The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Fuel Injector Clinic
Please Support ExtremePSI

How high can engine rev safely? [Merged 12-7]

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Eagle 5

20+ Year Contributor
380
2
Jan 26, 2003
Cincinnati, Ohio
How high can the 420A engine rev safely on stock springs and retainers without worrying about valves floating or what not? Also, what is needed to get rid of the rev limiters ? (7200 and 7800 fuel/ignition cuts) would a msd ignition work? just wondering. Im rebuilding my engine and Im trying to decide what to do head wise. Originally i was going to get stainless valves, crower springs, retainers, pt cruiser lifters, rockers but someone said I should get cams and get port work done instead of getting the wprings, retainers and lifters since the stock ones are fine. anyone know?
 
I know it’s possible, but what should be done and what to pay most attention to make it RELIABLE?
 
The obvious things need to be paid attention to- springs and retainers, cams to shift the powerband, and ATI or Fluidamper pulley. Most strokers don't have a powerband thay high anyways so there is no reason to rev that high.
 
a reliable dsm haha its hard to make our cars reliable you have to constantly keep up on your routine maintenance the most important thing in what your trying to do is making sure everything is balanced properly its great to see guys going out and trying something new not like cavalier guys who just get custom floor mats and a shift nob hope every thing works out for ya let me know how it works out for ya
 
I know it’s possible, but what should be done and what to pay most attention to make it RELIABLE?

Light weight rods and pistons will help compensate for the higher stresses that come with the longer stroke of the 2.3L.

There are several charts in the document referenced by turbosax2 that show piston dynamics vs. RPM for the stock engine and the stroker. Find the RPM on the stock engine that suits your idea of “reliable” and limit the stroker to the RPM that has the same load. Also see the table of Summary of Calculations on page 45 where the stroker loads are referenced to the stock 2.0L at 8000 RPM.

The author of that StrokeOrNot document (cough, cough) is an old retired guy that wanted it all. A Talon with low end grunt like the hemi of old, top end power even better than the beloved 98 TSI, and reliability to keep running a DSM on a limited income.

You can make a DSM reliable OR you can make a DSM a winning dragster. Pick one.
 
Im gettin ready to throw in the bc 272s, I was gonna leave my stock valve train but it would be nice to rev higher and get the most out of the cams.. so how high could i rev with titanium valve springs and retainers?:talon: Is it worth to rev higher than stock or will I just lose power, oh and Im sticking with the 14b til spring thanx guys!!
 
Cam's will allow your to rev higher.. But it doesn't matter how high you can rev your motor.. It's how high your turbo can spool while still making power... So if your not running a turbo that'll last as long as your new power band then it really doesnt matter how high you rev
 
Revving higher won't help if you're beyond the flow efficiency of your engine

That includes the size of your turbo, and how much air your entire setup as a whole system flows (Intake manifold, head, throttle body, exhaust, etc)
 
Just do the springs.

Valve float will cost you your motor and head, you might get lucky and only lose the head but $300-$3000+ in repairs if you can replace it yourself is not worth it.

Not to mention then you wont have to rip the cams out again and re-time it.

You cant rev any higher till you get a eprom chipped ecu and have a chip made that will allow you to rev higher.

You will notice more pull but youll notice it more with a non stock turbo.
 
I agree with silver... But the whole factor being that you are already doing the cams, which means you'll have the head off.. Just do the valve train over.. If you need some real good prices pm me.. I get the serious discount on them.. But IMHO i'd say up the valvetrain now.. Instead of worrying about a floating valve or hung valve later...:thumb:
 
I'm sure you couldn't rev to idle with titanium valve springs. ;)


I've always been under the impression that Ti is so brittle that you couldn't make a spring out of it, or it wouls snap the minute it moved.I've always just known the retainers to be made from Ti. Am i right? Or are they using an alloy on the springs containing Ti?

anytime i hear Titanium valve springs the first thing that comes to mind is The fast and furious.
 
I've always been under the impression that Ti is so brittle that you couldn't make a spring out of it, or it wouls snap the minute it moved.I've always just known the retainers to be made from Ti. Am i right? Or are they using an alloy on the springs containing Ti?

anytime i hear Titanium valve springs the first thing that comes to mind is The fast and furious.

I've done some research on this.. Being that i've only heard of titanium retainers.. On further research I found out that companies have Titanium Valves, springs, retainers, ect.. I think I even saw a set of titanium rockers.. But most of them are mad for top fuelers and cars like that.. Haven't seen any for dsm's yet.. Happy Hunting..

I found all of my info on a google search for titanium valve springs btw
 
I've always been under the impression that Ti is so brittle that you couldn't make a spring out of it, or it wouls snap the minute it moved.I've always just known the retainers to be made from Ti. Am i right? Or are they using an alloy on the springs containing Ti?

You're right. Titanium (and Ti alloys) are very rigid, and wouldn't make for a suitable spring.

Very useful in other situations though, where high strength and rigidity are needed with minimal weight, like connecting rods, for instance.

anytime i hear Titanium valve springs the first thing that comes to mind is The fast and furious.

Same here. The movie that taught the youth of America the fundamentals of automotive performance. :toobad:
 
Every set of Ti valve springs i've clicked on goes on to say " high pressure spring w/ titanium retainer" but i haven't found a DSM link to springs that said Ti Springs... *shrugs*
 
Every set of Ti valve springs i've clicked on goes on to say " high pressure spring w/ titanium retainer" but i haven't found a DSM link to springs that said Ti Springs... *shrugs*

You made me look. Over the years I have seen many references to 4G63s with Titanium valve springs but never a trusted source for them. Google still finds many references to Titanium valve springs from such sources as EBay, Craigslist, and Myspace. Not my favorite trusted sources.

Like turboglenn, every time I traced a reference back to a source such as Crower or Buschur Racing I found steel springs with Titanium retainers. Looks to me as people are conflating “springs with Titanium retainers” into “Titanium springs and retainers”.

For what it’s worth Titanium valve springs are made for extreme duty use. See Renton Coil Spring | Performance | Auto Racing

“Titanium springs are not “forever”, Titanium does not exhibit the same “infinite life” characteristic that carbon steel provide at low stress numbers. However for high performance-limited life applications such as racing, where the springs are replaced regularly titanium simply can’t be beat.
The titanium valve springs are also a better value. Although they cost more than the steel valve springs they will last 5 to 7 times longer. The steel springs will begin to take set during the burnout. Whereas the RCS titanium springs will last between 10 and 20 runs.”
From the sound of that advertising bit I think I’ll stick to my steel springs and Titanium retainers.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top