This thread again, what cams?

[Radugns]

Hi,

I've read all the topics I found here regarding the cams for a 1*2 Clio. Basically everything on Catcams cams.
I am building and engine for a little track and daily. I rebuild the whole engine, keep the original pistons and rods for the standard compression and uprate the valves with supertech ones and ARP conrod bolts for better reliability.
I have to choose from 428, 438 and 421. I know:
-428 are tested and give a little power ofer the 420 or OE ones, but not that much gain as 438 and 421
-438 have the same 'wild' profile as 421 but with a better idle and could run with standard ECU
-421 should be used with ITBs and standalone ECU and give some more power than the 438 on the end

So, taking this into consideration, I have to choose from 438 and 421.
I will have to use the standard ECU for reducing costs. I've read that some here run the 421 on standard ECU mapped and use a higher idle speed. From what I've read, the 421 give power up to 7500 and the 438 up to 7200. Now I have the generic RS tuner map.
I run the 197 inlet with matched head and 421 exhaust.

I know that catcams says that 421 could not run on standard ECU, but there are people here who got them working just fine on the standard with the driveability drawback and a higher idle.

And my big concern, could I run the cammed engine (with 421 or 438) for about 1000 miles before the mapping? I need to brake in the engine due to changing the piston rings.

Thanks,
Radu

 

[R3k1355]

Why not 197 cams?

 

[Radugns]

Need some more power than 197 cams could provide.

 

[Radugns]

Does 197 cams need different timing setings or can be done with standard lockers?

 

[bloke]

different timing.

 

[Radugns]

different timing.

And what about 438 or 421?

 

[bloke]

they are set to standard timing but you can re time 438 to 421 spec. with standard inlet i'd just stick with the 421 if you want catcams.

 

[Radugns]

they are set to standard timing but you can re time 438 to 421 spec. with standard inlet i'd just stick with the 421 if you want catcams.

421 or 438? Sorry to ask, but I am confused because it says on website that 421 are better with itbs.
And where I can find the 421 spec timing?

 

[bloke]

sorry, should of said 438.

figures are on the catcams website.

 

[Radugns]

sorry, should of said 438.

figures are on the catcams website.

The figures are there, but my knowledge to interpret them is...is not