S

SportAvServ

Well Known Member
If you have a 4 flying with a Sam James cowl, would you please post pictures of it? Construction pictures would be great also.

RT
 
I think in the "status" thread here in this section there is a picture of Jj's -4 with sam james cowl in progress, might check there!

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Not so fast...

I assisted a friend installing a Sam James cowl on a 160HP RV4 back in 99'. I flew alongside in my 150HP stock cowl RV4 prior to the change for comparison. After 2 months of hard work, sanding, plenum cutting, wheel fairing installation and wing fairing work, he took off with me in chase to see the difference...
Nada.

He did have some cooler temps and looks but not 1 knot faster. I bought alot of 100LL for what he spent on the mods...

My two cents...

Smokey
HR2
 
I Agree

The stock RV-4 Cowl is hard to beat. Unless you have already purchased the
SJ cowl I would stick with the one that comes in the kit. I think the only improvement to be made in the RV-4 cowl is in the exit area.

my 2cents

Chris Murphy
RV-4 Sport Air Race League RV-Red 2008 class champion.
 
Cowl

Thanks Smokey and Chris, I have been on the fence about this, thanks for your input, I don't think I will use the SJ cowl, I just like the looks of it. I have installed 2 prepreg cowls this year, and they are a lot of work up front, I dont remember my jelcoat cowl to be so much work, Van's cowl are in the $900. range so money wise it's a tossup. The less I deal with fiber glass the better I like it.

Smokey, looks like Miguel will be building another Moose, he asked if I was willing to fly up there to help. Have you been to the new place?

Randy
 
smokyray said:
I assisted a friend installing a Sam James cowl on a 160HP RV4 back in 99'. I flew alongside in my 150HP stock cowl RV4 prior to the change for comparison. After 2 months of hard work, sanding, plenum cutting, wheel fairing installation and wing fairing work, he took off with me in chase to see the difference...
Nada.

He did have some cooler temps and looks but not 1 knot faster. I bought alot of 100LL for what he spent on the mods...

My two cents...

Smokey
HR2
Click to expand...

I have always said that the only way anyone can make a valid claim to a performance increase is to install the modification on an already flying airplane and measure what the performance difference is.
Thanks Rob for posting some directly verifiable data comparing performance between a standard cowl and a S.J. cowl. This is the first time I have seen any.
 
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