8k rpm's on stock valves.

[bryanwheat]

So i am building my head up, crower single springs and titanium retainers, new revised lifters, ffwd 272 cams. I am wanting to turn this thing at the most 8 thousand rpm's, how do you guys think the stock valves will hold up with this kind of rpm?

 

[2gAWDTalon]

stock valves will be fine!

 

[damnslowtsi]

Sorry, I didn't get it but what is exactly your question? Are you questioning the physical strength of a valve itself? If so then drop your worries altogether.

 

[GVR4592]

Sorry, I didn't get it but what is exactly your question? Are you questioning the physical strength of a valve itself? If so then drop your worries altogether.

Having a little trouble with your reading comprehension?

how do you guys think the stock valves will hold up with this kind of rpm?

Seems pretty straightforward to me

 

[twicks69]

stock valves won't be an issue.

 

[damnslowtsi]

Having a little trouble with your reading comprehension?



Seems pretty straightforward to me

I think I understand English pretty well. I wasn't sure what he was asking. His question was not about specific valve train components being able to do the job at an x-RPM or something of that matter. Looked like he had already made the choice on those. He sounded like he was worried about a valve itself since it was stock. If that is the case then the question itself was a bit odd. Don't you think? Valve is just that a valve. If it doesn't meet a piston it will be fine. If he keeps the EGTs at bay and doesn't burn 1/3 of the valve head off it will be fine too. And so on.

 

[92awddsm]

He sounded like he was worried about a valve itself since it was stock. If that is the case then the question itself was a bit odd. Don't you think?

No, not at all. Some auto manufacturers use 2 piece valves that tend to break the heads off or tulip the heads at higher rpm or under severe duty. His question is legit and very understandable. Since you didnt understand what he was talking about or where he was coming from, it would have made more sense to just follow the thread and not reply. As Luke already stated, the question was pretty self explanatory.

And to the op, if the valves are in good shape and the exhaust valves have not been refaced to the point of having a razor edge, they will work fine at those rpm's.

 

[fourreGsixty3]

They will be fine as others have said, I would just pull them out, and go ever the stems, and also see how well the valve face, and seat interfer with each other...prehaps some slight grounding at them will be in order if slightly out of round. Also check the valves were not being sucked back upward's. Also you dont want too high of a spring pressure because it will make the motor work much harder to compress them, do some research into which set of spring's would be perfect for what your application is. When installing the cams dont instal them straight up, because there is a give set of min/max tolerances, there will be some strech in the belt, and thus retard the cams a few degree's. So install them 1-2* advanced, and break in period where the new part's are expanding will bring the cams into the correct range for lift/duration area. Also check the seat area for the spring's to make sure it is not pitted, ect, ect... Also instal height on the spring's are important so if you are doing this yourself ( very do-able) make sure all your math is correct for the perfect instal height, if you bring it to a head specialist they will do all this, and you most likely need not worry.

***Disclaimer*** When I said some grinding of the valve face might be in order to correct for out of round or to get a good interference do not do this yourself, take it to a machinist. It is very easy to mess them up if you dont know what you are doing, or dont have the proper tools...and for those wondering a die grinder, or sand paper is not the correct tool.

 

[GVR4592]

You're right about not installing the cam straight up, but you're wrong about advancing it a couple degrees. The only way to do it right is to install it according to the specs on the cam card or take it to the dyno and dial them in that way.

 

[fourreGsixty3]

I did not say it was going to be exact, but it would bring them into the ball park range. In an optimal set-up you would instal them a couple *s advanced break the car in, and use Adj. cam gears on a dyno to get exactly what you want out of them for valve overlap, when intakes open, and when they close in relation with the exhaust valves. Some advancement is better then some retarding of the cams, but like I said not an exact figure, but 1-2* is a decent # on which to go with.

 

[92awddsm]

I did not say it was going to be exact, but it would bring them into the ball park range. In an optimal set-up you would instal them a couple *s advanced break the car in, and use Adj. cam gears on a dyno to get exactly what you want out of them for valve overlap, when intakes open, and when they close in relation with the exhaust valves. Some advancement is better then some retarding of the cams, but like I said not an exact figure, but 1-2* is a decent # on which to go with.

Actually, if you dont degree them, straight up is the best bet. If I followed you procedure, my car would run like shit. After dyno tuning, my car made the most power with my in advanced 2* and exhaust retarded 3*. Alot of my friends with comps and fp cams end up the close to the same. Those with 272's that I have seen are usually somewhere around 1-2* adv on intake and 0-2* retarded on the exhaust. I would never suggest anything other than 0 on both unless there is a degree wheel attached to the crank snout.

 

[JayRolla]

Its always nice to have lighter valves in there though, this way less chance of breaking. My friend got some stainless steel ferrea valves for like $170 on ebay, but cant find them for under $220 now.

 

[fourreGsixty3]

Actually, if you dont degree them, straight up is the best bet. If I followed you procedure, my car would run like shit. After dyno tuning, my car made the most power with my in advanced 2* and exhaust retarded 3*. Alot of my friends with comps and fp cams end up the close to the same. Those with 272's that I have seen are usually somewhere around 1-2* adv on intake and 0-2* retarded on the exhaust. I would never suggest anything other than 0 on both unless there is a degree wheel attached to the crank snout.

