think you're jumping the gun on a rebuild. Those cylinder walls really don't look bad, they actually look pretty good from the photos.

Maybe I overlooked something. Where exactly are you seeing this? The cylinder head I installed was decked. I don't have a real straight edge but I am leaning toward the block is not exactly straight or my block prep was not sufficient.


I pulled the engine over the weekend and found two broken timing guide parts in the lower front case. Not the worst thing to find this I suppose. As of now I am sticking with the plan of a good refresh while trying to keep the additional costs down where I can afford too. I'm not after a massive amount of power. varg I think so as well. I could use that money to get some lighter valves and springs ect.

As things progress Ill see how we end up. I am still searching for a reputable machine shop to handle this work. Very limited options here in So. UT. Looking at Vegas/SLC for an engine builder. The builder who did my M42 short block is no longer in the game...

[moatilliatta]

A good Go / NoGo curve ball question is to ask machines shops for their profilometer readings.

[Dj Buttchug]

A good Go / NoGo curve ball question is to ask machines shops for their profilometer readings.

I would assume asking such a question could rule out shops that dont deal in such precision?

[moatilliatta]

Yeah, may rule out 95% of them though. Which could be ok.

[Dj Buttchug]

Yeah, may rule out 95% of them though. Which could be ok.

Seriously doubting the chances of any shop having such tooling to measure surface roughness in this area. Most of the machine work around here is heavy haul and diesel engine related. Not to say they couldn't handle it but it is definitely not an engine they are familiar with or see everyday...

[Northern]

In the end what you spend on the line honing and ARP mains is money best spent elsewhere

100% this. Ask Perry when you buy those pistons and he'll say the same thing.

I'd also be very tempted to find another stock 2.8 bottom end and basically leave it stock other than, slapping on an oil pump tensioner, secure the nut, replace chains/crank sprocket/guides/tensioners, swap your NV rods on and check bearings/gap rings while you're there.