Cam upgrades & valve springs....
Jan 12, 2008, 10:56 PM
#1
Cam upgrades & valve springs....
first off all of this is just an educated thought as of now.... Want some input and advice anyone can give...Install will be done by myself at home so no machining will be available...
My current engine mods include; AEM Cold Air Intake, 59mm bored/re-valved throttle body, Port Polished 4g93 Intake Manifold, RRM headers, RRM lightweight Crank Pulley, Stock Downpipe and Cat, 2.25" Catback, ECUFlash for tuning.
I'm thinking of purchasing the RPW stage 2 camshaft along with some 10.5:1 or 11.0:1 High Compression Pistons...Read on the RPW site that with the Stage 2 Cam it is recommended that you upgrade valve springs. does anyone have any instructions on how to go about doing this? did some reading on Hondas but I'm interested in accurate torque specs and torqueing order which is required for removal and re-installation.... does removal of valve springs require a valve job to reseat the valves correctly or is this not required as I will not be removing the valves, nor the retainers...
ALSO...
Considering porting and polishing the intake and exhaust side of the head. Not touching anything near the valves or on the inside of the head itself. Mainly enlarging the side that connects to Intake Manifold and Exhaust Manifold gasket matching. good idea or no???
Will also include required vernier cam gear from RPW to set camshaft back at TDC, or at least that was what I read. Granted total price will be in excess of 1500 without shipping, so these parts will not be purchased all at once.
replaced parts should include; head studs, head gasket, bolts that hold down the camshaft(dunno what they are called, feel free to inform me), and valve cover gasket...Total price around=????
I have read both positive and negative opinions on increasing compression via high comp pistons... But this will also include other mods so take that into consideration. I have read reviews on stage one camshafts but none include installation of a stage two nor do any include install with similar mods as I recall...
I am expecting some to mention a turbo setup costing a similar price and yes this is true but the turbo setup will be just turbo kit alone, not including any internals or camshaft. So what I am trying to say is the price that I will pay for these parts would be around the same as what you would pay for internals prior to a turbo kit and needless to say I am going the NA route...
I do not want to start any arguements or flaming...Just interested in what everyone has to say and any constructive advice anyone can give.
Thanks to everyone who took the time to read this long post but your opinion is greatly appreciated and I believe this can also benefit future Lancer owners willing to venture this route. thanks again
My current engine mods include; AEM Cold Air Intake, 59mm bored/re-valved throttle body, Port Polished 4g93 Intake Manifold, RRM headers, RRM lightweight Crank Pulley, Stock Downpipe and Cat, 2.25" Catback, ECUFlash for tuning.
I'm thinking of purchasing the RPW stage 2 camshaft along with some 10.5:1 or 11.0:1 High Compression Pistons...Read on the RPW site that with the Stage 2 Cam it is recommended that you upgrade valve springs. does anyone have any instructions on how to go about doing this? did some reading on Hondas but I'm interested in accurate torque specs and torqueing order which is required for removal and re-installation.... does removal of valve springs require a valve job to reseat the valves correctly or is this not required as I will not be removing the valves, nor the retainers...
ALSO...
Considering porting and polishing the intake and exhaust side of the head. Not touching anything near the valves or on the inside of the head itself. Mainly enlarging the side that connects to Intake Manifold and Exhaust Manifold gasket matching. good idea or no???
Will also include required vernier cam gear from RPW to set camshaft back at TDC, or at least that was what I read. Granted total price will be in excess of 1500 without shipping, so these parts will not be purchased all at once.
replaced parts should include; head studs, head gasket, bolts that hold down the camshaft(dunno what they are called, feel free to inform me), and valve cover gasket...Total price around=????
I have read both positive and negative opinions on increasing compression via high comp pistons... But this will also include other mods so take that into consideration. I have read reviews on stage one camshafts but none include installation of a stage two nor do any include install with similar mods as I recall...
I am expecting some to mention a turbo setup costing a similar price and yes this is true but the turbo setup will be just turbo kit alone, not including any internals or camshaft. So what I am trying to say is the price that I will pay for these parts would be around the same as what you would pay for internals prior to a turbo kit and needless to say I am going the NA route...
I do not want to start any arguements or flaming...Just interested in what everyone has to say and any constructive advice anyone can give.
Thanks to everyone who took the time to read this long post but your opinion is greatly appreciated and I believe this can also benefit future Lancer owners willing to venture this route. thanks again
Jan 13, 2008, 11:29 AM
#2
If you feel comfortable installing this stuff yourself then I would say go for it. Try to get the highest compression possible. AT LEAST 11.0:1.
I would not recommend porting and polishing the intake and exhaust sides of the head yourself because the flow is very dependant on the design of the ports so I wouldn't touch that. You might end up doing more harm than good.
All of the gaskets and bolts will probably run you 200-300 dollars total.
