Aero Vee High oil pressure FIX

[merle reppert]

On my first of 3 builds I had 100 # plus with oat's around 35/40 deg.---The adj didn't work --Still high when cold--
When I looked down into the pressure relief port ( flywheel end ) I could see the hole entering the bore where the oil bypasses. It was above the bottom of the hole where the plunger seats--The plunger has very little clearance to the bore
and when the oil is COLD it has to raise the plunger up high enough to bypass--This raises the oil pressure when the oil is cold.
What I do is machine the plunger like the propeller end plunger with the groove and reduce the diameter of the end of the plunger by .020 thousands ---This allows the cold oil to bypass without raising the plunger real high .
I have built three Aero Vee's with this mod and they start and maintain around 45/50 PSI whether cold or hot--
Some engines may not have this problem if the side hole intersects the plunger hole very close to the bottom---
The edge of the side hole on mine were about 3/16 inch above the bottom of the plunger hole which made the plunger raise a lot which raised the oil pressure-----It's not a hard fix ---Take the Prop end plunger and the flywheel plunger to someone
with a lathe and make the flywheel plunger look like the prop end plunger and turn down the end to .015 thousands Dia.
smaller---If you don't have the pressure you want , use an adjuster or washers on the plug ---Read carefully ---
Merle Reppert

[merle reppert]

OOps-------.020 NOT .015
MERLE

[jwd3ca]

Thanks for this, Merle, I'm certainly going to have a close look at this fix.