Is the 340 Stroker a fad???

[cjensen]

I've talked to several of the vendors about the engine, and they say they are selling a few, and James Ball of ECi, gave me a list of customers I could contact. The list wasn't long...

I have the mount for the 320 for my 7, but the 340 will work with this mount (probably with better WB results).

The reason I want to put this out there, is if I move ahead with the planning of the carb'd version 340, is it going to be around in two or three years when I can feasibly afford an engine?

I've talked to Larry Vetterman about an exhaust, I have Fred Felix working on the numbers for a prop for me, and these are items that I can afford to buy ahead of time without including them in the finance package for the engine and a few avionics. I think the engine will be around for quite a while, but I also have thoughts in my head that if I buy the exhaust, prop, etc...that I'll get news down the road that it's no longer available.

Anyone have any thoughts on this? Robbie?

[Brian Vickers]

Chad,
I seriously considered the O340 for my RV-4 in the finishing stages. Especially since my O320D1A crank failed the overhaul inspection. The "Stroker" crank & rod package is about the same cost as the O320 replacement crank. I decided not to use the O340 purely based on prop selection. I wanted to keep my options open for prop changes in the future. If you want more horses, the O360 has a huge array of propeller options. I don't think the O340 is a fad because not that many folks are using them.

[Yukon]

Chad,
Buy a mid-time 360 from Wentworth for about 12K when you are ready for it.
Not my idea.......Van's.

[cjensen]

Originally Posted by Yukon

Chad,
Buy a mid-time 360 from Wentworth for about 12K when you are ready for it.
Not my idea.......Van's.

I bought the O-320 mount from Van's...can't return it, and I want either a 320 or 340...If I go with a 320, I will be talking to Wentworth, as well as a local guy here that overhauls engines for us at my FBO.

The 340 is appealing with this engine mount though because it's ever-so-slightly heavier than a 320, still lighter than a 360, and I think the WB will work out great.

Brian,
I may have used the wrong word in "fad"...I used it in the sense that since there are so few using it so far, that it will soon pass... I do think that the prop selection wouldn't be an issue. The O-340 is rated at 177hp stock with mags. Could 180hp be had with EI??? Maybe, but I think the props available would be the same for the O-360. I'm more worried about getting a prop pitched for 177-180hp, then finding out I can't get the 340, and my only option is the 320 because of my mount.

I bought the mount knowing this full well...

[Radomir]

Doesn't ECI sell 320 kits? get one of those and assemble w/ help or have someone assemble it for you... I'd rather do that than Wentworth.. for about same money...

[cjensen]

Originally Posted by Radomir

Doesn't ECI sell 320 kits? get one of those and assemble w/ help or have someone assemble it for you... I'd rather do that than Wentworth.. for about same money...

Yeah, I've been talking to Jesse Robinson at A.E.R.O. in Stock about the ECi kits as well. Yes, they do have 320 and 340 kits for $12-13k. Great deals, and since I work at an FBO, I have many A&P friends to help me build it. Lots of planning routes floating thru my head...

[Joel]

Chad, I looked long and hard at the IO-240 also, but gave it up after finding the only way I could get one was with 9.5 c/r pistons. After my experiences of owning a '63 VW Beetle upgraded to a 1500 transporter engine with super heads & pistons (8.5 c/r) and a 1966 Porsche 912 with 9.3 c/r pistons, I won't build or buy an acft engine with anything greater than 8.7 c/r pistons.

You're probably wondering why?

Well, the bug was extremely anemic until after the aforementioned upgrade. Afterwards, it was a SCREAMING TIGER! Plus, it wasn't a problem to keep in tune.

The Porsche, even though it's compression ratio had been downgraded from the Super 90's 9.5 pistons to 9.3 to improve driveability, was still finiky, & required considerably more attention, unless you could run it hard. That was just not an option in the flatlands around Houston.

Therefore I prefer the combination of power when desired plus docility and reliability when desired offered by the lower 8.5 c/r engine, both in my automobile as well as aircraft engines. Caveat: This applies to AIR COOLED engines only.

Another thing to look at Chad, is the weight difference between IO-320, 340, & 360 engines. It really isn't all that much. Plus, the '360 has a slightly greater volumetric efficiency, POSSIBLY yielding slight fuel consumption advantages.

A couple of resources that have been particularly helpful in my acft engine research are:
1. Jack Norris' "Logic of Flight" & "Propellers" combo book
2. Sea and Sky Aviation Engines Page webpage, &
3. these forum's, especially Paul Lippes' comments.

Hope your choices enable you to fly long, safely, and enjoyably. Joe

[cjensen]

Originally Posted by Joel

<snip>Another thing to look at Chad, is the weight difference between IO-320, 340, & 360 engines. It really isn't all that much. Plus, the '360 has a slightly greater volumetric efficiency, POSSIBLY yielding slight fuel consumption advantages.<snip>

Trust me (others can verify), I've researched engines until my head was about to explode...I'm down to two, the 320 or the 340.

The problem with weight being a valid point, is there is no real magic number available. Yes, okay, the 320 might be lighter than the 340, and the 340 might be lighter than the 360. How much lighter? No two people can give the same answer because there's too much variation in installed weight. The engine itself, yeah, that can be a hard number, but at 8-10 lbs spread between them on average, an O-320 with mags and a heavy starter could weigh as much as an O-360 with dual EI and a lightweight starter. I am trying to build as light as possible, hence the 320 or 340 engine.

Anyway, as I've said before, I cannot use a 360 due to the mount I ordered.

Back to the 340...is it going to be around for a while???

[cjensen]

Originally Posted by Joel

Chad, I looked long and hard at the IO-240 (340?) also, but gave it up after finding the only way I could get one was with 9.5 c/r pistons.

Just a small technical correction...the pistons are 9.0:1, but you're right, that's the only way to get the 340. 100LL only.

[jferraro17]

Originally Posted by cjensen

Trust me (others can verify), I've researched engines until my head was about to explode...

I thought it did? I swore I heard a popping sound NE of STL one day...Must have been a Subie turbo going T.U. Glad to hear you're okay!

Joe