Well if thats the case for your motor, and some of your friends then just instal them straight up, and do your dyno tuning, he said nothing about dynoing them in, or anything about adj. cam gears sooooo. I will say it again...this is just to bring it to a ball park, so that with streching of the belt, and expanding head parts. With what you are sayingstal them one will be off unless you have the adj. cam gears or can tune them in on a dyno...but also I said this for instal, and thats it. All this dyno tuning changes things because you can instal them straight-up, do some beat run's to get everything streched, and expanded in the head, then dyno it in...adj. cam gears are most desirable.

 

[GVR4592]

Well if thats the case for your motor, and some of your friends then just instal them straight up, and do your dyno tuning, he said nothing about dynoing them in, or anything about adj. cam gears sooooo. I will say it again...this is just to bring it to a ball park, so that with streching of the belt, and expanding head parts. With what you are sayingstal them one will be off unless you have the adj. cam gears or can tune them in on a dyno...but also I said this for instal, and thats it. All this dyno tuning changes things because you can instal them straight-up, do some beat run's to get everything streched, and expanded in the head, then dyno it in...adj. cam gears are most desirable.

You might think you're right, but you're not. After you build a few engine's and degree the cams, you'll see your theory doesn't work. You're obviously making an uneducated guess and that's against the rules. Please refrain from doing so in the future.

 

[92awddsm]

Well if thats the case for your motor, and some of your friends then just instal them straight up, and do your dyno tuning, he said nothing about dynoing them in, or anything about adj. cam gears sooooo. I will say it again...this is just to bring it to a ball park, so that with streching of the belt, and expanding head parts. With what you are sayingstal them one will be off unless you have the adj. cam gears or can tune them in on a dyno...but also I said this for instal, and thats it. All this dyno tuning changes things because you can instal them straight-up, do some beat run's to get everything streched, and expanded in the head, then dyno it in...adj. cam gears are most desirable.

How much stretching of the timing belt is going to happen? The aramid fibers in the belt will not let it stretch enough to affect cam timing. If your timing belt is stretched that much, you better be replacing it. If not, it will break very soon. With the tooth design on our timing components, any stretching will be destructive.

And I dont quite get the last part of what you are saying. You are the one that brought up adjustable cam gears and dyno tuning. I was just adding in my personal experiences.

 

[Ultimatedsm]

Your original question was that can the stock valves handle at most 8000 RPM. The answer is yes. Now go build your motor and hopefully don't proove us wrong just kidding, you will be perfectly fine at 8000 RPM with your build up.

 

[diambo4life]

Reinventing the damn wheel again aren't we?

Pick up a good quality set of camshafts that have accurate index, leave your cam sprockets ZEROED like they are stock and rev that stock head to 8,250-8,500 rpm all day. How do I know? Did it for years.

Make sure your valvetrain is in good condition though. Factory stuff works just fine.

 

[danl]

I ran my stock valvetrain to 8200rpm's quite a few times. 8000rpm rev limiter for 2.5 years and 15K miles or so. Lots of time on the 8000rpm rev limiter. I ran it to 8500 a few times just seeing what would happen first, throwing a stock rod or kissing a valve. All was fine never hurt anything.

 

[nitrouskris]

i have been on a stock valvetrain for 2 years and i have been over 8000rpm a ton of times.

 

[damnslowtsi]

What cams do you guys (Dan, Kris) run? Stock or AM? I 've hit 7800 quite a few times now with HKS 272s with no probs. I 'm curious how big of a cushion I still have. I 've heard before of 8200 being ok with 272s. Just want to see more examples.

 

[nitrouskris]

What cams do you guys (Dan, Kris) run? Stock or AM? I 've hit 7800 quite a few times now with HKS 272s with no probs. I 'm curious how big of a cushion I still have. I 've heard before of 8200 being ok with 272s. Just want to see more examples.

i have customs cam now but i have had 272 and 280 without a problem.

 

[aliengotpsi]

You will be just fine with stock valves.

 

[Terrh]

totally stock head on my car, 7800rpm daily, no fear.

 

[MarkAngelo05]

Hi!

I just bought a 1995 Eclipse GST with a 6 bolt swap, TRE RACE TRANS, etc. The compression checked out, and it is a stock 6 bolt motor. The motor runs very smoothly and sounds very quiet, even though it's got stock 1G lifters.. He's only ran mobil 1 synthetic oil in it.

Previous owner seems to be trusworty, and showed me that he put on a new waterpump, timing belt, removed balance shafts, and the compression was healthy. Which is why he swapped it in the first place.

Should I do a rebuild before swapping it into my 97 GST? or should I just swap it over.

I know that I am taking the head off to put in a cometic head gasket and ARP head studs.

I'm not looking to go over 400whp. I'll be very happy to make over 300whp SAFELY. I'll be boosting around 20-22 psi with an 18G variant turbo with a 15 degree clipped TD05 wheel. Using Extreme turbo system's 10 inch tall 3 inch thick Race intercooler.

I'll also be installing BC 272's when we do all this.

To beable to rev to 8k rpms, will BC springs and retainers be good enough? or I do not need anything else, like rods/piston combo?

Currently tuning with DSMCHIPS/Jeff's help and AFC. with a wideband a/f system.
Looking towards dsmlink.

Thanks!

Mark Padilla

 

[JayRolla]

I would not fix it untill it needs it. The 6 bolts can take a lot of abuse. When I went to the dyno the tuner was like these cars have great motors. Cant even blow them up with a hand grenade.