Ragsf15e

Honestly, 50 degrees cht difference on an io360 with the vintage cowling / cooling setup isn’t much. If it’s making normal power and smooth, I wouldn’t worry about it at all.

Jeez, I usually have a bigger spread than that with no issues. Typically number 3 is hottest and 1 coolest as its right up front. Lean very slowly through peak and see what order the cylinders peak. When ROP, usually the hotter ones are the leanest although in my case 4 peaks first and is usually slightly cooler than 3. LOP, the last one to peak is usually hottest.

Welcome! Some of the speed mods are better than others, but they generally aren’t cumulative. If they were, my F would be faster than a J! I don’t know the specifics on the K model mods, but someone will be able to tell you the desirable ones. I’m guessing their first recommendation is the engine upgrade that provides an automatic waste gate. The early Ks have a more challenging setup for engine management which often led to early top overhaul. The diesel would be great, and I can’t wait to hear people’s thoughts on eventually having that as an option!

Interesting, I’m sure there’s something different about flush rivets that changed at ‘68... ill take similar pictures of my wing next time out.

If you look at a ‘67, I think all the rivets on the top of the wing all the way back are flush. My ‘68 only has flush on the first 1/3 as you move aft.

Well according to the logs, she was born with a johnson bar, but then modified with electric gear at the factory before being delivered. Weird. I definitely do not have all the flush rivets that the earlier models have.

Interesting. Im 68-0164. I guess they ran out of retractable steps somewhere between there and just started bolting on the steel tubes!

Nothing wrong with a G, but I doubt the extra length is gonna help your dogs it’s mostly in legroom for the backseat. If I was a dog in the back, I’d be curled up on the seat without needing any legroom at all! I guess what I’m saying is that you might be able to open up your search to Cs and Es too. There aren’t very many Gs. As far as the DA, all the vintage 180/200 hp models are going to be similar in that regard. You will have to tread carefully. They will definitely climb higher when very light but start to wallow as load increases. 12,500 at max gross isn’t really comfortable, but it’s doable with reasonable weather (no downdrafts). My quick direct Foreflight plan for your route says 2:12 and 27 gallons (F model, rich of peak, with current winds). So say minimum fuel load is 40 gallons with a nice reserve and maybe not direct. If you weigh 200, wife is 125, dogs are 45, baggage is 75, that’s a total of 685. I’d want to take off 100-200lbs or more below my max gross at those DAs. Even if it’s “only” 7000’. That’s just a guess from my flying in the last few years from our home in Washington. At least until you really see how it will perform. So you need an airplane with about 900lbs or more of useful. A G should be right about there or better. No hard and fast data for you and the old POHs are light on the data too, but that’s my 2 cents.

Glad you’re feeling better each day!

True, there’s some “middle ground” fixed steps before they got to the more aerodynamic ones. My ‘68 isn’t square like a retractable one, but it isn’t aerodynamic either. It’s a 1” diameter steel tube with a big fat step on the bottom. No fairing on the tube. Like an antenna, a circular tube has a pretty bad drag profile.

You’re definitely right about Google, i was using that a little loosely... you can find anyone that says anything you’d like to see! If you stick to MS threads, you can find the folks who attended Advanced Pilot Seminars (APS). They have engines on test stands and real documented data. Their data and operating methods are pretty solid and they have data to back it up.

You’re making a good sales pitch for the electric step! Mine is a ‘68, so fixed. Making it retractable would entail making a bigger opening in the side of the airplane for it to pull up? Does water get sprayed up there during ground ops?

Ok, with the IO360, your fuel distribution should be more balanced and allow you to be a little more precise setting all 4 cylinders to a particular egt setting reference to peak. @J0nathan225 and @carusoam nailed the reason not to be less than ~100 on the ROP side. It can be tough on the engine. If you do it low enough at a high power setting, you can cause detonation and destroy the cylinders pretty quickly. In practice, it’s pretty hard to cause actual detonation on an io360. Bigger, especially turbos, it’s much easier. Anyway, it’s not a fixed line - ie 90 deg ROP isn’t necessarily going to hurt anything. At 12,000’, you probably only get 55% in cruise, so maybe 20 ROP might not hurt anything, however it’s not doing much for you. It’s hotter than 100 ROP and basically the same power. Commonly accepted, ~100 is a good place to be for engine longevity on the ROP side. LOP is totally different and you can run closer to peak. The higher you are, the less power on the engine, the closer to peak you can run safely. You can safely run at peak at 65% power and some people use that as a good efficient power setting. Remember, all 4 cylinders need to peak, so 3 will be LOP and the richest will be at peak. Read about “red fin” or “red box”. Step 1 for you next time you fly is to check your gami spread. You can Google it, but basically, set up for cruise at maybe 7,000’ or so, 2500rpm and wide open throttle (just an example, other altitude s and power settings will work). Then lean very slowly and note the fuel flow when the first cylinder peaks, keep leaning and note the ff when the last peaks. The difference is your gami spread. Less than 0.5gph is decent and you can probably run LOP ok. There’s a lot of other writing on this but it tells you about the the fuel and air distribution to your cylinders.

Since SF no longer publishes their advance curve, we don’t know for sure, but I suspect their compromise between advancing for ROP and LOP goes too far to really improve ROP ops, even from a 20 BTDC starting point. Mine is at 20, but cruising ROP at 10,000’ where the advance is probably close to maximum, my CHTs are a little hotter than before but there’s no increase, or at least very little increase, in speed. For LOP ops, there are a couple knots increase ~ 10,000’ that I can document after adding the SF.

