Looking at Cams, which ones?

[Matty_GTS]

Thinking of getting some cams for my tubby (assuming i don't have any already, find out soon).

After looking about it seems like the HKS are the popular choice.

What do people with them think, what do people recomend.

HKS do intake and exhaust in profiles 256/264 and 276 again whats the general recomendation on a mildly tuned tubby with future plans for bigger turbo?

[ENSMR2]

2x HKS 264's.

Or speak to Dino about some piper ones.

[Mark Edwards]

Yep, piper ones from Dino are your best bet.

[Matty_GTS]

Either of your running cams?

Don't know who Dino is, that their imoc user name?

Cheers

[Mark Edwards]

Either of your running cams?

Don't know who Dino is, that their imoc user name?

Cheers

Not yet but will be soon.

MR2Mania is Dino's user name.

[CosmosblueMR2]

Not yet but will be soon.

TB Biatch !

[Mark Edwards]

Not yet but will be soon.

TB Biatch !

LOL

[cantfindausername]

Why are the Piper ones better than the HKS ones?

Whats the difference between the two?

[Mark Edwards]

Why are the Piper ones better than the HKS ones?

Whats the difference between the two?

Better profiles basically.

[cantfindausername]

But they state... 260 264 and 272... same as HKS apart from the 256/260 difference.

[Mark Edwards]

But they state... 260 264 and 272... same as HKS apart from the 256/260 difference.

Lift and duration are very different. Speak to Dino, he has all the details.

[^Trickster^]

I prefer the quality of hks cams myself. I know people who have had piper cams in other cars which have snapped in half. Bad enough to put me off, ive never heard of a hks cam snapping.

And you only really need 264/264 for a mildly tuned car, this is what i was going with but gtschris had no 264 intake cams in stock so i took a 272, overboard for my goals really.

you dont really need high lift, one bad side is that they cause valve to piston interference if the belt snaps, my 272/264 cams look like they would cause valve/valve interference if tuned into the right positions which i never dared get near too, and my machinist said they would as have other people, but ive known belts snap on people running long duration cams and have no valve/valve interference, the cams dont spin on for long unlike a crankshaft, especially if you dont get your foot on the clutch sharpish.

The standard lift hks cams will flow enough air to blow your block to pieces anyway.

Graeme

Edit: Lets not turn this into a pipe/hks battle, I know people have good results with them, I am simply sharing my personal opinion, the user can decide from what everyone has to say about individual brands

[cantfindausername]

Most people go with what they know or trust. Its completley horses for courses.

[Matty_GTS]

Well never had experience with either brand so im kinda in the dark ... hence the post!

Would probably go for the 264/264 as suggested (also read these are quite adiquate), guess this is better than standard but not too wild.

Whats the profile of standard cams just out of interest?

Cheers

[Rikki]

I need camshafts 101.

Why does a high lift cam mean more power, how does it work, whats the diff between normal and all those "degree" numbers, what do they relate to. Whats the best for a road car with light drag and track use etc... Go on point me to an FAQ LOL

R.

[MR2Mania]

I prefer the quality of hks cams myself. I know people who have had piper cams in other cars which have snapped in half. Bad enough to put me off, ive never heard of a hks cam snapping.

As someone else said, horses for courses, mate. I've NEVER heard of a Piper cam having a problem, although I've heard of a few HKS having failures.

Incidentally, bear in mind that many Jap Tuner parts are actually made in the UK by other companies, and then rebadged, eg JUN use Cosworth pistsons, etc. It could well be that HKS cams are made by a UK vendor, although I can confirm that it's not Piper.

you dont really need high lift, one bad side is that they cause valve to piston interference if the belt snaps, my 272/264 cams look like they would cause valve/valve interference if tuned into the right positions which i never dared get near too, and my machinist said they would as have other people, but ive known belts snap on people running long duration cams and have no valve/valve interference, the cams dont spin on for long unlike a crankshaft, especially if you dont get your foot on the clutch sharpish.

As I'll explain later as to what makes a cam increase the airflow into and out of your engine, but suffice to say that anything above a stock profile (at least the ones that I've seen!) will stop the engine being non-interference.

I don't agree about your thinking that the cams don't carry on spinning, etc. I've heard of STOCK engines doing valves in when the cambelt snaps, even at idle! Sure, it should be non-interference, but heavy carbon deposits on the pistons and valves can take care of any gap there should be.

[MR2Mania]

Right, let's talk cams...

Basically, there are 2 ways an aftermarket cam can increase airflow into and out of the engine:
1) Via extra "duration" (the amount of time it holds a valve open)
2) Via extra "lift"

There's been a couple of theories bounced about in the US by so called experts saying that an increase in valve lift past a certain point won't give extra flow. Well, I can tell you that I've used their supposed theories and formulae and used them to work out the point at which they considered there to be no extra benefit, and compared it to the figures I obtained from my head guy on a flow bench, both with a stock Rev3 head and also with a ported one, and I can tell you that these "experts" are WRONG! In fact, I'd even go as far as saying that there's more to be gained in terms of flow (and hence power) by a decent set of cams than you could possibly get from extensive headwork.

