Tu5Jp4 Pistons

[thomasrally 3]

I want to run an aftermarket camshaft such as the piper 300 in my 206 xsi engine but im told it wont have enough clearance due to the domed pistons??

 

If the above is true would pistons from any other engine fit or would i need to buy competition forged pistons?

Edited May 28, 2012 by thomasrally

[custard-rallye 25]

I'm sure pistons out of a 106 gti fit

Edited May 28, 2012 by custard-rallye

[thomasrally 3]

Would that allow enough clearance for the piper BP300 cam and how would it affect the compression?

[christopher 5 1 Cars]

I'm sure pistons out of a 106 gti fit

 

These pistons are flat with a tiny cutout..

[custard-rallye 25]

Could you not get the 106 gti pistons cut out for valve clearance I have some pistons if needed?

[thomasrally 3]

Ive no idea, are the 106 pistons the way to go or is there a better alternative? Its a forest spec 206 rally car so im trying to get as much info as I can on what would be the best way forward to getting more power out of it.

 

Someone also mentioned doing all the head work and fitting 106 cams which would retain the current pistons, question is how much difference would the 106 pistons make?

[Sandy 191]

All well and good machining the pistons for clearance, but without enough increase in CR it's going to be a pretty rubbish delivery. For standard J4/JP4 pistons, you're looking at around 1.5mm inlet and 1.8mm exhaust maximum net lift at TDC. If the head's skimmed, then obviously less. That limits you to fast road cams, such as Piper BP285, Newman PH3, Catcam 708 etc, all essentially the same profiles.

[thomasrally 3]

Hi Sandy, is 180bhp+ achievable using one of these fast road cams? and if so, which one would you recommend with the standard JP4 pistons?

 

How about the new cat cams 743, seems to be the 'new' version of the 708 cam?

Edited May 29, 2012 by thomasrally

[welshpug 1,661]

Doubt it, the Saxo I was out in Belgium with over the weekend runs 850's (solid tappet profile) which are much more lift and duration, advertised as a 273, where a 708 is only 256!

 

it has forged pistons and rods, standard head, 42mm bodies, 171 bhp 145 lbft, but a very nice broad spread of torque.

Edited May 29, 2012 by welshpug