why blok the original once?
im running ape studs in which are bigger than stock so though that and extra oil line would just be better - what do you do in the head?? do you just pull og drill the the plugs out?
(its a z1000 head and not J )
It's the same for any of the 900 to 1100 heads.
You either need to dry block or just run a 12mm drill down the 2 rear outer stud holes to give clearance for the oil to get past the HD studs.
If you drill the barrels you also need to do the head just deep enough to reach the diagonal oil feeds to the cams.
was thinking about only doing it on the exhaust side and then keep the oil from the studs...
still flows oil up around hte HD studs, but its in the exhaust you have the heat and that cam is the last to get anything..
Won't do any harm just feeding extra to the exhaust side but it is sort of defeating the object of external feeds and I would still open up the barrel at the rear 2 studs.
Because of the way they are cast the holes on these blocks taper inwards from each end and in some cases the HD studs barely squeeze through leaving very little clearance for the oil flow.
I run a 12mm drill through them and it gives the same clearance as you would have with the stock studs.
With the stud holes opened up you won't really need the exhaust feeds,.
My Turbo drag bike just runs the opened up holes and has no issues with exhaust cam oil starvation.
Lars! Something I forgot to mention.
Once the head has been drilled, tapped and spot faced for the banjo there is only around 7mm of thread before it intersects with the original diagonal oil feed.
The banjo bolt needs to be at least double its length into aluminium to avoid stripping out at the correct torque so will blank off the original feed.
The cam won't really get any additional oil by adding the external line except a slightly cooler supply as it won't be running up inside the hotter block.
thanks - ill look into it the next few days (especially the last you write about the 7mm thingie - thats interesting
its going on a 1260/1328cc mr turbo setup in which ill only use for the strip mostly
If you have got a big block or bored out cases you really need to dry block the case.
It will save problems in the long run.
The base gasket is very prone to leakage when the cases are bored due to the reduced area.
Same goes for the head gasket if you are using a copper one.
This is the reason why dry blocking was devised.