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William

Well Known Member
Curious who has installed the Sam James wheel pants on a flying rv6a, 7a, or 9a that previously had the new style of Vans wheel pants and seen a increase in airspeed. I will be ordering my finishing kit on tuesday from vans for my RV6A and will be ordering the Sam James cowling/plenum/ram air on tuesday as well. Sam James informed me that if I go with his wheel pants as well I will see a 4mph increase. If this is true I think I will go this route, but would like to hear some real world results on the wheel pants.

later,
Bill
 
SJ

i ordered my finishing kit from vans a few weeks ago and im doing the same thing as you dropped cowling and pants dont know if its any faster or not but im putting angle valve io-360 and sj says it will fit in their cowling i just like the look of their cowling anyway looks faster even if its not also a guy in MS just put up a thread about this and he pick up around 6 knots
 
Wheel Pants

I have them on my -8. Never had Van's, so I have no direct comparison. The frontal area is quite a bit smaller and thus you will have to adapt Van's or fabricate new hardware to attatch them. With the frontal area being smaller there has to be some speed gain.
 
turbo super rv-10 said:
i ordered my finishing kit from vans a few weeks ago and im doing the same thing as you dropped cowling and pants dont know if its any faster or not but im putting angle valve io-360 and sj says it will fit in their cowling i just like the look of their cowling anyway looks faster even if its not also a guy in MS just put up a thread about this and he pick up around 6 knots
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I love the look of the Sam James cowling as well. :) I'm sure there will be some speed increase with the Sam James cowling, but I wasn't sure about the pants. I know sam james pants will be harder to install as opposed to the vans wheel pants because it will be a tighter work space. I've been talking with the gentleman you're referring to in MS. via pm's and he is having an oil temperature problem. He highly recommends the use of a genuine Stewart Warner oil cooler. I brought this heating issue up to Sam James himself yesterday and he highly recommended the use of a genuine stewart warner cooler as well. Sam James claims there is a large oil temperature decrease if you mount the oil cooler on the plenum behind cylinder #4 as opposed to mounting it to the fire wall. :)

Bill
 
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mannanj said:
I have them on my -8. Never had Van's, so I have no direct comparison. The frontal area is quite a bit smaller and thus you will have to adapt Van's or fabricate new hardware to attatch them. With the frontal area being smaller there has to be some speed gain.
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It definately seems that this would be the case, but sometimes, especially when dealing with aerodynamic design, what appears to be the best design sometimes isn't. :D

Bill
 
As with almost anything.......Don't believe everything you hear.

I don't know if the the James wheel pants are faster, they may well be. I have oversized tires on my -7 and needed the big Vans pants to fit over them. My RV leans to the speedy side of RV-7's even with the big pants.

Also I have the James extended cowl and plenum. SW 8432R cooler off the rear baffle of my 180hp IO-360...and yet I have some minor summertime cooling issues also.
 
Curious what oil temps you're seeing during the summer months? Also I've seen some people that have the sam james cowling have cylinder heating issues as well and then others seem to have too low of cylinder temps. I take it this has many variables that would cause this, one of which would be how well the plenum and baffling was installed. How are your cylinder temps?

Bill



hydroguy2 said:
As with almost anything.......Don't believe everything you hear.

I don't know if the the James wheel pants are faster, they may well be. I have oversized tires on my -7 and needed the big Vans pants to fit over them. My RV leans to the speedy side of RV-7's even with the big pants.

Also I have the James extended cowl and plenum. SW 8432R cooler off the rear baffle of my 180hp IO-360...and yet I have some minor summertime cooling issues also.
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I've gone with the James Holy Cowl & Plenum; but stayed with the Van's wheel pants. I did this back in 2006. Did bunch of reading @ the time in Rvator & decided on the pressure recovery theory. I agree Sam's look better but Van has some convincing data. Sorry I cannot give it to you now.

Check with Vans on that. They can give you a quick referance.

Also, I switch to the oversize tire from time to time & Van's pants are more accomodating.

Best regards,

Deal Fair
RV-4 (N34CB)
George West, TX. (8T6)
 
William said:
Curious what oil temps you're seeing during the summer months? Also I've seen some people that have the sam james cowling have cylinder heating issues as well and then others seem to have too low of cylinder temps. I take it this has many variables that would cause this, one of which would be how well the plenum and baffling was installed. How are your cylinder temps?

Bill
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I would see 215-220 and increasing after a while of slow flight, 90*F OAT or climbing out at <120kts. Then in cruise flight(82*F) I would had oil temp of 204, and CHT's 395-405. Kind of worried about going to Texas or other hot spots. My plenum seals very well, but think I'm loosing some cooling due to the cowl/spinner area. I also had my cowl outlet extending back past the firewall to help direct exit air. I cut the cowl outlet, even with the firewall last month and seemed to have gained about 10* on the CHTs(375-390) ...but OAT's are dropping around here so hard to get a fair comparison..and oil temp is now 190.
 
Temps....

Bill,

We are installing 2nd James cowl presently so I don't have any current figures.

With my first installation, the oil temps would rapidly hit 210 upon climbout & cht would approach 400. I would throttle down & return to land w/temps dropping. I didn't like the situation & stopped it early on. Temps rising, return to base. We then started opening the bottom of the cowl by 1/16" at a time & retesting. I noticed improvement by about 1/2" total. Finally settled on & stopped with 1 1/4" removed. My temps were a consistent approx 100 degrees above ambient temp. I'm in deep south TX & it do get hot here. But I could climb to cool & all was well. CHTs would run 375 at the top end. Life was good.

So am going to have to see about this new installation. There is solace knowing "twixing" will rectify cooling problems.

Best regards,
________________
Deal Fair
RV-4 (N34CB)
George West, TX. (8T6)
 
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