Cam options (again)

[M4D M4X]

Have had a look for the answers but haven't come across anything related.
I all ready have a set of 428's in my engine (still a undergoing project) but now iv'e purchased ITB'S and with the car mainly being a stripped right out track car with the occasional road drive i was looking for more aggressive cams, i know a lot of people put 421's but as iv'e already purchased uprated valve springs i was thinking something along the lines of 5502432's or even 5502433's.

What i'd like to know is are there any advantages of going for the more "race" type cams over the 421's?, if someone could explain roughly what these 432's/433's would be like on revs that would be great.

I know that i'll have to compromise on rev range somewhere but what i don't want is under 5k the car not being able to pull at all.

Any help would be much appreciated.
Thanks

 

[Dan@SJM]

You don't want anything like that. Run 421's.

 

[M4D M4X]

Any explanation as to why not dan, have you had them in any of your previous cars?. From looking at the duration/lift on the 432's there pretty similar to the 421's.

 

[Ph1 Tom]

You'll need forged pistons or some other way of gaining valve clearance for anything bigger than 421.

Piper now do a BP285 cam which is similar to 421s. Its £300ish for them to be reprofiled. I've got the one below that (BP270) which makes 207bhp on mine with ITBs so with the 285 you should expect more.

Sell your 428s, send some standard cams to Piper and for roughly £100 you've got yourself a nice upgrade.

 

[mark123]

Not seen some of those cam profiles before. Maybe catcams have updated their range. Probably worth talking to ED about it.
http://www.catcams.co.uk/acatalog/Renault_clio_rs.html
I think you need high comp pistons, or the std ones machining to have deeper pockets for the valves to go into for 422/423 profiles, which look similar to the 432/433.
There are a few cars on here running 422/423 cam profiles with high comp pistons - you're likely to make in the 220-240 bhp range. From looking at the power graphs they don't seem to be too compromised lower in the rev range.
Not sure it'd be worth the expense of switching from 428 to 421, you're probably talking 5bhp.

 

[M4D M4X]

Ah didn't realise that it needed work for the valve clearance going over 421's, a bit stupid of a company not explaining that when giving the options to buy cams.

Wow that's cheap in respect for the price cat cams are, maybe i'm a idiot but I always think that you get what you pay for so don't think i'll go down the route of piper re-profiling standard non billet cams i'd rather spend the extra and know that there the proper ones.

Thanks for that tom cleared a lot of questions up.

 

[M4D M4X]

Thanks for that mark, I like the thought of having 220/240bhp in something that's going to be around the 800kg mk. Think i'll speak to ED and see what he says regarding gains-££££. To go down the expense of a extra £450 after selling the 428's and only gain 5bhp doesn't seam the best option imo.

 

[Dan@SJM]

Be prepared to seperate with around 8k for a forged engine and solid lifter setup to run anything over 421/438's.

 

[M4D M4X]

Wtf 8k, forget that then not prepared to pay that on the the engine alone the bloody car owes me over 10k as it is.

 

[Ph1 Tom]

Ah didn't realise that it needed work for the valve clearance going over 421's, a bit stupid of a company not explaining that when giving the options to buy cams.

Wow that's cheap in respect for the price cat cams are, maybe i'm a idiot but I always think that you get what you pay for so don't think i'll go down the route of piper re-profiling standard non billet cams i'd rather spend the extra and know that there the proper ones.

Thanks for that tom cleared a lot of questions up.

Cam snob! Nothing wrong with reprofiled cams whatsoever. You won't notice any difference in performance or cam life between reprofiled and blanks, all it does is save you money.

 

[M4D M4X]

Haha cam snob!, thinking about it i wonder if i could use the existing 428's i have and get them re-profiled to 421's?.

 

[mark123]

Be prepared to seperate with around 8k for a forged engine and solid lifter setup to run anything over 421/438's.

Why do you say solid lifters Dan? Catcams don't say they're needed for 422/423 and plenty on here have run engines with those cams using the hyd lifters.

 

[Dan@SJM]

To make the most of cams like that you want 8000rpm+

 

[mark123]

They're still worthwhile below 8k though and to go over 8k you'll need to upgrade more than just lifters (custom crank and pistons, oil pump, etc).

 

[NorthloopCup]

You could enlarge the pockets on the oe Pistons to run 422's or 423's. Iirc you need to increase the pocket depth around 1.5-2mm.
But those profiles work better with higher comp ratios. You could always fit a set of 197 Pistons if you really wanted to do it on the cheap and not bother with forged pistons.

