Manifold Pressure Equalization Tube


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Well-Known Member
May 2, 2015
Wauwatosa WI
I have thought about trying it but never did. After I installed the hot oil box the engine couldn't run any smoother and also had more power.

I usually relocate the oil dip stick to the rear of the engine case. Lot easier to use instead through the nose bowl air opening.
I have pulled my engine to work on the rear seal area it appears to be leaking through the dowel pins.

In the process I got a image of my crossover tube. I have never run without it. The Engine is smooth. I am now planning a hot oil box around my Y-tube. I noticed a fuel atomization issue when the OAT is below 38f and the throttle is below 1,000 rpm.

The warmed intake should resolve this and help in all seasons.

Cross over tube.jpg Y tube oil box planning.jpg Revflow on Y tube.jpg Side View of Revflow on Y tube.jpg

Dan can you show me a close up of your dip stick mod? Mine is hard to get to in the bowl.


Well-Known Member
HBA Supporter
Log Member
Jan 1, 2013
This is the best picture I have. Need to do this when the case is apart. At the lower rear of the case corner I drilled a 1/4" hole into the oil sump. Made a 1/8" 4130 plate and drilled two mounting holes for a AN3 bolt and high-temp locking nuts on the inside. Make sure you have room for the nut at the inside corner before drilling.
2 -- 3/16" dia holes at the end of the plate with a 1/4" hole in center of the 3/16" holes. Weld a 3/8 x 4130 tube about 1/2" long over the 1/4" hole in the plate and weld a cap over the end. Drill into the side of the 1/2" long tube for the 3/8" dia upright tube for the dipstick. Cut the length so the end of the dipstick bottoms in the 1/2" dia tube with the end cap. Mark dipstick for the Qts. Plug off front dipstick tube.

Hope you can under stand, I don't have a good picture. Chrome dipstick below and to the inside of the intake tube. Can also see the small spring with a hook that I use to keep the dipstick down and snug.

dipstick so it stays down tight. DSCF0015.JPG


Oct 31, 2018
Douglasville, Georgia
On that 1/2 VW with the 32 mm Mikunis. If it is a 45 HP engine, the 28 mm should be OK. If it is a lower HP engine then 26 mm will be better. Like previous posters have said, a little too small is better than a little too big. Keeping intake air velocity as high as possible just makes carbs work better.