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IO-540 from scratch questions

I just acquired a TIO-540 case (narrow-deck) that I'm getting machined by Divco to change to parallel valve and downward exhaust. This will be going in to an F1 and I'll be doing gentleman's aerobatics, not competition.

The end result will be an AEIO-540. I've done a lot of work on IO-520s and I've owned a couple of IO-360 based planes. I've rebuilt Ducati engines, Porsche engines, etc.

I've got the parts catalog for the TIO-540-A1A as well as the AEIO-540-D4B5 (I like the Bendix 1200 series) and I've got questions, especially after watching quite a few IO-540 videos on YouTube of some incredible pieces of craftsmanship.

I don't want turbos. (Yes, I do, but .. no.) I am planning 10:1 pistons with parallel valve cylinders.

I want a very smooth, very close formation of parts making as much HP as possible while not destroying longevity. 300hp is plenty.

Here's the question. Since I'm building it up to be a best of breed from scratch engine, whats the best way to go about selecting a crank? A cam? Rocker roller cam arms? etc?

I saw a TIO-540 crank for sale. No part number listed. The listed crank for an AEIO-540 is either a 13E17648 or a 13E17653. The AEIO-540 parts catalog is spec'ed off of the wide deck engine. Is it the same for narrow deck?

I've got Dave Prizio's book "Powering your plane" on it's way from EAA HQ as I type this.
 
Here's the question. Since I'm building it up to be a best of breed from scratch engine, whats the best way to go about selecting a crank? A cam? Rocker roller cam arms? etc?

I saw a TIO-540 crank for sale. No part number listed. The listed crank for an AEIO-540 is either a 13E17648 or a 13E17653. The AEIO-540 parts catalog is spec'ed off of the wide deck engine. Is it the same for narrow deck?

I've got Dave Prizio's book "Powering your plane" on it's way from EAA HQ as I type this.

Much like you, I bought TIO-540 crankcase, from DIVCO no less, but a wide deck version. The only real concern on selecting your crankshaft is the main journal size, where lycoming has a "small" and "large" journal. The good folks at DIVCO will be able to quickly answer that for you. And then I recommend giving Bob at Aircraft Specialties (DIVCO's next door neighbor) a call and I'd be willing to bet he has a crankshaft that will work. Make sure you tell them you want to do aerobatics and the case it's going in. If anyone has the best option for you, it's likely him.

I would not buy a crankshaft online without a guarantee that it will pass inspection. I've bought one years ago that came with a yellow tag, only to find I couldn't determine who the certifier was on the 8130 attached. I was concerned and sent it in to Bob and it failed NDA inspection at the prop flange. I personally would only buy a crankshaft from a high quality vendor at this point; let's face it, it's like bargain shopping for a heart surgeon. You can have a lot of accessory part failures and keep flying to a landing spot of your choice, but if the crank fails - hey, it's an immediately bad day.

Another interesting data point is that Lycoming significantly reduced their crankshaft prices a couple years ago (ok, so maybe now going back up with inflation, but...). If you compare a used crank price, and then add ~$1500-2000 for OH costs, you might find you're close to a new crank price.

Whichever crank you get, be sure - ENSURE - you check your end play and verify the correct tolerances around the front end and oil slinger.

Best wishes on building your engine. BTW, I'll make a plug for the folks at J&J Air Parts; they have a good website that shows the third party parts (i.e. less expensive) if you use the lycoming IPC part number in their search.

It's a great feeling the first time the sucker fires over knowing you built that; it's a nice "I have made fire!" moment.
 
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Much like you, I bought TIO-540 crankcase, from DIVCO no less, but a wide deck version. The only real concern on selecting your crankshaft is the main journal size, where lycoming has a "small" and "large" journal. The good folks at DIVCO will be able to quickly answer that for you. And then I recommend giving Bob at Aircraft Specialties (DIVCO's next door neighbor) a call and I'd be willing to bet he has a crankshaft that will work. Make sure you tell them you want to do aerobatics and the case it's going in. If anyone has the best option for you, it's likely him.

Whichever crank you get, be sure - ENSURE - you check your end play and verify the correct tolerances around the front end and oil slinger.

