turbo or type R?
WHAT!?! OK!......
Joined: Jul 2002
Posts: 201
Likes: 0
Originally posted by Cronic
Get the hell out of the tech forum if you don't know what your talking about. Quit spreading misinformation.
PSI has nothing to do with valves, the valvetrain, or anything.
17psi will run fine with stock valvetrain. It will not damage anything.
Get the hell out of the tech forum if you don't know what your talking about. Quit spreading misinformation.
PSI has nothing to do with valves, the valvetrain, or anything.
17psi will run fine with stock valvetrain. It will not damage anything.
Yes Higher than stock RPM causes the valvespring to compress and rebound in such a violent motion that the valvetrain assembly can lag behind the camshaft lobe and cause the piston to slam into the floating valve...
Yes, Higher Lift Cams at stock RPM Can Compress the Valvetrain and cause binding as when the coils of the spring bottom out and the piston can hit the valve if it doesn't have the clearance for it...This will also cause you to Drop a Valve, since the locks can and do fall right out, causing the valve to be dropped into the combustion chamber...
But, you have to realize that the High Pressure that is being Forced into the engine is pushing right into the back of the valves head and is resisting the valves return to the valve seat...This is why valvesprings are a neccessary upgrade on anything higher than, I will say, 12psi on a Boosted Honda motor...Now, 12psi on a T25 will produce a lesser volume of air than 12psi on t3/62-1, so maybe the resistance will not be so great that the stock valvesprings can't handle...
Using a Light Weight Flywheel is another reason to look into upgrading your valvetrain...Same with a lightened rotating assembly...The faster your engine will rev, the less time the valvetrain will have to compress and rebound...
And, as you know from driving boosted motors, once the turbo spools, the RPM rises very quickly due the volumetric effieciency of the motor reaching up and over 100%...This is another reason to upgrade the valvetrain...
If after reading these examples you feel I am wrong, please argue the point of the stock valvetrain not making a difference in a healthy boosted motor or any incorrect information in anything I have said...
This is all based on Engineering, Physics, and my Logic...Not 100% on my personal Experience...
Zee
__________________
I work too damn Hard...
04 Civic Si
01 Lexus GS300
I work too damn Hard...
04 Civic Si
01 Lexus GS300
Guest
Posts: n/a
Unfortunatly I can't base my logic on physics, as I don't have the book knowledge on that one. At least however your making assumptions on logic and not what sounds like hearsay passed on as propoganda.
Ive run 17psi on a stock valvetrain Honda, To use an example of another motor outside of the Honda world, let's take a 4g63 from a TSi Talon. They routinely run 30psi on a stock bottom end and have no issues from 50 trim t3/t4's.
Your right. I shouldn't have been so harsh with my reply.
However, high boost, say 20psi, will not float the valves.
I would like John or Taylor to also step in, perhaps they can confirm or disprove my belief on this.
I have also seen several stock head Honda's running 20+psi. (Specificly an Si making 400whp on a stock head, and an LS doing the same, making I believe 320.) Both were on race test. Both with forged internals.
Ive run 17psi on a stock valvetrain Honda, To use an example of another motor outside of the Honda world, let's take a 4g63 from a TSi Talon. They routinely run 30psi on a stock bottom end and have no issues from 50 trim t3/t4's.
Your right. I shouldn't have been so harsh with my reply.
However, high boost, say 20psi, will not float the valves.
I would like John or Taylor to also step in, perhaps they can confirm or disprove my belief on this.
I have also seen several stock head Honda's running 20+psi. (Specificly an Si making 400whp on a stock head, and an LS doing the same, making I believe 320.) Both were on race test. Both with forged internals.
WHAT!?! OK!......
Joined: Jul 2002
Posts: 201
Likes: 0
Originally posted by Cronic
Unfortunatly I can't base my logic on physics, as I don't have the book knowledge on that one. At least however your making assumptions on logic and not what sounds like hearsay passed on as propoganda.
Ive run 17psi on a stock valvetrain Honda, To use an example of another motor outside of the Honda world, let's take a 4g63 from a TSi Talon. They routinely run 30psi on a stock bottom end and have no issues from 50 trim t3/t4's.
Your right. I shouldn't have been so harsh with my reply.
However, high boost, say 20psi, will not float the valves.
