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

[Eagle 5]

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?

 

[mountain_man]

i am going to be blueprinting everything and balancing all the rods, crankshaft, pistons, etc...but i just haven't heard any deffinitve #'s... i will start with 7250 rpm and go up from there, b/c i am not worried about build quality.

and yeah ## probably right about not making the biggest #'s in the world but i am roadracer and mountain carver, so turbo's and lag aren't really my thing. But i am just hoping with about 10.5:1 compression and a stage 2 cam i can make about 200 whp. or is that being a little farfetched?

 

[VelocitàPaola]

But i am just hoping with about 10.5:1 compression and a stage 2 cam i can make about 200 whp. or is that being a little farfetched?

A little but... I forget what Mark's up to these days, but I believe it's only ~180whp. Mind you, he holds the record, not an average.

 

[DSM-ZERO]

i say go higher comp w/ stg 3 cams

I wwould not rev a sock motor past the 7250 redline.......but a built one. you only need to rev it as high as your making power........if your not making any power past 8000 why take it past 9000...there is no need to

I plan on taking my motor to 9k

 

[mountain_man]

this is still going to be a daily driven car, so i think a stage 3 cam is out of the question. I know the k20 motor makes 200hp stock, and that is also 2000cc...so what are some of the major draw backs to are motor compared to theres (cylinder head design, compustion chamber design, etc)?

if anybody tells me that they make all that power b/c of vtec, i will murder there first born...

 

[link16]

V-TEC does make a large difference, P&P the head, stage 2 cams. There is another step up in compression pistons I have seen 12.5:1 but I can't remember where. For N/A try finding those pistons b/c that would be nice to see a 420A hit 200whp.

 

[wvturbo2]

Variable Valve timing does play a large roll in Honda/Acura's success with their 4cyl. IF I was going to build a fwd N/a. I would build a new Civic Si or Rsx. In one of my old magazines they either made 400 hp or close to out of the k20 setup. I don't see why people don't like honda's if they like fwd. Good luck with your build, maybe you can be the first to make make your 420a have mivec . If you have a good tune for the cams you can get idle close to normal. I think you would be ok with stage 3 cams.

 

[Locke]

JE makes 12.5:1 pistons. Here is some that Howell sells.
http://www.howellautomotive.com/index.asp?PageAction=VIEWPROD&ProdID=257

Most companies will make whatever compression you want, you may have to call the manufacturer though.

 

[DSM-ZERO]

this is still going to be a daily driven car, so i think a stage 3 cam is out of the question. I know the k20 motor makes 200hp stock, and that is also 2000cc...so what are some of the major draw backs to are motor compared to theres (cylinder head design, compustion chamber design, etc)?

if anybody tells me that they make all that power b/c of vtec, i will murder there first born...

just know that the K stnd for killa because that thing is a murder'er MUAHHAHAHA
anyway
honda motor are desinged very very very good from the factory and the K series is pretty much the SHI%....

with a lots of had work and 10.5 C/R and stg 2 cams the record is around 180hp......
so if you want to get over that you might want to look into either higher compression, more aggressive cams, or ITB's

 

[DSM-ZERO]

talk to bulettdsm

he is the man right now for NA

 

[mountain_man]

speaking of ITB's...my father and I did fabricate a a twin throttle body setup. We milled the face off the off the top half of the manifold and created a closure plate for the original throttle body. the we went with a ram air intake system the throttle body's sat on top of the valve cover point to the front of the car. We then fabricate a U-shaped intake were 2 k&N airfilters picked up cold air through a modified cowl induction hood.

pretty nice but the hood looked like shit. But it was on a stock internals and head without a ecu tune to correct the air flow. But they worked and that is all we cared about so it is going to go on this new motor so maybe we can reach 185hp...

 

[xceler8]

Without much more than a ported head, I don't plan on pushing my rpm too much past factory redline. I don't have the ms soft rev limiter setup on mine yet. My mpas only go up to 7k. There's no reason why you can't run into redline as long as your fuel/spark can suport it and your motor is ready for it. You should also look into the benefits of going into redline, it might not gain you extra horses. Look into it more.