Best wishes on building your engine. BTW, I'll make a plug for the folks at J&J Air Parts; they have a good website that shows the third party parts (i.e. less expensive) if you use the lycoming IPC part number in their search. It's a great feeling the first time the sucker fires over knowing you built that; it's the nice "I have made fire!" moment.

Thanks Ron! I was just talking with Monty at DIVCO yesterday, but I didn't ask him that question. Sounds like the smart approach.

For endplay, I completely agree. When I was building my old Ducati 900 engine, there were a bunch of places to shim between the crank, transmission, and case. It took awhile to get right as shimming one place changed dynamics in the other places. But the end result was an engine that turned like a fine swiss watch and runs perfectly with no metal in the filter or magnetic drain. Less vibration, too.
 
End Play

So if one were to use new case halves and a new crank shaft the end play should be nominal, yes?
 
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So if one were to use new case halves and a new crank shaft the end play should be nominal, yes?

It wouldn't likely be grossly out of spec, but it's also not likely to be perfect. If it is, enjoy a small win and do a little happy dance. Otherwise, make sure you have the right amount and that it is as perfectly in the middle of the value range as specified. Not too much, not too little. Just perfectly right.
 
A TIO 540 that was a angle valve. That would have the large journal crank I believe. I was told and correct me if I'm wrong but the large journal crank is substantially heavier say 25lbs and is what makes the angle engine so heavy not the cylinders. If true that's alot of extra weight on the nose of a Rocket.
 
If you are building from scratch - I would strongly suggest you look at SDS for injection and ignition. Modern parts, superb stuff, just about to fit ours onto a 540 core.
 
A TIO 540 that was a angle valve. That would have the large journal crank I believe. I was told and correct me if I'm wrong but the large journal crank is substantially heavier say 25lbs and is what makes the angle engine so heavy not the cylinders. If true that's alot of extra weight on the nose of a Rocket.

Ah, good point. I was wondering where the extra weight was. I talked to DIVCO and they said it would be easy to convert it from angle valve to parallel valve, and re-orient the updraft to downdraft for the standard $1875 overhaul price. The one I've committed to has been on the shelf since it was yellow-tagged in '99. I'd want it gone through again.

But I doubt they can reduce the size of the main journal.

I DO like the fact that piston skirt oil squirters are built-in. But I think I saw that you can add these to any case, so maybe that isn't such an advantage.

I DO want to build this to put out 300+hp. Otherwise, why bother when you can build a 230hp 4-banger.
 
If you are building from scratch - I would strongly suggest you look at SDS for injection and ignition. Modern parts, superb stuff, just about to fit ours onto a 540 core.

Abso-frickin-lutely!! I'm 100% there. :D Especially with the ability to adjust the advance/retard to kill detonation and make it easier to start. And run LOP.

For $8K it seems like a no-brainer.
- No mags to purchase or fiddle with timing points.
- No IRAN every 500 hours.
- Integrated fuel system.

Ah, but yes, a computer to monkey around with. I'll still have to exercise some self-discipline. :cool:

Add GAMIs and GO!
 
You dont need big compression to get to 300. I have 8.5 pistons and the stock D4A5 camshaft and I did significantly better than 330 on the dyno. While the absolute number may be suspect, I have done several side by side drag races with my buddies and though I'm not the fastest, I will outclimb all of them at the same weight. And two of them are running "botique" shop built engines with big compression. The point being, whatever my actual power number is, I'm making a lot of thrust with low compression.

Lycon ported heads probably helps, and yes, I'm also a happy SDS EFI customer.
 
I have 8.5 pistons and the stock D4A5 camshaft and I did significantly better than 330 on the dyno.

How many different cranks are there for the 540? Which ones are "small journal" and which ones are "large journal?" Are they interchangeable? Where can I find the weights of each version?

I've looked through the TCDS and they really don't specify crankshaft model numbers.
 
A TIO 540 that was a angle valve. That would have the large journal crank I believe. I was told and correct me if I'm wrong but the large journal crank is substantially heavier say 25lbs and is what makes the angle engine so heavy not the cylinders. If true that's alot of extra weight on the nose of a Rocket.

