what are the signs of worn out valve springs on a cvh head, apart from them breaking is there a way to tell if they are worn out?

 

well they can only really go soft.

Why are you thinking valve springs?

 

well heres the thing. got a 2nd hand rs efi engine from down southand bought it already out of the car so did not hear it run. spent winter rebuilding everything, and as soon as it started it has a loud ratlle under load and backfires when going downhills in gear. since then ive changed camshaft, hyraluic tappets, cylinder head, injectors, rockers. I had however moved exisiting valves over from last head onto new head as they were in better condition along with valve springs. now thinking the problem must lie here! The strange thing is that when i bought the engine the cylinder head was apperetly recon and i had noticed when stripping that one of the rockers were a golden colour compared to the other 7 grey rockers. could it be that a machine shop has supplied the head to the previous owner with over or undersized valve stem or rocker etc, and could this cause probs if ive got it mixed up? The reason im thinking valve springs is there isnt much else i have now relaced top end and its def to end rattle.

 

Did you grind the valves you changed in??

 

yes on both heads

 

okay ive spent another day under the bonnet to no avail. that bronze looking rocker does appear idea did not work it was the same as the rest. all valve stems seem to be the same in length etc. i did notice that inlet valves have longer stems than exhaust ones is the correct?

piston probs slap or gudgeon pin rattle wouldnt cause this prob would it because i am thinking the backfiring im getting when going downhill in gear would be valve probs / timing but timing is all done automatically

when i pull off 3rd ht lead it goes away but obviously runs rough

 

could be a little end then!

 

would this make it backfire when in gear going downhill with no throttle?

 

shouldnt do

 

just a quick one if it was little end pin that was worn would it rattle throughout all the revs or just show at one point only. mine rattles under load between 2k and 3500k only!

 

Usually they rattle all the time but its not guaranteed to be an accurate diagnosis