GT6 rocker oil feed

[BestyA]

So I have the dreaded oil feed modification fitted by a PO, starving the bottom end and flooding the top end. Feed is teed off the oil pressure switch, so that is easy to remove. Question is how do I plug off the top end?

[Iain T]

It's a set screw and copper washer. Take a look at the Canley Classics website which gives size. 

Iain 

[thescrapman]

Just make sure the internal,oilway has not been blocked off, occasionally a proper job was actually done 

[Pete Lewis]

5/16/x24 unf setcrew quite short   one    and copper washer or some sealant 

Pete

[Mjit]

That's a SH605031 with a 500469 in parts book terms.  Also worth getting a 5/16" crush washer off eBay - in case it turns out yours HAS been done properly and so you need to refit the external feed.

From memory the advice on testing it I recieved on here when I bouth a 2500S with an external feed fitted was:
1. Remove from head/fit blanking screw+washer.
2. Remove oil pressure switch from 'T' piece/remove 'T' piece from block/refit oil pressure switch direct to block.
3. Remove rocker cover and wipe up any sitting oil.
4. Start and run the engine for 30s-60s.

If the external feed was just bolted on you should start to see oil weaping out of the rocker shaft, as it's still getting supplied via the internal oilway, so you're good to switch off/refit the rocker cover/get on with your day.
On the other hand if things stay bone dry at the top of the engine the external feed was fitted properly and the internal oilway blocked off and you're now running without rocker lubrication!  Switch off and swap everything back to 'T' piece and external oil feed+oil pressure switch at the block end/external oil feed+crush washer at the top - and then get on with your day.

[Pete Lewis]

to add the oil feed comes from the rear camshaft journal  this has a small flat machined on the journal so you get a small squirt for each revolution of the cam 

this gives the rockers a interupted feed  so it will appear  up the rear pedestal in a series of squirts /pulses 

 

another option is to drill and tap the banjo bolt and fit aa threaded plug( bit of a bolt )  drilled with a 0.5mm bleed hole to really restrict the full flow 

Pete

[Iain T]

Or fit a needle valve as I have. Gives total control over the rocker oil feed. 

Iain 

[JohnD]

Yeah,  Brothers and Sisters, Alleliuahya!  For Truthe is now the New Black, and Ye Spawne of Ye Deville is to be caste into Outer Darknesse!  For even a new brother, Brother BestyA, knoweth that the external oil supply is a Sinne, and an Abomination! 

But I have to say that, A/ just blocking the usual feed from the rear camshaft bearing isn't a 'proper job', unless there is also a restrictor in the line.   Where did your needle valve come from Iain, and how do you adjust it?

[Iain T]

1 hour ago, JohnD said:

 Where did your needle valve come from Iain, and how do you adjust it?

One of these, has a T handle to adjust. From memory I only have it on half a turn. 

[JohnD]

Thanks, Iain!

What criteria  did you use to adjust it?

A method is to note the oil pressure before fitting the external line, then adjust until that pressure is the same with the line. 

John

[Iain T]

Your welcome. I forget where I bought the extra braided hose and s/steel fittings but chose again a commercial not car spare supplier to hopefully ensure better quality. 

To adjust I ran the engine up to temperature and adjusted until I obtained a constant slow drip. Opening the tap really increased the drip to a constant flow and turning off reduced to nothing. 

The oil pressure is now 80+psi cold and 60+ at 3000rpm

Iain 

[JohnD]

Sounds like a a proper job!

John

[Iain T]

As a trial and before I bought the extra fittings I screwed it into a two port boss. The other outlet being oil pressure. It worked so I purchased the fittings and mounted the needle valve in a bracket on the side valance. No leaks......so far🤞

Iain