M54b30 Rebuild

[Vass 859]

50 minutes ago, dirtydoogle said:

Always check clearances. Plastigauge is easy enough and cheap enough 

Yeah, true. Just rewatched 50skid's videos on it and seems simple enough. Will pick some up today, $12 for a pack at Repco.

Interestingly as well, 50skid reused all of his old main bearing bolts. Apparently still going strong 3+ years later. Might just do that, clean them up properly and box on.

Also, unsurprisingly, you were spot on with the piston rings. Snagged a few photos before running off for work this morning and sure enough, the bottom ring is well gunked up. Very happy I'm changing those now.

[dirtydoogle 383]

If the bolts look okay then re-use them. They're not under much stress and they're not tight enough to stretch them. 

Yup those rings are yuck 🤮 

 

[Vass 859]

Wee progress update. The engine is now fully dismantled and dropped off at the machine shop to get some love from people that actually know what they're doing. Decided to go with Car Aid. Not the cheapest shop in town but have heard good things about them both from some mates as well as Eurocare recommending them. They've got a bit of a backlog so will only get to it in a few weeks, which is fine as I've got plenty of other bits needing tinkering to keep me occupied.

From what I could see, all components seemed in fine nick and perfectly serviceable. Besides the heavy carbon buildup on the exhaust valves, all seemed straight and no visible scoring. After looking into the topic, I decided that valves were something I will leave to the professionals to refurb, test and seat properly. Apparently, it's best not to lap valves on these engines as that would increase the contact surface beyond what would be optimal. They come with 3 surfaces cut at different angles from factory so the shop will re-cut those if need be. Dropped off a new set of stem seals along with everything and will have them do a full valve job.

Tested the clearances on a couple of journals taking off the crank, all fell at the 0.05mm mark, which is within tolerance (0.020-0.058mm). The journals seemed in decent shape overall, no visible scoring on any of them so was pretty happy with that. Left it at the machine shop just for looking over and a wee polish.

Rod bearings look a bit worn so I'm definitely replacing those. The main bearings looked less bad but I thought I might as well replace those too, at just about $150 a set it seemed reasonable to do but interestingly, the shop guys said they'd just need a wee going over with a scotch brite and they'd be good to live on. Instead they recommended I spend the money on new valve springs, which was an interesting take. Naturally, brand new springs would have more compressive strength than ones with 160k km on them but I hadn't come across any info of that being a troublesome component on these engines. I considered it, but at $17 (USD) a piece, I'm not sure what the ROI should be to justify that. Think I'm going to stick with the current ones.

Another thing of note whilst pulling it all apart, I kept on finding this black rubbery goo all over the place, likely RTV from somewhere. One bit was even stuck right inside one of the oil squirters, which couldn't have done much good. Doesn't pay going overboard on that sh*t, folks.

But yeah, this is where it's currently at. Along with the block and head, I also dropped off the oil pan, rear main seal and timing chain cover to go for a nice acid bath to have everything equally fresh and shiny for when the time comes to put everything back together again. In the meantime, I'm ripping into redoing the subframe bushes and compiling a list of parts to order. Received a first small batch including the head and lower gasket sets, along with a few other bits earlier this week. First time ordering from RockAuto and must say, I'm mightily impressed. I usually swear by FCPEuro and whilst their inventory is more extensive, I found the prices for some of the identical OE items on RockAuto to be 1/2 - 2/3 of those on FCP. Having put the order in on Friday, the package was already at my door by Tuesday morning. Rapid.

[Eagle 1670]

Yeah Rockauto is priced very well for certain bits and pieces (bearings being a common one). Their lower pricing and Fedex shipping costs more than make up for GST.  

 

[Braydon 40]

That RTV in the oil squirter terrifies me tbh.

[Vass 859]

9 minutes ago, Braydon said:

That RTV in the oil squirter terrifies me tbh.

Yeah it ain't great. It was also clogging the non-return valve and the pickup tube was full of it. Glad I'm ripping it all apart instead of just dropping the engine in.

[dirtydoogle 383]

OEM springs and retainers are pretty mediocre on most BMW motors. If they're willing to check a few valve seat pressures you will get a good idea of condition 

Chances are the old springs will be at 45-50Lb of seat pressure. Fine for tootling around, not particularly good for giving the bash 

A fast road m5x requires 85lb at a minimum for 7000rpm and a moderate cam

 

 

All that sealant gives me reflux man

[Vass 859]

On 3/1/2022 at 9:34 PM, dirtydoogle said:

OEM springs and retainers are pretty mediocre on most BMW motors. If they're willing to check a few valve seat pressures you will get a good idea of condition 

Chances are the old springs will be at 45-50Lb of seat pressure. Fine for tootling around, not particularly good for giving the bash 

A fast road m5x requires 85lb at a minimum for 7000rpm and a moderate cam

sh*t. That makes me think twice now. Although not really keen to shell out $600 on just springs alone.

