How many RPMs to spin the engine?
How many RPMs to spin the engine? I think i pretty much have all my parts in my sig. Seems like it is mostly based on the bottom end and valvetrain being able to handle the REVs, along with the cam profile? Last time i had it dyno tuned only went to 5500. With my new set up i think my air filter is going to be my main restriction....not sure how to improve this i might have the tuner do a pull with no filter 
. but anyway i just cant find much Info on how good the SLP 402 cast iron block can turn.....
. but anyway i just cant find much Info on how good the SLP 402 cast iron block can turn..... Why not ask SLP? Generally, engines are rev'd around 100 RPM or so past the RPM where the engine's peak power drops off. We can't tell you for sure where that is, but, w/ that set up, would estimate max HP to be around 6000-6200. Also, wouldn't expect the block to be an issue @ that max RPM.
Again ,this is a general description regarding max RPM. I would confirm w/ the block supplier & your tuner. The dyno will confirm where peak HP RPM is.
Again ,this is a general description regarding max RPM. I would confirm w/ the block supplier & your tuner. The dyno will confirm where peak HP RPM is.
That shortblock will handle 7000 RPM no problem with H-Beam rods and ARP rod bolts. The problem will be the cam, springs, and 1.8:1 rockers.
As it stands, I think you're going to choke the engine out at 6k+ RPM with that topend setup. And I think you might have some valvetrain instability at 6k+ RPM as well with those heavy HS 1.8:1 rockers. With Beehive springs that would be my guess as to what will happen since the HS rockers are hard to control even with beefy dual springs. If you had really stout springs and pushrods, it probably won't nose over with valve float, but it probably won't make a ton of power up there either, because that cam is pretty small for a 402.
As it stands, I think you're going to choke the engine out at 6k+ RPM with that topend setup. And I think you might have some valvetrain instability at 6k+ RPM as well with those heavy HS 1.8:1 rockers. With Beehive springs that would be my guess as to what will happen since the HS rockers are hard to control even with beefy dual springs. If you had really stout springs and pushrods, it probably won't nose over with valve float, but it probably won't make a ton of power up there either, because that cam is pretty small for a 402.
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Joined: Sep 2009
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From: PA/MD
I wouldn't see your bottom end being a problem at all.....I spin my iron 408 to 8,000rpms...like said above, I think your cam will choke out before anything, and the rockers will lose stability....but I see you being able to spin to atleast past stock 6,200 rpm redline.
Oh wow , i didn't know the HS's would be that bad lol... yeah i just bumped up the rev limiter to 6500 i dont mind the cam being small it makes a very nice TQ curve from very low RPMs. And not being "production" heads i have no idea what kind of piston to valve clearance i have .... so i wanted less lift to be on the safe side. Pretty sure i am going to rip the motor out this fall and go turbo or get the NOS set up.... i need mopar !
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
I don't like the 1.8s but other then that 7k shouldn't be a problem. Doesn't mean it will make good power that high but I can see how that would be a good torquey setup.
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Verdad Gallardo TECH Addict
Joined: Sep 2009
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From: PA/MD
I bet your car has almost stock street manners too doesn't it? (With a lot more *** than stock a the same time lol)
Dyno guy called ... said i am getting tons of false knock and the TPS is not working correctly.... hope she gets done today i have a car show im entered in tomm. lol
