Steel Crank Turned .040 ?
 

OK THIS IS ENGINE BUILDER'S 4TH TIME REBUILDING THIS ENGINE. ENGINE KEEPS TEARING UP ROD BEARINGS. :mad: NOW HE WANTS TO TURN STEEL CRANK .040 NOT SURE THIS IS OK, ANY THOUGHTS? 454 MAG ENGINE 4 BOLT MAINS
IN THE NEXT DAY OR SO I WILL ADD PICKS OF SOME OF BEARINGS. I SURE WISH I WENT WITH A BOAT ENGINE BUILDER. THERE WAS WATER IN NO. 1 CYLINDER WHEN I TORE IT APART NO DAMAGE TO PISTON OR ROD JUST SPUN ROD BEARING. I HAD BLOCK PRESSURE CHECKED HEADS AND MANIFOLDS CHECK NO CRACKS IN ANYTHING.
WHAT IS ODDS THAT INTAKE WATER JACKET HAS CRACK IN IT?

Re: Steel Crank Turned .040 ?
 

I would strongly recommend that you have the crank magnafluxed to check for cracks. If you were my customer i would insist on it. I would do a .040-under crank for myself (and I have) but I would NEVER do it in a customer's engine.
Pick your stuff up and take it to someone else.

Re: Steel Crank Turned .040 ?
 

4 times rebuilding the same engine is enough of a reason to go somewhere else.

Re: Steel Crank Turned .040 ?
 

If he is using Michigan / clevite77 bearings make sure there is a H marked on the out side of the bearing. If there is a P marked in the bearing then you have passenger bearings and not high performance bearings. There is a difference.

What is done to the motor. Is it stock ???

A lot of time water in the cylinder can be from reversion of a leak in the exhaust manifold

Re: Steel Crank Turned .040 ?
 

What you can get away with in a car motor, you can't in a boat motor. It works too hard. You need to deal with someone who really understands the motor as applied to a boat. I would not recommend going to .040 on the rod bearings, maybe the rods arent right either. Get them resized and maybe arp bolts too. Pm me if you would like, I've been through way too much of this stuff to see it repeated over and over, and watching others suffer... BBB

Re: Steel Crank Turned .040 ?
 

Root cause needs to be found - it looks like it hasn't.

Is rod bearing damage from detonation possibly ? Or clearances/installation/etc ?

Was this a stock rebuild or have there been other parts changed like pistons/cyl heads/ cam / etc,etc ?

Say a motor comes in broke, the engine get's rebuilt fine, and then it goes out but breaks again with the root cause being a carb that is way out of whack but the engine goes in, get's rebuilt again and the same carb goes back on. I see stuff like this happen a lot and wonder how some rebuilding companies make any money because of the rebuilds/replacements they do under warranty or pressure all over something like leaking manifolds, bad carb, ignition, fuel suplly, or etc/etc that is out of their hands.

Anyway - just bringing this stuff up for some thought. I, of course, have no idea what's being done on your case.

Good luck, and no, I wouldn't feel too comfortable at .040" over.

Re: Steel Crank Turned .040 ?
 

I've used "P" copper-lead bearings in marine applications with great success, even in 500+horsepower engines. I prefer to use them with cast cranks as they are a little more forgiving than the super-duty alloy "H" bearings. That being said, I would also recommend the "H" bearings in this customer's engine.
One other thing about grinding a forged crank-unless it is nitrided after grinding it is actually softer and more prone to cracking than a cast crank.

Re: Steel Crank Turned .040 ?
 

on a car eng. i will go .010 - .020 on a hp boat i will not turn it at all the most i will do is polish it the crank is only hardned so deep cranks and rods are to cheep to buy new also all my eng get line bore checked

Re: Steel Crank Turned .040 ?
 

.020 should be the max on the rods and .020 mains on a forged crank in a boat, anything else is potluck even these numbers can bring trouble with alot of HP... .040 is a little crazy... If these were acceptable the crank would have originally have been machined under to save materials etc...
Not the case...
I've thrown many cranks away because they were marginal and not worth magnafluxing or spending anything on them because they were on their last leg so to speak...BBB
Why piss money away on poop !

Re: Steel Crank Turned .040 ?
 

Run !!!

Re: Steel Crank Turned .040 ?
 

i hear fifth times a charm :evilb: you really need to find a new engine guy fast

Re: Steel Crank Turned .040 ?
 

SB hit the nail on the head! You have to find the root cause. In a sense you are lucky you arenot dealing with a shop familiar with marine motors. Water would have voided your warranty. What about the oil cooler and lines? Fuel delivery and timing? When does the engine die, right away, 10 hours 50, WOT? If he has built engines before there is likely nothing MAJOR wrong with the build but something else trashing your bearings.