The only problem about a stage two cam is that you are going to lose a decent amount of low end torque and move the powerband more up top. This is fine on cars that can rev to the sky like honda's. If you do this I would recommend going with some titanium valves and valve springs and raising the rev limiter 1k- 1.5k RPM's.
Any more questions I would be glad to answer. I almost went with high compression pistons but the cost was WAY too much considering I would want a proffessional shop to install them.
I would not recommend porting and polishing the intake and exhaust sides of the head yourself because the flow is very dependant on the design of the ports so I wouldn't touch that. You might end up doing more harm than good.
All of the gaskets and bolts will probably run you 200-300 dollars total.
The only problem about a stage two cam is that you are going to lose a decent amount of low end torque and move the powerband more up top. This is fine on cars that can rev to the sky like honda's. If you do this I would recommend going with some titanium valves and valve springs and raising the rev limiter 1k- 1.5k RPM's.
Any more questions I would be glad to answer. I almost went with high compression pistons but the cost was WAY too much considering I would want a proffessional shop to install them.
Jan 13, 2008, 04:33 PM
#3
prolly gonna get 10.5:1 pistons and instead of a stage 2 cam, a stage one instead as the powerband would be a lot wider and I could reuse the stock valve springs etc. Also vernier cam gear is optional...
Increased compression also means that you have to watch your piston to valve clearance very closely right? Cuz increased compression is achieved by increasing the length of each piston thus to create more pressure in each cylinder.... increased piston height and increased cam lift would make it even more of an issue i believe...
the issue of connecting rods was also brought up.... With my mods in addition to 10.5:1 high comp pistons and a stage 1 cam, would the stock rods hold up for sure? I do not want to upgrade them if they can definately withstand the mods as they cost in excess of $400.....
As far as raising the rev limit to 7000 or so i cant help but wonder if the 4g94 can handle that. The 4g93 has a shorter stroke which also helps it rev up that high. If we used the existing 4g94 and reved it up to the same as the 4g93's wouldn't this cause excess wear on the block and crankshaft as it is already moving a larger stroke to beign with? Sounds like a good idea tho...I am not worried about the tuning, just the wear on the engine caused by increased rpm while still maintaining the existing stroke..
Increased compression also means that you have to watch your piston to valve clearance very closely right? Cuz increased compression is achieved by increasing the length of each piston thus to create more pressure in each cylinder.... increased piston height and increased cam lift would make it even more of an issue i believe...
the issue of connecting rods was also brought up.... With my mods in addition to 10.5:1 high comp pistons and a stage 1 cam, would the stock rods hold up for sure? I do not want to upgrade them if they can definately withstand the mods as they cost in excess of $400.....
As far as raising the rev limit to 7000 or so i cant help but wonder if the 4g94 can handle that. The 4g93 has a shorter stroke which also helps it rev up that high. If we used the existing 4g94 and reved it up to the same as the 4g93's wouldn't this cause excess wear on the block and crankshaft as it is already moving a larger stroke to beign with? Sounds like a good idea tho...I am not worried about the tuning, just the wear on the engine caused by increased rpm while still maintaining the existing stroke..
Jan 13, 2008, 06:12 PM
#4
prolly gonna get 10.5:1 pistons and instead of a stage 2 cam, a stage one instead as the powerband would be a lot wider and I could reuse the stock valve springs etc. Also vernier cam gear is optional...
Increased compression also means that you have to watch your piston to valve clearance very closely right? Cuz increased compression is achieved by increasing the length of each piston thus to create more pressure in each cylinder.... increased piston height and increased cam lift would make it even more of an issue i believe...
the issue of connecting rods was also brought up.... With my mods in addition to 10.5:1 high comp pistons and a stage 1 cam, would the stock rods hold up for sure? I do not want to upgrade them if they can definately withstand the mods as they cost in excess of $400.....
As far as raising the rev limit to 7000 or so i cant help but wonder if the 4g94 can handle that. The 4g93 has a shorter stroke which also helps it rev up that high. If we used the existing 4g94 and reved it up to the same as the 4g93's wouldn't this cause excess wear on the block and crankshaft as it is already moving a larger stroke to beign with? Sounds like a good idea tho...I am not worried about the tuning, just the wear on the engine caused by increased rpm while still maintaining the existing stroke..
Increased compression also means that you have to watch your piston to valve clearance very closely right? Cuz increased compression is achieved by increasing the length of each piston thus to create more pressure in each cylinder.... increased piston height and increased cam lift would make it even more of an issue i believe...
the issue of connecting rods was also brought up.... With my mods in addition to 10.5:1 high comp pistons and a stage 1 cam, would the stock rods hold up for sure? I do not want to upgrade them if they can definately withstand the mods as they cost in excess of $400.....
