I have heard of taking the deflect tubes off the rocker assembly and plugging the hole the raise the pressure in the top end but could you cross down on the deflect tube to help raise it or would it require completely closing them off to make any differance? With the modern oil now days is getting oil to the top end as much trouble as it was with the old oil? What is the average oil pressure
On a y block?thanks for the advice.

Well, there's a lot of opinions on that. My Y blocks have the tubes removed but the replacement plugs are drilled to meter oil out. There was a post here a while back about modifying the tubes to "neck" them down and still direct oil to the timing chain and dizzy.

I think most of the top end problems on Y's were the result of poor maintenance and non detergent oil. That problem is largely gone. But be careful of modern oils. The reduction in zddp doesn't work well for flat tappet cams (not just Y's). Ted Eaton has articles on his site I think, and numerous opinions posted here and other sites.

Average oil pressure seems to vary widely, especially from idle up. One of mine ran really high, about 80psi. I found one of the gaskets was blocking about half of the oil relief passage. Solved that problem. Mine, generally, warm, 30-50lbs. Low milage so pretty much the same at idle.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I block the tubes off toatly,the oil will returnfront and back with out the tubesas main drains in both ends of the valley.my 292 ranchero has lots of miles and presure is 25psi at 600rpm hot, 60 psi at 2500 hot. most of todays oils moble 1 10/30 quaker state 10/30 bothe have plenty of moley and aditeve package to be a vastley beter fit for flat tapet cams.

Freeing up the restriction at the center cam journal either be deepening the groove in the center camshaft journal or adding a groove behind the cam bearing will increase the oil flow to the top end of the engine.  Verne Schumann offers a cam bearing set for the Y that has the groove on the outer diameter of the center cam bearing which also increases the oil flow in lieu of machining a groove in the block.

Here are some links to past threads on the subject.
Center cam bearing
Grooving the center cam hole in the block
Oil Flow Diagram 

Slotting the rocker shafts for improved oiling 

Timing chain oil trough

Lorena, Texas (South of Waco)

I punched my tubes down till they are about 80% blocked. Figured I'd get the best of both worlds, has it done anything.. who knows..?



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