What's the highest you can rev a stock bottom end...
05-01-2002, 11:14 PM
#1
What's the highest you can rev a stock bottom end... With a solid valve train? What would be the best compromise b/w longetivity and power for say Cartek SII heads with their H-cam? (asking for a friend) He was told he could rev to 7K but I was kind of leary about that. What do you think?
Thanks.
Thanks.
05-02-2002, 12:29 AM
#2
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Re: What's the highest you can rev a stock bottom end... My rev limiter is set at 7200 RPM. 7k is no problem with the right valve-train set up.
<small>[ May 02, 2002, 12:33 AM: Message edited by: DARTH VETTER ]</small>
<small>[ May 02, 2002, 12:33 AM: Message edited by: DARTH VETTER ]</small>
05-02-2002, 01:11 AM
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Re: What's the highest you can rev a stock bottom end... There have been several board members who are shifting at 6800 or higher on the stock short block. The SAM SS data logger recorded revs as high as 7500 on the stock short block I believe (accidental of course) and that wasn't exactly a daily driver either.
J.
J.
05-02-2002, 10:09 AM
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Re: What's the highest you can rev a stock bottom end... Ok it goes like this...
You CAN shift the stock bottom end up around 7400 or so. It CAN live up that high, for a time.
BUT, many folks have found (me included) that 6800 is about the limit that the stock bottom end will live for any length of time at.
It all depends on how well the factory cleaned up the bottom ends oil galleys and what the stock clearances are on the bearings.....not what they should be at, but what they are at.
As the motor RPMs go up.... heat inside the motor goes up and loads go up. This causes thermal expansion-side loading-bearing load-etc. and if the clearances are not up to snuff.....you end up with bearing failure.
In mine and many other enthusiasts mind....6800 should be about the limit of a stock bottom end.
Again, they CAN spin higher than 6800, but most wont-havent lived long at that level.
You CAN shift the stock bottom end up around 7400 or so. It CAN live up that high, for a time.
BUT, many folks have found (me included) that 6800 is about the limit that the stock bottom end will live for any length of time at.
It all depends on how well the factory cleaned up the bottom ends oil galleys and what the stock clearances are on the bearings.....not what they should be at, but what they are at.
As the motor RPMs go up.... heat inside the motor goes up and loads go up. This causes thermal expansion-side loading-bearing load-etc. and if the clearances are not up to snuff.....you end up with bearing failure.
In mine and many other enthusiasts mind....6800 should be about the limit of a stock bottom end.
Again, they CAN spin higher than 6800, but most wont-havent lived long at that level.
05-03-2002, 08:51 AM
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Re: What's the highest you can rev a stock bottom end... i have no intentions shifting that high in my car maybe when i do heads/cam up to about 6.5k at the max.....how will this have an affect on longevity of the stock bottom end?? i know it obviously wont be good for it but how long before im looking at a rebuild?? motor has 57k miles on it now and im looking to do heads and cam at the end of this year....
05-03-2002, 09:30 AM
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Re: What's the highest you can rev a stock bottom end... Another big problem is the stock rod bolts. If you can install ARP's throughout run a decent oil 7K rpm is livable but it wont last forever <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Cheers,
Chris
Cheers,
Chris
05-03-2002, 02:19 PM
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Re: What's the highest you can rev a stock bottom end... Good information all, FWIW I have 54k on my 99 Z and just got the heads and cam, right now I have the limiter set to 6600rpm but I know the car can and will shift a lot higher than that, I'm looking at 6800-6900 RPM shifts depending on my tuning. This is a daily driver than isn't going to be seeing too much track time to I'm not worried if my shift points are that high. Of course I did go with Comp R Lifters, Titanium Retainers, 987 Dual Springs, modified oil pump, etc.
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05-03-2002, 02:27 PM
#8
Re: What's the highest you can rev a stock bottom end... Just be careful folks.
My rev limiter was set to 6700 and the engine decided it didnt like that much. Good thing it didnt completely total the head castings. The rest of the enigne is toast. 22k miles.
Just another datapoint. I suspect rod bolts let go.
\chris
My rev limiter was set to 6700 and the engine decided it didnt like that much. Good thing it didnt completely total the head castings. The rest of the enigne is toast. 22k miles.
Just another datapoint. I suspect rod bolts let go.
\chris
