right how does the vvt work. i know it advances the timing on the intake side via solenoids at the back which allows oil to flow through the intake cam to the front sprocket but how does it actually adjust the cam. whats special inside the sprocket apart from the spring. oil flows into the sprocket but what does it actually do. is there a way of checking that the oil passageways are clear in the cams without removing the sprockets or damaging anything??

 

 

the vvt springs job: is it to just take up the slop in the cam or do they do something else??

 

 

vvt solenoids: can they be removed and refitted without stripping down half the engine and how can i check operation of the solenoids ( to see if they alow flow of oil through the cams)??

 

 

:confused: cheers

 

 

gazzumpt!

bump

ok i take it that inside the intake sprocket is a similar design to this:-

 

 

 

 

 

 

 

 

 

which by oil pressure being exerted into the chamber advances the timing by up to 20 deg

just incase anybody is interested how it seems to work this is a good read. vvt vs vtec

 

 

VVT vs VTEC

ime not ignoring you gaz but ime not sure how it works and dont want to send you down a blind ally by bad advice ;) wtf is duffer when you need him

The cams have an oil pressure feed which is fed to the intake sprockets. Also at the back of the cam are the VVT solenoids, which open to bleed off the oil pressure feed. When the solenoids are closed the oil pressure causes the intake sprockets to rotate relative to the camshaft and decrease the overlap between intake and exhaust valve opening/closing. This is done to prevent backfilling the combustion chambers with exhaust gasses when the exhaust back pressure is high (back pressure is greater than intake pressure). Thats the best I can describe it lol. When using larger turbos, the backpressure is decreased so the vvt switch point can (and should) be increased to aid efficient cylinder filling....

The cams have an oil pressure feed which is fed to the intake sprockets. Also at the back of the cam are the VVT solenoids, which open to bleed off the oil pressure feed. When the solenoids are closed the oil pressure causes the intake sprockets to rotate relative to the camshaft and decrease the overlap between intake and exhaust valve opening/closing. This is done to prevent backfilling the combustion chambers with exhaust gasses when the exhaust back pressure is high (back pressure is greater than intake pressure). Thats the best I can describe it lol. When using larger turbos, the backpressure is decreased so the vvt switch point can (and should) be increased to aid efficient cylinder filling....

thanks andy. a star as always.

 

virtual pint to you fella :duffer: