driversdomainuk 8 Posted April 5, 2006 Hi Are these worth the cost: http://www.forgedpistons.co.uk/catalogue2....eugeot&catid=17 Raising the CR to 11.5:1 with these..?? from 9.6:1 what benefit would these forged jobbies have over standard ones - sorry, still areas of the engine I know little about and am trying to learn more Cheers Share this post Link to post Share on other sites
Dom9 2 Posted April 6, 2006 They are quite expensive, but then again, all forged pistons seem expensive over here especially when you compare what they pay for pistons in the US. If you need high compression then you are probably running a fairly wild spec. In which case, you are likely to have a fairly highly stressed engine. The benefit forged pistons have over syandard/cast pistons is that they are a fair bit stronger, so will take higher power outputs or rpm before failing. If you want peace of mind for your engine and you have the money and you need high CR, then buy them! Just beware that you may need slightly larger clearances between your piston and liner as the forged pistons have a different coefficient of expansionn when compared to cast pistons, so the engine may be a little noisier and use more oil when cold. Share this post Link to post Share on other sites
petert 587 Posted April 6, 2006 (edited) You don't necessarily need forged pistons to get a high CR. For example, you can use an Mi16 or 1.9L DFZ piston to get above 11:1. However, neither will be of any use if your liners are stuffed. The first thing you should do is inspect what you've got. If you do have excessive liner wear, then a new piston is a must. Also, if you're planning on building a high hp engine you'll want full floating pins anyway. So therefore Mi16 pistons, rods and liners become a good idea for cheap, reliable 8V hp. What ever you decide, you won't make good hp with a big cam and low compression. Big cams have late closing inlet points which severly lower effective compression at low RPM. Fitting a 300 deg. cam with 9.6:1 won't go any better than a 270 deg cam with 9.6:1. It will go worse. If you read the Piper cataloque, it says you need to skim 0.028" off to get 120hp at the wheels with the 270 cam. That's because it needs to be at least 10:1 to work properly. Edited April 6, 2006 by petert Share this post Link to post Share on other sites
driversdomainuk 8 Posted April 6, 2006 (edited) umm, think I will just stick to standard ones. I am focusing on reliability so am looking at replacing: pistons rings liners big and main bearings oil pump (can buy at below cost from FAI) What are Autofive like for prices - I think thewy charge £279 for a piston/liner/ring kit for a 1.9 Edited April 6, 2006 by driversdomainuk Share this post Link to post Share on other sites
petert 587 Posted April 6, 2006 Get some more opinions. Speak to people like SRD and QEP. There used to be some nice cast flat tops available. Perfect for what you need. Share this post Link to post Share on other sites
GVK 0 Posted April 7, 2006 (edited) http://www.racetep.com I have just bought a set of JE forged 83.5mm pistons for my Golf 16v engine build from these guys in the states, for £381 including rings,shipping etc etc Not sure if they do Pug stuff but thought it worth mentioning. They're very cheap for ARP fasteners too. Edited April 7, 2006 by GVK Share this post Link to post Share on other sites
