What kind of revs can a stock motor take? what about after a head and valvetrain upgrade(excluding a cam)?

 

The stock shortblock can pretty routinely handle 6500 with some guys going to 7-7100, the stock springs are going to float probably by 5300 or so though and the stock cam with upgraded springs is probably only good for 5800-5900.

Far as "head upgrades excluding cam" if you have ideas about running a stock cam with head and valvetrain upgrades please just sell the car to someone who will at least try and do things right.

 

K, well I guess youve already answered my next question. which is what you could rev it to after a cam aswell . Thanks

 

The amount of usable revs depends on the cam. Revving a stock cam to the moon does absolutely nothing since it stops making power far before 6000rpm.

 

really with stock rod bolts? well that makes me feel better about a 6500 red line, I've seen so many people say you shouldnt go past 6300 w/ the stock rod bolts, I'll def take your word over theirs.

 

If I was gonna do some Upgrades to a Stock motor & its a high milage motor Id first get a complete rebuild kit Ive seen too many younger guys do heads & a cam Just to blow it up A rebuild kit can be had for 500 from a non sponsor & thats with good parts!!!

 

How can you rebuild for $500?
IMO the most important part of a "rebuild for reliability" such as you are suggesting is reconditioning the rods.
Just reconditioning the rods when you consider pressing the pistons and buying some ARP hardware plus the reconditioning itself will easily be over $200. Last I checked rings are over $100 a set for these metric pistons.

$500 is an unrealistic number once you throw in additional labor for cleaning things trueing any surfaces, bearings, gaskets etc..

IMO a lot of failures come from mediocre inconsistent parts combined with tuners who are popular but not good.
You have a pair of heads that the flow port to port varies, then combine it with the inherent inconsistency in intake flow and you already have some rich and lean cylinders with the PORT INJECTION this would be less of an issue with a carb or TBI that mix the fuel before the port. Then combine it with a tuner who halfasses the majority of his work and sends guys tunes that are good for 14:1 ARF and 40degrees of timing at WOT and yeah **** breaks.

I spun a rod bearing in one engine but I had tried running that setup with a GM pump and homemade relay kit and it was lean till I put a Racetronix kit on and the tuner I was using at the time didn't really make the changes he should have which lead to detonation in hot weather too even once I had the fueling resolved. That engine only lasted a few months, the next junkyards shortblock has seen more rpm for a longer time but I never let it detonate from fueling and tuning issues like I had the first.

People think of detonation as something that damages pistons but it can damage pretty much everything.
They also think a wideband tells them more than it does. If your ports vary, then the intake manifold imbalance align with a injector that flows on the lowend and a port that flows on the highend a single cylinder can be quite lean while the wideband shows the bank to be properly fueled. Then you use a tuner that doesn't bother to adjust say the IAT temp vs timing scale and in hot weather it detonates a little and hammers away at the bearing bit by bit. Maybe that sounds like "perfect storm" of things gone wrong but it is all very common things and on each engine you have 8 changes for it to happen. Hell throw some poor fuel into the mix or a car that sits and gets run on stale fuel.

So IMO good parts and a competent owner have a lot more to do with stock shortblock reliability than miles or the fact it is a "stock shortblock".

 

Exactly, we used to test bone stock LT's and the power was all over by app 5300 RPM, so GM had it pretty close to the 5700 RPM rev limit.





[QUOTE=96capricemgr;16729110]
People think of detonation as something that damages pistons but it can damage pretty much everything.


Yup, pass the pistons to the rods to the crank,

 

Original motor in my '94 Z28 peaked at 5600. There was no use in going higher.

And yes, detonation can pound on everything. Last motor failed due to detonation and it even managed to break a lifter (among other things).

 

^^^^Where the heck have you been?

 

It is well worth reving past peak HP to use the whole top of the torque curve and keep the engine higher in the power curve after the shift.

 

Working on the Blue Beast and Camaro6. Both are running now.

 

How true, my peak power comes at 5600rpms but at 6000rpms it only drops off about 7 hp. Meaning when it shifts into second gear (auto) I'm at about 3900rpms which is my peak torque. At WOT the car doesn't bog when shifting into the next gear like it would if I shifted at 5600rpms. These are the great things that can be learned here. Whether this great info is used remains to be seen.

 

We set my last combo up to shift from peak HP, dropping to peak torque. That resulted in the best timeslips. If the revs were dropping too far down on the upshift, we raised the shift point. Main goal was to keep it in the meat of the powerband all the way down the track.

The setup I was referring to (LONG time ago) nosed over after 5600. It was done after that.

 

On the stock cam i shifted at 6000 and grabbed the next gear, it in turn went down to 4000...= no bog!

 

With properly sized stall, the engine drops right where you want it....

 

Properly selected converter AND a proper PCM tune.

 

This is a prime example of why a well thought out and setup car can run so much better than a torn together one. So many little tricks that make a huge difference in performance and drivablity.

 

Alright guys one more, would it help any to have rebuilt the engine with all ARP hardware? mainly rod bolts

 

Yeah a well refreshed engine with arp rodbolts can handle all the rpm the pcm can handle.
That is going to cost you more than you think though, the $500 number tossed out was a pipe dream.
Then you will need to spend easily $2500 on heads and valvetrain to support it well and make power up there. How modded is the rest of the car, the car needs a lot of supporting mods to handle an engine like that.