[Phyrexia]

Originally Posted by bbnks2

99% chance your spun the rod bearings and seized the motor.

welcome to the party, try reading the rest of the thread (this is not what happened)

[hassmaschine]

lol - spun bearings are from oil pressure issues, not an over-rev.

I was thinking today how little damage was done at 9000+rpm. Would still be cool to pull the actual max RPM counter from the DME.

[bbnks2]

Originally Posted by Phyrexia

welcome to the party, try reading the rest of the thread (this is not what happened)

Yeah for some reason I only saw 1 page. I see he somehow managed to have an engine that wouldn't turn over but nothing wrong with it? Just valves that kissed the pistons? Did it jump timing to not start?

I don't see anywhere where he addressed the bottom end but I wouldn't slap it back together without tearing it all the way down and replacing bolts and bearings.

[bbnks2]

Originally Posted by hassmaschine

lol - spun bearings are from oil pressure issues, not an over-rev.

I was thinking today how little damage was done at 9000+rpm. Would still be cool to pull the actual max RPM counter from the DME.

That's crazy for sure. I was expecting carnage lol The abrupt loading of the crank can absolutely stretch bolts and scuff bearings.

FIY to OP: the repair instructions for the entire car can be found on NewTIS.info

Also, poly filled engine mounts make a massive difference. Stock mounts, just like everything else in the car, have tons of deflection. Why do you think think people have so much issue getting locked out of gears in turns? The engine and trans are flopping all over the place under load.

Remove your transmission bushings and you can displace the engine several inches by hand.

[Joebie]

Originally Posted by PORTMOODY

bravo. bravo.

Did you see the method with the string that I believe hassmachine made videos about? The tension gets removed completely if I'm not mistaken. If you are just renting the tool for minimal cost then thats really the best bet.

I did see that method and i like that method better than the washer method, but Marty is letting me rent his tool for cheap so its worth it for me to just do it the right way with the right tool.

Originally Posted by hassmaschine

The tool would be easier. I'm not sure how well the string method would work on a stand, I'd be worried about pulling the engine over on top of me. Maybe if you have a 4-wheel stand (mine is only 3) or you have a buddy to help you hold it down. you can't break anything really using the string method though (unlike the washers).

Yeah I've got the 3 wheel $40 harbor freight stand lmao

Originally Posted by bbnks2

Motor didn't end up being seized? You just bent valves? That's lucky but I would guess you have bottom end damage as well... Not just valve damage. I'd at least put new rod bolts in.

I've not confirmed what exactly broke, my suspicion is bent exhaust valves and maybe jumped/lost timing. Bottom end looked fine but 9000+ rpm is when I start to question if the rods, bolts, and bearings are all okay. Even with the head off and the pistons out the crank was actually kind of hard to turn so there might have been damaged bearings there but I've not confirmed any of that. I might bring some of my valves into work and indicate them on the lathe but idk if I even care enough to do that.

Remember momentum is m*v SQUARED so a piston at 9500rpm has almost double the momentum that a piston at 7000rpm has (85% more to be exact.)

That's half the reason I opted for a whole new engine. I might have been able to repair mine but when stuff spins that fast I no longer trust any of it to be sound for the long run.

Didn't BPC throw a rod on their N52 at like 8500rpm or something?

[Joebie]

Originally Posted by bbnks2

That's crazy for sure. I was expecting carnage lol The abrupt loading of the crank can absolutely stretch bolts and scuff bearings.

I was actually really surprised after it happened that there wasn't a hole in the side of the block and oil everywhere!

[bbnks2]

Originally Posted by Joester

Remember momentum is m*v SQUARED so a piston at 9500rpm has almost double the momentum that a piston at 7000rpm has (85% more to be exact.)

That's half the reason I opted for a whole new engine. I might have been able to repair mine but when stuff spins that fast I no longer trust any of it to be sound for the long run.

Didn't BPC throw a rod on their N52 at like 8500rpm or something?

Yeah if it was a commuter car then go ahead slap it back together or trade it in lol. For somethign you want to hoon around in? I'd be skeptical of everything.

It's not just being spun to 9000 rpm that's the issue... I think it's more the abrupt load change (no rev-match) that makes a mechanical over-rev so much worse than just an increase rev limit. You can literally stretch the rods.

Pretty cool seeing people start to rebuilt these engines though. I just rebuilt my N55 and they really aren't all that scary like everyone like to say. You don't actually need THAT MANY special tools. Every modern engine has special timing and cam tools so that's a given ($125 on amazon). N5x does require the bed-plate sealant injector (just a $5 needle) and the intake valve spring removal tool. You can actually even get the valvetronic springs off fairly easy with many backyard mechanic methods just don't let one loose and take your eye out lol.

