Mark w Posted October 29, 2019 Share Posted October 29, 2019 So today i fitted a new cambelt on my daughters VW .No verniers so cam timing is down to the accuracy of the components and assembly .The issue is that with the top sprockets locked in position the crank sprocket needs to be set half a belt tooth off the marking for TDC .So i either fit it so the top sprockets are running " late " or "early " relative to the perfect timing with the bottom spocket dead on the TDC mark .( if ive explained that right !?) Any preferences ? It runs OK but the idle seems to be more lumpy than it was .No i dont have a dial guage to check it .I need to rely on the timing marks on the car Link to comment Share on other sites More sharing options...
SM25T Posted October 29, 2019 Share Posted October 29, 2019 The way I do my k-series is to put spots of Tippex on sprockets and edge of belt ... 2 spots on each toothed sprocket. Then I transfer the spots to the edge of the new belt. Fit it in the same place. Job done. Link to comment Share on other sites More sharing options...
garybee Posted October 29, 2019 Share Posted October 29, 2019 Does the engine have keyways on the crank and cam pulleys? Most modern engines I've worked on rely on the clamp of the pulley bolt(s). If you've not had the pulleys off I do the same as SM25T. If I feel like being a smartarse and the tensioners don't need replacing (and it's my engine) I like to do the cut it in two with the engine running trick. Can't mess the timing up that way. Link to comment Share on other sites More sharing options...
Mark w Posted October 29, 2019 Author Share Posted October 29, 2019 Havent had the top sprockets off .The bottom pully only goes on in one location as its keyed to the bottom spocket ( which hasnt come off either ) . Link to comment Share on other sites More sharing options...
Mark w Posted October 29, 2019 Author Share Posted October 29, 2019 If you look at the above photo the belt runs from the top left sprocket down past the fixed pully to the bottom sprocket which looks like this .The ridge with the two splayed ends needs to line up with the mark on the engine casing ( which it does in this photo) however at this stage the belt wasnt on the top sprocket ! put the belt on the top sprocket and tension it round the bottom sprocket and the sprocket is half a " pitch off the mark .Hence my original question . Its basically a function of the belt ( a Gates one ) . Link to comment Share on other sites More sharing options...
Mark w Posted October 31, 2019 Author Share Posted October 31, 2019 Just in case anyones interested the problem is sorted , i took the belts off and started all over again and low and behold the timing marks were all spot on .I dont really understand what changed but am pleased its done . Link to comment Share on other sites More sharing options...
SM25T Posted October 31, 2019 Share Posted October 31, 2019 Good news Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now