And on that note I'll await the flaming for suggesting pocketing the oe pistons! Lol

 

[M4D M4X]

Thanks for all the input guys really appreciate the time you've taken to write your info, given what has been mentioned I think i'll just get my 428's re-profiled to 421's, going down the 422423 Seams to be hassle and not to mention a extra £1000 on forged Pistons/pins/bolts.
I know i could do the cheaper option and get my standard pockets enlarged or go down the route of 197 but there's still the headwork to get the compression ratio right to get the best out of the cams.

Maybe in a year or 2 when i get used to the power and how it's delivered and decide i want more i can look at this option again and probably alter gear ratios at the same time to get the best from the car.
Also in that time period the prices might come down so giving me more and better options.

 

[NorthloopCup]

Thanks for all the input guys really appreciate the time you've taken to write your info, given what has been mentioned I think i'll just get my 428's re-profiled to 421's, going down the 422423 Seams to be hassle and not to mention a extra £1000 on forged Pistons/pins/bolts.
I know i could do the cheaper option and get my standard pockets enlarged or go down the route of 197 but there's still the headwork to get the compression ratio right to get the best out of the cams.

Maybe in a year or 2 when i get used to the power and how it's delivered and decide i want more i can look at this option again and probably alter gear ratios at the same time to get the best from the car.
Also in that time period the prices might come down so giving me more and better options.

1k for forged Pistons is a bit ott mate. You can get piston AND rod packages for £600-£700 from pec if you go to th right places.

 

[M4D M4X]

I've just calculated the prices from engine dynamics website I did see pec ones but there was no compression ratio, but they were only £100 less than the others.

What compression ratio Pistons would be best 11.8.1or 12.8.1?

 

[Dan@SJM]

Plus the rebore etc it still ends up over £1k

 

[NorthloopCup]

I've just calculated the prices from engine dynamics website I did see pec ones but there was no compression ratio, but they were only £100 less than the others.

What compression ratio Pistons would be best 11.8.1or 12.8.1?

All depends on the engine and cam spec. 421's = stick with stock imo.

 

[NorthloopCup]

Plus the rebore etc it still ends up over £1k

Agreed. Rebore may not strictly be necessary though if you've got a block in good order. Obviously needs to be measured before any decisions are made.

 

[Dan@SJM]

Be stupid (IMO) to spend out £700 odd on Pistons and rods to throw them in an old bore.

 

[NorthloopCup]

Be stupid (IMO) to spend out £700 odd on Pistons and rods to throw them in an old bore.

Yeah I can see your logic there mate, and it's a valid point you've got.

 

[Adey.]

are the 197 pistons a direct fit? straight swap or do they need pocketing aswell?

 

[NorthloopCup]

are the 197 pistons a direct fit? straight swap or do they need pocketing aswell?

Straight swap as long as your bores are good mate (82.7). You may need to adjust the head combustion chamber though.

 

[Ph1 Tom]

If they've just got a thicker crown to raise the compression ratio you could skim them.

 

[NorthloopCup]

If they've just got a thicker crown to raise the compression ratio you could skim them.

They look similar to my R3 maxi pistons mate, just not so much of an intrusion into the combustion chamber.

 

[M4D M4X]

Thanks again guys, I've decided to stay with stock internals i've already been on the phone today to piper cams about sending the 428's to get re-profiled to their 421spec, a simple 10min job tomorrow while over the garage remove the cams to be posted off.

I can always go down the forged route at a later date with a spare engine.

 

[Ph1 Tom]

Have you got any standard cams knocking around? It would work out cheaper to send them off and sell the 428s. You'll get decent money for the 428s on here.

 

[M4D M4X]

Na i used the standard cams i had in another engine that these came out of, i'll have a dig about through the FS section and see if i can get a pair of standard ones and sell the 428's.

Good thinking batman .

 

[chaski]

Na i used the standard cams i had in another engine that these came out of, i'll have a dig about through the FS section and see if i can get a pair of standard ones and sell the 428's.

Good thinking batman .

I have a set of standard cams you can have cheap as chips mate, they're sitting around collecting dust. My car's a road car with 428's in and the standards will never go back in. That way you can sell the 428's and probably get your upgrade for free. PM me.

 

[chaski]

@M4D M4X

 

[MiniCooper1380]

Goodmorning,
does someone know if Piper BP285 full lift inlet ATDC (110°) is measured with VVT dephaser pulley engaged or disengaged?
Did someone measure which are BP270 and BP285 lifts @ TDC for inlet and exhaust (with OEM timing )?
I sent an email to PiperCams but they answered me only to run standard timing, using the slot on the rear of the camshaft!
Thanks for your help!

 

[Ph1 Tom]

My BP270 cams are timed to standard Renault values. I didn't measure lift