Re: Steel Crank Turned .040 ?
 

CARBS ARE NEW
FUEL IS MECHANICAL HOLLEY PUMPS
BASICALLY MAG MOTOR INTERNALS
ENGINE NEVER MAKES IT PAST 10-15 HRS
2 ENGINES DONE ONLY THIS ONE CAUSING THE GREEF
VOODOO CAMS NOTHING TO WILD REVERSION SHOULDN'T BE AN ISSUE ? ALL CYLINDERS ON THAT BACK SHOULD HAVE WATER IN THEM NOT JUST NUMBER 1
MY BEARING PICS ARE COMING, PROMISE
ANY IDEA OF ENGINE GUY IN PA? IF I WIN LOTTERY NEW BOAT!! OLD IS TOO MUCH AGGREVATION :rolleyes:

Re: Steel Crank Turned .040 ?
 

Oil cooler and lines?

Re: Steel Crank Turned .040 ?
 

If that crank has any radius on it at all, according to how they are cutting it, and it should have .125 radius for strength, the P bearings won't work properly. You would tear them up, they are not radiused bearings. They are for a stock crank for a reason, stock cranks have a small radius to them. It would be his mistake not yours.

Re: Steel Crank Turned .040 ?
 

The stock radius is fine for that application but yes, if the crank grinder is adding the increased radius there will be a bearing issue. That issue would definitely show up when the engine is assembled.
As a side note, Clevite uses a "P" designation that references the eccentricity of the particular line of bearings rather than referring to a passenger car application.

Re: Steel Crank Turned .040 ?
 

The Round Groves I Undersatnd It's The Taper In Bearings I Don't Get. I Think Crank Grinder Or When The Resized The Rods?
Engines On Have 10-15 Hrs On Them When Tis Happens

Re: Steel Crank Turned .040 ?
 

Is the engine builder using full-groove bearings?
Federal Mogul H-bearing mains have 3/4 grooves.

Re: Steel Crank Turned .040 ?
 

I'VE TRIED 3 DAYS TO LOAD PICS EMAIL ME
[email protected] I WILL SEND THEM TO YOU IR YOU WANT TO SEE THEM OR THINK YOU CAN GET THEM POSTED

Re: Steel Crank Turned .040 ?
 

Make sure not to miss what a couple of these guys have mentioned. Oil cooler, lines and all passages will collect metal. If not cleaned very well and new coolers installed, it is likely to keep trashing an engine after the first legit problem. Non marine guys are not usually up on the fact that the coolers are near impossible to clean properly thus new is best.

BTW.... Good to see many of you old timers; crazyhorse, dang man I thought you packed it in. Kinda feels like old times round here :drink:

BT :cool:

Re: Steel Crank Turned .040 ?
 

Hey, I'm still looking at the grass from the green side, although one of these days my luck with surgeries is gonna run out. Had my one remaining real knee worked on Thursday before last. I'm running out of cartilege.

Re: Steel Crank Turned .040 ?
 

Too much grind and the nitriding and set rockwell hardness of the crank is gone. It's almost like case hardening. Cut and polish heavily, after that and all bets are off... maybe there are a few people who have thought otherwise, and found out the hard way, lets learn from them ...not by repeating their bull headed mistakes... BBB

Re: Steel Crank Turned .040 ?
 

Tryme, taper in a bearing is this: The shell halves are actually thinner towards the rod bolts. This is to allow a margin so oil film is not wiped away due to the rod cap flexing at high rpm. The bearing is actually thicker on H bearings in the middle than on the ends where the tangs are. If you build an engine with the clearances (rod bearings) on the low side of the clearance band and don't have bearings like this, your oil film can be scraped away, and well, you know what comes next.

Crazyhorse, hang in there. I never had knee surgery but know many that have. Very tough.

BT :cool:

Re: Steel Crank Turned .040 ?
 

Thanks BT. This is actually the best surgery I've had so far.
Clevite "P" bearings have more eccentricity than the "H" bearings, according to their catalog information. They "P" bearings are for extremely high rpm applications that result in the maximum amount of big-end flex. Again, that is the information in their bearing catalog.
The "H" bearing does have the increased chamfer to allow a .125 radius on the crank pin. Clevite also offers a bearing with the same characteristics as the "H" without the chamfer but my supplier does not stock them.

Re: Steel Crank Turned .040 ?
 

I CAN'T DOWNLOAD PICS I HAVE
BUT EMAIL ME AT [email protected]
I WILL SEND THEM TO YOU
MAYBE YOU CAN GET THEM POSTED? :(

Re: Steel Crank Turned .040 ?
 

