Thrustyjust wrote:Lots of cams are reprofiled original cams . So by doing this, there isnt too many places to be able to stamp their model on them. Usually as you can see , its a little bit of investigating to confirm. Agree this is the 285 profile from Piper cams . Sadly , its not just a case of chucking in new cams and you get more power. Cams are designed to be part of modification to an engine and work in conjunction with other mods. This is the case moreso for more aggressive cams. These can require pistons to be machined, head porting , induction changes and even manifold and exhaust changes, from bore sizes to pipework primary lengths and how they are connected , such as 4 into 1 or 4 to 2 to 1 .
Misconception by people is to fit the lumpiest cam they can and it will reap power. Cams should be relative to what you want. High profile and large overlapping cams can create an engine which is 'cammy' , so will idle crap and pull away shunting and slow until the port velocity speeds up enough to 'come onto cam' and then they create power. So, there is a lot of dimensions than just buying some cams and putting them in. Turbocharging doesnt want high overlapping cams, which is why a lot of turbo modded cars use standard cams. If you have a car which uses a cat and has emission checks for MOT then big cams can be an bum for getting a car through.
Just some fuel for thought and probably gone too far as I usually do. But theyre are masses of books just on cam design, applications and other things like A Series scatter cams , which is another story.
Thanks for the info - well i found it interesting!! I know there is a lot of science behind engine tuning, simply bolting on new bits doesn't always reap the rewards.
TBH the car was running well before imho but the head gasket had gone, so strip down was needed. A couple of valve seals leaking a bit too revealed some guide wear. Took it to Classic and Modern Engine Services in Bracknell. Don't know if anyone else has feedback but seemed very knowledgeable, recommending what work could/needed doing without ripping me off (I hope!), new valve guides, re-seat the valves and head skim, looks good, will add photos later. Head not back in the car yet but so far i'd recommend them. He confirmed Piper 285 cams, the 'H' is for hydraulic lifters apparently! Also found the head has been ported and polished too, a bonus.
So Weber Alpha TBs, Piper285s, ported/polished head with triple cut valve seats, 4-1 stainless exhaust, spec is the same, just nice and shiny now - must be worth an additional 10 horses right?
Just ordered vernier pulleys too to help with dialling in - and they look nicer!
Would like to get it checked/mapped on the ECU side but no one seems to touch weber alpha ECUs any more. oh well start saving again ...
Tiger Supercat 2.0 Zetec.
) and bolt onto the crankshaft. Cheaper than buying from Burtons etc. and you have a red and green arc specifically for your set up, made it a lot easier.