oil pressure and rough running issues

[jacks906]

following on from my old thread http://www.volkszone.com/VZi/showthread.php?t=641191" onclick="window.open(this.href);return false;

after 1000 ish miles have gone but its started running really rough, sluggish and noisy and oil pissing out from the crank pully. so i have taken the engine out stripped and split the case.

first oil leak:
the pulley looks fine from the back that the screw thread is on also the baffle plate is fitted correctly.

now the other bit:
the crank, before the case was split, would move up and down at the front pulley bit as the bearing are worn, also the cam shaft bearing are worn, now i was told today of a friend of a friend that his has similar issues and it was due to the straight cut gears meshing too tight which you can hear very loud on its very first start up http://www.youtube.com/watch?v=ji4NECdrOWw" onclick="window.open(this.href);return false;.

now my plan is to send crank away again and get it looked at an polished and get new bearing and a non straight cut gear (altho dont like the idea of this as the ones you get a ally ) another thing he mention was the case may have been skimmed and thus making the bearing too tight

any advice or thought on what has happen before i go and wreck it again

cheers

dave

 

[mattd1984]

With regards to the oil leak near the pulley. Mine was doing the same think it was due to blow-by as the rings were warn. I think a quick fix is to fit an oils breather. That's what I've read anyway.

 

[K@rlos]

It may be a quick fix but it won't be a long term repair.

 

[mattd1984]

It may be a quick fix but it won't be a long term repair.

Indeed you are correct.

 

[jacks906]

sorry should of put the spec plus old thread up

hi all
well i after realizing my engine was on its last legs me and me mate have rebuilt it, basically everything internal is new apart from the crank, push rods, rockers and the case, crank was measured before rebuild and was within tolerances, but i am having issues with timing it back up it seems to always have a slight miss at tick over (this could be due to the 110 engle cam but with it being so mild i'm not 100% convinced, cam lube was used, plus oil change after run in)

also how noisey should straight cut gears be, i know they make a constant wering noise as they do but they sound a little knocky too.

i'll put a list of whats new:

crank shells
big and small ends
cam shells
cam ( 110 engle)
cam followers
high pressure oil pump
H/D oil pressure springs
barrels and pistons (1600)
heads
bolt up rocker shafts (these could be a problem as they didnt come with a how to fit but we fitted them so they were loose but not too loose, also used spring washers etc from old rocker shafts is this right)

basically everything you would change has been changed for new

it may just be me with the cam gears thinking its noisey but its not actually noisey i have a vid of its fisrt run up but you cant really hear it over me mates citron jump start

http://www.youtube.com/watch?v=ji4NECdrOWw" onclick="window.open(this.href);return false;

it does sound a little tight but sounds loads better now will try get another vid tomorrow of it now

cheers for any advice

dave

engine was totally rebuilt and ran fine

my consern is tat the straight cut cam gears were meshing to tight and have worn the mains and thats why i have lost oil pressure

 

[BJ1]

You may well be trying to use a skimmed case. If so the cam gears will be too tight as will the dizzy drive. Did the crank spin freely with the case bolted up? You should be able to turn it easily by hand.

 

[jacks906]

a mate of mine thought this but all span ok when being bolted up not too tight at all but on the first run the gears were very noisy so i wonder if theseare the problem :?

 

[BJ1]

That sounds OK - straight cut gears are normally noisy.

Did you actually measure your crank journals and then check the bearing clearances with Plastigauge? If not you may have been fitting a very worn crank to new mains. Surefire way to get oil pressure problems especially if you are using high output pump and HD pressure valve. Hopefully you are also using a negative pressure breather system otherwise you'll get postive case pressure, adding to your oil seal problems.

 

[jacks906]

the crank was sent away to be checked and was told it was well within tolerances so it got a polishing and i left it at that and bought std bearings and away i went or so i thought :?

thing was i was going leave the bottom end alone i had no issues there and just do a full top end but alot of people said for what it was to change the mains etc so thought that was best now wish i'd left it

what size plastigauge is best to get?

 

[BJ1]

You should aim for bearing clearance of around 2 thou (0.002") +/- 1 thou. Buy Tom Wilson's book " How to rebuild your VW air-cooled engine" and follow his advice on rebuilding the bottom end.
You fitted standard mains but how did you know it was a standard crank and not reground? who measured the journals?

 

[jacks906]

crank was measured and polished at an engine builders near by

 

[jacks906]

wellllllllllllllllllllll all sorted (touching wood)

stripped it all down and remeasure everythin me self this time and found the case had had a line bore so the bearings were out by .5mm that has solved the rough running and oil pressure issues and now runs like a dream straight cut gears have been binned for an ally helical gear so that has got rid of all the noise too, it actually sounds like a normal dub engine :mrgreen:

down side is there is still oil, all be it not as much coming out of the pully, but more at higher RPM not much and no were near as much as last time, just a drip every now and again which eventullly builds up to be enough to drip on the manifold which is the puff of smoke me mate behind see's

so am thinking as advised to fit a case breather (think mine is too small anyway and is not the correct one) or do i remove the high flow pump or H/D oil pressure booster kit and go back to standard there, i also need to change the pulley as this one doesnt look to good (egde is dented and not true) do i go with alloy or standard?

cheers

dave

 

[BJ1]

Told you it was worth measuring the crank and bearings! Pleased to see you now have a good bottom end.

Firstly - there's no point in having boosted oil pressure on your standard engine so yes remove the HD stuff. You mnay find that cures the oil leak.
Secondly - you MUST have a good breather system or you will always have oil leaks. So you need a tube from the oil filler connection to the negative pressure side of the air filter. I'm guessing you have a pancake filter (these are rubbish) so at the least you should connect the tube to the underside of the filter. It's best to fit a standard air filter and use the take off on that - it'll give you more case scavenging.
Thirdly - use a standard pulley unless you can find a good quality alloy one i.e. one that can easily be removed. Avoid solid pulleys that don't have cut outs where you can fit a puller.

 

[jacks906]

Cool will take them out on the next service and pop originals back in

The breather on the oil filler neck is not the standard one as the hole looks too small also I have twin dell 36 so the top of each filter will need drilling etc to fit a breather is a breather box worth getting to connect to both an maybe rocker covers too or is that not really needed