Starting to build my 1600 TP , crank and rods all fine , but I'm not happy with the rotation of the camshaft , it just doesn't feel a smooth or fluid movement when the crank is turned ,all the main bearings on the crank are fully seated , the cam isn't jumping out of the bearing carriers , just doesn't feel right , could it be badly matched cam gears , anyone use straight cut cam gears , is that the way forward ?
Trust your instincts... If it "doesn`t feel right" it probably isn`t. Farmer Rob will come along with advice....
straight cut gears will be noisy, have you torqued up the case with the cam and crank fitted to check the rotation or just done it open on the bench.
just done it open on the bench
Some engineers blue is your friend it will show you how all the teeth mesh after 2 full crank rotations best done with the case together and the big nuts torqued up.
Have you fitted a new camshaft and bearings? And have you fitted one or two thrust bearings? I fit the camshaft first in the case half that has the thrust bearing or both if your fitting two, and then check for 3-4 thou end float between thrust bearing and cam thrust edge. If you haven't got this, sometimes a clout with a drift on either end of the camshaft while fitted; will square the thrust sides up so you have clearance. If not, just rub the thrust surfaces on a fine oil stone till you get the clearance. When you are happy with that, fit the crankshaft in the case half, when you are happy the bearings are sitting correctly on all the dowels, Fit the camshaft. Genuine VW camshaft gears came in different diameters. So the cam gear should be able to rock in the crank gear! If its too tight, it will walk out as they say, when you turn the crankshaft round one way. As you say it doesn't feel right, it might be the crank gear got damaged taking it off or re-fitting it. Just turn the crank round one tooth at a time and see if the cam gear will rock each time. As Snoopy say's, some engineers Blue will highlight a damaged tooth which you could then rub down with an oil stone.
Hope this helps Rob
straight cut cam gears are not needed and after so long they get on your tit.. And is why straight cut gearbox's 4-5 etc are not straight cut ..
Quote from: farmer rob on July 19, 2022, 02:19:06 PM
Have you fitted a new camshaft and bearings? And have you fitted one or two thrust bearings? I fit the camshaft first in the case half that has the thrust bearing or both if your fitting two, and then check for 3-4 thou end float between thrust bearing and cam thrust edge. If you haven't got this, sometimes a clout with a drift on either end of the camshaft while fitted; will square the thrust sides up so you have clearance. If not, just rub the thrust surfaces on a fine oil stone till you get the clearance. When you are happy with that, fit the crankshaft in the case half, when you are happy the bearings are sitting correctly on all the dowels, Fit the camshaft. Genuine VW camshaft gears came in different diameters. So the cam gear should be able to rock in the crank gear! If its too tight, it will walk out as they say, when you turn the crankshaft round one way. As you say it doesn't feel right, it might be the crank gear got damaged taking it off or re-fitting it. Just turn the crank round one tooth at a time and see if the cam gear will rock each time. As Snoopy say's, some engineers Blue will highlight a damaged tooth which you could then rub down with an oil stone.
Hope this helps Rob
[/quote Thanks , I'll try that