Starting Question O-145 B2 1940 BL65 with the original engine

[ddrewry]

After more than a year working on our project I finally tried to start it today - with no luck. Installed ovhl carb, new harness & plugs, ovhl Bendix SF4 mags, new fuel hoses and refurbed the gascolator - actually a fuel strainer.

Tried hand propping today until I gave up, didn't seem to get a spark or in the least bit interested in starting. My real question is on the hand-propping, not sure how much prop it takes to start this thing...

I have enough compression that with a full hard swing of the prop - it stops after about a third of a rotation??? It seems in my limited experience with continentals that I got quite a bit more arc out of a swing but its been a while. I start this one in about a 10 o'clock position and it stops by 6'oclock usually with a slight rock back. Trying to figure if this is normal? I'm no light weight (210 lbs) but that's all the rotation I get out of a swing putting everything in it trying to get as much prop speed as I can get - which isn't much.

So is this normal? I'll start trying to verify mag timing and spark when I get back to the airport this week also. By the way, there are 4 hash marks on my prop flange about an inch from the TDC mark. The last and furthest one away from TDC has a dimple put in it with a small needle punch. I did all my mag timing off of this mark as all the numbers around the hash marks (lines) are long gone and I assumed this one was marked as the one to use by someone through the years. Does anyone know what degree each mark actually represents?

Thanks, Doug 713-206-3160

[jim cooper]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

It has nothing much to do with how "hard" you prop it. If the carb is set correctly, the spark is correct , the gas is not old auto gas, set on idle, it should fire right off. I would find someone familiar with these engines to check things out. It should start right up. If everything is set correctly, they start! Which is why we are told ever to touch a prop unless you are prepared to start it. They will, if correctly set up, oftentimes start with the slightest of movement. Many will tell you the Stromberg carb is simple and easy to repair. Many were not set correctly when manufactured and many more are messed with by people who are unaware of what they don't know. If correctly overhauled, they are excellent! Best JC

[M Towsley]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

Doug, I would think it is in your set-up. You don't have to muscle these. Mine has very good compression and all I have to do is literally 'walk' the blade through the impulse and it starts.

[ddrewry]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

Thanks for the info and I'll start tweaking the install. Carb was just overhauled by Marvel at an astronomical price, Fresno rebuilt both mags and a new harness (steel braid outer with angled plug heads for less than $150 by the way!), I've cleaned the tank completely, built all new hoses, and its got a couple gallons of brand new 100LL with an ounce of MMO - so its GOT to be in the mag timing... I think. The )145 manual I have says set the mags at 20 deg BTDC for the 65HP but there is no indication of which mark on the crank is how many degrees. Anyone have any idea?

[Hank Jarrett]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

PHYSICALLY measure when the piston is at TDC (DON'T use the marks). Back the crank around 20* and see if that is where you have it set with a buzz box. It won't be that accurate using a finger tip in the exhaust to feel the piston top but if it isn't even coughing I would bet you are WAY off. Sounds obvious, but are you sure the #1 piston is TDC on the compression stroke and not the exhaust stroke? Even then it SHOULD at least cough. If it isn't doing ANYTHING it almost has to be that the mags aren't sparking at all or no fuel at all is getting in. (did you run a full check of the mag switch and mag grounding circuit?) I saw one guy who hooked the mag switch up so it was grounded out with the switch on (actually it was grounded ALL the time!) Take a meter and check the ground stud on the mag is not going to ground with the switch hot. If you unhook the P leads and put two different wires on them to a second switch to ground you can make SURE the mags are hot. Just make SURE you can still ground the mags to stop the engine!!!! DON'T do what the guy I saw did and think closing the circuit to the ground stud makes them hot. When the circuit is OPEN the mags are hot!

Hank

BE VERY CAREFUL!!! That engine could start suddenly when you fix the problem and you are very used to it being dead right now. When it does start it will have a NASTY bite!

