Do the helical oil gears drop Oil pressure??

[EclipticalGS]

Well, I may have significant evidence that helical gears provide lower oil pressure starting from here.

Girlfriends talon underwent recently a nice complete maintenance/mod rebuild and went from; An old 6-bolt Oil pump with straight cut gears, stock unported OFH, and Balance shaft removal was already done.

Oil pressure at idle with no OFH porting and Balance shafts removed was @ 25 psi.

Went to a new OEM 6-bolt oil pump, with new helical gears, stock unported OFH still and the same BSEK installed before..

Oil pressure at idle is now 17 psi..

All I changed out was the a new oil pump and went to helical gears, keeping the same un-ported OFH and BSEK as before...Why the drop in oil pressure??

Has anyone had the same thing happen..

Personally Im at a more stable oil pressure which just reaches 100psi at redline (used to reach 120), so im thanking myself I didnt port the OFH while everything was off because there are no leaks causing this drop and it seems better IMO Also theres no pump noise now that used to be a hum before.

 

[sniver]

Strait cut gears make a humming noise, like a manual trans in reverse. Helical are quieter, like any forward gear.

I have never heard of a difference in the two gears, though it sounds possible. 8psi oil pressure difference between two pumps at idle could be do a change in oil , a oil filter, or tolerance changes between the two gears. Also the temp of the oil make a big difference.

Also if it was the case that the helical gears were always 10 lower at idle, and 20 lower at 7k, I'd probably pick the helical due to the lower noise and fuel savings. 100psi at 7k is plenty.

I'd love to see some people chime in about there oil pressure, if they know what style pump gears they have, otherwise it'll just obscure the info.

 

[TSIfreek]

I had a 5 psi diffrence between the 2. The helical gears read higher at idle for some reason.

 

[sniver]

^^ this kind what I think will be more common ; more surface area, more oil moved, more pressure.

 

[TSIfreek]

^^ this kind what I think will be more common ; more surface area, more oil moved, more pressure.

This is only at idle as the oil pressure relef valve controlls maximum oil pressure.