James cowl

I’ve recently purchased a Rv6 180 hp an
It has a James cowl. It does not have the plenum in a climb the chts are
Over 400 number 2and 4 should I get the plenum for the cowl and running
380 in cruise?
Will it help

Thanks
Dan carley
N15vr

There's a lot more to this story than just adding the plenum.

First things first - what are your max temperatures in a hard sustained climb? Let's start with that, decide if they are OK or not and go from there.

Hard clump 425 cht

That's at the top edge of acceptable, if you can keep it below 420 I think most engine experts would say you are fine and below 415 nearly everybody would be happy with it. Lycoming says max of 500 degrees, but they are also in the business of selling you replacement cylinders, so take that with a grain of salt.

Keep the engine full rich to keep it cool while climbing, if you aren't already. Don't go lean until you've leveled off at altitude and start picking up speed.

What CHT's do you normally see in cruise? Is the engine carb or injected?

Cowl

Cruise highest 385 normal carb it kinda strange it’s number 2 cylinder
Danny

Cht

I just went through this in a piper Cherokee pa28-140/160 1969 model with a new carb on a 0320 e2a powerflow exhaust.. I contacted lycon in Visalia ca, and sent the carb to them and they wet flow tested and found the new carb was lean.. so they jet for 185 hp... it knocked 20 degrees off the cht. It cost me 214.00 with shipping. I may go with a carb on my six as I have two on the shelf now.. Billythekid

Gauges correct?

Since its "new to you", and been flying, I would do some checking of the indicating equipment first, then move into the cowling dynamics. I haven't seen a Sam James that didn't have a plenum, but I'm sure someone will chime in on that.

fixnflyguy said:

Since its "new to you", and been flying, I would do some checking of the indicating equipment first, then move into the cowling dynamics. I haven't seen a Sam James that didn't have a plenum, but I'm sure someone will chime in on that.

Click to expand...

They've always sold the cowl and plenum separately - I have seen several RV with the James cowl but not the plenum. My James cowl fit like a glove right out of the box, but the plenum was awful and I would have saved time and money by starting from scratch. I had to cut off and reglass 3 of the 4 corners and the entire front. I hope the new James owners have corrected that issue.

Cowl

Hi bill
I have a dynon ems10 I already had a problem with the fuel pressure in the unit
I will check the probs not sure how but I’d
Really would like to fix this problem
Any one else have a idea on how to
Check the probs
Thanks
Danny

Probe checks

Dan, A friend of mine (on here) purchased a -4 that I ferried from Fla to NC. It had a Dynon 10 that was all over the charts, 90 PSI fuel pressure, erratic EGT, ect,. I am not an expert on all the Dynon stuff by any means, but he found a bad pin connector that corrected his fuel pressure. As far as the temp probes, you can switch them around if the leads are long enough and see if the temps follow the probes. As far as individually checking, it requires a controlled heat input and you may need to reach out to an AVX shop or otherwise do resistance checks. BTW, this -4 has a SJ cowl and handmade plenum, which has nothing to do with all the crazy Dynon readings.

A few things to check.

Do the CHT probes read correct ambient temperature prior to starting the engine? If they do, they are likely reading correct CHT when running.

Are you running electronic ignition (e.g. P-Mags)? If so, be sure the jumper is installed and timed 1 tooth after TDC to reduce base timing from 26.6 to around 25°. Regardless, make sure timing is correct.

Your max FF during climb at sea level should be 15-16 GPH. If not, it is too lean.

Make sure all holes in baffles are sealed, no matter how small. The plenum would likely help but rubber baffles work fine when installed properly.