Ahhh judgement day....I love the smell of napalm in the morning

So we cracked the engine open


Looks good right? WRONG!

Look at that crack on the crankshaft counterweight!!! :eek:

Oh let's turn the crank a little!

Dammmmmn!!


So yeah the crank is cracked all the way through...it's like 2 pieces. Interesting to note that the crack is not near any of the knife-edged parts.

But wait! There's more! Did anyone notice the main cap? :eek:


Let me make this more obvious



Look at the bearings, completely melted/spun/messed/FUBAR




Actually I should say I had a good laugh when my engine builder said he had never seen anything like that in his 20+ years of building race engines

Full size pics are here http://www.imagestation.com/album/?id=4290532631

So what do we think happened?

- Main bearing spun
- Huge heat generated
- Cracked main cap/crank

?

Cause I'm starting to think there's no way the crank cracked first, the crank snapping is what stopped the motor. It wouldn't turn after that

 

Whoa man...
<nervous look at H23 project in the corner>

Can you list wht you had done to the engine?

 

That sucks bro sorry.

It probably started with the bearing failure as you said. I'd tend to agree that the crank was a symptom not the cause. Loss of oil pressure perhaps? Improper bearing clearances? Perhaps the crank was slightly warped and not allowing proper oil flow around that bearing. How did the other 4 mains look?

 

5 and 4 looked fine. 3 was not so great, which I point to the vibration from #2 it was also spun. didn't look at 1 very closely. I'll call my builder in a hours.

I don't think it would have been warped. My builder always sends out the cranks to make sure they are 'true'.


[Modified by satan_srv, 1:35 PM 3/13/2003]

 

AEM CAI
64mm TB
stock IM is ported
AEM FPR, stock rail and pump
RC 370cc injectors
TechTom 97 P72 (like a hondata)
Crower Stage 3 cams, JUN valvespringsngs, JUN retainers, stock valves, AEM cam gears
Ported/Polished Head by Top Power Racing
Darton 87mm Sleeves
H23A rods shot-peened
H23A crank balanced, lightened knife edged
Arias 11.5:1 Pistons and rings
UR Crank Pulley
DC Cermaic, Tanabe G-Power Medallion catback
CM Ultralight Flywheel
CM stage 3 clutch
KAAZ LSD

 

Well if the cylinder bores & piston rings don't show damage from overheating and it's only 1 or 2 main bearings that are burned you can probably rule out oil breakdown and pressure loss(pump failure). Then you're onto incorrect bearings, warped crank, improper main cap torquing, damaged crank journals, or a freakish one in a million mishap.

Sorry for your loss. Have you made any re-build plans yet?

 

Hmmm...I just noticed you had Darton sleeves. Was the block inspected prior to assembly? Sleeve installs can be rather rough on these blocks. I had GE sleeves installed on mine and the machine shop doing the boring(85mm) said the cylinders were way way out of round. They wrecked a bit rounding and honing them for me. After that I had them carefully check the crank journals for warpage. They were fine but I wouldn't have expected the GE sleeves to be so warped out of shape on the install. Perhaps the trauma of the sleeve install damaged your crank journals. A disaster waiting to happen. Just a thought.

 

The sleeves and cylinders look good from the block side anyway...so I would agree with you there.

 

Did you have the main caps/saddles line bored after installing the sleeves? Installation of the sleeves can (and does) distort the alignment of the main caps. It almost looks like the bearing that spun was caused by a distorted main cap/saddle.

Sonny

 

Well if we can save the block...we would use the F20B stuf I have...the mains are 55mm vs. the old H22A1 50mm so we have some room to bore out and save the sleeves. That's are only option for saving the block at this point.

so

Option A - save block, F20B

In the interests of trying to save the block, we are going to take it to the machine shop and see if it can be saved. The only way this works is with the F20B crank. Since it's 55mm mains vs. the blocks 50mm we have some room to work with. I have 98 main caps I bought so we can bore out the others that are still good and replace the busted one. Bore it to match the F20B crank and we're off to the races. I found out the 55mm main caps are the same height as the 50mm caps, so they can be bored out for f20B with no issues.

However....if the block can't be saved...

Option B - toss block, H22A

Throw the block out. Buh bye darton sleeves. Sell the Arias pistons. Start fresh with a bare H22A block. Buy wiseco pistons, talk to endyn, put them in a stock FRM sleeve and try it out. Put in H22a crank/crower rods. Or just use type-s pistons and build another block next winter.

 

good question I am going to find out right now

 

Spoke to my builder. He confirmed a few things. He was talking to his machine shop today too.

The mains were lined bored after the sleeves were installed.

He is 100% convinced that the crank broke first. I am tending to agree with him. There is no other way to explain the heavily spun bearing on #2 as well as #3. #3 isn't as bad as number #2 but it is still spun. And what is in between the two mains? Where the crank is cracked, which is cracked closer to the #2 side. It's his opinion that the crack took out the bearings, then excessive heat cause the main cap to break, then the timing belt skipped stopping the motor.

 

Any suggestion as to what broke the crank? They don't just break everyday especially at that power level.

 

Do you agree with their analysis? I tend to agree by the degree of damaged to 2 and 3...

Really no idea why the crank cracked. Unorthodox pulley? Knife edging?

 

What was the reasong that you chose that particular block to build?
Had it thrown a rod before? Unless the crank was Xrayed, you couldn't tell if there was a crack already existing. Even if the main had gone first, a healthy crank would have torn **** up, and then broke.
I kinda suspect the knife edging was at the heart of the problem.
You only hear of breaks like this in domestic cranks, i.e. cast (bleh)

 

...actually I'd sooner suspect the crank pulley. Does that engine come w/ a harmonic balancer stock? I personally don't care for the aftermarket crank pulleys that remove the harmonic balancer. The knife edging shouldn't be a problem assuming it was balanced properly and I saw the tell tale balancing dents all over it. If you get some resonance in the crank w/o a dampener to absorb them it can lead to problems.

Hope you can save the block, it'd suck huge to have to start over, especially since you said the sleeves are fine. Good luck.


[Modified by TimoneX, 3:28 PM 3/13/2003]

 

Hey, satan_srv, you're in Kitchener...sweet! Lived out there for a little while.
Where did you get your machining done?

 

Yeah the H22a has a stock harmonic dampener...

 

I believe it was Nash in T.O. scarborough or something.