I noticed slightly higher chts with my SF initially, maybe 10-15 degrees more each cylinder at ~10,000’. Maybe 350-380 in cruise ROP. 330 Lop. Then last summer I noticed higher oil temps to go with the higher chts. So at annual I sent my vernatherm and oil cooler to Pacific coast Oil Cooler. It was so corroded that they said they couldn’t even overhaul it. I now have a nice new $725 oil cooler and the oil temp is right at 185. Summer will be the real test.

one thing I just noticed... you posted the O360 manual. I didn’t realize you’re not injected. Carb engines are definitely tougher to operate LOP because the fuel distribution is not as even between cylinders. It’s possible, but people struggle to get it to work well because your GAMI spread is likely to be rather big. So there’s how it works in theory and books, then there’s how it works in practice. I have no doubt that you understand the engineering theory of this, no doubt, but you should do a little reading on how we apply it in our IO360s. The way you’re operating your engine is likely ok, and I’m glad you’ve read the manual, but the APS folks have done the “graduate” work on engine operation. If you google “Mooney Gami spread” or “Mooney lean of peak” or “red box” you’ll get all kinds of MS threads on this from folks much smarter than me. You have to realize that you don’t have 4 identical cylinders either. They are each getting slightly different air and fuel mixtures. Rich of peak is based off the first cylinder to peak. LOP is based on the last cylinder to peak. In no case should a cylinder be say 20 ROP or “around peak”. It should be definitely on the lean side or 100 ROP. 100 degrees LOP isn’t a practical power setting to use and/or compare with anything. LOP is measured off the last cylinder to peak, so if you’re 100 lop, 3 cylinders are even more lean than that. Power falls very quickly on the lean side. Much faster than rich. Somewhere around 20-40 lop is about the best you’ll do for efficiency. You’ll notice a big speed drop off more than that. On the rich side of peak, power is governed by MP and RPM. But on the lean side, just FF. So for our engine, about 9 gph LOP is 65% power. This is a safe place to operate your engine with whatever mixture you like, so a good place to experiment.

So, the egt is not the cht. Just because egt is higher, that doesn’t mean the cht will be. For example, when you do your mag check, egt goes up, right? Cht actually drops because more combustion is happening later and not all inside the cylinder. Lean of peak egt will be higher than rop egt, no doubt, but the combustion is taking longer at the lean mixture and carrying more heat down into the exhaust. The cht ends cooler. The place you don’t want to be is just rich of peak which is why I asked if you’re sure all your cylinders were past peak. That’s not good for your engine but probably won’t hurt it at lower power settings. Read about it on MS, not just my reasoning, there’s a whole APS course about engine management and theory. The target egt isn’t in the poh because we’ve got better in the last 50 years and because we now have egts/cht on all our cylinders instead of just 1. Basically, you just need to know your sea level takeoff full rich egt, then you lean as you climb to maintain that number. Every couple thousand feet is fine. Most airplanes in the 70s started to say lean above 5000’ in the climb. Target egt takes that a little further and smoother. Monitor your chts, enrichen if required, but your Engine will remain happy. Edit- To answer your question about ROP being higher cht, lower egt... the extra fuel allows the burn (flame front I think APS calls it) to happen faster. This allows more heat contained in the cylinder vs the exhaust. Thus cht is warmer. Yes, some of the extra is cooling, but at 100 rop, you end up with warmer cht than you do at 10-20 LOP. Maybe at 200 ROP the cht would be cooler than Lop but that’s just a waste of fuel.

Slight hijack... if you’re really 10-20f lean of peak (just barely past peak), you should see cylinders cooler than 100 rop. Mine are all at least 30 deg cooler. Are you sure you’re getting just past peak on all cylinders? Also, have you tried target egt in the climb instead of full rich? Works much better and is pretty easy to execute. Both of the above require knowing all 4 egts. Do you have an engine monitor that shows all or just one?

Dude that plane looks awesome! Love the prop! Can you guys use the G5s like us “N”tails? Those were a nice ifr upgrade. If you don’t mind spending a bit more, 2xGI275s will do the same thing and fit in existing holes. Does it have an ifr gps? That might be step 1?!

My personal minimum is 2 weeks of sitting for the airplane. It’s real tough to fly it every 2 weeks in the winter for me too just because of the typical low/icy clouds we enjoy from December through March, but I can usually do it. I have had it sit for a month a couple times and two months one summer due to long lead time maintenance/parts. I didn’t see any ill effects in the oil analysis. I do not run it on the ground, I will only run it if I’m planning to fly it. Sightseeing and breakfast runs are still fun in the winter. I went to Bonners Ferry Idaho (which is basically southern Canada) last week (9 degrees F) just because it’s a beautiful flight and they have $3.54 100LL vs the $5.54 I have to pay at my airport. I use biweekly flights to keep the airplane full of cheap gas!

Ha! Thanks. I got the “better”, low stress/high ratio gears about 5 years ago and they were expensive! I sure hope they last like the originals! It still comes up fast, but it’s noticeable. Yeah, the NBS thing, I probably should figure that out, but it’s one of those things I just haven’t got to yet... Sorry about the hijack folks, carry on.

I’m gonna hijack this whole thing for a simple question, sorry... I have a ‘68F with electric gear installed at the factory right after it was born. Do I have the no-back spring that I’ve read so much about or no? I read all the expensive complaints, but never figured it out!

Wow, where were you, middle of central NV going into Ely?!

Ha! Been doing this 30+ years and never even heard one given! I forgot, what’s different than vfr on top clearance? Still need to remain vmc?

After reading that whole BT thread, it appears that the G5 will only work as an encoder for certain transponders (using 429, like gtx345, gtx330, etc) if you have it connected to a garmin gps using Mapmx. If you don’t have it connected using Mapmx, it can output pressure altitude on serial at the correct baud to other transponders. Clear as mud?