The limitation of lift therefore is more mechanical, ie:
1) How much available space you have in the head for the cams to spin
2) How much lift the valvetrain can handle

The latter of those 2 points affects the Rev1/2, and NOT the Rev3. This is because the Rev1/2 are of a "shim over bucket" design, whereas the Rev3 has "shim under bucket". Basically, if you run too high a lift, and the "ramp rate" (the rate at which lift increases) is too aggressive, you run the risk of spitting shims out. Personally, though, I think the space limitation on a Rev1/2 is more of a restriction than the bucket issue. Notice why HKS do 2 different lift versions for the more aggressive profiles they sell - essentially one set is for Rev1/2, and the other for Rev3 which has more space in the head.

Now, on to duration...

Duration is the one key factor that can make an engine lumpy on idle. This is because the duration is so high that there is quite a bit of "overlap" between the inlet and exhaust valves. What this means is that, the time that both the inlet and exhaust valves are open together is increased. This is actually good for you're revving high, as it allows the engine to get filled more, but at low revs when you don't need this (ie idle) and where gas speeds are much lower, this means that you can get some incoming air going straight out of the exhaust. Also, this excessive overlap can reduce your cylinder pressures, because the amount of time that all valves are closed during the compression stroke is reduced. This reduction in compression also has an affect in how the car drives when off boost.

Now, on to cam timing...

By having adjustable cam gears, you can finely "advance" or "retard" each individual cam. What you're actually doing is open/closing the valves sooner or later, depending on what direction you're turning each cam. The effect this has on tuning is to move the peak volumetric efficiency of the engine. For example, you may try and give yourself more midrange, at the expense of top end stuff, or vice versa. Whilst adjusting the timing, you can also obviously adjust the overlap.

IMHO, to get the best out of your cams, it's best to get them timed in on a dyno, so that you can tweak the cams to give you the desired effects. And in all honesty, you're probably going to have to pay more in dyno time to get them timed in properly than you are going to spend on buying the cams in the first place! Figure on a MINIMUM of half a day on the dyno, just for the cams!

You MUST bear in mind though that everything to do with selecting aftermarket cams has a compromise. You make a gain somewhere, but you'll be losing somewhere else. This is why a lot of modern engines have variable valve timing, and the better implementations of this variable valve timing are the engines that produce great power at the top end but without compromising low end or mid-range performance. To do this day, the likes of Honda are the best, closely followed by companies like BMW and Ferrari.

The reason I like the Piper cams is because they were developed based on flow figures that we measured at various valve lifts for both the stock head AND a ported one. We recognised that there was something to be gained by going for more lift than HKS did, and to also change the ramp rates and durations. We've yet to conclusively prove the difference on a dyno, but an associate of mine worked with Piper to develop a series of cam profiles for the Evo in a similar way to the way I have, and it's no secret that the cams they produced beat the HKS equivalents hands down.

Also, it's no secret that not much time was spent developing the HKS set of cams for the 3SGTE, unlike other Japanese makes of cams.

AndyF has a set of Piper cams in his engine. Hopefully, within the week, he should be able to quote some power figures to help people see how good the Pipers are. Also, Muhsin has also chosen to run Piper cams in *his* engine.

Hope this helps.

[Rikki]

Very good answer, thanks for that

[MR2Mania]

If anyone wants to ask any questions that will help them in their decision on which profiles would suit best, then please ask.

[V8Killer]

Never heard of of either Piper or HKS cams having problems TBH. The only reason i went with Piper was because of a few reasons.

1) Recommendation from Dino

2) They have more lift then any other camshaft on the market (except Toda i think). However, Toda/HKS camshafts are based on the 3SGE head whereas the Piper ones were built specifically for the 3SGTE head...not that theres much difference, but after speaking to Tristan (Flupstar on the US MR2OC), he reckons cam timing can be set more precisely with camshafts designed specifically for the 3SGTE head. He is running a set of Jun cams IIRC.

3) After speaking to the chap who built my engine...and after comparing the 2 cams and doing some measurements, etc etc he reckons there has been alot more thought gone into the Piper cams...the ramp angles on the Piper cams are not as steep as those of the HKS cams. In other words the Piper cams are alot more easier on the valvetrain and in-particular the valve springs. Having a shallow ramp angle can also help with off boost driveability and a much better idle, though its probably negligable.

4) I also remember weighing the 2 sets of cams i had aswell. I can't remember the exact weights, but the Piper ones were a fair bit lighter from what i remember.

In terms of quality, both cams were excellent.

Contact Dino here if you want a set, he can do you a good deal on them. Piper also do matching valvesprings, which are also of high quality

Muhsin