I would like John or Taylor to also step in, perhaps they can confirm or disprove my belief on this.
I have also seen several stock head Honda's running 20+psi. (Specificly an Si making 400whp on a stock head, and an LS doing the same, making I believe 320.) Both were on race test. Both with forged internals.
Unfortunatly I can't base my logic on physics, as I don't have the book knowledge on that one. At least however your making assumptions on logic and not what sounds like hearsay passed on as propoganda.
Ive run 17psi on a stock valvetrain Honda, To use an example of another motor outside of the Honda world, let's take a 4g63 from a TSi Talon. They routinely run 30psi on a stock bottom end and have no issues from 50 trim t3/t4's.
Your right. I shouldn't have been so harsh with my reply.
However, high boost, say 20psi, will not float the valves.
I would like John or Taylor to also step in, perhaps they can confirm or disprove my belief on this.
I have also seen several stock head Honda's running 20+psi. (Specificly an Si making 400whp on a stock head, and an LS doing the same, making I believe 320.) Both were on race test. Both with forged internals.
The DSM 4g63 is a Turbo Built motor from the factory so I'm pretty sure that the valvetrain is setup with plenty of room for more pressure...
And I don't know man, but when boost hits on any of these Honda motors and you drive thru the gears, they go by sooooo quickly that I can't see how stock valvetrain can keep up with this sudden rise in speed without missing a beat...
Zee
__________________
I work too damn Hard...
04 Civic Si
01 Lexus GS300
I work too damn Hard...
04 Civic Si
01 Lexus GS300
Guest
Posts: n/a
The pressure against the valve isn't something that would cause the valvetrain to fail, but I can see where it may be possible to have such a fast reving engine that the valvetrain may not be able to fully compensate. However I _believe_ this should be fine.
For example... rev in neutral. It moves VERY quickly, but it holds up.
For example... rev in neutral. It moves VERY quickly, but it holds up.
Guest
Posts: n/a
Also, the reason I used a DSM valvetrain for an example. They can rev to about 8krpm stock before they begin to have issues, similar to a B series VTEC Honda head...
So it's feasible to assume they are made from similar material... as such also feasible to assume they can handle similar boost pressures... See where Im comming from?
Hope I was clear enough, this is new ground for me.
So it's feasible to assume they are made from similar material... as such also feasible to assume they can handle similar boost pressures... See where Im comming from?
Hope I was clear enough, this is new ground for me.
The G-14 Classified
Joined: Sep 2002
Posts: 5,265
Likes: 0
well, if boost pressure on a stock engine/valve train would cause it to fail, you better come over and tell that to my stock wore the fuck out nisan L24e with a T engine, that i boost the ever living FUCK outta..i have NEVER had a valve train problem unless i over reved it, like a few times i have turned it to 8600 rpm's, and had a cam follower spit out, but so long as you keep it in the stock range (7k or less for my car) it has NEVR EVER EVER been a problem...like cronic said, you ARE the weakest link, good bye
__________________
Boost...it's a hell-of-a drug
Boost...it's a hell-of-a drug
TR Balla Donor Supreme
Joined: Aug 2002
Posts: 35,247
Likes: 0
Originally posted by Cronic
I would like John or Taylor to also step in, perhaps they can confirm or disprove my belief on this.
I would like John or Taylor to also step in, perhaps they can confirm or disprove my belief on this.
__________________
onecattyKat: everybody wants colby
onecattyKat: everybody wants colby
Hi Hi Hi?
Joined: May 2003
Posts: 5,184
Likes: 0
timing is everything on honda motors.....depending on how fast the revs come will determine it. making 250 hp may not break a valve or valvespring but will definetly wear it out a lot faster. all it takes is one worn valve or spring.....and im not so sure about a 400 hp stock valvetrain si....if someone is pulling this off it must be really well tuned or something is gonna go wrong. that seems a little out there. you're creating a lot more pressure in the cylinders with a turbo so the valve is under a lot more stress with each opening.....they're not designed to handle the pressures boost brings and thats when they get worn
TR Balla Donor Supreme
Joined: Aug 2002
Posts: 35,247
Likes: 0
Originally posted by Cronic
Yeah Im just making everything up.
Yeah Im just making everything up.
__________________
onecattyKat: everybody wants colby
onecattyKat: everybody wants colby
