PTP RS140 Kit

[gorrie]

Anyone on here got this, or tried it... in an otherwise standard k-series?

I'm not expecting miracles with it to be honest as it's a fairly mild cam setting compared to some others, but just wondered if anyone had feedback on it. From what I can see on the PTP website, it basically consists of a set of Rover/MG 135 cams, a 52mm TB... and some stickers.
£500 ain't particularly cheap for that.

However, I've just got hold of a set of 135 cams from an MG TF 135... and also a 52mm TB. I managed to pick them up for £220 which is a fair saving over the PTP price so it seemed rude not to.

I wouldn't necessarily have bothered, but Ali is going to be changing the belts in just over a week anyway... so thought it was as good a time as any to try it out while he was rummaging about.

Interested to hear if anyone has driven a similar spec car and how it compared to standard (graphs I've seen don't look too bad for killing low down torque).

[Shug]

(moved to technical)

Ask Ali about heads - TBH, I've read variable reviews of PTP's power upgrades. Better to spend the money on a better breathing head with standard cams, then change cams further down the line as with just a cam change, you'll lose low down power and shift it up the rev range.

If it's just cams and you don't really want to take the head off, you'd be better going a little cheaper for something like Piper 270s, which will make it lumpier and shift the power up the range, but it'll zip round to the limiter instead of running out of breath. Will feel a little more gutless in everyday driving though...

[gorrie]

Yeah, the Ali Stage 1 was my 1st choice... but, it needs an A-serv plus belts... then another £1K for the Stage 1... bit more than I want to stump up right now (as I've just got new discs/pads for all corners too).

Just thought I'd try some cheap cams while he had the belts off anyway... it's not really costing much more from a labour point of view.

I did have concerns about losing low down torque, but the graphs I've seen for the 135 cam don't look too bad (I guess it is just a mild upgrade to standard). Just wondered if anyone had tried it already.

[Shug]

My guess it'd be £500 for the square root of eff all in terms of real-world difference, but not tried them back to back, so not in a place to say for sure.

Your old 135R went down the route of porting as opposed to cams & TBH, I take power graphs on the internet with a pinch of salt. Odds on, when the head was off, other stuff (simple things like deflashing the exhaust manifold on an S1) could have been done, filling the torque back out at the bottom end.

Speak to Ali anyway though - bearing in mind the cost for the stage 1 is in labour as well - it'll cost to take the cam cover off, swap and time cams, so the difference may not be as much as you think (adding £500 for kit to labour for cam change and belts)

[Shug]

Just re-read your original post - as you've actually got the cams, different story!

[graeme]

I thought you sold the 135R to free up some cash? Stop spending it all on that shed!

[gorrie]

Yep... definitely wasn't paying £500 though Shug. Totally agree with you that at that price I'd have held off for Ali-Stage1 for sure.
I'll report back once it's done then... be about 2 weeks time before Ali can fit it in.

Greame... I've set a limit... don't worry !! Will still have £5K spare from the 135R after all the spending is finished.

[robin]

Those cams produce a torque curve not dissimilar to the 135 porting but without the fuss of removing the head.

The TB will do next to nothing, but is sought after, so if you got the TBs+cams for 220 I would sell the TB (I'll bet you could get 75 or more for it on Ebay/Seloc if you were patient). Different story on the S1 where you'll want the TB to replace the plastic one when it starts to stick, but S2 already has metal TB so no need to swap.

The one thing I cannot say is whether the extended overlap is going to give you a lumpy/erratic idle. They're tame enough that it shouldn't but who can say ...

All IMHO, of course.

Robin

[gorrie]

Cheers Robin...
If it can produce a similar delivery to the 135 head (even if not quite the same power), I'll be a happy chappy. I've limited experience in my standard car, but seems to have a surge up to about 3K and then not quite as much push after that. The 135R was to be a bit more progressive through the rev range which I like....

Andy.

[robin]

Actually it's a bit of a crossover at 3,000 RPM - you'll have a wee dip in torque there on any K as far as I can tell, but the standard plastic plenum engines have the least dip; they are correspondingly asthmatic at the high end, but there should be plenty of go to 5,750 or so; the majority of standard 1.8's have run out by 6,500 for sure, though some will rev to 7K happily (e.g. Peter's old one before he messed about with it!).

The metal plenum 135 cars are worse at the low end, then no better than standard until about 4,500 RPM or so at which point they creep ahead - the only really big difference comes above 5,500 where the standard engine starts to run out and the 135 head keeps going.

If you fit these cams I expect the torque to 3,000 RPM to worsen slightly, perhaps similar to 135 head, but the engine will deffo rev to 7,000 RPM happily (the standard engine nearly does anyway - some of the looser ones pull to 7K without any mods), and so will produce more power - probably 135BHP or so in fact

The only thing you will actually notice is that it wants to rev - the true difference in power is tiny, and when you add in the slight losses lower down, the in-gear times in the mid-range of the engine will be more-or-less identical.

Cheers,
Robin

[gorrie]

Thanks for that explanation Robin... very enlightening.
I didn't realise the metal plenum affected low-down torque... every day is a school day.

[gorrie]

I now have the 135/RS140 cams fitted (cheers Ali)... and pleased to confirm that it idles very well indeed. No lumpiness at all. Not fitted the 52mm TB as yet... probably will though.
Managed to cover about 200miles at the weekend (inc Dukes Pass) and am very happy with the result.

Without a RR print out, this is purely subjective. There doesn't seem to be a great deal of torque lost at lower engine speeds... sure, the initial kick at 2K isn't 'quite' as noticeable but it certainly still pulls no bother at all. From 3.5K you start to feel a wave of torque coming in, but it's very nicely delivered growing smoothly all the way to redline it seems.

As I don't spend a great deal of time down at 2K/rpm when driving, this suits me nicely.

I wouldn't pay PTP £500 for their kit... and I probably wouldn't go to the bother unless the belts were going to be off anyway... but, if anyone is looking for a cheap-ish upgrade whilst they are getting their belts done... then I can certainly recommend trying to pick up some MGTF135 cams from a breaker. 'Should' be able to get them for £120-£170 I reckon... and if not, try Rimmer Bros as they have MGR cams listed for £210i iirc, and the part# seems to match the PTP part#.

I know PTP also do a 165/170 cam plus other people will recommend getting a set of piper cams for ultimate performance, but, for that kind of cam upgrade, you then need to start considering pulleys, and maybe an emerald... so it soon becomes a pricey option in comparison.

Gets my thumbs up... (I wonder what they would be like in conjunction with an SLS/135/Sabre etc head??)

[robin]

In combo with a 135R head it will go well. In combination with well ported head with bigger valves it will deliver more than the standard ECU can manage.

Cheers,
Robin