4 replies to this topic

[dogboy]

Firstly can someone tell me or even better show me where the camshaft oil restrictor goes (do I have to fit one) and secondly do I have to have oil restrictors in my cross drilled crank? 1275 non A+ block

 

[Spider]

I may have a photo of the resitrictor in the Block. There's only the one, that feeds the Centre Cam Bearing. If you look at the Centre Crank Bearing housing (in the Block), you'll see two Oil Way Drillings. The one the comes from the Distributor side of the Block, is the feed in from the Main Oil Gallery, the other, angled off toward the Cam feeds the Cam Centre Bearing. While I've not measured the dia of the holes, the Drilling is about 1/4" dia and the hole in the resitrictor would be around 3/32" .

 

You wouldn't normally fit restrictors in to a Cross Drilled Crank (a non cross drilled you might), but depends on application.

[carbon]

The cross-drilled cranks I have seen typically have 3 oilway drillings for each big-end. One of these is the original drilling coming from the main bearing, the other two are drilled to come out at about 120 degrees to the original.

 

The original drilling is blocked so that oil is only fed to the big-end via the two new drillings at 120 deg. The reasoning here is to reduce oil being centrifuged away from the main bearings at high rpm, help them to last when running wider clearances.

 

The original drilling is blocked either with a tight fitting brass plug (typically with a 1/16 hole through it) or tapped and blocked using small grub screws.

[Spider]

The original drilling is blocked either with a tight fitting brass plug (typically with a 1/16 hole through it) or tapped and blocked using small grub screws.

 

The factory used threaded plugs, at least in the cranks I've seen.

[dogboy]

Thanks guys. Just got to have a look at the centre main part of the block to see if there is a restrictor already fitted.