AGENTKB Hi guys🙂 is there a procedure to use after refitting a head with new valves? ill be starting it with all the plugs out to build oil pressure first, maybe a wee bit of oil in the cylinders as well. also remove the fuel pump fuse too.
vocky thats about all you need to do, I usually just start them up with a head rebuild as the oil pressure is pretty much instant.
evocarlos 5-10sec for oil on the chain put it all back together then crank with the coil pack unplugged till the oil pressure lamp goes out then count to 5 🙂 this was already primed for 10sec till the lamp went out 🙂 https://www.youtube.com/watch?v=FhQiU9K920A
AGENTKB evocarlos said: 5-10sec for oil on the chain put it all back together then crank with the coil pack unplugged till the oil pressure lamp goes out then count to 5 🙂 this was already primed for 10sec till the lamp went out 🙂 https://www.youtube.com/watch?v=FhQiU9K920A thanks carlos(y)
patricks I got 190psi across all four and i have just changed the chains - i did mine from cold but i think the compression readings would be higher if it was done on a warm engine.....not sure what the correct procedure is to measure ie hot or cold engine
AGENTKB patricks said: I got 190psi across all four and i have just changed the chains - i did mine from cold but i think the compression readings would be higher if it was done on a warm engine.....not sure what the correct procedure is to measure ie hot or cold engine Sounds like a good reading you got from a cold engine bud
patricks AGENTKB said: Sounds like a good reading you got from a cold engine bud So then compression gets better with a warm engine?? I wasn't sure if a cold engine has thicker oil and hence greater compression or conversely warm engine have the pistons expanded fully into the bore and higher compression. Dunno confuses me....
HarleyPete As an engine gets hotter the tolerances get smaller. This should increase the compression as the ring gap gets smaller I assume due to the piston expanding slightly more than the bore.
patricks HarleyPete said: As an engine gets hotter the tolerances get smaller. This should increase the compression as the ring gap gets smaller I assume due to the piston expanding slightly more than the bore. Yep id say that makes sense my engine sounds a lot quieter once its warmed up so u would have to assume tolerances including piston ring to bore would be tighter. Hmmmm wonder what compression i could expect from my warm engine then..........im too lazy to do it and find out lol
evocarlos compression test are meant to be done walm but if the car wont run you can get a fairly accurate reading with it cold you also have to consider the oil factor when the engine is warm as the oil would get flicked up in to the bores
