I am the current owner of RV-4 #1702 (not the builder, however).
Following an incident where the airplane found an "area drain" in a friend's airport yard, a prop strike inspection was performed. The shop did a great job, but was unaware of the dipstick tube length issue on RV-4s.
The builder of this airplane had done the "piece together" method and it worked for 30+ years.
The shop didn't like the looks of this piece and replaced it with a new Lycoming aluminum tube and dipstick combination. The problem with that is that it is too tall and the top cowling won't go on. So, a solution was needed and found.
Using a Lycoming part number LW75767 - or - Superior Parts SL 75767 filler tube, I cut the tube just below the threaded "neck" and shortened it exactly 1.5". It was tig welded back together.
The dipstick was disassembled by removing the roll pin and heating the cap to soften the LocTite enough to remove the stick. The dipstick was then shortened to create a measurement of 11 5/8" from the bottom of the threads on the cap to the 8 quart mark on the stick. It was then re-installed in the cap by drilling a new roll pin hole and using green LocTite to further secure it.
I just finished the first oil change at 10 hours on the rebuilt engine and checked the marks on the dipstick when refilling. The oil level appears to be 3/16 - 1/4" too high, but the filter is still empty.
So...The tube is at a great height, but you might want to re-assemble the stick with only the roll pin until you're happy with the length.
Following an incident where the airplane found an "area drain" in a friend's airport yard, a prop strike inspection was performed. The shop did a great job, but was unaware of the dipstick tube length issue on RV-4s.
The builder of this airplane had done the "piece together" method and it worked for 30+ years.
The shop didn't like the looks of this piece and replaced it with a new Lycoming aluminum tube and dipstick combination. The problem with that is that it is too tall and the top cowling won't go on. So, a solution was needed and found.
Using a Lycoming part number LW75767 - or - Superior Parts SL 75767 filler tube, I cut the tube just below the threaded "neck" and shortened it exactly 1.5". It was tig welded back together.
The dipstick was disassembled by removing the roll pin and heating the cap to soften the LocTite enough to remove the stick. The dipstick was then shortened to create a measurement of 11 5/8" from the bottom of the threads on the cap to the 8 quart mark on the stick. It was then re-installed in the cap by drilling a new roll pin hole and using green LocTite to further secure it.
I just finished the first oil change at 10 hours on the rebuilt engine and checked the marks on the dipstick when refilling. The oil level appears to be 3/16 - 1/4" too high, but the filter is still empty.
So...The tube is at a great height, but you might want to re-assemble the stick with only the roll pin until you're happy with the length.