The main journal on a small journal crankshaft is 2.3745" compared to a large main journal crankshaft at 2.6245", for a difference of 0.25" on the main journals; a significant difference, but not anywhere near approaching 1/2 the shaft weight.

I weighed all of the major parts before I built my engine as part of a balancing effort, but also out of curiosity. My large journal crank weighed about 60 pounds, with counterbalance weights installed. I've also held a small journal crankshaft, but did not actually weigh it; while it is lighter, the small journal crank would only be 35 pounds in weight if a 25 pounds difference were accurate. From my own experience, I would say it is closer to a few pounds difference.

Lycoming made the change to add strength to the crankshaft. If you're intending to seek higher than stock horsepower, I HIGHLY recommend buying a large bore crankshaft. Turning to a smaller diameter crankshaft as a weight saving measure is like...well, I just wouldn't do that, but would look at less critical components for weight savings.

How many different cranks are there for the 540? Which ones are "small journal" and which ones are "large journal?" Are they interchangeable? Where can I find the weights of each version?

I've looked through the TCDS and they really don't specify crankshaft model numbers.

I don't know the exact answer to the first question, but probably "a lot". Practically speaking, the differences are in counterweights, prop shaft/flange and journal size.

No, they are not interchangeable from a large to small journal. You can't put a small journal crankshaft into a large journal crankshaft without building up the crankcase journals and re-mill them (You could ask, but I don't know if any of the crankcase shops even offer to do that). You can have your small journal crankcase line-bored to the larger diameter as an experimental aircraft builder, but it's still probably less money to just source a serviceable large bore crankcase, which I believe is the majority, if not every, crankcase produced since the late 1970's.

Also note that while Lycoming still sales parts for and services standard deck crankcases, they changed to the wide deck design also in the late 70's. As far as I can tell, this is what all new Lycoming engines have been delivered with since around that same time.

The best way to tell the difference, and know which engines specify which crankshafts, is with the Illustrated Parts Catalog (IPC). I recommend using the IO-540 Parts Catalog PC-615 - Wide Deck version, and then just select the part numbers that match your selected crankcase, which is the foundation for your engine.

If you don't already own a crankcase or crankshaft, I HIGHLY recommend you pursue a wide-deck crankcase with a large bore crankshaft.

DITTO on using SDS EFII; works very well on my engine, and Ross is great to work with.
 
Abso-frickin-lutely!! I'm 100% there. :D Especially with the ability to adjust the advance/retard to kill detonation and make it easier to start. And run LOP.

For $8K it seems like a no-brainer.
- No mags to purchase or fiddle with timing points.
- No IRAN every 500 hours.
- Integrated fuel system.

Ah, but yes, a computer to monkey around with. I'll still have to exercise some self-discipline. :cool:

Add GAMIs and GO!

If by GAMI's you mean fuel injectors, SDS's electronic fuel injectors go way beyond the ability of a fixed orifice injector. And You can trim fuel to a single injector, or as you implied with "a computer to monkey" with, tweak the system ad nauseam... in flight no less.
 
If by GAMI's you mean fuel injectors, SDS's electronic fuel injectors go way beyond the ability of a fixed orifice injector. And You can trim fuel to a single injector, or as you implied with "a computer to monkey" with, tweak the system ad nauseam... in flight no less.

Oh, cool! I've only researched it enough to know I'm going that direction. Didn't realize the injectors were also covered. Well, there's another $1,000 towards the SDS purchase price. :)
 
If you don't already own a crankcase or crankshaft, I HIGHLY recommend you pursue a wide-deck crankcase with a large bore crankshaft.

DITTO on using SDS EFII; works very well on my engine, and Ross is great to work with.

Thanks for the PC-615 reference!

That makes sense to go with the large journal. The TIO-540 case is large journal.

Someone made a blanket statement that I read somewhere that a narrow-deck parallel-valve is going to be much lighter than a wide-deck angle-valve.

