experienced engine builders only.

iceminion · 05-21-2008

Ok, last night I spun a rod bearing.

This was Bills engine, he works at MAP, he does not build engines for customers, I in no way believe that his craftsmanship was in any way responsible for the failure. 2.3L eagle/mahle (9.5:1) ~500 miles on engine.

I am 1/2 qt overfilled with oil, been that way for a couple weeks. I have no oil leaks.

Did a high revving launch (first time on this engine)

The engine makes a terrible noise, and there are small golden flakes in the oil.

The car is running on keydiver chip (for the 780cc's)

I have been running the car at 11-12psi because of the high compression ratio.

Shell 92 octane.

I think I have listed all the important factors here. what do you think? if it is just a rod bearing, can I just replace it?

what are the odds that I dont have to pull the crank?

Thanks

**Shane@DBPerformance** · 05-21-2008

How much timing did Keydiver remove from your chip, did he know it was a 9.5:1 motor? Factory 1G timing is way too much for even a 8.5:1 compression engine. Running 11-12psi wouldn't make it safe either, at lower load often runs even more timing depending on where you land in the timing map. A 9.5:1 compression pump gas DSM wouldn't be able to take barely any timing/boost without knocking. Did you pull the spark plugs and check for detonation the plugs and piston tops? Did you set the base ignition timing? Did you have a wideband on it?

**Shane@DBPerformance** · 05-21-2008

You shouldn't have been running it with too much oil either, that isn't good. Have you changed the oil/filter a few time in the ~500 miles? Did you have non-synthetic and thick enough oil in it?

Speedfreak · 05-21-2008

What Shane said^^^.

But no chance of leaving the engine in place. You now have shavings floating around everywhere, and the crank will probably/possibly be damaged(as could be the rod). Complete rebuild is in order.

**v8klla** · 05-21-2008

Alex,

I'm sorry to hear about your difficulties. I think you are referring to the motor you purchased from Bill correct? I'm pretty certain that Bill assembled that with Kyle's guidance, but in any case we would love to take a look at it as we have yet to spin a bearing or have a failure of any sort in our shortblocks.

Also, can I ask what you were revving the engine to? I recall you saying it was somewhere in the 9k range when you were last in?

Chris Carey

blageo23 · 05-21-2008

Im not an expert but I do have some experience with blowing up engines. Both times I had metal flakes in the oil my crankshaft needed to be replaced as well as all the bearings.

DSM_421 · 05-21-2008

Quote:

Originally Posted by ecoli

You shouldn't have been running it with too much oil either, that isn't good.

I always knew this, but never why. Is it because you will have too much oil pressure?

**Kracka** · 05-21-2008

Overfilling too much can cause the crank to drag in the oil creating extra resistance and also causing the oil to foam. I'd say a 1/2 quart is not a big deal though as it shouldn't be enough to interfere with the crank.

**scheides** · 05-21-2008

Quote:

Originally Posted by v8klla

Also, can I ask what you were revving the engine to? I recall you saying it was somewhere in the 9k range when you were last in?

Wow, 9k and only 12psi? what on earth for? RPMs could be your cause of death here, my friend.

iceminion · 05-21-2008

I mentioned that Modern built my engine....so that you would all know that the workmanship was perfect and you could RULE OUT my in-experience.

I revised my first post

-------------

8k max.

will take a look at the crank later tonight.

didnt know that the stock timing tables were too much.

Kyle did recommend that I run wastegate pressure (which I am doing, lightest spring) I guess I should have also said that I was not running any kind of professional engine management. Chipped/SAFC, was planning on using 'squirt or link before I made any more boost.

I assmed my new knock sensor would have retarded the timing enough.

Guess I was wrong.

Sooooooo, now what? assuming that the crank cannot be re-used.

Can I turn the crank? re-apply the nitride coating?

I do plan on going megasquirt, so I will have full control of the fuel AND timing.

what do you think?

**scheides** · 05-21-2008

rebuild, DSMLink, and a tune before you go beating on it again

I would just get a new crank, but pull it apart and inspect the damage. Before you do that, do as shane suggests above and look for signs of detonation on the spark plugs/pistons.

**v8klla** · 05-21-2008

I believe that crank was turned once before, so I don't know that I would recommend it again.

**Goat Blower** · 05-21-2008

I don't like turning cranks anymore, the only one I've ever had a spun bearing on was a .010" under crank, renitrided and everything. Some people have had great luck with them.

A half-quart high isn't going to make any real difference except maybe a few horsepower at high rpm. A couple extra quarts will.

I have a hard time believing you could knock hard enough to spin a bearing without breaking a ring land or something else. I'd lean towards some sort of oil blockage to that bearing.

sleepydsm · 05-22-2008

Yeah my friend found RTV pluging a bearing oil hole once, no good...

If you can get a new-to-you good condition crank, thats the best path. Check the bearing journals for the hell of it...

iceminion · 05-22-2008

what are the side effects of re-grinding cranks? I know they get slightly weaker.

Goat blower, logically, if you spun a bearing on a turned crank, how can you blame it on the machine work?

I get the impression that turned cranks get weaker, and the side effect is broken cranks.

If nobody has had turned cranks crack and break on them, then I am going to have the crank re-ground for ~$100

Last I checked 6-bolt 4g64 cranks go for upwards of $300, unless I can find a motor in a junk yard. (good luck with all you fuckers picking the junk yards bare, I know, I checked 6 months ago)

iceminion · 05-22-2008

Quote:

Originally Posted by sleepydsm

Yeah my friend found RTV pluging a bearing oil hole once, no good...

If you can get a new-to-you good condition crank, thats the best path. Check the bearing journals for the hell of it...

I know you can get RTV all over the place if you use it on your front case and/or oil filter housing. But I didnt. The only RTV on my engine is for the water neck and the oil pan, I highly doubt that any RTV got picked up through the uptake tube, and somehow made it through the filter.

I might be able to have it taken apart on sunday, stay tuned for carnage pics!

Andrew7dg · 05-22-2008

Quote:

Originally Posted by iceminion

Last I checked 6-bolt 4g64 cranks go for upwards of $300, unless I can find a motor in a junk yard. (good luck with all you fuckers picking the junk yards bare, I know, I checked 6 months ago)

sold one to MAP not that long ago...

Super Bleeder!! · 05-22-2008

Take the crank over to Crankshaft Supply and have them take a look at it. You MAY be able to run the crank with only some polish work put into it if its not FUBAR.

blageo23 · 05-22-2008

Quote:

Originally Posted by iceminion

If nobody has had turned cranks crack and break on them, then I am going to have the crank re-ground for ~$100

$100 my ass.
To check for cranks, Grind, Recoat and balance my crankshaft was $355

iceminion · 05-22-2008

I think for a simple grind its pretty cheap, I know that if I want to re-nitride it I will need to spend upwards of $350

I am sold on using nitride, but its freaken expensive.