[ddrewry]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

thanks to all who replied and those who called. More trouble shooting tonight ... and more questions! The book says 20 deg BTC but the data plate on the engine says 25 deg.
I figure the peen mark on the crank is prob close to the 25 deg so will try that tomorrow. I verified proper rotation on the mags tonight and all is good but did come up with an interesting discovery... maybe

also verified valves are working as they should on #1 cyl at least.

Book says to align timing marks in mag window and install w/#1 piston set at specified deg before TDC prior to installing mag.

Discovered that lug on internal rotor of mag is aligned with number 3 wire terminal on mag when marks are aligned in viewing window. Since mags fire 1-2-3-4 I think this should be under the number 1 spot on the mag (for the number 1 cyl)... may just be mislabeling or I may not understand the system as well as I think - will report back tomorrow.

[Mark Julicher]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

And please don't forget that if you have impulse couplings then you must first turn past the impulse release point and then rotate the prop backwards to the firing angle.

[ddrewry]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

I wish I had impulse couplings but no such luck on these mags. So first problem solved when I figured out the top of the mag was labeled wrong. Second problem solved when I rebuilt the primer so now I'm getting a good prime and fuel directly to the cylinders. Yes, I've verified TDC on the compression stroke and that valves in all cylinders are opening and closing when they are supposed to. I was also able to see that each spark plug wire is firing when it should but the spark seems very weak to me and I could not even see it unless it was completely dark. I definitely saw a brighter spark with a faster prop swing. I've got good compression but there may be something else going on there. With everything hooked up I still get only about a quarter turn of the prop swinging it as hard as I can. With the plugs pulled I get about 1/2 a rotation, maybe slightly more, and with the plugs pulled and the mags removed I can easily swing the prop a full rotation. Still I should be getting some indication that the engine is an engine even if the timing is off by a few degrees (the book says 20 BTDC and the data plate says 25). But I get nothing, I even tried a squirt or two of starting fluid first into the carb throat and then directly into cyls 1 & 3 (quickly reinstalling the plugs and wires and swinging the prop) - still deader than a door nail.

Tonight I pulled everything off intact and will try to get a local mag shop to look at the end to end system (mags, wires, & plugs). If unable I'll prob send it back to the mag shop - I just don't think I'm getting enough spark...frustrating to say the least! (By the way I also verified the exhaust system was clear with a borescope, couldn't see all the way to a valve so I'll prob pull the exhaust if the mags check out fine.. just to be positive

[TimHicks]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

I remember when I swapped a runout A-65 with a freshly overhauled A-65 on my TCraft. I was all ready to start her up for the first time. It was a cold winter day (cold being a relative thing, it's still South Louisiana). I was familiar with the starting routine from my old engine, but when I pulled the prop through the first compression cycle, I didn't hear the familiar "click" of the impulse coupling. I thought, "Wait a minute..." I tried a few more blades. No click. Then I called the engine overhauler who is very reputable but pretty old-school. He said, "Nope. Neither mag has impulse coupling. You don't need that. Just give it a good heave." I could hardly believe that I was dumb enough to not verify this before I bought the engine. But I thought, "Oh, Heck no." I went and pulled the impulse mag off of the old engine. Once installed on the new engine, the -65 started right up and I flew happily behind this combination until I took the plane out of service to recover it (a couple of years ago now).

[ddrewry]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

Caught a cough last night with a kick back! Very exciting as the first sign of life!!! I took the mags and harness to a local guy who confirmed the mag holes were mislabeled as I thought. He said the overhaul shop did a nice job but he did charge up the rotor saying it was pretty low. I also removed the ground wire from the mag to get the cough...

I have the A-9 mag switch which has the two P-leads, a common ground run to the block and separate ground wires to each mag. I had hooked the ground wire under one of the cap screws on the mag but evidently it was doing more because I got nothing before removing it. I quit messing until I get smarter... cannot be positive whether I got the cough because I removed the ground or possibly I've got an open mag circuit?

Anyone familiar with this ignition switch? Ideas on how to positively identify which is the P-lead?

Thanks, Doug

[Hank Jarrett]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

DANGER DANGER DANGER!!!! THE ENGINE IS COLD WHEN THE MAG SWITCH IS CLOSED, NOT OPEN!!!! When you put the MAG switch to L, R, or BOTH you are REMOVING the ground from the P lead.