Would you look at aftermarket springs instead of OEM?

[dirtydoogle 383]

On 3/2/2022 at 10:12 PM, Vass said:

sh*t. That makes me think twice now. Although not really keen to shell out $600 on just springs alone.

Would you look at aftermarket springs instead of OEM?

All depends on what you are wanting to do with it. If you plan to give it the bash, I would be a little hesitant to use stock springs. 

New orm springs will be okay for a stock rev range on a stock cam 

[Vass 859]

Great news! We've got an update. Got a call from the machine shop today. They've finally gotten enough bodies back in the shop to clear away some backlog and get onto my heap of junk. They got the head cleaned, checked aaaaaaaaand... it's warped and gone soft from being overheated at some point. Lovely.

Checked the block as well, said that a good block is usually 100, maybe 105. Mine is 90, which isn't ideal but apparently still usable. 90 and 100 what, exactly? I didn't think to ask, of course.

Took a good 2.5 months to get to this point, and it's back to square one.

At the very least, I'll need a new M54 head. As far as I know, both the B22 & B25 have the same one as the B30, so would make it a bit easier to find. The main guy at the shop said he'll shake a few trees and see if any of his contacts have one laying around, might be able to get one for a couple hundred bucks. If anyone else has any leads, throw them my way. Can always strip one off from Pick-A-Part but that's another wild stab in the dark.

Another option is to just strip the head off the current B25 engine and go with that. Haven't had the temperatures spike in my ownership, not even on long drives, so assuming it'd be a fairly safe bet? Otherwise, what's an M54B25 with 226k km's, bit of oil burning and suspected vacuum leaks worth anyway? $500 max or something? No idea what the market would be for something like that, in that condition. Haven't thought too far ahead to figure out what I'd have done with it post-conversion. Getting the head off it might actually be the best use for it.

No clue, I'm just spiralling at this point. Been a long silly workweek this with a damp squib of a conclusion to it. Happy Fridayyyy?

[dirtydoogle 383]

That's a real bummer man. B25 and B30 use same valve sizes, I believe B22 has smaller valves. 

90 would likely be Brinell or Vickers hardness test numbers 

Alternatively if you can't find a complete motor, an M52 or M52Tu stroker build could be the go. 

[Eagle 1670]

Yeah that sucks. Since you rebuilding it anyway the B25 head sounds like the best option. As you say the market for a stuffed B25 is basically no one so its scrap anyway. Even good B25's aren't really wanted as far as i know, just the B28 & B30 for the swaps. 

[wrs 120]

I have a M54B30 I'm taking the rotating assembly from. I'm not sure what the state of the block and head is but you'd be welcome to them if you're prepared to take the gamble on freight and them being no good. If they're of some use I'd be open to some beers...

[Vass 859]

11 hours ago, wrs said:

I have a M54B30 I'm taking the rotating assembly from. I'm not sure what the state of the block and head is but you'd be welcome to them if you're prepared to take the gamble on freight and them being no good. If they're of some use I'd be open to some beers...

Awesome man, that's a mighty fine offer, thanks so much! If you have any clue about what it might cost to freight, let me know, I reckon that might be what it'll come down to. I'll message you to discuss further. Thanks again!

[Vass 859]

Yay, shiny bits!

Got all this rejuvenated metal back from the machine shop. Pretty nice seeing it clean enough to eat out of.

Full list of work done so far:

Quote

Acid wash parts, surface block and front cover, hone bores to straighten, measure and expand pistons to suit, polish crankshaft, remove pistons from rods, clean and machine ring grooves, wash pistons, assemble and align pistons on rods, final wash parts, hardness test head and advise head is too soft to re-use.

Will probably cotton wrap it all and put on temporary hold until I get the head situation resolved. Still have the subframe bushes to sort out and gearbox detents to replace so plenty to keep me busy in the meantime.

The shop guys reiterated that the main bearings don't really need replacing but I managed to find a new Glyco set for just around $85 so might still chuck new ones on whilst I'm at it. Still weighing up whether to drop ~$520 on new valve springs though. Would be nice but then again... $520. Money pit problems.

[dirtydoogle 383]

Get them to check your  bearing clearances and ring gaps if you're not too confident. There's 3 different bearing clearances used and with a crank polish it's likely increased clearance by 0.002-0.005" 

If you're feeling handy, plastigauge/flexigauge is fine for a street engine if used correctly 

All those clean parts look 👌 😍 

[Vass 859]

9 hours ago, dirtydoogle said:

Get them to check your  bearing clearances and ring gaps if you're not too confident. There's 3 different bearing clearances used and with a crank polish it's likely increased clearance by 0.002-0.005" 

If you're feeling handy, plastigauge/flexigauge is fine for a street engine if used correctly 

All those clean parts look 👌 😍 

Yeah I'll do the clearance checks. Got some plastigauge and a feeler gauge handy. Will take the rings in if they happen to need a bit filed off. Some special tool required for that apparently. 

