Teach me something new - Cams...

[Corranga]

So, leading on from this in classifieds:
http://www.scottishelises.com/phpbb/vie ... =7&t=24271
and assuming I have a very limited understanding of cams - they control valve opening and, erm, the K series has 2 and they are at the top of the engine...?

What would the overall benefits / disadvantages of such a change be?

What parts would be required beyond the cams themselves?
I assume fitment would require removal of the head, and therefore at least a gasket kit would be needed?

Lets say the car wasn't quite standard 118, but SLS Stage 1a
(described as Removal of standard cylinder head, replaced with SLS spec head. Ported, with bigger valves, this head running on standard cams and MEMs will allow a power increase from 118bhp to approximately 145-150bhp.)
with a 4-2-1, 52mm tb, think that's about it.

would the same reasoning apply, or is there a better alternative, also would the standard MEMS cope?
Is it likely to become unreliable, hard to cold start, likely to pop etc

Please discuss

This is a learning experience for future reference, not something I plan to do now.

Chris

[Doc883]

I was about to ask similar questions having seen the Piper Cam offer in classifieds. Checked the Piper website and the part number doesn't seem to tally so based on the 16-20bhp claim I am assuming they are the entry level Fast Road version for the 1600/1800 non vvc K series. The site specifies Vernier Pulleys as being required so another £211. Not sure if anything else is required ? What would it cost typically to fit these cams/verniers or would the SLS Stage 1a head work be a better option for what appears a similar increase in bhp ?

The PTP RS140 upgrade seems to tick all the boxes although interestingly is does away with the verniers that Piper say are required and adds a 52mm ally throttle body

[Stu160]

You dont need to take the head off to do the job, and yes, mild road (275)cams in a std K will give about 10 to 15 bhp extra. take about 4 hour for a DIY install, BUT , you must know what you are doing.This will run on the stadard ecu.
Fitting bigger valves in a head is a big job , and to be honest , is not required unless you are looking for over 170 BHP or there abouts, my S160 with a ported head, 160 cams , emerald and a 52mm throttle bdy made 172 BHP.

Cheers

Stuart

[Stumpy Nugget]

I am up for a C service soon and to be honest I was thinking of putting in Cams at the same time... but I am not 100% convinced. Although you get the increase in BHP - what are the negatives? There must be some as you get nothing for free. Emission problems? Idle problems? Extra wear on the other parts of the engine? Can anyone give more details? Cheers.

[Shug]

Cams more or less just shift the torque curve about. So, simplistically, a set of cams giving more horsepower, would (nothing else being changed) reduce torque lower down the rev range.

That's a very rough rule of thumb. Will rev harder and easier, but will be a bit more sluggish 'off cam', down the revs. IMO, a revvier engine suits the Elise, but it doesn't necessarily make it 'quicker' in everyday use.

[gorrie]

These cams (15bhp) sound like they are similar to the ones I put in my S2 (ie, the ones you get from PTP as part of their RS140 upgrade... or get cheaper from Rimmer Bros, which are basically the cam out of an MGTF135).
The LGC part number in the classified confuses me though, because Rover parts use the LGC part numbers (LGC000280 is the part# of the 135 cams & also what PTP list).
So, I wouldn't have expected to see that kind of part number on a Piper Cam??

Stumpy Nugget... I had 135 cams put in my car by SLS at the time of getting my C-Service (well, the belts were coming off anyway). Have a word with Ali, but it didn't dramatically change the cost of the C-Service since he was in about it anyway.

As for performance, I liked it. I found the 135 cam did not really affect low lown torque. My main issue beforehand was that there didn't seem to be much go higher up the rev range. It was all down at 2krpm->4krpm... and quite frankly when you are in the mood to play you don't really spend a lot of time down at that rev range.
I found the 135 cam allowed you to get a good bit of performance out of the engine at rev ranges where the standard engine would have run out of puff... but it didn't cause any noticeable lack of torque down low.

Chris, can't comment on it with those mods. All I had was a 52mm TB & a K&N 57i with the cams. Everything else standard.

http://www.scottishelises.com/phpbb/vie ... lit=LGC%2A

[gorrie]

PS... googling that part number (LGC106970 ) in the classified seems to be bringing up a few people suggesting they are standard Rover Cams out of the 120bhp 1.8 engine... not Piper, and not even the Rover 135 cams.

http://forums.mg-rover.org/archive/inde ... 67238.html
http://themgclub.org/showthread.php?p=3220439

I can't find them on Rimmer Bros either, but can find LGC106960 as a standard Rover cam.
I'd be looking for lift measurements before considering splashing wonga. Mines were the LGC000280 cam which is from a 135.

This might be of interest as well.
http://www.mgf.ultimatemg.com/group2/en ... ptions.htm

Andy.

[BiggestNizzy]

These cams (15bhp) sound like they are similar to the ones I put in my S2 (ie, the ones you get from PTP as part of their RS140 upgrade... or get cheaper from Rimmer Bros, which are basically the cam out of an MGTF135).

Thats whats in my car along with a 135 cylinder head and it decimated all the low down torque I was gutted until I realised it made a difference at the other end of the rev range. Once I fitted the 4-2-1 manifold it made a hugh difference and the car was happier tootling around

[gorrie]

Were fine with a standard head
Looks like you've answered Chris's question though !!