 

[dr1665]

Given what I know of Mark's current build and tune, I'd venture to say that Crower 3s, ITBs, and some seriously high engine speeds might just take someone to the mythical 200whp number on a stock displacement 2GNT.

I've looked into the C3s myself, but I'm not sure how drivability on the street plays out below 4krpm. C2s with 10.5:1CR and heavy portwork results in a loss of low end on the street. This sucks big time. C3s might be fun on a daily with mild portwork which keeps the intake velocities sharp.

I'd stay away from any CR > 11:1. Unless you like pinging at idle on race gas.

Back on topic, my bottom end was balanced out to 15krpm. Back when I was planning on MSnS, the idea was to set a hard limit around 10krpm and strap it to a dyno with WBO2. Keep an eye on the AFR and wind her out until the power peaks (I was guessing somewhere closer to 8500rpm). Then get into Megatune and set a soft-touch limiter around 8700rpm, just before a hard cut at 9000.

That was my plan. :shrug

 

[mountain_man]

hmm...dr1665 where u going to run the stage 3 cams?

What is working with Mega Squirt like? I have no ecu tuning experience, if someone could direct me to a thread or give me a idea of how hard it is to hook up i would appreciate it. So that way i can either go ahead and buy a premade unit or get started on making one myself?

thanks

 

[VelocitàPaola]

www.megasquirt.info

Read and decide how confident you are about building one.

Several of us here have built them for other members if you get stuck, or you want a pre-made unit.

 

[mountain_man]

if i wanted to get one yall to make one for me what would be a ballpark figure? I have seen them go for ~$350.00..

and after reading what all is involved I am def. not up to the task or do i possess the knowledge on how to do it?

does anybody in the Charlotte, Statesville, Ashville, Boone area have one where to where i can see it installed and talk with you. I am kind of a hands on guy and i don't really understand stuff untill i see it in person, sorry...

I would be wiling to meet u halfway, or drive to u meet @ your house, or whatever. I am in college so the best payment i can give you is a 6 pack of your favorite beer.

thanks

 

[bullettdsm]

Given what I know of Mark's current build and tune, I'd venture to say that Crower 3s, ITBs, and some seriously high engine speeds might just take someone to the mythical 200whp number on a stock displacement 2GNT.

I've looked into the C3s myself, but I'm not sure how drivability on the street plays out below 4krpm. C2s with 10.5:1CR and heavy portwork results in a loss of low end on the street. This sucks big time. C3s might be fun on a daily with mild portwork which keeps the intake velocities sharp.

I'd stay away from any CR > 11:1. Unless you like pinging at idle on race gas.

Back on topic, my bottom end was balanced out to 15krpm. Back when I was planning on MSnS, the idea was to set a hard limit around 10krpm and strap it to a dyno with WBO2. Keep an eye on the AFR and wind her out until the power peaks (I was guessing somewhere closer to 8500rpm). Then get into Megatune and set a soft-touch limiter around 8700rpm, just before a hard cut at 9000.

That was my plan. :shrug

Hmm, I've had a hard time getting on the last couple of days. Server errors. Anyhow;

This ^^^ f****r may not of followed though on his plan (yet), but he speaks in great wisdom

I agree with all except the CR. After my last dyno trip, I'm not believing that anymore. I want to step up to 12.5's (maybe even 12.9). BUT that is just my untested opinion. I'm TRYING to work on that

If you go with the C3's, probably no fun on the street. Low rpm problems.

IMO, 1mm larger valves, unnecessary. Won't help unless you're going turbo. The port work on these heads is pretty good. I'd tell you what I did but that's one thing I don't talk much about (other than generalities). Not that it's some secret special thing, it's just that my way is not the norm and many don't agree with my thought process. Their's probably get better flow, but I like my P + P.

As for rev's, I bounce mine off the 8200 rev limiter in the wet pit, all day long (alright, just until I heat up the slicks ) . Stock rods, stock crank, stock springs, My shift points are 7200- 7600 depending on a lot. Check my mod list to get an idea of what I'm running. Over 9k miles on the engine.

As for exhaust, oddly enough I used to think that 2.5 was ideal. I'm not buying that anymore. I really think that it's too big. I'm leaning toward 2 1/4 to 2 1/8 id (maybe even 2" id). This is just from testing different exhausts (no, no long tube header yet. Though I would suggest that someone work on that).