I've heard there are thousands of narrow-deck engines still in the field. The gentleman I spoke to at DIVCO said he kind of preferred the narrow-deck. I forgot exactly why, but I think it was it's having a stronger internal structure? I think he said there were trade-offs with both in that one had case advantages and jug disadvantages and the other had the opposite. Or something along those lines. In other words, Lycoming fixed a case problem, but it transferred the problem elsewhere, so it's really a wash.

I'd be interested in where the weight gets added, and what the weight difference might be between a narrow-deck parallel-valve and a wide-deck parallel-valve.
 
I'd be interested in where the weight gets added, and what the weight difference might be between a narrow-deck parallel-valve and a wide-deck parallel-valve.

There's a lot of thoughts, opinions - and a lot of myth - on this topic, however I'd point to the fact that Lycoming changed to, and has continued to build for decades now, large journal, wide deck engines.

Engine dry weights are listed for the 540 models in the front of the Operator's Manual (free download from Lycoming's website). You'll find the most significant weight differences are between the parallel and angle valve engines, with the heads providing the majority of that extra weight. While the wide deck engines weigh slightly more than standard deck ones, I wouldn't make an engine decision based on that minor difference; I would focus more on what you want to do with the engine, your power needs and also talk with other F1 builders to see what they have used and recommend.
 
The main journal on a small journal crankshaft is 2.3745" compared to a large main journal crankshaft at 2.6245", for a difference of 0.25" on the main journals; a significant difference, but not anywhere near approaching 1/2 the shaft weight.

I weighed all of the major parts before I built my engine as part of a balancing effort, but also out of curiosity. My large journal crank weighed about 60 pounds, with counterbalance weights installed. I've also held a small journal crankshaft, but did not actually weigh it; while it is lighter, the small journal crank would only be 35 pounds in weight if a 25 pounds difference were accurate. From my own experience, I would say it is closer to a few pounds difference.

Lycoming made the change to add strength to the crankshaft. If you're intending to seek higher than stock horsepower, I HIGHLY recommend buying a large bore crankshaft. Turning to a smaller diameter crankshaft as a weight saving measure is like...well, I just wouldn't do that, but would look at less critical components for weight savings.



I don't know the exact answer to the first question, but probably "a lot". Practically speaking, the differences are in counterweights, prop shaft/flange and journal size.

No, they are not interchangeable from a large to small journal. You can't put a small journal crankshaft into a large journal crankshaft without building up the crankcase journals and re-mill them (You could ask, but I don't know if any of the crankcase shops even offer to do that). You can have your small journal crankcase line-bored to the larger diameter as an experimental aircraft builder, but it's still probably less money to just source a serviceable large bore crankcase, which I believe is the majority, if not every, crankcase produced since the late 1970's.

Also note that while Lycoming still sales parts for and services standard deck crankcases, they changed to the wide deck design also in the late 70's. As far as I can tell, this is what all new Lycoming engines have been delivered with since around that same time.

The best way to tell the difference, and know which engines specify which crankshafts, is with the Illustrated Parts Catalog (IPC). I recommend using the IO-540 Parts Catalog PC-615 - Wide Deck version, and then just select the part numbers that match your selected crankcase, which is the foundation for your engine.

If you don't already own a crankcase or crankshaft, I HIGHLY recommend you pursue a wide-deck crankcase with a large bore crankshaft.



Agreed. Thunderbolt built my motor and during the build they asked me if a 7 lbs increase would be OK. They said they wanted the large journal crank with the added hp (300+) and the penalty was 7 lbs. This is a "Red Bull" motor with 10:1, roller, CAFI, Slicks.
 
Just an FYI...

Standard-deck (aka narrow deck) does not mean small journal crankshaft.

There are standard-decks with large journal and small journal crankshafts.

The standard-deck I've been talking about is a large journal crankshaft and was for a 350-hp turbo Navajo.

Thanks for the input on the wide-deck. I had considered that, and I know it limits doing things like adding the water-cooled AC Aero cylinders, but I haven't really found any other reason to favor the wide-deck. Everything is still available to build standard-deck engines. (And if I buy anything from AC Aero, it's likely to be the Hawk V-4, anyway.)

4 out of 4 F1 builders I've talked to so far used standard-deck engines. But I know there are plenty using wide-deck as well.
 
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