Drop gears oil jet
Turbo Mini Forums

As assembly of my engine is coming close (finally!) I am thinking about last things to sort.
I remember reading about a mod to route oil over the SC dropgears to reduce noise.
IIRC Joe C did this mod.

I spent this morning searching the site but only found a thread discussing it many years ago.

I was wondering if this mod is worthwhile and if someone can provide pictures/directions for this modification?

Cheers,
Han

Dazed and Confused....

id thought about doing something like this along the lines of blocking the oil pressure releif where it dumps into the box and re drill the end of the block to intercet the origanal hole

this whould re route the execive oil pressure to the gears more or less but this only flows when the max psi is reached for the releife valve so at idle you whont see the benifets but at higher rpm it will see oil flow under load

cant see this hurting anything? ive not bothred yet as im lookign for a way to stop that idle noise the straight rollers give as you say if you could flood the gear mesh with oil it may help reduce noise

im hesatent to remove oil volule ferthr as im useing a x drilled cam oil jets turbo couldent thing theres muh more oil volume to go else where

Sprocket has done this in the past. There will be pictures somewhere.

Just don't squirt directly onto the mesh. 45deg before would be a safe target.

Thanks for the reactions guys.
I would be interested in some pictures.

TurboDave, you mean squirt against the aluminium 'housing'? (don't know the proper word)

Dazed and Confused....

I think you are talking about a pressure fed idler bearing aren't you?

If something is worth doing, it's worth doing half of.

It is quite possible I am (hence my signature.... :) )
Though I am pretty convinced there was a discussion about reducing SC whine aswell.. nothing might have come out though..

Must say that is a nice bit of engineering Sprocket (and Turbo Harry)!

Dazed and Confused....

Yes, if you want to squirt into the gear me3sh to help the gears, perhaps also assist in chatter, then don't squirt into the mesh... Too much oil in the mesh is bad. Even inside the gearbox at high speed the gears beat th oil out of the way so there is a "wall" of oil around the gears, but not in the mesh. If you force excessive amounts of oil into the mesh with no method of escape prior to the flanks contacting, then you will create a whole load more problems than you were attempting to solve.

Dazed and Confused....

thats a sweet looking mod to the thrust faces perhaps this could be a fix for roasted housings as well

Yes this was me.... sort of.

I tapped the gallery that drains downward from the relief valve to the gearbox M10 and stuck a grub screw in there.

I then merasured the depth of the relief valve and put a drilling from the end of the block in to meet the oil relief valve.

I was going to put a 90 deg onto the end of the block to point the oil toward the drops, but never got round to it, it looks like the oil will do a fairly good job of pissing onto them anyway with the hole where it ends up.

You can buy an additive but I can't remember who by, but the demonstration for it is three plastic gears in a clear box and the additive helps keep a thin film of oil on the upper gears, whereas without it barely reaches the top one. Someone may know the brand and product.

Addatives........ Hmmmm......... Skeptical

you can just make out the drilling in this pic, above the water take off is the main gallery plug ( gold coloured) and above this and slightly left is the drilling I added,

IIRC there is a peice of casting in the flywheel housing that acts as a chute and directs the oil onto the top drop gear.

Edited by Joe C on 27th Mar, 2014.

Thanks for that Joe.
Did you notice any difference noise-wise before and after the modification?

Dazed and Confused....

Bit of an old thread dust off.
While looking for something else I stumbled across this.....
I'm very curious with the oil fed thrusts of Harry and Sprocket, has anyone else tried this with long term success? It looks a very simple easily engineered solution if so?

Shane

Nothing to add from me, just throwing some pictures from turbo harrys build in.
http://www.minifreunde.at/harry/links/oilpressure.htm

I had found Harry's site after some further digging, thanks though.

Shane