Well one OEM choice
I'm hoping to take delivery of my ECI kit in the next week or so, and the only thing I didn't order was the carb. Is there a difference between different manufacturer's MA4-5 carbs, or will any brand work? Is there any reason to stay away from used or re-manufactured carbs?
Any advice or suggestions in this area would be much appreciated.
There is really only ONE OEM maker of carbs, Precision Airmotive.
http://www.precisionairmotive.com/
The other manufacture of parts who also overhauls units is Kelly aerospace.
http://www.kellyaerospace.com/pricelists.html
There is the special Ellison so called "throttle body" Carbs (google, see forums for reviews opinions):
http://www.ellison-fluid-systems.com/
There are MANY part numbers for the MA4-5 model; you want the richer one. The common part number 10-3878 is OK but usually too lean and needs the main jet drilled, like many RV'ers have done. The better dash number is part 10-4164-1. Call Precision Airmotive on Monday. I'm pretty sure. They may have a different suggestion but the problem is there are no stock carbs that are rich enough for some RV's (due to ram air from higher speed, better airbox and exhaust). Tell them its for a RV, on a O-360-XYZ, they'll know assy/part # to use. It's most likely the 10-4162-1. Here's their "LIST" 2007 price list: Ouch
10-4164-1 CARB ASSY
MA-4-5 Model
*CALL* NEW OUTRIGHT LIST PRICE
*CALL* NEW EXCHANGE LIST PRICE
$2,430.27 REBUILT OUTRIGHT LIST PRICE
$1,521.18 REBUILT EXCHANGE LIST PRICE
$2,220.86 OVERHAUL OUTRIGHT LIST PRICE
$1,311.77 OVERHAUL EXCHANGE LIST PRICE
$500 CORE VALUE
Kelly aerospace from link above list price is $1200 (comparied to $2,220.86 overhaul exchanged from Precision?). Spruce aircraft has a Kelly rebuild for $1190 (and that is adding in $500 core charge). Not bad
LINK
I personally think Precision has better parts, but if its $2,200 verses $1,200, I'd have a hard time going with Precision. May be there are discounts on the above LIST retail prices. May be not? Dealers are Aviall, Spruce AC, Sacramento Skyranch and so on. Dealers are on the Precision and Kelly web sites.
Both companies are fine and bought out other companies that originally made carbs or carb parts, either OEM or through PMA (parts manufacturer approval) and STC's. Precision for example has new float designs with composite material. Kelly aerospace is still selling and using metal floats for example, ONS, old new stock, they bought from the previous company. Nothing wrong with metal floats, just saying Precision is the OEM and active in design improvements. Kelly is a PMA company selling parts and doing overhaul assemblies. I'm guessing the price above illustrates Kelly parts are way less expensive than Precision's because they are working on ONS. I had mine overhauled and it cost me about $600 years ago, but I had a "core".
An Ellison TB for the 360 is $1650 out right new. The advantage of Ellison is no float so you can do acro with inverted tanks and oil. Personally I'm not turned on by the Ellison unless I was doing sustained neg-G Acro. If that was the plan from the get go, I'd just go FI. A lot of the Pitt's guy's use them, because they are cheaper than FI and a semi bolt-up converstion from the Carb. Some folks have had problems dialing them in on RV's. The Achilles heel in my mind is the spray bar with tiny tiny holes, so fuel filtration is critical. Also the airbox can affect airflow into the TB and affect it much more than a Carb. They seem to be a little finicky.
You may be able to buy direct from Precision Airmotive or Kelly aerospace but most likely they will direct you to a distributor. ECI probably can sell you the carb at a good price since you bought the engine from them. I am almost sure they can get you a carb.
I know you are going carb, me to, but if going FI you have three real different choices:
ECI's
RPM regulated FI system**
Bendix / Precision Airmotive
Silver Hawk EX:
AFP (airflow performance)
** ECI's system is unique in that it uses RPM only and throttle position and mixture control to regulate flow. The other FI systems use mass air flow sensing thru mechanical diaphragms, which is better in that the FI system controls fuel more accurately and automatically. There was an article in kit plane this year about the ECI system. Its a new product. I don't think the price ($3,500 list?) is great when
AFP cost $3,300 and
Silver Eagle EX $2,200(add $600 for hi-flow boost pump). Im sure I'd prefer the Silver Eagle EX or AFP over a totally mechanical RPM regulated ECI's design. The RPM FI control design was used on older Continentals, in planes like Bonanzas. They later incorporated an altitude compensating fuel pump to partially overcome the draw back of not sensing mass airflow. As you climbed it lowered fuel pressure to the FI to lower fuel flow. All new Continentals are mass airflow FI systems, like the Silver Eagle EX or AFP. If the ECI system was cheaper I'd consider it, but it does not seem to be. There are some advantages and could be considered a slight step-up from a Carb, but if you don't get with the mixture knob in a climb, you'll waste lots of fuel. Carbs actually have some limited self correcting mixture to compensate for altitude as you climb. It varies by carb model.
You might find a good used MA4-5 for exchange. Most salvage yards want a mint for their junk. Try trade-a-plane, internet, ebay.... That might turn up one from an individual cheap. Even better occasionally you find RV'ers changing over to FI has an airworthy used Carb to sell.
A regular mechanical pump and $40 Facet boost pump is all that's needed for a carb.
FI is going to cost about $3,000 or more. You need high flow electric & mechanical fuel pumps as well, which may not come with a FI "Kits". Vans pump/filter kit is $580 and a high pressure mechanical pump is about $240 (that looks like a $30 Chevy mech pump? humm). Some systems come at least with the high pressure pump. Also some require a fuel return line to the tank, which calls for an expensive duplex fuel select valve and extra lines to the tank.
