I’m after some advice in regards to the oiling system on a Dart Windsor based block.
The block I have is Dart part DRT-31345295
Dart Aluminum, Cleveland/SVO Main, 9.200 Deck Height, 4.125 Bore
The block is set up for priority oiling to the main bearings before the oil goes to the lifter galleries.
Dart recommend restrictors to be fitted to the lifter oil galleries.
But they don’t state the size of the restrictor required or the reason why restrictors are required.
Now although I understand how this oiling system works I have read lots of conflicting reports as to if you should install these restrictors or not.
CNC motorsports built up the short block with a rotating assembly & when I asked them about restrictors they said, No, don’t fit them.
But I’m struggling to get an explanation from them as to “WHY”.
Dart recommend fitting restrictors, but are very short on information as to for what reason & the size restrictor that should be fitted.
Here is the Dart blurb below:
"LIFTER GALLEY RESTRICTORS
The lifter feed at the front & rear of the lifter valley are threaded for an 1/8” NPT plug. There are two
lifter feed passages under the cross over plug (1/2” NPT). It is the one coming from the main oil galley,
towards the passenger side. The threaded portion is between the main oil galley and the passenger side
lifter oil galley. This restricts both right & left lifter galleys. Because it restricts both sides the orifice size in
the 1/8” NPT plug should be large enough to feed both sides. These restrictors are located at both ends of
the block. To restrict the lifters you need to either install restrictors at both ends or plug one end and
restrict the other. Some engine builders prefer to plug the end they are feeding the main oil galley from
and install restrictors at the opposite end. This gives you priority main oiling before feeding the lifters."
Opinions from knowledgeable builders?
I don't want to screw up one of the most important aspects of a new engine.
Regards,
Tony.
Original Post