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Post by splischke on Oct 20, 2011 23:21:28 GMT -5
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Post by oahupilot on Oct 21, 2011 0:50:29 GMT -5
my carbon fiber baffles have that feature incorporated into the the design. I get great cooling
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hans
Full Member
Posts: 166
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Post by hans on Oct 21, 2011 4:05:00 GMT -5
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Post by juergen on Oct 21, 2011 4:06:01 GMT -5
on my 2011 setup, I had made similar additional inner baffles, but there is no chance to upload pictures in the sub-board.. with best regards Juergen
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Post by splischke on Oct 21, 2011 9:23:34 GMT -5
my carbon fiber baffles have that feature incorporated into the the design. I get great cooling What are your CHT temps in cruise and climb? Where is your CHT probe(s) located? -Scott
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Post by oahupilot on Oct 21, 2011 10:44:09 GMT -5
Scott
The cht probes are screwed into the heads next to the spark plugs. I have not had a chance to fly the new baffles but I did do a full throttle ground test for one hour and never got the cht over 270.
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Post by soneraifred on Oct 21, 2011 14:44:23 GMT -5
I have used the stock VW intercylinder baffles like you show, and the lower head baffle that is shown in the Fournier site on both of my engines. I built my baffles to try to keep as much of the airflow as possible on the cylinder and head fins for as long as possible. With my CHT probes mounted under the inboard upper head nuts, my #4 cylinder CHT runs between 225F and 250F at cruise, and maybe as high as 275F on climbout on a hot day.
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Post by n3480h on Oct 21, 2011 16:50:06 GMT -5
Thanks for the links Scott. Its very helpful to see what cleaned up cylinder head air passages can look like. I have a lot of work to do.
Tom
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hans
Full Member
Posts: 166
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Post by hans on Oct 22, 2011 4:38:11 GMT -5
Thanks for the links Scott. Its very helpful to see what cleaned up cylinder head air passages can look like. I have a lot of work to do. Tom It's almost scary to see how much this head region can be opened up Hans
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Post by gaston on Oct 22, 2011 8:45:51 GMT -5
Hi Guys interesting thread here... I had something very similar installed on my first 1835 that came with the plane,but I didn't use it neither on my new 1835 in 1998 and on my 2276 in 2008. my air passages are upgraded but far less than what we see in this thread. I wouln't dare going that far in cleaning these heads unless I have gone this far on a pair of junk heads before...taking care of casting variation in the process...
actually my heads temp in always between 225 and 275 at worst and my oil temp around 190/200 and I like it like that. These may be wrong or non exact numbers but I don't mind,these are reference numbers only anyway. I will only care when these numbers change for unknown reason. if this hapens I will investigate the cause. But as of now performance ,fuel burn ,oil loss or burn,and reliability are great so it may not be that bad... when things go fine ,I tend to keep them going that way.I prefer spending my spare time flying than working to make it better, and dreaming of flying ...
take care Guys
Gaston
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Post by o2koold on Oct 22, 2011 11:35:45 GMT -5
Great link Scott. I would be very careful cleaning up the air passages. The side by side heads there are from two different casting bases. I would not be surprised to find you need a welder if you tried to make the one one the left look like the right one. Looks like an afternoon well spent on better cooling. Scott R
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Post by n3480h on Oct 22, 2011 11:44:24 GMT -5
Moderation in all things.
Tom
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Post by racegunz on Oct 22, 2011 12:54:26 GMT -5
Hi Guys interesting thread here... I prefer spending my spare time flying than working to make it better, and dreaming of flying ... take care Guys Gaston Aha! well said Gaston, the siren call of "perfection" is hard for some to resist and someone will always point out something else that could be better/different ect. ect. Most airplanes are talked about more than they are flown. I didn't come up with that but it's true. I'd rather fly a good enough/safe plane than spend years chasing unattainable, shortlived "perfection" Of course airplanes were invented to give a guy something to work on or spend money on. (Chucks favorite saying). ;D
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Post by splischke on Oct 22, 2011 15:29:25 GMT -5
I recently purchased a set of "Premium" heads from GPASC. On the first few flights, my CHT was hotter than what I ever experienced with my original heads. After a little work and consultation with guru Fred, I lowered my cylinder head temperature a whopping 60 degrees! I did several things to get this much cooling. First, I cleaned the flashing from all the passage-ways in the heads -- in moderation so as to avoid a welder . I estimate that I nearly doubled the area for air to pass through. I also cleaned the flashing from the cooling fins near the exhaust ports. In some cases, flashing blocked an estimated 30% of the opening between fins. Second, I added inter-cylinder baffles to each head. I also tightly wrapped new baffles on the outer perimeter of the heads from the exhaust ports down and around the bottom curves. Air now has no choice but to cool the bottom of the heads. Again, this netted a 60 degree drop in CHT. Not bad for a few days work and $0. -Scott
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Post by oahupilot on Oct 22, 2011 19:34:22 GMT -5
I have yet to clean out the flashing on my heads or jugs so I wonder how much more cooling I can get from my baffles? Granted the motor does not get over 270 wot as is so their might not be to much more to chase here for me.
I am kinda in the I just want to fly and stop trying to make improvements mood, but I just got access to a really awesome shop, so I may just start coming up with new projects just to use the new tooling. Some of which include cnc mills and lathes, cnc laser cutter, heat treating ovens, autoclaves, foundry, tig/mig/oxy-acet welder, friction stir welder, tensile tester, all sorts of ndi equipment, and other tools I forgot about. I feel like a kid at my favorite park when i enter the shop. Lately I have been using the rapid prototype machine to make models to test in the wind tunnel ;D. The ability to go from autodesk inventor to printed 3d part is awesome!
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