M

moll780

Well Known Member
Are there longer lengths of blast tube available someplace?
I can only find 5/8" x 18" plastic corrugated tubes on Vans site.
 
moll780 said:
any advice how to attach this tubing to the baffling? I see nice flanges for 2" scat tubes but no good ideas for the smaller corrugated type.
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I made my own flanges out of fibreglass using an appropriately sized socket from a socket set as a mould.
 
We did manufacture a 3/4" flange but have discontinued them. Use a Uni-Bit and drill the hole one size smaller in the baffle that the conduit tube then use install the conduit and use a bead of RTV around the conduit to the aluminum to hold it in. It will not go anywhere. :)
 
This sounds workable and super easy.

LifeofReiley said:
We did manufacture a 3/4" flange but have discontinued them. Use a Uni-Bit and drill the hole one size smaller in the baffle that the conduit tube then use install the conduit and use a bead of RTV around the conduit to the aluminum to hold it in. It will not go anywhere. :)
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Flange

Go to Lowes and get some electical fittigs for ETM they come in 1/2 to 2" and have a nut on one side to fasten it to electric box that woud work great for firewall and threads on other side that you can file off and clamp hose on .
Homebuilders dream its cheap
Bob
 
DanH said:
P-mags get hotter after shutdown, yes?
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Yep, of course :). A very touchy subject.

Did you know that the fins on the neck of the 114 units "...are not necessary for cooling. They are turned on a lathe and it is just easy to do, but not necessary." Directly from Brad, first hand.
 
DanH said:
P-mags get hotter after shutdown, yes?
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Yes indeed & that concerns me. I always prop open my oil fill door after shutdown. When local, I place a fan in front of the cowl.

I hope it helps. I can certainly feel the heat escaping out the open door.

Makes me feel better at least. :D

Cheers,
 
The builder of my 9 put blast tubing to the one slick mag and also to the vacuum pump (dry). Are they even needed? Would rather not have the leaks out the back of the baffles as number 3 is running hot and it is only February.
 
I simply drilled a hole, friction fit the tubing and secured with rtv to prevent it from turning. I installed on both mags and alternator per plans,IIRC. Ive got extra if anyone needs the corrugated from Van's.
 
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flightlogic said:
The builder of my 9 put blast tubing to the one slick mag and also to the vacuum pump (dry). Are they even needed? Would rather not have the leaks out the back of the baffles as number 3 is running hot and it is only February.
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Put a thermocouple on the slick housing at the coil and measure the temperature with and without the blast tube. If the housing temp is above 185F, then, yes - you need it. Please report your results as this question has not been quantified here that I can find. This is one data point I will take in phase 1. Suspect your high #3 is another issue.
 
Just reviving this thread.

Can someone expound upon the stealth statements about p-mags getting hotter after shutdown, the controversial need for blast tubes on them and what the manufacturer says and/or thinks about them?

That is a detail I have to address very soon. Thanks.
 
As suggested... I did a temp test of the side of the Slick mag just after flight. 200 deg. F.
I put the blast tube back on... the mag has behaved well since that time.
I suppose I could generalize a bit and admit heat almost always is a bad thing. Unless it is directed at my feet in winter.... and then it bounces off the electronic ignition box on the floor. Some days, you can't win.
 
flightlogic said:
As suggested... I did a temp test of the side of the Slick mag just after flight. 200 deg. F.
I put the blast tube back on... the mag has behaved well since that time.
I suppose I could generalize a bit and admit heat almost always is a bad thing. Unless it is directed at my feet in winter.... and then it bounces off the electronic ignition box on the floor. Some days, you can't win.
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Thanks for the update. This is a very good data point. At the risk of digging too deeply, how did you measure this temp? Stick on indicator, bonded thermocouple, non-contact infrared? This might help others on their equipment.
 
flightlogic said:
As suggested... I did a temp test of the side of the Slick mag just after flight. 200 deg. F. I put the blast tube back on...
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We know it's going to rise to 200F or so after flight. There's no air movement then, so the mag or p-mag temp adjusts to the ambient temperature of the engine block, with some convective contribution from hot pipes, etc.

Did you record the inflight temperature with and without a blast tube? I'd put the probe on the side opposite the blast tube. To do it right I suspect the probe needs to be glued to the coil.
 
Slick mag temp

I put in a extra thermocouple in the engine compartment. Last few flights I have had it taped with aluminum tape to the side of the mag. I have been getting readings inflight in the 130-145 deg range. I don't have a blast tube. Just a data point. Rv-10. Vans standard io540
 
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