Pressure fed thrusts!

Maybe you're squeezing all you can out of a 998, or going large-bore with a 1380 (or even larger!) - either way, let us know all about it here!

Moderator: The Midas Forum Staff

Pressure fed thrusts!

Postby max midas » Mon Jun 26, 2017 9:58 pm

I noticed an interesting thread on Turbo minis recently, it dealt with enabling helical transfer gears to take the sort of loads that high torque A-Series engines can produce nowadays.

The Problem
The helical gears are strong enough in their original design for the power output of the original spec engine, but with turbo A-Series engines now being made to put out over 200lbft, the original spec thrust washer design doesn’t last long.
The thrust washers are normally lubricated from oil splashed about the transfer case, but as the torque of the engine increases, the side loading on the helical gears increases, and the oil doesn’t get a look in. The thrusts wear, the idler gear rattles around and pretty soon it’s out of alignment and losing teeth!

The Solution
The remedy to this problem was first proposed by ‘Turbo Harry’ on his website
He feeds the thrust washers pressurised oil.

Harrys idea was refined by ‘Sprocket’ on TM ... 104&fr=150
(it gets interesting from page 7).
Sprockets elegant solution takes the oil feed from the oil gallery above the gear, feeds it through the thrust, through the gear itself to the other side.

Harry also suggests removing the metal cage from three of the roller bearings, and filling the spaces with more rollers, thus spreading the load over an increased roller area

Harry has used these mods for a while now, and has put over 220bhp through his helical gears for a number of years with little wear.
max midas
Posts: 181
Joined: Tue Dec 02, 2008 11:32 pm
Location: somewhere under the engine - again!

Return to A series engined projects

Who is online

Users browsing this forum: No registered users and 1 guest