Staggering Evo Cams
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Staggering Evo Cams
Hi,
Just wondering what the benefits of this is and how much is 'too much' to stagger.
I only really understand the lift in cams which if too much = new springs required to stop the spring maxing out and causing the cam to 'float' (I think!)
And that higher lift means more air that can be taken in, but also less pressure!
But why stagger the cams, what are the benefits? I want low down torque but also able to push a decent high end.
Would HKS 264 in 280 out produce a decent amount of low down torque while still providing the power I'm after further up?
I'm not after huge amounts of power. At first 400bhp, then maybe stop at around 500bhp.
Just wondering what the benefits of this is and how much is 'too much' to stagger.
I only really understand the lift in cams which if too much = new springs required to stop the spring maxing out and causing the cam to 'float' (I think!)
And that higher lift means more air that can be taken in, but also less pressure!
But why stagger the cams, what are the benefits? I want low down torque but also able to push a decent high end.
Would HKS 264 in 280 out produce a decent amount of low down torque while still providing the power I'm after further up?
I'm not after huge amounts of power. At first 400bhp, then maybe stop at around 500bhp.
It would take more than a pint or two of Shepherd Neame to give a complete treatise on camshaft design here, but a few things you should know ...
- Staggering the cams can be beneficial in certain cases, but that isn't of much advantage here, simply because the EVO head is fairly well balanced. Even fairly mild cams will deliver the power you're seeking without compromising low speed tractability. What is more useful is a means of retiming the cams (e.g. adjustable gears), depending upon the cams used. Some cam sets function better when retimed, while others are smartly timed as-is.
- Cams with more aggressive lobe ramps tend to generate more power, but the more rapid bouncing action exceeds the ability of the factory springs to maintain pressure on the lobe, which reduces power and reliability. This is why the better cams require upgraded springs.
- More lift generally means more air, but only to a point. The factory inlet ports stop responding to increased valve lift at around 10.5mm.
- Longer effective duration (duration at 1mm lift) generally reduces vacuum at low speeds. Keeping the valve open longer makes the engine more mechanically efficient at higher speeds, but reduces some low speed performance. Effective duration (not to be confused with advertised duration) affects low speed performance more than lift.
Some tried staggering the HKS cam sets in the early days of this forum, but there wasn't really any advantage there.
- Staggering the cams can be beneficial in certain cases, but that isn't of much advantage here, simply because the EVO head is fairly well balanced. Even fairly mild cams will deliver the power you're seeking without compromising low speed tractability. What is more useful is a means of retiming the cams (e.g. adjustable gears), depending upon the cams used. Some cam sets function better when retimed, while others are smartly timed as-is.
- Cams with more aggressive lobe ramps tend to generate more power, but the more rapid bouncing action exceeds the ability of the factory springs to maintain pressure on the lobe, which reduces power and reliability. This is why the better cams require upgraded springs.
- More lift generally means more air, but only to a point. The factory inlet ports stop responding to increased valve lift at around 10.5mm.
- Longer effective duration (duration at 1mm lift) generally reduces vacuum at low speeds. Keeping the valve open longer makes the engine more mechanically efficient at higher speeds, but reduces some low speed performance. Effective duration (not to be confused with advertised duration) affects low speed performance more than lift.
Some tried staggering the HKS cam sets in the early days of this forum, but there wasn't really any advantage there.
Thread Starter
Newbie
Joined: Jun 2015
Posts: 8
Likes: 0
From: USA
It would take more than a pint or two of Shepherd Neame to give a complete treatise on camshaft design here, but a few things you should know ...
- Staggering the cams can be beneficial in certain cases, but that isn't of much advantage here, simply because the EVO head is fairly well balanced. Even fairly mild cams will deliver the power you're seeking without compromising low speed tractability. What is more useful is a means of retiming the cams (e.g. adjustable gears), depending upon the cams used. Some cam sets function better when retimed, while others are smartly timed as-is.
- Cams with more aggressive lobe ramps tend to generate more power, but the more rapid bouncing action exceeds the ability of the factory springs to maintain pressure on the lobe, which reduces power and reliability. This is why the better cams require upgraded springs.