I have'nt seen the pics, but how about the rod bolts, where they tested or replaced?
I had two different motors in different applications that were rebuilt and came back from a machine shop. After about 10 -12 hrs use, one started to pound out the rod bearings because the rod bolts would not hold a torque.
The other motor was not a marine application and it took longer to manifest the problem, but it turned out to be the same issue. Costly in time and money but lesson learned.
ARP bolts from now on for me.

Re: Steel Crank Turned .040 ?
 

EVRYTIME IT WAS REBUILT HE INSISTED ON A NEW COOLER
EXCEPT WHEN I TOLD HIM THE LAST TIME THAT HE'S GOING TO BUY ONE. THEN IT WAS I'LL GET IT CLEANED 6 HRS OF RUNNING SOLVENT THRU IT....SO NOW HE'S DOING IT AGAIN
IT REALLY DOESN'T MAKE SINCE TO TURN CRANK COST 105
BUT PITTSBURG CRANK WILL SELL YOU A REMAN CRANK FOR 250 WITH BEARINGS. THIS TIME HE WANTS TO PUT IT ON HIS DYNO FIRST THEN RUN IT AT 5500 THEN CHECK BEARING BEFORE I INSTAL IT IN BOAT.
I FIGURE IF HE DOESN'T BREAK THE CRANK AND THROW A ROD OUT THE BLOCK...MAYBE I COULD GO BOAT NEXT SEASON. :evilb:

Re: Steel Crank Turned .040 ?
 

I had knee surgery and can say IT SUCKS, don't have it done unless you really need it. Although not in constant pain anymore, My Knee constantly pops and cracks and is not fun to deal with... BBB

Re: Steel Crank Turned .040 ?
 

Has the oil cooler been replaced? I bought a 26 scarab with a 454 mag in a box, the previous owner rebuilt the engine 3x because of bearings, within 8 hours of each rebuild. the oil cooler was flushed each time. The machine shop had cleaned the cooler before we got it as well. When we got it, we flushed the cooler again, and got metal. Replaced it, and have had no trouble in over 30 hrs of use this season.

Re: Steel Crank Turned .040 ?
 

Change the oil coolers and all the hoses.
If you do a search on previous posts, you will find an oil cooler I cut open after it had been flushed :eek:

YOU CAN NEVER GET ALL THE PARTICLES OUT.

Why risk an engine for a couple of hundred of dollers.

Re: Steel Crank Turned .040 ?
 

Like I Said Before
I Have Replaced Oil Cooler Each Time We Have Rebuild This Engine, Except Last Time When I Told Him He Needs To Buy It. I Want To Just Get It Rebuilt And Get A Different Engine, I Personally Think That Someone Isn't Cleaning The Block Like It Should Be.
What About The Remote Oil Filter Adaptor On Side Of Engine? This That Spring In There Is Causing Me Any Issues? This Time He Is Going To Run Engine On Dyno And I Will Be There Before We Check The Bearings. If It Isn't Right I Will Insist On Return Of All Monies Involved.

Re: Steel Crank Turned .040 ?
 

TRYME's picshttp://www.hotboat.com/image_center/...5_Large_2_.JPG

Re: Steel Crank Turned .040 ?
 

TRYME'S BRGShttp://www.hotboat.com/image_center/...004_Large_.JPG

Re: Steel Crank Turned .040 ?
 

TRYME'S http://www.hotboat.com/image_center/...003_Large_.JPG

Re: Steel Crank Turned .040 ?
 

Re: Steel Crank Turned .040 ?
 

I see a contaminent issue(upon assy) with some lube starving would be my guess?

Re: Steel Crank Turned .040 ?
 

Thanks For Help Down Loading...
My Concern With These Pics
Is Taper On Worn Bearing, Deep Grove Are Understandable..objects Thru Oil
But Taper And One Bearing Is Obviously Spun
Notice Main Bear Thou....what Looks Like Flaking?
Anyone Ever See This Before?
I Have "turned Crank At Work Right Now, I Will Be Able To Check It With A Adcole Machine "before We Do This Again? I'm Thinking Crank Turner Has Machine Issues?
Thanks Again

Re: Steel Crank Turned .040 ?
 

It looks like it the brgs got hot and started to flake off babbit material. Dry at start up, lack of prelube on assembly, or maybe Tolerances too tight?

Re: Steel Crank Turned .040 ?
 

What oil temps are you running. Yes, at least one journal is tapered. The crank grinding is suspect. I also wonder what clearences the builder is setting up.

Re: Steel Crank Turned .040 ?
 

Oil Temp I Don't Know However I Have Coolers On Oil
And Temp Of Engine Never Hotter Than 165
I'll Keep You Posted.