The Long Run...
Hi all
Currently I am doing a lot of study on my next aircraft and am leaning toward the rv4. Has anyone fitted the Titan 320 or 340 stroker to the rv4 and if so have you experienced any problems eg cowls? As an engineer I've cut my teeth on certified lycomings and believe there is a lot of potential and areas for improvements. My preferred engine for the 4 is a worked io320 eg port and polish, emags, 10:1 comp, nice exhaust, Sam James cowls with high flow filter etc and the Titan comes with a lot of these goodies if needed! Any help would be great!
James
James,
Age old question, 0-320 or 0-360? Or 0-340...Most of your decision making will depend on your mission and your budget.
As you know, the RV4 is a 70's design with the 0-320 as it's primary engine of choice. If kept at design weight (950# or less) it performs extremely well with a strong 0-320 and the right prop. The 0-360 has more HP and a bit more weight but not much more cost. The 0-340 is a re-introduction of an old design and is a great idea. However comma, you can easily achieve a light weight 180HP engine (320,360) using light weight accessories, magnesium flywheel and a composite FP prop. The RV4 flight quality differences with the 0-320 and 0-360 are really minimal.
So, which one?
The Stroker 340 is a great concept born in the 1950's by Lycoming. They needed more horses from what was then the only available engine, the 0-320A so they simply lengthened the stroke of the crank, different cylinders and pistons and thus, more HP. Hot rodders have been doing it for years. The twin Navion was the first recipient of a pair of them. Of course, then, like now, there aren't alot of them out there, so parts are unique, in the big scheme of things. ECI as far as I know is single source on producing crankshafts. In contrast, there are over 30,000 0-320 crankshafts out there.
The 0-360: More HP, longer stroke (same as 340) a bit more weight, a bit tighter fit in RV4 cowling. Lots produced, lots of parts, lots of options. With a Catto 3 prop and 9.0:1 compression you would have a screamer, trust me, I've flown that setup.
The 0-320: I built my RV4 in 89' and decided on rebuilding a used 0-320, balancing and blueprinting it and installing high comp (9.0:1) pistons. At 950 lbs it still consistently outperforms higher HP RV's. I'm an A&P and did most of the work myself and was flying with a total expenditure of $6K. I installed the first Electronic Ignition available and still believe it adds a huge boost in efficiency. That same 0-320 still runs like a watch today and provides the new owner a reliable, powerful engine for a reasonable cost with a huge parts base available. It could still be done for not much more expenditure in the current market. My current RVX has an 0-360J2A with lightweight accessories. It's installed weight matches the 0-320A it replaced with a 10% improvement in performance. Yep, not much difference...
So, why plunk down $25 grand for an engine? Heck, you can buy a
flying RV4 now cheaper than you can build one, for not much more than a new 0-340 costs!
Good question...What's in your wallet?
V/R
Smokey
