ragedracer1977

That and as @EricJ can testify, if my engine started running like it did on just the surefly, I'd be looking for a place to land, right now. I think we both expected it to quit any moment. back to both and as smooth as it could be.

agreed. In theory, it shouldn't be advancing the timing at takeoff, but it could be if something's wrong. If I capped off the MAP line to it, would it not advance at all, because it's not seeing a MAP decrease? This is an advance schedule I found, but I don't know the accuracy .

see above. I'm pretty sure. You set the engine to TDC, then the surefly has a light on it, sort of like a magneto timing box. It shows you when the magneto is also at TDC, and you torque the hold down nuts while watching the light. Don't laugh, but I was very very careful to be exactly at TDC. I used the soup bowl thing on the spinner, the piston stop pin, etc, and then verified I was at TDC with a digital dial indicator. If its off, it's by 100ths of a degree.

I'm going to reach out to them tomorrow and see what the heck. I checked the timing, and it's showing good. Also, it's the starting magneto. I would imagine if it was that far off, I'd have starting problems, but it fires right up. It starts like a modern fuel injected toyota, lol.

Quoting this as an update. @EricJ and I went and flew it today. Temps were better, 20-30 degrees cooler at full throttle, full rpm. Much higher (near 18gph) fuel flow. But something is wrong with the surefly mag side. We ran it on just the Bendix for a while. Temps on #4 came down to about 380. Switched to the surefly, temp nearly immediately jumped to 400 and then a steady climb to 430+. And then it started stumbling. We ran it on the surefly mag for a while, a few minutes, and it was very "stumbly". Rich or lean didn't make much of a difference. We were at 5500', 2400rpm, 23 ish inches. 75% power or so. I haven't downloaded the data yet, but I'm hoping I can see the stumbling in the data. Besides it *really* advancing the timing, I can't see how it could temps that quickly. I mean it was nearly an instant jump. And then the rough running. Plug going bad? Bad harness? But we now have a carburetor providing the correct amount of fuel. We know the doghouse is good (Bendix cht temps were really good), we know there isn't any intake or exhaust leaks. So it seems to be narrowed down to an ignition system issue on the surefly side.

Just one quick note. When you're doing the first start up after replacing the carb, you should be getting fuel pressure. If you're not, cranking the prop for 30 seconds is useless... Especially if you forgot to turn the fuel selector back to a tank after you turned it to off so you didn't drip fuel all over when you unhooked the lines... Don't ask how I know....

New Carb installed, unfortunately that's as far as we got. Did a short ground run to get the idle and idle mixture set, but it was too late to put the cowl back on and go fly. So, you'll have to wait until tomorrow to see how it turns out.

I spoke to a guy at Marvel over the weekend. I have a new Carb coming today. We'll see what happens. Im going to try to get it installed this afternoon and I'll be sure to post numbers after!

I see alot, like 500 lol. Just a quick peek, on every flight I looked at, your FF peaked near 18gph right at the start. I think that's the breaking point for me. I'm not getting that initial cooling, the temps start getting out of control, and then FF starts dropping with altitude, never getting a chance for the cylinders to cool. So they're starting really hot

Highest 15. something for a few seconds then under 15. Can you share the link to it so I can look at all the parameters? @orionflt

Interesting, right? In the longer example, even CHTs swapped.

I’ll take a look at that, thanks!

I have no idea. But that's why I always refuse a glass of wine or a beer if I'm going flying that day

Read 14 CFR 91.17. it says not under the influence, but then says not over .04 BAC. To me that says they believe under .04 is not under the influence

It doesn't matter what your BAC was 8 hours before, as long as you don't have another drink, and your BAC is under .04 when you actually take the controls. 14 CFR 91.17. Seeing as they say don't fly under the influence, and then seem to define under the influence as .04 and over, it would be legal to fly at a .03 BAC, as long as it's been 8 hours since your last drink. But it would not be legal to fly with a BAC of 0.00 if you had a beer 5 hours earlier. This isn't a big deal to me, I don't drink hardly at all. It's just a very strange way of dealing with it

Can you upload your data to savvy? Here's an interesting data point. And I have no idea what to make of it. It was considerably warmer here, 30 degrees or so, but my carb temp was really low. When I applied take off power, it dropped from 70+ degrees to 40 almost instantly, and then continued to drop down into the 20's. Even lower later. Look what happens when I turn on carb heat. EGT drops and so does CHT. In one example (I only have 2 short samples, #4 was pretty stable, carb heat on, then off. After I turned it off, it started climbing. Does anyone else have any data points on carb temp? Seems a little strange that mine would be so cold. I don't know what would cause that, it's strange

It's a crazy reason with no basis in reality. A guy can go fly an airliner with a .03 BAC 8 HOURS after his last drink. That means the dude was blitzed. There's no way he's as sharp as a guy who had a single beer or a glass of wine with lunch and wants to fly home 5 hours later. That's crazy.

Excellent!

Great info! Your fuel flow numbers vs temps are mirroring what I'm seeing. My instrumentation prior was a UBG16 and FP5L. I remember when I installed the FP5L I was originally seeing 16gph plus, but the last few flights prior to the EDM it was under 16. I did have the mux8a. It stores data. I wonder if there's a way to power it up on the bench and pull the old data off? I never did, because I didn't have the right cable, but I'm thinking it could be interesting. There should be at least 100 hours of flight time recorded, as much as 600 hours

Book or better. 7-900 fpm through 6500

We've gone off topic. Is it legal to fly with a BAC of 0.03 if your last drink was more than 8 hours ago? Yes or No. I'd it legal to fly with a BAC of 0.00 if your last drink was 4 hours ago? Yes or No. I'm not asking if it's smart or good ADM, just whether it's "legal" or not.

Takeoff roll was 886' on the last flight. Quick extrapolation from the POH says that's probably a little faster than expected. Accelerated to 100 knots before reaching 100' agl. Climbed at 105-108 knots.

Yet, it's totally legal to fly with an alcohol concentration of 0.03. but it's not legal to fly with an alcohol concentration of 0.00 if you had a glass of wine 4 hours ago

Yet for whatever crazy reason, you can go on a bender and be legal to fly 8 hours after your last drink, but you can’t have a single glass of wine at a 5pm dinner and fly home at 9pm

Replacing spark plugs was the first thing I did when this started. Didn’t help. Then I installed the surefly and new fine wires. Didn’t help. I thought I addressed this earlier in the thread, but maybe I didn’t. I pulled all the intake tubes and oil return lines. New gaskets and new connector tubes on all 4 intake tubes, and new rubber connectors on the return lines. Didn’t help. I have to assume the AD was taken care of sometime in the last 57 years.