Rocker Shaft Oiling

[dereklola]

I'm building an Indy Lights engine for vintage road racing and have a query on the rocker shaft oiling. I know it needs an external hose to each rocker shaft - I think some other Stage 2s also use this method - but I'm not sure of some of the details.

First pic - the -10 hose is the main oil feed from the external Cosworth pump - is the -3 fitment next to it tapped into an oil gallery? I assume it is and obviously this then feeds the -3 fitting on the rocker cover. (The -3 hose shown is just loosely installed to help make the picture clear.)

Second pic - at the rear the engine came with two small hose fittings - a -3 on the side of the boss on the block and the -4 on top into a -10 adapter. Again I assume that boss on the block is an oil gallery. And if it's similar to the front the -3 hose will feed the other rocker shaft. But can anyone think what the other hose, the -4, might be for? I will need a feed for electric pressure senders (oil gauge, oil light and fuel pump safety switch) but a -3 would be more than adequate for that.

So my questions are -
1 - can you experts confirm that those locations on the block are in fact oil galleries?
2 - does using a -3 hose seem adequate for feeding oil to the rocker shafts?
3 - any ideas what the -4 hose might be for?

Thx - Derek

[turbodave231]

Derek,

In both pictures you are plumbed into oil galleys (oil pressure source). The first picture is feeding the 1/8" NPT port in the head. You need to be sure the rocker shafts are also hollow. T&D made solid shafts that can't be used for external rocker shaft oiling.

The second picture has the line plumbed to the valve cover and not the head. Long track engines used spring oilers inside the valve cover. The spray bar basically sprayed oil directly on the spring to keep it cool. Based on the type of racing you plan to do, I'd say you don't need spring oilers. I'd move the line into the port in the head.

I have a couple sets of -3AN lines and fittings made for rocker shaft oiling. The fittings all have restrictors to limit the amount of oil going to the shafts. You need very little oil to keep the rockers happy.

Nice pictures.....post some more please!!!

Dave

[turbodave231]

After looking closer at picture #2, is that line going to the valve cover, or is it capped off? Can't tell??

Dave

[dereklola]

Hi Dave - thx for replying. Don't try to figure out where the hoses go to - they don't go anywhere! They are just old ones I grabbed from my scrap box to make the location of the block mounted fittings more obvious.

My question was more - are the locations in the block in fact into oil galleys - I think you confirmed that.
And any ideas what the larger (-4) hose might have been feeding?

However, as you say, the -3 fittings on the heads are the correct ones for the rocker shaft oil feeds - and yes I do have hollow shafts and I now remember the small restrictors - wonder if I can find them again. Any idea what the hole size is?

Ignore references in my first post to rocker covers - I meant the fittings in the heads of course - just getting senile I guess!

Thx - Derek

[dereklola]

deleted

[BlownV6]

I have used restrictors anywhere from .012 to .035 with no problems. I strictly drag race, If you are going to road race I would lean towards the bigger size since more oil will help with cooling the valve springs. Mike

[Chuck Leeper]

-4, for feed to a gauge?

[dereklola]

Do mechanical gauges typically use -4 hoses and fittings? I've been using electrical gauges for so long I can't remember. If so it would certainly answer my question and stop me worrying that I'm supposed to feed oil somewhere else!

[Chuck Leeper]

Originally Posted by dereklola

Do mechanical gauges typically use -4 hoses and fittings? I've been using electrical gauges for so long I can't remember. If so it would certainly answer my question and stop me worrying that I'm supposed to feed oil somewhere else!

-3 for the fuel pressure gauge, and the oil ga. It's easier to route, and is a bit less $$.

[turbodave231]

I guess a -3 line would be OK to the oil press gauge. I ran a -4 from the back of the block to the gauge and it is as responsive as my tach. You can see every small change immediately.

Derek, I wouldn't trust any electronic gauge. I've seen too many bad sending units.

[dereklola]

Dave

I take your point - but then -
- the ECU wouldn't work
- my street cars and tow vehicle wouldn't work
- my home heating/cooling wouldn't work
- Endeavour couldn't have taken off (and won't return)
- Concorde couldn't fly (Oh, that's right it doesn't now does it)
- none of my race cars for the last 12 years would have worked
- digital displays for race cars wouldn't sell
- data logging wouldn't log

- and finally - there just isn't the space in the cockpit of this car for all those hoses and gauges - each temp and each pressure gauge will take signals from three sensors via selector switches - even the tach has to be a tiny 2" unit.

Other than that it's good advice - thx - I'll try and use it some time -

[turbodave231]

Derek,

More to the point, Most commercially available electronic gauges don't allow the user to calibrate the pressure transducers. I'll bet most of the high end applications you mention all allow some sort of calibration process.

In the price range I can afford, most of the electronic gauges don't provide high quality/high accuracy sending units or the ability to calibrate............and yes I agree, my car wouldn't run or data log without them either!!

[dereklola]

That's OK, Dave, I was just having a bit of fun.

I do think however that we sometimes get caught up in "Naw, that new stuff's no good for me - I want some good old mechanical stuff for mah race car".

Mind you I didn't go the local speed store and look among the blue neon lighting strips - I did go for good old German quality for my gauges and sensors - like VDO. They aren't adjustable but then I don't need an accurate 'number' just a relative "that's hotter/lower than usual".

Two more races this year - a 1-1/2 hr enduro VIR this weekend and a 1hr at Road Atlanta in 3 weeks.

The back to projects for the winter.

Enough ranting - Derek

[turbodave231]

Derek,

Good Luck, Go out there and knock them dead with Buick Power!!