If the P lead lug on the mag is going to ground the MAG is OFF! The engine does NOT start when BOTH MAG P leads are GROUNDED, It is HOT when EITHER P lead is removed from ground.

You have probably been propping the engine with the ignition off and not knowing it. The EXTREME danger is when you thought the engine was safe, the MAGS were HOT!

DON'T TOUCH the prop until you are SURE it is wired right. In the interim, make up a couple of wires with alligator clips on both ends and clip them to the P lead posts on the mags and to a ground to BE SURE the engine is safe. I would go so far as to pull the ignition leads and pull the top plugs until you are SURE it is set up right. If the lower plug fires with all the top plugs out at least it MIGHT not kill you, but I would bet with a good mixture the prop will still jump enough to hurt you.

Hank

Make sure you check this before ANYONE gets within arms length of that prop. We have had people DIE because of MAGS hooked up wrong. It ISN'T pretty.

If you aren't POSITIVE the MAGS are right DO NOT TOUCH THE PROP and keep everyone else away from it too.

[ddrewry]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

Not to worry, I've been around airplanes ... forever. Since I haven't been sure of the wiring set up, I've ALWAYS removed all of the plug wires while I'm troubleshooting or stepping away from the airplane. I quite often pull the plugs as well depending on what I'm doing. The ONLY time everything is hooked up is when I'm trying to start it & I ALWAYS treat a prop as hot. Many years ago I literally touched C150 prop and the engine started, quite unexpectedly. I had just landed and refueled and was doing a quick walk around. I later found a broken ground wire - but it scared the crap out of me at the time. Thanks for the concern though, its appreciated.

But back top my problem, is anyone familiar with this A-9 switch or possibly have a wiring diagram for it?

Thanks, Doug

[Hank Jarrett]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

You have been through it too. I had an engine start when I didn't expect it and must have lost several years of life (Continental 220 radial). I also had a thumb re-attached from a prop accident MANY years ago and when I was in the Navy we lost a Tech Rep who was killed by a prop. I am pretty sensitive to prop dangers.

That said I am still totally confident when hand propping, but VERY careful EVERY time and NEVER trust an engine not to start.

Right now the prop for my engine is OFF while I am working on it. Of course I am wiring the MAGS and I also have half the plugs out. I am NEVER going to get hit by a prop again.

Hank

Now if I could just stop banging my head on the wing! I'm going to start wearing a Cranial in the hangar.

[ddrewry]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

It STARTS & RUNS GREAT! Did some more tweaking today, reset the mags for 20 deg instead of 25 and adjusted the timing with the buzz box again (I've nearly worn out the brand new set of mags just from installing and reinstalling them so many times... getting pretty good at it.

Pulled it through a couple of times and primed and primed again. Got a short backfire on about the 4th attempt using a little starting fluid. A little more starting fluid and she purred to life on the next swing - smooth as can be. First time its run since 2007. Taxied around a little and confirmed the brakes are for crap so didn't run up to full power but taxied down the runway at more than an idle and shut off just like it was supposed to with the mag switch back at the hanger. One thing is I did not reconnect the extra ground wire to the mags so if someone has a diagram for that A-9 ignition switch would still appreciate it.

Hope to swap out struts at OSH and maybe have her flying by mid August. Great to hear her run though... thanks for everyone's help!

[3Dreaming]

Re: Starting Question O-145 B2 1940 BL65 with the original engine

The TCDS says 20° for the engine with a note saying if you are using greater that 73 octane fuel you can go to 25°. Now that you have it running I would try and move the timing back up th 25°. You will want all that power you can get. An other thing you will want to check out when you get flying is the prop. When I had mine I went with the recomended 70x36 and the engine wouldn't turn up like it should even in flight with the nose down it wouldn't turn up to redline. After much testing Sensenich built me a 70x34 to minium blade thickness and cord and it worked really well. I think at some point between when these airplanes were new and now Sensenich changed the way the measure pitch, and the new props have more bite than the old ones.