Oil bypass modification

[NevenM]

Dave

Also Thanks for the details on the case squirters, when you say they take 42psi to open are they 'active' ie do the have a pressure release valve in them or something.

Neven

[ChrisBennet]

Originally posted by NevenM
Dave

Also Thanks for the details on the case squirters, when you say they take 42psi to open are they 'active' ie do the have a pressure release valve in them or something.

Neven

The piston squirters have a little ball with a spring to keep them from opening (and dropping oil pressure) at low RPM's/idle.
-Chris

[RobFrost]

Originally Posted by 69911e

This is for those people who do things themselves simply for the knowledge and pleasure of it (or those who are very cheap). Those who would rather have someone else do machine work need not read any further.



Any case which needs a oil by pass mod (7R or earlier I believe) is very cheap unless it already has updates, so find one without any updates just in case something goes wrong.



Doing the oil bypass mod is easy. There is plenty of extra metal all around where the hole goes, unless you miss by more than 6 mm (on a 12mm hole) there will be no problems. The 12mm hole goes about 28deg off vertical. The only way to hurt the case is for the sealing lip for the oil pump passage to be damaged.



Just grab any variable speed hand drill with a small end mill to start the hole. Calculate where the start of the hole must be. Drill in slightly with the end mill. Then drill all the way with a standard drill. Check to make sure the hole is where it belongs, if it isn't adjust with an endmill (I did not have to make any adjustments). Go up 1 drill size at a time until 12mm or there abouts is achieved.

Total time for drilling , 10 min.



Then the side hole must be tapped for the plug. The hole is already the right size for the tap, no drilling is needed. A slight modification to a standard tap and 10mm wrench is needed. Then carefully start tap, use plenty of oil and remave tap to clean shavings a few times in the tapping process.

10 min to modify tap and wrench.

10 min to tap hole.



Total cost $5 tap, $1.5 plug.

Total time 30 min



PS: Anyone who want to use my modified tap and wrench, just email me.

I'll just add my experience to 69911e above.

I did this job in my garage with a hand drill.

I was unable to start with a small end mill because it wasn't long enough to get in without the chuck interfering with the case. So I started with a 10mm end mill. I also pulled the stud from the case which was in the way, in order to get slightly better access.

I realised early on it was best to start with a good 12mm gap from the top of the case, to make sure the hole was away from the case join.

I think it would be very difficult to miss your target because you can see the aluminium plug on the end of the case, which is in the end of the oil channel you're aiming for.

The most controlled way to get the end mill started was at high speed and with very gentle pressure, and with oil. It did skip from side to side a little at first scratching the inside of the hole, but eventually it stabilised.

I found the end mill cut really well to a point, then stopped due to having a non-cutting part at its heart. I had to put a screwdriver in and break off the nib that left, in order to continue.

Then I switched to a drill bit and worked up through the sizes. It went in a lot further than I thought before breaking through, but because I could clearly see I was heading for the tube blocked off by the aluminium end cap, I was pretty confident I was on target.

Remember to dispose of the magnesium swarf carefully due to fire safety reasons.

Thank-you for the guidance!


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