Has anyone on here had a CAT rod or crank break?

[WELTERRACER]

Curious if anyone on here has had any bad luck with a FORGED CAT rod! or Crank!

[yody]

I know this is from the other thread, but it also isn't necessarily a "break? it can be faulty machine work, like the rod ends out of round, or the crank takes huge amount of mallory to balance, or break. Not a lot of guys on this site build their motors their selfs, you might try team chevelle@ chevelles.com I have seen numerous posts there but a search didn't dig up anything for some reason. Also make sure people don't get it mixed up with "Scat"

[yody]

also check nastyz28.com there are a few posts about cat there

[graycamaro]

Are you thinking of useing them for your 700+ hp engine because I wouldn't. We have tryed them in some Modified stock car engines in the past with failure in nearly every case. FYI a modified engine puts out in the neighborhood of 650+ hp NA so for a 700hp supercharged car I would not even consider it.

My boss considers Callies to be the best crank in his oppinion but we use Eagle and Scat as well.

Hope this info will help you in your decision James

[WELTERRACER]

Are you thinking of useing them for your 700+ hp engine because I wouldn't. We have tryed them in some Modified stock car engines in the past with failure in nearly every case. FYI a modified engine puts out in the neighborhood of 650+ hp NA so for a 700hp supercharged car I would not even consider it.

My boss considers Callies to be the best crank in his oppinion but we use Eagle and Scat as well.

Hope this info will help you in your decision James

Did you actually used CAT rods or are you talking SCAT rods..

RPMs are the biggest killer of rods... What RPMS where you running in your modified stock car? (stock cars use alot higher sustained rpms than a street car with ocational drag racing)

[graycamaro]

Actually I was speaking of cat cranks being the failure point in these engines. The number 1 reason for rods to fail as for as spin a bearing is probably do to the fact many engine builder think if the rod is new that must mean it is on size. At the machine shop where I work we comonly have to recondition brand new rods to make them in perfectly in spec. When a customer asks us how much rpm they can turn safely we tell them as much as they want because generally they will run out of their powerband before they will damage the engine.

Stock cars generally turn 7500-8500 with a few guys turning them harder. Depends on the drivers likes, the chasis, and the track.

A guy recently brought in a new 302 Dart block and Cat crank among other parts for us to do some machine work and despite what my boss has told him about our experience with Cat cranks he is still going to use it. The engine is going to be blown and stroked so we will see how it holds up.

How much is the Cat crank and how much is a comparable crank from callies, Eagle, Scat , or Lunatti? Remember the old adadge you get what you pay for!

James

[WELTERRACER]

i paid $360 for the crank and $250 for the rods (H beam).. they are both forged 4340 steel! a similar eagle crank would cost $900 and eagle rods would cost $500

Actually the crank im using isnt CAT is a made by MADDOGRACING(im not sure if it makes it better or not) The crank is supposidly good for applications over 1000 HP and the rods are good for applications over 700hp

My blown engine will not see higher than 7000rpms for short drag stip burts!

[yody]

you can keep telling yourself whatever you want and using !!!! after everytime you mention that your rods are forged steel, but that doesnt' mean anything. And do you really think some place on ebay called "maddogracing" makes cranks?? Just think about it for a minute. YOu are not guaranteed a failure but for a 7000rpm motor with wha 12-15 ilbs of boost at 700hp you are asking for it!! I know what boat you are in right now, you know you shouldn't use those components but at the time you were cheap and ignorant and now you are trying to convice yourself htat it will be allright. Just forget about using those components, and get yourself a scat steel crank/rods. Just resell the stuff on ebay, if you take a small loss, who cares. It will be worth the piece of mind.

[Blown353]

I wish you luck. Have them thoroughly checked out, especially the rods. Don't be surprised if the rods have all sorts of issues on the big end.

If there's anything I've learned over the years after replacing broken parts, it's this: If you buy cheap, you buy twice.

If you keep an eye out, you can often get sweet deals on lightly used high end stuff. I would take used higher end stuff over similarly priced new "cheaper" product lines any day of the week.

Troy

[blown69nova]

I have a buddy who is making 900+ rwtq and hp with a stock Chrysler forged crank and stock block with twin turbos. He has been using this combo for years and has made more than 50, 9sec passes and not one failure! The moral-precision machining, maticulous assembly and careful, methodical tuning! Good luck.

[yody]

yeah, a stock forged crank is way more dependable than some chinese forged stuff, at least scat and eagle stuff is checked and measured in the U.S.
I have heard that eagle has good rods and that their cranks suck
scat has good rods and their cranks sometimes suck but are more likely to be good than eagles

[WELTERRACER]

o.k. Im glad you know it all yody! Like i said before im having the parts checked at the machine shop and soo far soo good!

[yody]

o.k. Im glad you know it all yody! Like i said before im having the parts checked at the machine shop and soo far soo good!

hey, thanks! me too! Well maybe you will prove us wrong or just have a lucky experience. who knows.

[graycamaro]

Yody thanks I wanted to put it that way but I was being nice, It seems like everytime I make a recomendation or suggestion or post my experiences someone always chimes in saying Im wrong thanks for backing me up on this one.

Believe me when I say it is not a matter of who checks out the parts or machines them if you have a crappy part it is a crappy part. You cant make a Cadillac out of a Pinto no matter how good you are. there is a reason those parts are so cheap. Also are you having the assembly ballanced because usually with these cranks it will take alot of work to get it ballanced right or even close to right.

I would take yody's advice and resell the stuff you got and buy new or have fun trying to prove everybody else wrong.
James

[WELTERRACER]

Im a risk taker and i would love to prove everyone wrong.... If she blows up i will be the first to admit the parts were junk... But hey anything has to be stronger than the CAST rods and CAST crank i was using before that DIDNT blow up..

Had i ran the race fuel i was told to use or retarded the timing or ran an intercooler or added the thicker head gaskets i probobly wouldnt have blown up my motor in the first place... BUt im sometimes lazy or looking for a reason to rebuild my worn motor... Pretty much everything on my car has come from either the internet or was purchased thew ebay!

[yody]

I just don't think you understand what we are talking about here, it doesnt' necessarily mean what it is made out of, but how it is made, you could make a crank out of titanium, but if it isn't made to spec and have very high machining tolerances, it will be a piece of crap. Hey you might be fine with the stuff, good luck. Be sure to post up when it does blow though

[SatisTraction]

i know your feelings are hurt but they are telling you the truth. in the end you could have built a much better and longer lasting engine for about $800 more. once it blows you have to start over and you have wasted all that $$$ on scap metal. a crank driver blower (if that is what you are using) is WAY harder on the snout of a crank then any other combination. Go to any performance site with lots of blown cars (www.corral.net) and look at all the pics of cars with broke crank snouts.

[SatisTraction]

repost

[SatisTraction]

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[SatisTraction]

how did that happen?