As for whp, my current number is 176whp. That is with the ase correction. I actually made 184whp that day but with the correction factor..blah, blah.. The dyno numbers are more of a play game for me. Dyno's are for testing set-ups; changes and tuning. The numbers are just a fun way to play. Though I would like to see 200whp ase corrected. That brings me to the most important part of your set-up (IMO).

Tuning. This should actually be your first mod, . Gotta unlock that crappy stock ecu. My thought is MSnS. I'm very happy with it. You NEED to study if you want to do it, but it is well worth it. I literally gained .4 in the quarter because of it. That is a pretty big change. Without a system to adjust fuel AND spark, you're pissing in the wind. MSnS FTW WTF

Great to see you playing with ITB concepts. You partially describe one of my ideas with the intake cut down. I've got a really goofy intake idea that, if I can get my guys together, I think you'll find pretty interesting (it may work for shit, but it will be pretty interesting).

Keep in mind guys, this is just the way I set-up my car. What is really, really cool here is the new interest in getting the NA to go. The more people that work on it, the better and faster she will be.

MB

 

[xceler8]

About the MS,find Terry Starturbotalon, he's the man. He'll put one together for you with base maps in it that will help out a lot. YOu won't have to worry about the little configurations taht are needed to set the car. A litle more tuning on itand you should have it running.
Go to the site Paola posted and just start reading, take a few notes on the important stuff and ask questions here and there. Defenitly not a hard thing to do, just takes some time and your trusty laptop.

 

[mountain_man]

thanks guys for all the help, i it has really answered alot of my questions.

Bulletdsm: I have been messing around with exausts also for quiet some time. I have run the whole gammit 2" side exit, 2" full", 2.5" full, blah, blah. Maybe you should try 2.5" exaust with a tip that narrow to 2.25". My Dad and I did that and I could FEEL a very noticable difference, so maybe with MSnS you might be able to get more power out of it. It has been my experience that if you want more backpressure you can always make you tip smaller and choke it down, just some food for thought. Maybe I should start a thread about what we have found that works and doesn't, b/c your right on some of your points...and i also have a few tricks that I've learned that everyone with might get some usefullness out of.

thanks again

 

[bullettdsm]

thanks guys for all the help, i it has really answered alot of my questions.

Bulletdsm: Maybe you should try 2.5" exaust with a tip that narrow to 2.25".

Funny, that's what I'm running right now. 2 1/2 with a reducer.

MB

 

[Locke]

It has been my experience that if you want more backpressure you can always make you tip smaller and choke it down,

That would be creating a venturi, to increase velocity to help scavenge the cylinders during a calculated rpm area. The resulting backpressure is an unwanted, yet unavoidable side-effect.

 

[dr1665]

This ^^^ f****r may not of followed though on his plan (yet), but he speaks in great wisdom

Dude. This cactusf****r. Get it right.

I followed through with the plan. I bought all the shit, put it together, and drove it daily for more than a year with a blown headgasket. I even drove it to Kansas City and back as recently as this past Christmas, through a blizzard in northern New Mexico on freaking Sportlines of all things. Despite wanting to fund my rally program these days, I could never revert the Talon back to stock. That engine... OOOOoooo.... that engine. I love it.

We'll see what comes of the Talon over the next couple years. Right now, it seems the head would really treat a turbo well (I've got those valves), but that's never really been my design. We'll see...

 

[ZLODEY]

Is it possible to have a combination of 2.3L stroker + high-rev engine?
I mean what are the requirements for getting quite safe redline let's say at 8000rpm?

 

[turbosax2]

A stroker should be safe revving to 8k as long as it's properly balanced.

Read this article for more information.

http://www.dsmtuners.com/forums/newbie-forum/271451-hard-calculations-strokers.html

 

[JayRolla]

8k rpm is about all you want to spin a stroker too. If you want a high rev motor with a little more torque look into a destroker kit. You would need a 2.4 block and a 2.0 crank. That would give you around 2.1. Read about them, they usually run 10.1 compression

 

[sbr240sx]

The stroker kit would be fine at 8K if you balance the rotating assembally. If you really want a high reving motor go with the de-stroke like JayRolla said.