'Sploded my block, rod took a dump. (Plus rebuild thread)

[E30_Crazy]

Haven't pulled the engine yet to see the full extent, but here's what I can see from top-side

[Speedtouch]

Streuth, you've really nailed that!

What sort of revs were you doing?

[magpie]

that takes some doing,a 6-pot block weighs a tonne

[E30_Crazy]

It revs up to around 7.5 or 8k, but it blew going about 2.5 or 3k cruising on the highway

[E30_Crazy]

Lost power, similar to breaking a rocker. But I figured it was the AFM freezing, like it has previously. Messes with the air/fuel over around 3 or 4k. I slowed down to allow the heat to build up in the engine bay to warm it back up, then bang. A thud, and some metal "tinking" sounds of the block bits hitting the exhaust. Saw the big blue smoke cloud of the oil burning on the exhaust. Turned the engine off right away and pulled off the road.

[magpie]

lot's of work ahead

[E30_Crazy]

Found a pre facelift 325e for $800. That'll have a block, rods(?) and crank if mine is warped or bearing faces damaged. Figure while I'm at it, I might as well build for boost, and get ready for my Rotrex build. Sleeves with 1mm overbore (to make it a 2.8 ) custom pistons, MAF, valves redone, etc.

Might get some lightweight rods if I can source some way up here.

Oh, and the donors panels will fit the Tech 1, to help with the restoration.

[daimlerman]

Found a pre facelift 325e for $800. That'll have a block, rods(?) and crank if mine is warped or bearing faces damaged. Figure while I'm at it, I might as well build for boost, and get ready for my Rotrex build. Sleeves with 1mm overbore (to make it a 2.8 ) custom pistons, MAF, valves redone, etc.

Every cloud...

[Speedtouch]

Behind every cloud, etc.

[Simon13]

ouch, that won't of liked 7.5k 8k rev action forsure unless it was uprated.

I've a good 8.8 CR 2.5 bottom end here but your about 8000 miles away at a guess

[ross_jsy]

It revs up to around 7.5 or 8k, but it blew going about 2.5 or 3k cruising on the highway

What have you done to the lump to allow such high rpm?

[e30topless]

first time I have ever seen an M20 chuck a leg out of bed

[verde]

first time I have ever seen an M20 chuck a leg out of bed

Same, mine shattered a piston but the block itself actually stayed intact.


My guess is that the OP is in alaska and maybe the cold had something to do with it? Made the block Brittle ?

[E30_Crazy]

It revs up to around 7.5 or 8k, but it blew going about 2.5 or 3k cruising on the highway

What have you done to the lump to allow such high rpm?

I didn't do anything really. Bought it built by someone else. Has uprated valve springs to go with the schrick 288. 325e crank, 320 rods. Generic 2.7, minus the cam.

[E30_Crazy]

first time I have ever seen an M20 chuck a leg out of bed

Same, mine shattered a piston but the block itself actually stayed intact.


My guess is that the OP is in alaska and maybe the cold had something to do with it? Made the block Brittle ?

It didn't spend a whole lot of time in extreme cold. Kept it garaged. Short stops at the store. At work, I would go start it every 3 or 4 hours for 20 minutes.

[E30_Crazy]

first time I have ever seen an M20 chuck a leg out of bed

Same, mine shattered a piston but the block itself actually stayed intact.


My guess is that the OP is in alaska and maybe the cold had something to do with it? Made the block Brittle ?

It didn't spend a whole lot of time in extreme cold. Kept it garaged. Short stops at the store. At work, I would go start it every 3 or 4 hours for 20 minutes.

[billgatese30]

Short stops at the store. At work, I would go start it every 3 or 4 hours for 20 minutes.

Did you leave it idling for these 20 minute intervals or did you keep the revs above 1500-2000 rpm?

What oil were you using (SAE grade, not interested in brand).

When you strip it down, take a good look at the crank journals/big end bearings and small end of the rods & gudgeon pin on the piston and let us know how they look.

Was there any knocking from the bottom end at any time before its demise?

[snakebrain]

I'm not an expert, but I'd say that's fooked.

[Jon_Bmw]

Looks like battery failure...







A rod went through it!

[Kos]

Nothing a bit of JB weld won't fix

[E30_Crazy]

Short stops at the store. At work, I would go start it every 3 or 4 hours for 20 minutes.

Did you leave it idling for these 20 minute intervals or did you keep the revs above 1500-2000 rpm?

What oil were you using (SAE grade, not interested in brand).

When you strip it down, take a good look at the crank journals/big end bearings and small end of the rods & gudgeon pin on the piston and let us know how they look.

Was there any knocking from the bottom end at any time before its demise?

I would idle for a few, until the temp was around 1/4 up, then give it about 2k for a
few to actually circulate the warm coolant.
Used 10w30 generally

[E30_Crazy]

Looking for a parts car. Do convertibles have all pre facelift panels, or just the tailgate/tail light panel? Namely the front wings, rear quarters (the wheel arch area, not the pillar obviously)

[andyp]

chemical metal sorts most things out

[E30_Crazy]

chemical metal sorts most things out

Would you be so kind as to elaborate on what chemical metal is? Is it like JB Weld?

[Morat]

We definitely need a full forensic examination of the carnage

[E30_Crazy]

We definitely need a full forensic examination of the carnage

Will do. Gotta wait til the guy renting my spare room ships his car, no room in the garage at the moment.

[Speedtouch]

Yes, Chemical Metal is similar to JB Weld.

[E30_Crazy]

Was that a joke, or would it seriously hold against heat and oil pressure?

[Speedtouch]

I personally wouldn't want to risk it with a hole that big - if I couldn't get a replacement block, I'd get it welded.

[E30_Crazy]

Looking for a parts car. Do convertibles have all pre facelift panels, or just the tailgate/tail light panel? Namely the front wings, rear quarters (the wheel arch area, not the pillar obviously)

Anyone have an answer to this? Found another vert for sale. 95k miles

[E30_Crazy]

Looking for a parts car. Do convertibles have all pre facelift panels, or just the tailgate/tail light panel? Namely the front wings, rear quarters (the wheel arch area, not the pillar obviously)

Anyone have an answer to this? Found another vert for sale. 95k miles

[E30_Crazy]

Got the engine out.. another hole on the other side by starter motor. I can see the piston is destroyed, along with a huge gouge in the bottom of the bore. Don't think the block is savable. I'll get more pictures once my phone decides to let me upload them.

[billgatese30]

If the holes aren't actually in the cylinder bore or near a load bearing part (i.e. near a crank journal) then I have seen several blocks held together with JB weld, although personally I wouldn't ever do it, it really is the pikeyest way of doing things. Either weld it or bin it and get another.

Not sure on the cabbie parts. I know that rear panel/rear arches are different, not sure if the front changes or not. You should be able to tell if you look at anywhere supplying panels as they should list pre/post facelift and cabbie/saloon as different part numbers if they are different.

Even if the entire bottom end is scrap, it would be worth pulling it apart to see if there is any indication as to why it let go.

[E30_Crazy]

Trying the last several hours to pull it apart... so much junk and pieces in there that got tumbled to the rear while pulling the engine that it's fouled the fly/clutch and I can't get the box off. I'll pull the head and check if its all good, then roll the block and box down the drive and see if they separate haha.

I've been awake way too long...

[billgatese30]

Wow, that sounds properly screwed up. If in doubt, give it a clout!!!