Discussion in 'Race 400/430/455' started by 71bskylarkk, Mar 21, 2021.
Can see the line here.
Also I will have a oil temp gauge this next time.
Curious if there would be any benefit to the TA pump cover, and using external pickup, also possibly a HV set up on it?
While it's apart and down, I don't mind spending money to upgrade. But at the same time want to figure out what the issue actually was.
May be un related but the filled lifter galley on my last build had/has small drain back holes and that engine did much the same thing in the same way with about the same run time. The build before that had the TA lifter bore girdle and the OP was great on that one until it went over 8K
For what it's worth, if I had to do it over again I'd run the TA girdle. Not feeling chipping out a ton of jb weld at this point
Any chance of to little clearance between your pick-up screen and Aluminum oil pan bottom? Thin flat Aluminum sheet being more flexable and sucking up closely to the pick-up starving the pump. You've checked the obvious, so now going to the no freakin way level.
Because it seems to have pressure even on a hot start, I am also in the drain back issue camp.
I wouldn't go crazy changing and adding things. Troubleshoot what you have first?
Lots of smart/experienced people here. Listen to them ;~)
Wouldn't hurt to pressure test the oil pump feed galley (from pickup tube to pump). I believe I saw on the site somewhere where someone had opened up the galley and it ended up sucking air...
No matter what you find in the bottom end I'd make some mods for better drainage on the valley
No, only too small is an issue on the line.. gauge reading is strange.. not sure I trust it.
Someone's been busy with the water transfers - looks good! Back to the issue at hand.
Update: tore everything apart, didn't find anything out of the ordinary.
Changed rod bearings to .001 tighter clearance, re used mains, crank was fine.
Added more drainback holes, and went to TA scavenger pump housing with external pickup, put it all back together, annnnnnnddd STILL had the same issue but wasn't nearly as bad.
I called TA and spoke to Tim, as soon as I mentioned the crossover line he mentioned I should just cap that off, and they don't do it, ever.
5 minutes later I had it capped off, pressure was about 10 lbs higher across the board and doesn't drop off anymore.
I had the same mod on my other engine, and never did it. No idea, but it fixed it and I'm not questioning anything lol.
Thanks for all the replies and info and thoughts. Greatly appreciated. Posting my dyno vid/numbers up Tonight.
Good news, appreciate the update
Yah get me thinking now why it made a difference.
Im theorizing when the rear galleys (lifter) are looped (connected) it allows the right galley which feeds the mains, another huge area (left galley) to bleed pressure.
Putting the allen plug back in isolates the right galley from the left and allows the right galley to build pressure easier, instead of the left galley trying to drain it (lifter bores)
I had this same thing with a filled valley. Cost an engine after 2 passes.
Way back I had a buick engineer tell me to tie the galleys together to help drop oil pressure. I had high oil pressure. Never did the the suggestion as other problems had developed.