[Stumpy Nugget]

So If I have read this right. Cams can be fitted with a C service (for some extra cash) and to avoid any torque loss low down fit a 4-2-1 (PITA to fit I believe)... There are no real ill effects from doing this (emmisions, poor idle etc) and will give approx 15BPH extra. Any failing head gasket issues later in life can mean head work and more BHP if desired still using existing cams... Tempting. But sounds like sourcing Cams should be done elsewhere?

[BiggestNizzy]

Like all things it’s not simple.
Brake Horsepower (BHP) = RPM x torque
Cams are designed to work with specific engines, airflow and RPM every cam will be designed to work at a specific and very small RPM band. Think of your VTEC it has 2 positions one for power at the higher end of the rev range one for everyday driving. If the VTEC cam was to stick in the lower position it would run like a bag of mince at the bottom end. The rover VVC system has a constantly variable system that gets the cams working more across the range (in my opinion this is a better system but people like the force you back in the seat thing the VTEC’s give you) Ferrari had a system of 3D cam’s on some engine similar to a VTEC but the cam had a fluid horizontal movement to precisely match the cam to the engine rev’s (you don’t ever want to replace one of those they aren’t cheap). If you fit different cams they change the sweet point moving it further up the rev range. Why didn’t rover do it? Because it is to the detriment of the lower engine speeds they have different criteria for their engine it went in everything from rover 75’s to 25’s and economy was more of a factor and let’s face it grannies don’t want to be bouncing off the rev limiter on the way to church on a Sunday.
So…
Fitting wilder cams with increase torque at higher RPM’s hence increasing your BHP, but at the detriment to your bottom end power.
What I found was when I fitted the 135 head and 135 cams things started to come together at 4k and the car will pull like a train from there on, before I fitted the 4-2-1 manifold it was rubbish between 1-3.5k rpm the manifold helped this but it was not a cure. (Not that terrible to fit with 2 people a sunny day and some beers) The car still isn’t as powerful as it launches but I have to be wary about wheel spin half way up the rev range.

I am sure someone will pick holes in this but its how I understand it.

[Corranga]

Cheers Niz, that makes perfect sense to me, sounds like a bit of a gamble so it's something i'll pass on for now.

...and to avoid any torque loss low down fit a 4-2-1 (PITA to fit I believe)...

I fitted mine to my S1 and it really wasn't that bad. You do need 2 people, 1 working it from below, the other pulling it from above, and it is a bit of an experience trying to get it between the engine and the bulkhead, but if you follow the tutorial (seloc techwiki?) and undo the bottom engine bracket / move the engine a bit it's not too bad. More awkward laying on your back twisting and turning the manifold to make it fit into the gap, a bit of a square peg, round hole kinda thing. Everything else was straight forward enough.

Chris

[gorrie]

So If I have read this right. Cams can be fitted with a C service (for some extra cash) and to avoid any torque loss low down fit a 4-2-1 (PITA to fit I believe)... There are no real ill effects from doing this (emmisions, poor idle etc) and will give approx 15BPH extra. Any failing head gasket issues later in life can mean head work and more BHP if desired still using existing cams... Tempting. But sounds like sourcing Cams should be done elsewhere?

No... if you have a standard head & plastic inlet manifold & have a c-service coming up, you can get away with fitting just the cams at your C-service & get about 135bhp with no 'noticeable' difference to low down torque (but allowing the engine to pull better to the red-line).
Check out the link http://www.mgf.ultimatemg.com/group2/en ... ptions.htm for comparison of low down torque... there's only a range of about 1000rpm where the standard 120 engine is marginally giving more torque which is at a rev range you barely use. From experience in that configuration of when I did it on my car, lack of torque was not noticeable whilst driving.
It will run/idle fine with 135 cams on standard ECU & standard head.

The torque issue with uprated cams comes to light once you start hunting for more power by playing with heads etc.. so at that point you may need to add a 4-2-1 to alleviate any loss of torque.

If you can find a low-ish mileage MGTF135 at a scrappies which you can get the cams from at a good price... you are already due a C-Service, and you have a standard head... then it's worth considering.

Andy.

[Doc883]

The 135 cams in Classifieds are now £175 delivered. I have read through the above but still a little unsure as some are saying they don't recognise the part number and think they are standard cams ? I have an unmodified S2 and this could be a cheapish route to getting another 15bhp ?

[gorrie]

Unconvinced they are Piper, or even Rover 135 cams...
Could be wrong, but it's not coming up on any searches I've tried (lots of people asking the same question in the searches, with not much to back up answers). I guess Rover may have changed the part# at some point but it's just not coming up anywhere.. I'd be wanting to make sure.

The Rover 135 cams were the LGC000280... The casing was actually stamped LGC000300 though. Mines came out of a TF135, and they had the correct lift (9.5mm). (Picture of the ones I got attached)

If it were my money, I'd be asking for lift measurements etc etc before spending. I'm sure the seller is the chap who recently supplied a whole bunch of 52mm Throttle Bodies, so I guess he'd be receptive enough to answer your questions.
In fact, if it were my money I'd be tempted to get a set from a low mileage MGTF135 at a scrappies & have change... but it's your call as it's your money.