[dirtydoogle 383]

You can pick up ring grinders pretty cheap, but it's a pretty boring task and not exactly a tool you will use often. Mine spends more time being on loan than in my toolbox 🤦‍♂️ in a pinch you can use a diamond file or points file. 

They will need the block to do them 

[LsBeema 466]

Yo man, I'm contemplating on doing the same recon on a m54, can you please text me to have a quick chat. 

Appreciate brru

022 689 5884 

[Vass 859]

Quick wee update.

Had no luck finding a spare head locally. A few places claimed to have one but either couldn't find it or just failed to get back to me, so those hopes fell through. Unfortunately also, the head on @wrs' engine turned out to be borderline unusable. Was super helpful though that he went through the effort of stripping it off and taking it in to his local machine shop to get tested before going through the trouble of shipping it down. Top man, greatly appreciated.

My wagon had decided to spit the dummy and started misfiring in the meantime so it made it an easy decision to park it up and start tearing it apart. Rolled it into the garage and spent all of last week tearing into it. Finally got the head off on Sunday, stripped it and took it in to the machine shop yesterday. 

They did a quick hardness and straightness test on it and it looks all good to use! Much better than the first candidate I took in so well chuffed with that.

Will have them clean, pressure test and seat the valves properly, as well as getting the injectors tested and cleaned. Should be a week or two before I get it back but happy to be making progress again. Happy days.

[Vass 859]

After a very long "one to two weeks", I got the call yesterday telling me the head work was done. Jumped straight on it and went to pick it up. Great to see some shiny parts.

Work done:

Quote

Hardness Test Head (Ave = 90 - been a bit hot but o/k)
Acid Wash, Decarb
Vacuum Test Valves (poor - seats and valves pitted)
Face Valves
Face Seats
Re-Set Valve Stem Heights
Surface Head
Final Wash & Assemble Cylinder Head
Test & Clean Injectors

Even got a bit of a discount for the long wait. Was pretty happy until I got home, flipped it over and, umm... really don't know how to feel about this.

I took it straight back to the shop to see what that's all about, the guy was completely unphased and assured me it's nothing to be worried about. The head gasket surface is of course the one that has to be absolutely perfect, and it does look to be fine. The valve cover, thermostat, exhaust manifold won't be under anywhere close to the same pressure as the head but damn, they're still sealing surfaces and to have score marks that catch on the nail and all sorts of chipped edges all over the gaff surely isn't ideal? Changing valve covers and thermostats previously, I've always been super careful not to scratch any of the surfaces, always stopped short of even using scotch-brite out of fear of damage, this just looks like it's been dragged along a gravel road.

Had a chat with a mechanic mate of mine who also thought it shouldn't cause sealing issues but definitely would have expected a tidier finish from a professional shop.

I guess I can live with it so long as it works and seals fine but am I right in being concerned at all, or is this just purely visual?

[Eagle 1670]

Wouldn't think it would be a issue either but yeah looks rugged like someone(maybe apprentice?) used the wrong abrasive. You could probably tidy it up with a sanding block and some high grit wet and dry sandpaper

[tawa 150]

A stone (1000+grit) with some oil will take off the high spots if the scratches have left any, though mostly it looks ok, I wouldn't go with sandpaper for anything more than a light go, as it's more likely to create an uneven surface. But yeh, would have expected better from a machine shop, presuming it was in better condition when it was dropped off to them, I wouldn't expect them to fix those surfaces if they were already like that.

[Blackie 510]

That's just the surface the cutting machine leaves. Pretty typical. You can tidy it up but sealng surfaces generally like to be a bit rough.

[Vass 859]

14 hours ago, tawa said:

A stone (1000+grit) with some oil will take off the high spots if the scratches have left any, though mostly it looks ok, I wouldn't go with sandpaper for anything more than a light go, as it's more likely to create an uneven surface. But yeh, would have expected better from a machine shop, presuming it was in better condition when it was dropped off to them, I wouldn't expect them to fix those surfaces if they were already like that.

No, absolutely nothing like the state they're in now, looked close to immaculate when I took the valve cover off.

13 hours ago, Blackie said:

That's just the surface the cutting machine leaves. Pretty typical. You can tidy it up but sealing surfaces generally like to be a bit rough.

Wouldn't it come all rough as guts from factory if that were the case?