[Joebie]

Originally Posted by bbnks2

Yeah if it was a commuter car then go ahead slap it back together or trade it in lol. For somethign you want to hoon around in? I'd be skeptical of everything.

It's not just being spun to 9000 rpm that's the issue... I think it's more the abrupt load change (no rev-match) that makes a mechanical over-rev so much worse than just an increase rev limit.

Pretty cool seeing people start to rebuilt these engines though. I just rebuilt my N55 and they really aren't all that scary like everyone like to say. You don't actually need THAT MANY special tools. Every modern engine has special timing and cam tools so that's a given ($125). N5x does require the bed-plate sealant injector (just a $5 needle) and the intake valve spring removal tool. You can actually get the valvetronic springs off fairly easy with many backyard mechanic methods just don't let one loose and take your eye out lol.

The valve springs come out just fine with the socket and hammer whack-a-mole method, its getting them back in thats the problem!!

And I had no clue about the bedplate sealant that was really cool to see as i took apart the motor. Lemme see if I have any pics.

EDIT: I do have a pic! Check out the sealant stuff BMW uses between the bed plate and the crankcase! You can see the little trace of it around the edges of the motor here and you can even see the little ports on the left and right through which it is injected.

[bbnks2]

Originally Posted by Joester

The valve springs come out just fine with the socket and hammer whack-a-mole method, its getting them back in thats the problem!!

And I had no clue about the bedplate sealant that was really cool to see as i took apart the motor. Lemme see if I have any pics.

Let me tell you... that stuff is a PAIN the inject back into the block.

[hassmaschine]

Originally Posted by bbnks2

Let me tell you... that stuff is a PAIN the inject back into the block.

I'd be interested in hearing your experience with that. Did you use the special injection tool? I've heard about people just using RTV, but that seems like a horrible idea. I've had an N52 on the stand for a couple years now but haven't totally dug into the bottom end because I'm not sure about putting it back together yet.

I think the BPC N52 blew up due to boost, not RPM (pretty sure a rod snapped). the 8500rpm dyno was when it was N/A. IIRC the valves started to float but nothing bad happened. I think an 8k redline with that VAC damper would be pretty safe.

[Efthreeoh]

Originally Posted by Joester

I did see that method and i like that method better than the washer method, but Marty is letting me rent his tool for cheap so its worth it for me to just do it the right way with the right tool.



Yeah I've got the 3 wheel $40 harbor freight stand lmao



I've not confirmed what exactly broke, my suspicion is bent exhaust valves and maybe jumped/lost timing. Bottom end looked fine but 9000+ rpm is when I start to question if the rods, bolts, and bearings are all okay. Even with the head off and the pistons out the crank was actually kind of hard to turn so there might have been damaged bearings there but I've not confirmed any of that. I might bring some of my valves into work and indicate them on the lathe but idk if I even care enough to do that.

Remember momentum is m*v SQUARED so a piston at 9500rpm has almost double the momentum that a piston at 7000rpm has (85% more to be exact.)

That's half the reason I opted for a whole new engine. I might have been able to repair mine but when stuff spins that fast I no longer trust any of it to be sound for the long run.

Didn't BPC throw a rod on their N52 at like 8500rpm or something?

I wonder how straight the crank still is. The rate of acceleration change of the pistions would be damaging for sure.

[bbnks2]

Originally Posted by hassmaschine

I'd be interested in hearing your experience with that. Did you use the special injection tool? I've heard about people just using RTV, but that seems like a horrible idea. I've had an N52 on the stand for a couple years now but haven't totally dug into the bottom end because I'm not sure about putting it back together yet.

I think the BPC N52 blew up due to boost, not RPM (pretty sure a rod snapped). the 8500rpm dyno was when it was N/A. IIRC the valves started to float but nothing bad happened. I think an 8k redline with that VAC damper would be pretty safe.

I thought the "needle" was the right tool. TIS is vague on the procedure. Turns out that is only for the little grooves in the front and rear crank seal. TIS seems to show a needle but it is NOT the thin one everyone sells.



So, I took the needle (blue thing below) off the dispensing tool and pushed the tube of sealant itself right up against the injection fitting. All I used was the little orange fitting (orange screw on fitting seen below):

I used my body weight to create a tight enough seal between the tube and the pressure valve in the block. You then have to build up pressure in the sealant tube with the tool. It takes several minutes of turning the dial, waiting for the fluid to displace air in the block, and the turning the dial more to build pressure again. All of this had to be done without allowing the seal to break between the tube and the valve. Pressure has to be kept up enough to force the valve open and push the sealant into the block. It takes a long time before you it starts oozing out of the front and rear seals. Of course, this didn't happen at the same time so I had to have a helper put their finger over the rear seal hole until fluid came out of the front too. I needed two tubes to get the job done. I did waste some though.

