Blast Tube

[MikeB]

I'm thinking I might have trouble holding the oil temperature down on my L16/0200 engine conversion so I'm also thinking it might be a good idea to put a 'blast tube' on the oil filter as it's the most accessable and I'm not sure putting one on the oil temperature adapter won't give a false reading which would only make me feel better . Sooooo........I'm looking for suggestions as to adaption and size, etc. from some who might have done this. Maybe it won't be a problem.........

I think the 'start engine point' might be tomorrow if I can get some 100LL (yippee). It's recommend no 'mo-gas' during the break in period.

MikeB

[joea]

Would fly it first and see how the temps are running.

[MikeB]

I guess that's probably the plan at this point. Up here in the Northwoods if we put a blast tube on we also need to put some kind of a 'gate' to block it during colder weather. I've never been much of a fan of just cutting a hole in the rear baffling for a blast tube on the pressure cowl as it tends to steal some of the cooling air away from the rear cylinders. Technically there should be plenty of air flowing through the engine anyway. I did install dual cylinder temperature gauges.

MikeB

[Nathan K. Hammond]

I had a post but it disappeared into outer space....

First I tried one of those finned garters that slides over an oil filter, but only dropped maybe 5 degrees. Then I added a one inch blast tube bent 90* above the filter on the rear baffle and pointed down on the finned oil filter. That dropped it another solid 10-15 degrees.

Something similar to this, but cheaper in price.


I bought a piece of 5" (?) SCAT tube that could fit over the finned oil filter, and planned to added a 3" scat fitting on the rear baffle, but the airplane came apart before I could finish that project. Mine ran hot from day one; 210*F. Ended up doing the firewall mod, enlarged eyelets, and blast tube to cool it down to 190*F on a 90* day.

nkh

[MikeB]

Thanks Nathan,
I remember you having some posts on the subject before. Guess we'll just see how things work out. Maybe it won't be necessary but I expect to see some higher oil temperature when the ambient is up there. With my old 65 I'm lucky to see 170 degrees but they don't hardly burn enough fuel to make any heat. When the temperature is down to 30 or less I close the cowl outlet some.

[jepropst]

I had a blast tube on the oil screen housing and from everything that I could tell it resulted in a false low oil temperature. This was based on using a non-contact temp sensor to compare the oil temp of the oil filter and oil sump versus the indicated oil temp. I ended up removing the blast tube from the oil screen housing. I have a C85 with the O200 conversion and I don't have a oil temp problem. Basically I see about 100 degrees plus ambient. As Joe suggested, I would also recommend flying it first.