The rod showed in this post is out of my motor. At the time Royal purple 10w-30 was being used, rod bearing clearances were at .0017. The damage became audible just after a low boost pull (17 psi) @ 568 whp. The motor was taken to 9,400 rpm. It was shut down as soon as we heard the knocking coming from the bottom end. All other rods, bearings, pistons, and wrist pins appeared to be fine. Pretty bummed with the customer service over at Crower though. I am weary of taking the motor passed 9,200 now, I can't really say that I'm am confident that they will hold up. I did, however, take my b16 up to 10,600 with crower rods with no problems. BTW, I'm not on here to bash Crower.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Marlon88 &raquo;</TD></TR><TR><TD CLASS="quote">I had E-mailed the link to this Post to Crower and Brian Crower sent me back and he told me :

There's obvious heat (discoloration) in the rod as a result of a spun rod
bearing.

Run your rods with confidence.

Thanks for your interest in Crower.
Guess now I could sleep better at night </TD></TR></TABLE>
Without a doubt, that is the worst case of lack of customer support I have ever seen. Of course the rod bearing spun, duh. Why did it spin? Now, I think they deserve all the bad karma they are gathering. I officially give up my Crower dealer status...well I never bought anything from them anyway

 

Where are those rods made???

In USA or Asia, maybe that is the problem. I know that there are difference not only in price.

 

I was probably on borrowed time, but my last engine had eagles and making over 500 whp was spun to 9800. However, on an engine that revs that high making more than 125hp per hole, I would have set the bearings up looser than 17 thou. Not placing blame at all, because I still think it's a chicken and the egg thing, very difficult to tell if the bearing spun first or if the rod deformed first, there will always be advocates of both.

 

I agree. I would never set the clearance that tight on a turbo motor making that much power.

.002" is the minimum for me on ANY motor I build for performance.
That is just me, but I learned my lesson a long time ago with tight clearances and low weight oil!!!

 

I have to agree, less than .002" is pushing it. It looks to me like a case of bolt failure or one that was improperly pre-loaded. What did the bolts look like ? The only way the rod could open up like that is if the bolt stretched beyond it's designed capacity. Were they torqued at assy. or was the bolt stretch measured? I had a rod (Non-Crower, High end) that wasn't tapped (thread rolled) deep enough and would not stretch when torqued to spec.. It was caught before assy, since we disassemble, clean, re-torque, and measure all rods to determine clearances. We have used Crower, Pauter, Manley, without problems. A rod that has discolored like that shouldn't be re-built, since the heat has changed the metalurgy of the rod. It is heat treated to a certain spec. during mfg. and that has changed due to the heat build up when the brg. spun. All rods flex (everything flexes before it becomes strong, that's why you pre-load concrete bridges) and that's part of the reason a bearing is thinner at the parting line to allow extra clearance for it. There are so many variables other than how much HP it makes. The highest load is at the top during overlap (intake and exhaust both open, no back pressure) . This means the reciprocating weight and RPM is the most critical since the force increases by the square of the RPM. In general, a Pauter weighs more than others, but they still work well as do the others. Without a doubt, Crower needs to fix their delivery and customer service.

 

wow, just from reading this post, i realize that i have ALOT to learn.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NuclearB18B &raquo;</TD></TR><TR><TD CLASS="quote">wow, just from reading this post, i realize that i have ALOT to learn. </TD></TR></TABLE>
Yeah, I don't think I have ever felt so dumb in all my life (and I am in law school right now) to all the smart guys in this thread and to me for having a lot to learn

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Marlon88 &raquo;</TD></TR><TR><TD CLASS="quote">Guess now I could sleep better at night </TD></TR></TABLE>

I added this sentence , that`s why I made the line so I can say something about what he said

There is alot of technical stuff that had been said and I can`t get that technical to say some thing that I can compare to you guys

Hope that my Billet Crowers will hold up fine in my Street/Strip motor

 

I agree with a .002 clearence but my motor has .0016 on the rods. I spin that lil ho to 10,000 rpm and make 812hp. I use royal racing#41. I ripped it down after 12dyno pulls and 8 passes at the track and they look great.

 

I know of some other big hp hondas that run less than .002 as well with no problems

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">A rod that has discolored like that shouldn't be re-built, since the heat has changed the metalurgy of the rod. It is heat treated to a certain spec. during mfg. and that has changed due to the heat build up when the brg. spun. </TD></TR></TABLE>I have to disagree with you here. The pretty purple/blue discoloration is only on the surface of the metal and does not affect the strength of the rod at all. I got this straight from the mouth of Don Pauter. However, if they were really ugly, I just as soon throw them away.

 

Whats that old saying? something about too tight and everyone knows about it, or something like that??

 

When your motor is too tight everyone knows about it, when it's too loose only you know about it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2.0Coupe &raquo;</TD></TR><TR><TD CLASS="quote">I ripped it down after 12dyno pulls and 8 passes at the track and they look great.</TD></TR></TABLE>

You realize that really isn't ****, right? Especially ona GSR Crank...I personally run .002 or larger on all of my personal stuff. You just have to get your oil viscosity right.

 

Correct on the oil weight. You can run .0017" or .0022" with the same results by just changing weights. Not sure which route is the most proper for long life at high performance. They both seem to work although I won't go more than .002" personally.

 

Ok cuz, I'm just sayen though.

 

Damn this thread makes me nervous.......

 

This is probably the best tech oriented thread I've read on H-T in probably a year or two. It almost makes me want to get engineers involved, Camplete / various design software, and free beer, to get the import community some serious knowledge

I'm on a second build with my Crower Billets. Most they ever saw was 400whp / 10,000rpm. On the rebuild they were all within spec when they came out of the box originally. They again made 360whp and 10,000rpm's on my last tune.

No complaints here, but its not saying a company isn't impervious to bad batches, or someone putting out a "Friday" rod vs. a "Monday" rod. I remember back when Crower cams snapping into many pieces was the big fear.

 

I wouldn't lose any sleep over using the Crowers. It looks to me like a case of bolt failure or one that was improperly pre-loaded. What did the bolts look like ? The only way the rod could open up like that is if the bolt stretched beyond it's designed capacity. Were they torqued at assy. or was the bolt stretch measured?
Of coarse the discoloration is only on the surface. when you heat treat steel the outside is black or blue (depending on how much oxygen is present). If you grind off the surface it shines like a non-heat treated piece. The metalurgy has changed on the heat treated piece. Another issue could be running the short skirted (truss style)pistons with too much clearance vs. the full slipper skirt piston in a high HP turbo application. The shorter skirt can rock more as clearances are opened up for the turbo's added heat expansion. If the piston created added drag by rocking excessivly on the down stroke, it would create abnormal stress at the rod's seam and bolts. I prefer the slipper skirt in turbo applications for this reason. At the PRI show I spoke with Bill Miller BME about a build coming up and he is pretty animated about not useing a light design to make big HP (he makes the 8000 HP TOP Fuel pistons and aluminum rods) . Oliver Rods has a good FEA comparison of their parabolic beam vs. an H-beam design in their catalog. It's not on their web site or I would give you the address. If anyone is going to throw their Crowers in the trash, IM me and I'll pay postage for you to send them to me . I'm off the wagon on Crower's bad, on the wagon Crowers service stinks.