I could not figure out any other way to do it. I did not think it was going to work but it did. Apparently this type of sealant tube is made by a company that sells other fittings that can be used with compressed air. That might be the way to go. Maybe even try injecting the sealant without the pressure valves in place. There are plenty of shops out there doing rebuilds. Someone knows of a better way that's for sure!

[nsjames]

certainly the factory has a powered tool that shoots it in there very quickly.

Volvo specs a similar sealant to seal up the midblock and the lower block in the 2.5L motors. It doesn't get injected. Just put on in a thin and consistent layer with a foam roller.
So I wonder if you couldn't just do the same with the bmw stuff. I'm sure the injected bit is for factory ease.

[bbnks2]

Originally Posted by nsjames

certainly the factory has a powered tool that shoots it in there very quickly.

Volvo specs a similar sealant to seal up the midblock and the lower block in the 2.5L motors. It doesn't get injected. Just put on in a thin and consistent layer with a foam roller.
So I wonder if you couldn't just do the same with the bmw stuff. I'm sure the injected bit is for factory ease.

People have tried sealants like that and it usually always leaks pretty quick. More examples on the M forums than here.

The correct procedure is to inject the sealer using tool 114370. It's the needle tip that seemed to be the issue for me.

[Joebie]

I got a few gaskets and parts Friday

I got my 3 stage intake manifold here today.

Engine and clutch should be here tomorrow. Taking a trailer to work tomorrow cause I had them ship the engine to my work instead of home (i probably wouldnt have been home to receive it)

MILVs and more various bolts and gaskets will be here thursday.

It's all coming together!

Does anyone know if the flywheel has to be clocked a certain way relative to the crank? Is it poke yoke with the bolt pattern not being symmetrical or do I have to really pay attention to how it goes?

Does anyone know a good way to clean out this old intake manifold without getting pockets of water stuck in there? If I take out the DISAs there are no sealed cavities in there, right? Then I could blow it out with a leaf blower.

[hassmaschine]

I don't think it matters. the timing wheel is on the crank itself.

I would just use some carb cleaner to wash it out, since it will evaporate, rather than water.

[Joebie]

Originally Posted by hassmaschine

I don't think it matters. the timing wheel is on the crank itself.

I would just use some carb cleaner to wash it out, since it will evaporate, rather than water.

Good ideas.

I know the timing wheel is part of the crank, but there's no additional timing marks on the flywheel itself? For like setting TDC?

Also I just received my new engine here at work. Anxious to get it home on the stand and cleaned up. Its pretty gross, looks like it came from a salty state. Any pro tips on how to remove salt grime/oxidation from aluminum/mag block? I'm assuming there's gotta be a good chemical out there somewhere for this.

[hassmaschine]

no, I don't think so. BMW hasn't done anything like that, as far as I know, since the early 80's.

[Joebie]

Okay so here's some pics of the "new" engine. Definitely from a salty area so that's a bit of a disappointment, but whatever. I just have to accept that no one sane takes care of their car like I do so this should be expected.

Hopefully some chemicals + elbow grease + a good brush + hose will take care of most of this crap.

[Joebie]

I'm concerned about the harmonic balancer / crank pulley / whatever you wanna call it. Its very rusty.

I want to put the pulley on from my blown engine because it appears to be in great shape, but I have a few concerns

-Is the pulley matched to the engine somehow? I see these drill marks in it that I can only assume are for proper balance but that's not done for one particular engine, right? That's just so the pulley itself is balanced? (meaning I could swap for mine with no problem)

-There's nothing tricky about the install, right? Just unbolt the old, rebolt the new?

-THE BOLTS ARE LIKE $8 EACH AND I NEED 6 OF THEM, WHAT THE HELL?!?! Are these one time use? They seem like they would be.







EDIT: okay so here an answer to one of my questions... the bolts are steel and reusable, here's the bentley page on the vibration dampener



I'll almost definitely be swapping over my old pulley instead of this rusty one. Should look and function way better.

[PORTMOODY]

maybe you can clean the rust of the damper bolt before taking the balancer off and shooting it with something like a rustoleum. I'd also think about changing the exhaust manifold studs. Those look like they're ready to go too.

[hassmaschine]

I would swap it with your original. The bolts are not one time use - just clean them up with a wire brush and reinstall. No big deal. Don't need to undo the center bolt, but it wouldn't hurt to clean off the rust and paint it.