As far as raising the rev limit to 7000 or so i cant help but wonder if the 4g94 can handle that. The 4g93 has a shorter stroke which also helps it rev up that high. If we used the existing 4g94 and reved it up to the same as the 4g93's wouldn't this cause excess wear on the block and crankshaft as it is already moving a larger stroke to beign with? Sounds like a good idea tho...I am not worried about the tuning, just the wear on the engine caused by increased rpm while still maintaining the existing stroke..
Jan 13, 2008, 06:33 PM
#5
Something to consider is whether raising the rev limiter is even worth it. If peak power is observed at 6000 RPM and drops off after that, raising the limiter is a waste of time. If it continues to go up all the way to redline, it's a viable option. As far as compression goes, you have to ask what kind of car do you want and how much are you willing to spend. You could go 11:1 or higher but you'll need to run higher octane, get it tuned, upgrade the cam, cam gear, valvetrain, head and basically anything else to make it worth your while.
Jan 13, 2008, 06:36 PM
#6
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well it might be valid depending on what you're going to drop your revs to when you shift--i mean if at 7k its still pushing more than if you were to shift and be at the same speed with 4.8-5k then its worth it no?
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Jan 13, 2008, 09:53 PM
#8
dyno tests prove the 4g94 doesn't make power past 6k but this is with the stock cam and stock pistons correct? But the longer stroke of our motor gives us more torque at the cost of RPM...the 4g93 is the opposite; shorter stroke, higher rev limit with less torque....So wouldn't it be impossible to effectively gain power higher than 6k without shortening the stroke?
And any opinions on octanes which must be used with 10.5 compression or 11.0? And also if the rods need to be uprgraded..
And any opinions on octanes which must be used with 10.5 compression or 11.0? And also if the rods need to be uprgraded..
Jan 14, 2008, 06:54 AM
#9
I'm sure there's a way to make more power up top but I would assume you'd need a more aggressive cam, adjustments to timing, and various other mods. If you're at 10.5:1 or 11.0:1 I would use 91 octane or higher just to be safe. 89 might cut it (I used 87 with 10:1 compression) but better safe than sorry.
Jan 14, 2008, 07:19 AM
#10
My .02, You might want to research this a little more..forum opinions ( not to offend anyone here) are just that--opinions. Most of what you are looking for is in engine building, cam design books...to attempt to give you ALL this info here would be impossible...a lot of factors come into play depending on needs.. From what you have said here...I think you might want to brush up on your info..for yourself..BTW the compression question.....isn't a guessing game for arm chair mechanics..you get knock with HC and your motor is gone...just like a turbo motor..so yes, you need the highest octane you can get..93 likely..but then again thats in some ref material somewhere..Not giving you a hard time--just that I think you would be more secure with your decisions if you researched and little more from engine /cam manufacturers.. Don't guess, know.
Jan 14, 2008, 12:54 PM
#12
meckert...try...not...to...type...like...this
It is very hard to read.
Amby is right, there is a member on here with high compression and turbo. I wouldn't recommend it but obviously they got away with it and are enjoying the best of both worlds.
With your current mods you should be running at least 89 octane fuel and possibly 91 if you have been messing with the timing part of ECUflash. I run 93 octane just running the AFC (although I know its overkill) I will be switching to ECU flash and adding in timing etc. so I will need the higher octane at that point.
If you do decide to upgrade pistons, I suggest you go at LEAST 11.0:1 if not slightly higher. Most honda guys go 12 or sometimes in rare cases 13. Most of them are on pump gas although as you get towards the upper end racegas becomes needed.
There is nothing dangerous about high compression if it is tuned correctly and made sure valve clearance is ok etc.
It is very hard to read.
Amby is right, there is a member on here with high compression and turbo. I wouldn't recommend it but obviously they got away with it and are enjoying the best of both worlds.
With your current mods you should be running at least 89 octane fuel and possibly 91 if you have been messing with the timing part of ECUflash. I run 93 octane just running the AFC (although I know its overkill) I will be switching to ECU flash and adding in timing etc. so I will need the higher octane at that point.
If you do decide to upgrade pistons, I suggest you go at LEAST 11.0:1 if not slightly higher. Most honda guys go 12 or sometimes in rare cases 13. Most of them are on pump gas although as you get towards the upper end racegas becomes needed.
There is nothing dangerous about high compression if it is tuned correctly and made sure valve clearance is ok etc.
Jan 14, 2008, 07:56 PM
#13
My .02, You might want to research this a little more..forum opinions ( not to offend anyone here) are just that--opinions. Most of what you are looking for is in engine building, cam design books...to attempt to give you ALL this info here would be impossible...a lot of factors come into play depending on needs.. From what you have said here...I think you might want to brush up on your info..for yourself..BTW the compression question.....isn't a guessing game for arm chair mechanics..you get knock with HC and your motor is gone...just like a turbo motor..so yes, you need the highest octane you can get..93 likely..but then again thats in some ref material somewhere..Not giving you a hard time--just that I think you would be more secure with your decisions if you researched and little more from engine /cam manufacturers.. Don't guess, know.
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