Jump to content
LegacyGT.com

Built Spec B Rebuild 3rd Time


Recommended Posts

How did you rule out the AOS?

 

Because I've never heard of oil in the intake causing bearing failure. I suppose it could if you sucked so much oil out of the oil pan and dumped it in the intake that the pan ran dry. But there wasn't THAT much oil in the intake. And the pan still had plenty of oil on the stick.

 

Do you think it could have?

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

  • Replies 144
  • Created
  • Last Reply
I don't know either way, my question was more out of curiosity since I'm installing an AOS. I would think you'd see seal failure before bearing failure. Is excess oil heat the usual cause of bearing failure (beyond low oil)?
Link to comment
Share on other sites

What weight oil were you running? Acl bearings?

 

Drew had changed the oil just before I picked it up, and I topped it off for the track day with the spare quart he left in the trunk. I think it was 5-30. Not sure now.

 

ACL Race Bearings. KillerBee Pan- Pickup-Windage Tray. Manley Forged Pistons and Rods. ARP headstuds and rod cap bolts.

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

Never used any fuel additive and oil was always Shell Rotella-T.

 

"I've never heard of oil in the intake causing bearing failure", agreed and never have I. It would reduce octane and increase det. potential under load but the ECU will also pull timing. This wasn't an explosive event so couldn't be the oil in the intake. There are issues with ACL bearings that I have heard of but not read up on but I'd search for an oiling issue or maybe even the tune?

 

The heads were magnificently done by one of the very best luckily they look ok from here and I'll bet there are fine.

 

Glad you put to rest the AOS install issue. I always thought there was more oil in the intake than there should be but then always was told that no one could figure it out and there wasn't enough yet to worry about-so I didn't.

[URL="http://legacygt.com/forums/vbpicgallery.php?do=view&g=1586"VbGallery/URL]
Link to comment
Share on other sites

5w40 Rotella should have been fine for one session. Detonation can cause more stress to rod bearings due to the sudden increase of cylinder pressure. Still, I would be surprised if that caused a bearing failure with no other signs of cylinder or piston damage. Was the engine build with stock bearing clearances?
Link to comment
Share on other sites

I was thinking of engine #2. This last engine was running what the builder suggested. 20-50 Valvoline racing but I later mixed it with 2 qts of Castrol 0-30. Oil pressure was always good. I had it up on the CampII as one of the gauges displayed. A little over 90 when cold and 21-22psi fully warm (never lower than 20 but sometimes up to 23).

 

The block halves were new and so were the crank, rods, pistons.

[URL="http://legacygt.com/forums/vbpicgallery.php?do=view&g=1586"VbGallery/URL]
Link to comment
Share on other sites

I think detonation. You have great pistons and rods, the next weak leak...bearings.

 

Check the tune on that cylinder.

 

Think of what happens when an engine detonates, all that force has to go somewhere. Thought I don't see any sings of it int he picture above of those two cylinders. The piston tops look ok.

 

 

There's no bluing of the main journal, so it looks like oil flow was keeping it cool.

 

Do you know the bearing gap when the engine was assembled ?

 

Just working through the ideas...

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

Link to comment
Share on other sites

Do you know the bearing gap when the engine was assembled ?

 

I don't, Drew may have the specs.

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

  • 3 weeks later...

The heads off the spare longblock I was going to use on a new OEM shortblock are toast. There are hairline cracks from almost every valve to the spark plug holes:

 

ShQXAAXwfm7SGOrSgQEBr9qMCmho4LmvMgOAHwdqOc0=w886-h410-no

 

These are from the same block that had the cracked cylinder. It definitely got way too hot!

 

So these are junk. I'll save the cams and covers, and maybe the buckets.

 

I was going to save the ported heads for a race engine build. I'm not sure whether to go ahead and use the ported heads in the Spec B or buy new heads for it. Cash is a bit tight now, I'll probably use the ported heads. Seems like a waste though.

 

The ported heads should be finished in a day or two, I took the new SuperTech exhaust valves over today.

 

Anyone got a spare set of EJ255/257 heads for sale?

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

  • 4 months later...

The race season is over, the race car is mothballed and stored away until this build is done. I'm ready to get this going and have a nice AWD GT car for the ski season here!

 

A few pics:

 

A New Shortblock is in and up on the stand:

 

http://i527.photobucket.com/albums/cc359/MS6Hayate/DSCN0786.jpg...

http://i527.photobucket.com/albums/cc359/MS6Hayate/DSCN0792.jpg

 

Parts tables arranged. Old parts on one, new parts on another plus the intake and rebuilt heads. These are the "Cosworth like" heads with new SuperTech valves.

 

http://i527.photobucket.com/albums/cc359/MS6Hayate/DSCN0789.jpg..http://i527.photobucket.com/albums/cc359/MS6Hayate/DSCN0787.jpg

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

Detonation due to reduced octane (oil in take) adds stress to the rod bearings in addition to the pistons.

 

It can crack ringlands but if you think about it, it stresses the rod bearings too because the explosion is trying to push the piston down while the crank is pushing it up... overloads them leading to increased wear. This is why I run Rotella T6... it has higher zinc content which acts like a "dry" lubricant so when the liquid oil is forced out due to pressure between moving parts, the zinc is supposedly left behind to lubricate the parts. Supposedly. Allegedly.

Link to comment
Share on other sites

I see them still.

Are all the pics in this thread not showing for ya'll or only the most recent?

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

I know you mentioned you saw a pinched line on the AOS. Are you attributing the bearing damage to just the AOS not functioning correctly? I ask because I also saw that you sold it, so Im curious if you now feel that system isn't up to par.

 

Do you have any logs or a learning view you can reference to see for certain whether it was mostly destroyed at that one track event?

 

I will say this, you do bring up a damn good reason to have some type of visible knock detection on the car at all times. Like a knocklite...

Link to comment
Share on other sites

I know you mentioned you saw a pinched line on the AOS. Are you attributing the bearing damage to just the AOS not functioning correctly? I ask because I also saw that you sold it, so Im curious if you now feel that system isn't up to par.

 

Do you have any logs or a learning view you can reference to see for certain whether it was mostly destroyed at that one track event?

 

I will say this, you do bring up a damn good reason to have some type of visible knock detection on the car at all times. Like a knocklite...

 

sbw, I'm not sure what caused the failure. It was a built engine with a ton of aftermarket parts. The FMIC had a LOT of oil in it. The AOS had a pinched drain back line to the block. Can that cause bearing failure? Maybe, maybe not. It had a shimmed 11mm oil pump which I now know is not necessarily a good thing on a non dual avcs engine.

 

Could it have been the tune? Or that I was running premium pump gas instead of a high octane mix of Torco + Premium?

 

My biggest regret is that I should have taken it to Cobb Surgeline for a Test & Tune BEFORE I took it out on track. They might have caught the issue on the dyno before I popped the engine. I won't make that mistake again!

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

Pictures in post #62 are dead for me, the rest are good.

 

I edited post 62 to remove two pics. Let me know if that doesn't do the trick and I'll shrink the image size on them.

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

Still deadzo

 

I found the problem, Google Photos no longer supports posting in Forums /Web Pages!

Nothing like a race track to find the weak points in man and machine.

"Good Judgement comes from Experience. Experience comes from Bad Judgement"

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.




×
×
  • Create New...

Important Information

Terms of Use