- More lift generally means more air, but only to a point. The factory inlet ports stop responding to increased valve lift at around 10.5mm.
- Longer effective duration (duration at 1mm lift) generally reduces vacuum at low speeds. Keeping the valve open longer makes the engine more mechanically efficient at higher speeds, but reduces some low speed performance. Effective duration (not to be confused with advertised duration) affects low speed performance more than lift.
Some tried staggering the HKS cam sets in the early days of this forum, but there wasn't really any advantage there.
- Staggering the cams can be beneficial in certain cases, but that isn't of much advantage here, simply because the EVO head is fairly well balanced. Even fairly mild cams will deliver the power you're seeking without compromising low speed tractability. What is more useful is a means of retiming the cams (e.g. adjustable gears), depending upon the cams used. Some cam sets function better when retimed, while others are smartly timed as-is.
- Cams with more aggressive lobe ramps tend to generate more power, but the more rapid bouncing action exceeds the ability of the factory springs to maintain pressure on the lobe, which reduces power and reliability. This is why the better cams require upgraded springs.
- More lift generally means more air, but only to a point. The factory inlet ports stop responding to increased valve lift at around 10.5mm.
- Longer effective duration (duration at 1mm lift) generally reduces vacuum at low speeds. Keeping the valve open longer makes the engine more mechanically efficient at higher speeds, but reduces some low speed performance. Effective duration (not to be confused with advertised duration) affects low speed performance more than lift.
Some tried staggering the HKS cam sets in the early days of this forum, but there wasn't really any advantage there.
The 280 cams are 10.2 lift so should be fine on standard springs.
Were there any disadvantages to the staggered HKS cams? I have a 264 inlet cam already and a 280 has come up on eBay quite cheap. if there are no disadvantages then I might go for it.
Also whats the difference between an inlet cam and an exhaust cam? If you put them side by side, what would be different? If that makes sense
Thats great thanks!
The 280 cams are 10.2 lift so should be fine on standard springs.
Were there any disadvantages to the staggered HKS cams? I have a 264 inlet cam already and a 280 has come up on eBay quite cheap. if there are no disadvantages then I might go for it.
Also whats the difference between an inlet cam and an exhaust cam? If you put them side by side, what would be different? If that makes sense
The 280 cams are 10.2 lift so should be fine on standard springs.
Were there any disadvantages to the staggered HKS cams? I have a 264 inlet cam already and a 280 has come up on eBay quite cheap. if there are no disadvantages then I might go for it.
Also whats the difference between an inlet cam and an exhaust cam? If you put them side by side, what would be different? If that makes sense
"Staggering the cams can be beneficial in certain cases, but that isn't of much advantage here, simply because the EVO head is fairly well balanced." Normally you add duration to the side of the head with bad/worse flow to help compensate for that reduction...as stated not needed. can you run 264-280? that's a wide spread--usually I see 10* max.. but be the first. You ought to really take some time and read up before you buy anything, if you don't already have an idea of intake and exhaust cams and the difference--I think you will find yourself in trouble.. Good luck.
Or buy a set of proper cams, GSC S1 or S2, kelford 272, hks 272, etc, and have great all around power characteristics.
That huge difference in duration is just that, huge. And it may not play well..
That huge difference in duration is just that, huge. And it may not play well..
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Joined: Jun 2015
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From: USA
I think ditching the HKS cam is going to be the best option. I might sell it on, maybe someone will need one!
Another question though, why are some labelled Evo 4-6 and others 7-8? Whats the difference in the engine that affects the cams?
Another question though, why are some labelled Evo 4-6 and others 7-8? Whats the difference in the engine that affects the cams?
Evolving Member
Joined: Mar 2015
Posts: 180
Likes: 1
From: Boring Oregon
I belive some are interchangeable but its a useless pursuit
Cam design on the 4G63 has changed with almost every model
It's would compromise performance gains if they were swapped so to get the actual hp figures stick with your model number
Cam design on the 4G63 has changed with almost every model
It's would compromise performance gains if they were swapped so to get the actual hp figures stick with your model number
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