Crawfish

@Q The Engineer I have the aerospace logic MP/FF gauge we removed to install our GI275 engine monitor. I believe we still have the sensors themselves. worked perfectly when removed, acts as a fuel totalizer as well. PM if you’re interested in it.

Both are types of "charge coolers" it just depends where in the system they fall. Aftercoolers are after the Compressor section whether it be turbosupercharger or mechanical Supercharger. Meaning they cool the air right before it enters the engine. Intercoolers are between one compressor unit to another. Think twin charged; where a an turbosupercharger feeds into a mechanically driven Supercharger and between the two you have the "intercooler" to cool the air from one compressor stage before the next. My grandfather was a big gearhead, Thanks to him for teaching me to get my knuckles dirty.

The Economy is definitely a huge thing for me. Truly a marvel for the price You can pick up a nice 231 for the low 100's cruise at 165KTAS on 10GPH. This allows 3 hour trips with 3 large people and bags, or 4 small people and bags. Think South Indiana to Nola, I don't know another plane that you can do that for these operating cost and initial purchase price. F33's Is another example I can think of that will do the mission at similar speeds but you're going to burn more gas and Spend an extra 100K on purchase. In my opinion they are beautiful looking planes, but so are F33's and plenty of other aircraft.

I put the gear down somewhere around 115KIAS first notch of flaps at about 95KIAS and work in the rest as I slow. Trying to put less stress on the airframe than limits.

In my 231 it makes a large difference going from 2500 to 2300 and then even more to 2100. The plane already had the thicker glass STC installed when we bought it so I can't give you a before and after. But with RPM pulled back the plane is fairly quite. I imagine you can use the adhesive backed sound deading like Soundex to help as well if you don't already have it. Before I had the money for ANR I used DC's and ear plugs underneath and that made the piston singles I was flying at the time very quite.

You could also use desiccant packs also to absorb any moisture.

@231LVYou might even have them bring it up by a full Gallon per hour. The guys at SAVVY recommend 24.7GPH as the bare minimum.

I often fly between 13-16K since I’ve had fuel flow adjusted to ~25.5GPH at full power, CHT’s don’t get about 350 on the way up. Full power all the way up, (no Merlyn so MP starts to fall off after about 13K) Cowl flaps full open, mixture full rich, 110-115IAS. At max gross gives me about 700-800Ft/min. oil temps I have yet to see get over 185 at any altitude or power setting. I’d start by checking fuel flow if you’re operating it the same way as me. If you don’t operate the same way I’d read the articles published by John Deakin I believe it was “operating the fire breathing turbo” and make your own decisions from there on how to operate! Best of luck! TSIO360 LB1B No intercooler, no Merlyn

Thank you @Steve Dawson & @hubcap for the breakdowns! I appreciate it!

Okay, but take off fuel flow was set way up… about 26.5 GPH, I climb at 115IAS with cowls full open, I assumed all that fuel was why full power ran cool. GAMI spread is .3 with cylinder #5 being my richest. While my hottest cylinder is number 3 followed closely by number 4. The rest being 20-50° cooler.

I’m not sure I understand what you’re trying to get across? I ensure I’m lean of peak a couple different ways. One of which is verifying my richest EGT is lean of peak EGT. FF while lean of peak is the only way to determine power from my understanding. My question isn’t so much on Lean of peak operations, I’m plenty comfortable with that. I should have been clearer, how much of a drop to CHT’s are people seeing in cruise post intercooler install?

Yessir I’ve read that thread and posted in it as well! Sorry trying to make sure I understand correctly are you saying 231’s have heat issues or that the aftermarket intercoolers do? If the former I know haha I’m trying to find out how much the intercooler helps with temps. Honestly my 231 isn’t bad when it comes to temps just cruise in the summer needs a little help. If I go cowl flaps to trail 12,000’ ISA+ 19 I could run 65% LoP (10GPH) with the hottest cylinder at 370°. I’ve read some people had their mx adjust how open the closed position is in the summer time vs winter. That’s also an idea.

Cylinder for temps, fuel flow for power.

I'm thinking of adding an intercooler at my next annual. Climb CHT's aren't a huge concern for me I have no trouble keeping them down in the 350 range on climb. (Fuel flow is set up above the 24.7 GPH the book calls for.) In cruise with the summer temps I can't keep the CHT's below 380 with cowl flaps closed 65% power Lean of Peak. I would like to be able to cruise the majority of the time with cowl flaps closed. Would that be doable with the intercooler, I also plan on looking at baffling next oil change, but because its not an issue in climb my logic was its probably not baffling.

I'd like to second the K models! My M20K is a 79 231, I've owned it for 8 months; had one annual already, and two STC's added (Gami's and engine monitor.) I climb out at 115KIAS, at max gross it climbs at 700FPM until MP starts to drop in the low teens. I don't have Merlyn or Intercooler otherwise I would imagine you'd get several thousand more feet of 700FPM. On my way up to 16k I just lowered the nose to 500FPM once MP started to drop (somewhere between 12-14k each time) and made it the rest of the way up without issue. My 231 runs great LOP, I've learned in the summer time I need to have cowl flaps in trail but expect 150-165 KTS at cruise altitudes (11,000'-16,000') on 10GPH, In the winter I was able to do the same with cowl flaps closed giving me an extra 5ish knots. (This is all based off the airspeed indicator so throw in some room for error.) Range wise, I've done several 3 and 4 hour flights now. A 5 hour flight is what I would be comfortable with Std range Tanks! Easy math here Cruise and decent of 4.7 hours at 160KTAS= 752nm plus .3 hours of climbing at 115Knots = 35nm grand total being 786 nm of still air range. And all that in a package you could buy in the 130K-160K range, Seems like a true steal to me. (Thinking of 231's here. 252's, and Encore's cost substantially more money.) The big "drawback" of the 231 is engine management, honestly I think that's overrated. Not firewalling the throttle on takeoff and monitoring temps in cruise (a thing you should be doing anyway) are not hard. Boot strapping can be an issue in any turbocharged plane, just bump up the RPM a little bit and it should resolve the issue. To be fair I have about 80 hours in my 231, so take what I've said above with a grain of salt. But with that I've used the plane for what it really was designed for, long legs with two-three people. Several trips in the 550 mile range and a couple in the 650 mile range. The one upgrade that I do want to make is an intercooler, if the claims of lowering CHT's is true. I'd love to be able to cruise at 65% LOP in the summer with cowl flaps closed. When I upgrade it will either be a Rocket or Bravo both seem to be steals for the purchase price to capability. Either one will have TKS