Cam choice..

Chaps

Got a freshly rebuilt DX motor - all stock, with a 4 branch manifold ( haven't got an exhaust yet.

Been offered a 305 cam cheap! - Good / bad? likely characteristics? lumpy idle? nothing below 4k rpm then all hell breaks loose?

any offerings greatly appreciated..

Can timing is a mystery to me!!

do you know the spec of the cam? duration, lift? assuming it's a 305 deg duration cam, i would expect it to be rather nasty in a standard dx engine

Cheers for that - but can you define "nasty"…

I've asked the seller for spec info - if it comes up i'll post..

thanks again

a 305 degree would be very lumpy and would take forever to get going (like at about 3500/400rpm). you would be bumping all over the place whilst stationary but may give you 10-15bhp if set up properly.

h'mm not want i wan then me thinks - can you recommend a decent fast road cam thats not toooo lumpy?

285 or 280 is a good comprimise.

i've heard of those numbers before - i'll keep looking then!  cheers to you all .

i'd go more towards a longer duration cam and keep the lift a bit lower on a standard head. like the kent cams.

so is the number (eg 275, 285 etc) the duration?

not nessecceraly. piper do bp275 bp 285 and bp305 if i remember correctly, but that is not the duration. it's the same model number for hydraulic  and mechanical but different duration and lift for them.

KDXdestroyer said

so is the number (eg 275, 285 etc) the duration?

generally speaking. I would go for a Piper 285 if you can get your hands on one. they pop up from time to time on ebay and here.

ok… slightly clearer..

i understand the degrees of opening - eg 6' BTDC etc, but duration.. does that  indicate how long the valve is open? - if so any ideas what is std…?

std gti is 255 iirc

ta..