Questions about IO-375/WW 200RV /Sam James cowl

[Bastien]

Hi everybody,
This is my first thread/post on the VAF's forum
I'm a French RV8 builder and I need some help

I will order in few days an IO-375 (low compression), a SJ cowling/plenum and a Whirlwind 200 RV

1) My aerosport IO-375 will turn a WW 200RV prop but which spinner will fit the best the SJ cowling, the Van's or the WW's or maybe another one ?

2)It is written on the SJ website that a prop extension is required for the RV8 cowl but which model for a Whirlwind?

3)Will there be any interference between the sump and the cowling?

4)Which exhaust system can I use in this configuration

I know I can have all the answers of my question with James Aircraft but I'm not enough fluent in English to give them a phone call.

I apologize for my poor English.

Thanks

Bastien LE ROUX
FRANCE
RV8
Empennage----->completed
Fuselage-------->70%

[n615ks]

Bastien,
I can't answer your questions, but I'm certain that someone that has had conversations with Will James in the past would be willing to ask those questions for you.

I'll bet you that my French is worse than your English......I have great respect for anyone able to communicate in more than one language!

[hevansrv7a]

Bastien,
I, too, applaud your English and especially because my French "est pauvre".

The best answers will come from Will James, of course. However, the spinner should be 13" because that is the size that Van's uses. Thus, that is what Will James uses in his design.

The WW200RV prop was designed for a standard Van's RV8 cowl, so it should expect to be 13" as well.

Write to him at will@jamesaircraft.com . Or, use Skype and call him at: 850-342-9929.

Will James will need to know ahead of time which engine and prop you will use. He will also want to know which induction system.

[rwtalbot]

Originally Posted by Bastien

Hi everybody,
This is my first thread/post on the VAF's forum
I'm a French RV8 builder and I need some help

I will order in few days an IO-375 (low compression), a SJ cowling/plenum and a Whirlwind 200 RV

1) My aerosport IO-375 will turn a WW 200RV prop but which spinner will fit the best the SJ cowling, the Van's or the WW's or maybe another one ?

Hi Bastien,

I'd suggest you email Will to get the answers to your questions.

The IO-375 is a very nice engine. The Whirlwind Propeller is also excellent. Personally I would not install a SJ Cowling for the following reasons:

? The installation is more time consuming. Particularly the induction and plenum
? The SJ parts/cowl are heavier than Van's standard install.
? It takes longer to get the plenum off for maintenance. I like to see my engine every time I take the cowl off. It?s a pain.
? Instructions are a little hard to follow and outdated. There is an email group, but I don?t think too many of them speak French ? so that may be an issue.
? There is very little evidence of any speed gain or improved cooling that I have seen. Very few people have installed both systems on the same airplane and even less have tested in the same conditions. The performance of those with the SJ cowl just doesn't seem that much better
? The air inlets in the SJ cowl are perhaps ideal at high speed but not so efficient at slow speeds/high angle of attack. Reduced airflow, is just reduced airflow which ever way you look at it. You don?t get anything for nothing and a good set of baffles is fairly efficient.
? You are not in the US, so freight would probably be a lot more.

The one thing I would say for the plenum is that the cooling "may" be more even across cylinders with a plenum but plenums need to be tuned as well. The SJ cowl does look good.

For what it?s worth I have a SJ plenum in my hanger that I never installed. It was expensive, not particularly well made and definitely won?t fit a stock IO-360 without a lot of cutting and shaping. You could easily make one better. I have a carbon fibre plenum on the aircraft that I did install. For all of the reasons I gave above, I wish I had just installed the baffles and got flying sooner.

People will tell you baffles are bad, but there are a lot of Van's planes out there running them just fine. The truth is Van?s design is pretty good. My advice is to save the cost and time. Follow Van?s plans.

(I?m putting on my flame suit now)

Cheers
Richard

RV- 7A Flying.

[Andy_RR]

...take a look at the Showplanes cowling as well. 15" spinner is a plus and a minus though...