New to me P337 - Is this a problem?

[GearUp]

Curious, what MP, RPM, & fuel flow are you running on the front, and are the cowl flaps open at all?

[Rule303]

An example of the settings before adding fuel to rear to cool are:

RPM both 2460, MP 30 both, FF 85lbph both, Front CHT ~375, Rear 400.

Even cracking the cowl flaps is costing around 8kts, and as we are getting ready to ferry trans Pacific, 8kts makes a bigger difference than an extra few gph.

All the baffles look to be in their correct places, and a 337 experienced A&P said they are fine, but he also said that this is normal.

My reading of the forums and your responses suggest it's atypical.

Re the type of monitoring, temps are via the original gauges, and she has E.I. Graphic Engine Monitors and a Shadin FF.

[mshac]

Pull the data and upload it to Savvy aviation so you can check your data.

On mine, the factory analog gauge always reads near the red-line on the rear while the front is in the green, yet the JPI digital shows the temps to be very close. I can usually run my rear 1-2 GPH richer than the front and achieve similar temps.

Rear engine running hotter is a common tale among Skymasters. I've read that if you get the rear baffling right, the rear engine can actually run cooler than the front, but I've yet to see it.

[GearUp]

I'm told our plane had a similar problem years ago and the A&P spent a significant amount of time on the baffling and plugging holes (i.e. spark plug wires, etc.) that let air bypass the cylinder cooling fins. And after he was finished the rear ran as cool or cooler than the front at cruise.

[Rule303]

Thanks to all.

A combination of long delays getting a simple avionics upgrade finished, and a subsequently bored and grounded company pilot who is also a mechanic seems to have fixed the problem.

A few days spent aligning and plugging all baffles seems to have done the job.