Pitts S1-SS

Ok, today was a big day, and one for the milestone list. I got the engine onto the airframe!

The new set of bolts arrived during the week along with washers and nuts. I got two sets just in case. When I pulled the first old bolt out of the engine rubber mount, I was expecting it to go off slightly again, but I was happy to see it allremained lined up perfectly. Obviously it has settled into the right location now. Popping the new bolt through the engine mount and spacer and tightening it up was a synch. Both top bolts went this easy. I then tightened them down and planned to torque them but I got conflicting  numbers from various sources, so just tightened them until they firmed up when the isolators pushed down on the spacer and left them at that. I’ll torque them later – looks like 405 inch pounds, but maybe 450?

Bottom two bolts were harder, but I twigged onto a new idea just as I was about to cut the bullet shaped bolt into a smaller peice to knock through the engine case and out the other side. I took a small crowbar and put it between the engine case the mount, and just pushed outwards softly. Presto, the engine mount move into alignment.. it’s quite flexible. I held it in place and tapped the bolt through, and for the 4th and final hole too. Wish I has figured this out first time. Really easy. Tightened them all up to clamp down on the spacer bushing, and then set about hoisting the engine higher and lining it up with the fuselage. Of course the dualmag needed to come off, and so I made up a cardboard cutout to cover the mag hole temporarily and packed away the dualmag.

Took a few adjustments but I soon go them lined up and tapped the firewall engine mount bolts through and tightened them up as well. Then the big moment, releasing the hoist and see the plane mated with its engine! Woohoo. What Stuart has joined together, let no man put asunder !!

After patting myself on my back a few times, the odd celebratory woop, I had a look at the firewall and how things fit. The oil filter fits as expected, with enough space, but I reckon I am still keen on the airwolf kit. With the magneto gone, the space looks quite manageable enough now to add all the bits I need, so that is cool. I took the time to install the alternator properly. I had the main U-bracket the wrong way around so it subtly didn’t fit, but once I had figured that out, it was easy to get all the parts lined up and tightened all the bolts. I used all the new shiny hardware kit stuff from the box. Didn’t even realise I had them until I damaged the turnup washer on the U-bracket and found a brand new one in the box with all the other new hardware. Neat.

After this, I took a few photos of the engine and fuselage mated together. It does look cool – first time it looks like a proper plane end to end with all the parts needed in one view. Cool.

Time taken: 3 hours. Total time: 1188 hours.

Ok, well after many hours of wrestling with it, I ended up ordering the Dual EFII ignition setup. It was a narrow race between it and the Light Speed Plasma II. On paper, the Light Speed is the one to go for, as it has decades of flying time and air race performance specs to its pedigree, but Rob Paisley won me over with his good customer service. I really like the look and simplicity of his system, and his components have also been tested extensively in the automotive market, so in the end the nice finish and solid look to the system won the day. Even if there are only 100 or so sold, and a quarter of that for Lycoming, and only a handful flying,  all the reference customers were very happy with it. I have to send off the flywheel for magnet installation which will happen tomorrow!

The picture that convinced me to go EFII..

Anyone looking for a Bendix DLN3000 dualmag..?  0 hours after it’s 500 hour inspection!

On top of that, I spent half an hour with Gary from APS again discussing the engine mods I am planning (I’m also looking at the Airwolf oil filter kit) and he was happy and confortable with all of it, but mainly had a good squizz at my engine mount rubbers and pronounced them .. all good! So I am relieved. A new fresh set of sparkly AN7-35A’s with nuts and washer arrived also, so they will go on for final fit this weekend.

Then it’s time to plan the fuel plumbing beyond the firewall.

I got quite a bit of good advice on the biplane forum on how to tackle the alignment of the engine mount bolts, and Raven also gave the same advice – use an alignment pin. I basically ground down an old engine mount bolt to be shaped like a bullet. I was going to cut it down to bullet length as well so I could feed it first then let it pop out the other end, but decided to just give it a bash anyway – I was please, the first two bolts were quite easy. Just a bit of pushing and jiggling and they worked their way in. After that I removed the bullets and fed the bolts in. I wasn’t expecting the bolts to go in easily after that, but they did with only a little bit of a tug here and there. Great.

I tightened up the top 2 to a guess torque – have no idea how to fit my torque wrench in here – no clearance, so I think I’l lhave to torque from the firewall side – not the best, unless someone has any other ideas.

After this, things got a little more challenging. Bolt 3 was actually not too difficult, but did require tapping with a rubber mallet to get the bullet in. And thereafter getting the bolt in was not as easy, but obviously the bullet does brig tings into alignment and it does help. I managed to angle the bolt at the hole with the outer isolator not quite sngly into the engine mount, and then when I tapped it in, the isolator slipped into alignment as well. Tightened it up and it was only bolt 4 to go.

Bolt hole 4 was a bit more difficult. I managed to get the bullet in with a bit of tapping, but the isolators look skew. I tried several times but they rubber mounts still pull to the one side. Maybe this is ok, but may not, I need some advice here. I also know when I take the bullet out, I will nto be able to get the bolt in, so I will probably need to cut the bullet short and push it out the other side – fortunately no 4 hole seems to have more space on the other side the the others. I’ve added a few pics of the situation – and hopefully will get some advice soon.

Time expended: 2.5 hours. Total time: 1185 hours.

After bringing the final bits and pieces to the hangar from my shed, I set about checking the clearance between my firewall and the back of the engine. I hitched up the engine on a hoist and removed it from the engine stand that came from APS. I then removed the engine mount from the fuselage. I figured whilst this was still easy to do, it would be the best way to play with clearances. I was kinda expecting the engine mount to fit onto the engine quite easily in this configuration .. but it did not go according to plan.

First the magneto leads were all in the way, so I removed all the leads from the spark plugs and fed them through the centre of the engine mount. After that attached all the shiny new Lord mount rubber isolators and bushings onto the engine mount ring, and I pushed it up against the engine. I fed the top right side bolt through, but when I went over to the other side.. erk.. the hole was off the bolt by about 1/4″ possibly more?

I know this engine mount was made up in the Raven jig so should be dead spot on, and I know that the bolt holes only line up nicely when the rubbers are compressed but this seemed a bit much. I made use the right hand bold was only in by a 1/8″ so that the alignment would be easier, but the left side still looked way off. Puzzled I gave up for the day. I will chase up Raven and see what they say.

Time expended: 1.5 hours. Total time: 1183.5 hours.