This has been discussed on other threads but I put it here because it is a modification and Iím sure others will encounter the same problem as stated below.
I have recently had some problems with my Honeywell oil sender which caused me to do some research on this problem. I started by calling all three Rotax dealers in the USA, California Power Systems, LEAF, and Lockwood Aviation. No one had a new Sender in stock as of Monday 11/8/2010 but said that some were possibly coming in later in the week, CPS said they had one customer waiting for 3 weeks for a new one. All 3 dealers said that they have seen several new Honeywell senders fail since Rotax started putting them on, which has only been a little over a year now. Lockwood Aviation said they canít keep them in stock. They also said that the VDO units failed even faster. If you want to talk to a Tech guys at Lockwood you must call between 9-10amet & 2-3pmet. Lockwood is now selling a kit, Part #EAPSIRK, price 74.95, which will provide you with all the parts to move your sending unit to the firewall. See picture below. They also sell the old style VDO sending unit, Part #GAV360-430, price 44.95. If you want to search for the part on the web put in VDO V360-430, itís a two prong unit, which is the one you will need on the RV12 with the Dynon. I installed the Lockwood remote kit on Wednesday and moved my Honeywell sender to the Firewall to the same location as the fuel sender unit. Now I get rock solid indications on the Dynon with no fluctuations in oil pressure.
Conclusions! The reason we are getting erratic Oil Pressure indications on the Dynon is because of the location of the sender unit on the engine not anything that has to do with the Dynon its self. Sorry Larry G! Mounting the sending unit on the front of the engine where there is a lot of vibration and heat is a poor design by Rotax. Anybody see sending units mounted on the front of a new Continental or Lycoming! Having this sending unit mounted on the front of the engine will cause premature failure of the unit sooner or later. I do admit some senders may last longer than others. But if you have one fail out of warranty its going to cost you some big bucks to replace it. I recommend that RV12 owners move the sender unit back to the fire wall after you receive their Airworthiness Certificate. This will increase the life span of the unit as well as give better indications on the Dynon.
Installation Notes: If you want to build your own remote kit here is some info. The hole on the front of the Rotax where the Honeywell sender is screwed in is a 1/8 inch pipe thread so you will need a male and a female, female to screw the Sender into back at the fire wall, 3 feet of tubing is about right, 3.5 feet will give you a little more room to maneuver, Lockwoodís kit comes with 3 feet. Itís a good idea to have a restrictor in the male part to reduce the time before your engine runs out of oil if you get a leak in the hose running back to the firewall sender, see pic below, the Lockwood kit comes with this part. I donít know where you can find this part other than Lockwood. The Lockwood kit comes with fire sleeve to put over your tubing. In order to get the tubing into the fire sleeve inject air in to the sleeve as you push the tube into it. Itís a pretty tight fit. If you use the Honeywell sender donít clamp it to tight, the sender has a partial plastic case and you could damage it. If you could incase the sender in some cushion material all the better. I ran my tubing up and across the top of the engine for cooling as seen in the picture. Running it under the cylinders next to the exhaust headers seemed like the warmer of the two options. I used the same screw that holds the fuel sender in place to attach the Oil Sender with an adell clamp to the fire wall. If you are going to use the VDO unit there are two prongs on the back of it. One is a negative/ground and the other one is the positive lead. Take a small length of wire and ground the neg prong to the fire wall where the adell clamp is bolted on. Then run the positive lead to where the red wire of the Honeywell unit is connected to the wiring harness. Cut the white wire off from the Honeywell and put some heat shrink over it to seal it off. Now go into the Dynon and change the sender from 4 to 1. See pages 3-6 and page 6-7 in the Dynon installation manual. I didnít do this because right now my Honeywell unit is still working, but Iím pretty sure that it will work ok. If someone does switch over to the VDO unit and this works ok Post it on this thread.
Fact: The old style VDO Oil pressure sender was replaced in late 2008 to the current Honeywell unit which is very expensive.
Fact: Both of the units are mounted on the front of the engine where there is a lot of vibration and heat.
Conclusion: Oil pressure on the Dynon in RV12s fluctuates plus or minus 5 to 8 psi. Since we have a wide green arc it doesnít seem to be a problem. I think this fluctuation in the Dynon is caused by the vibration of the sender on the front of the engine not from the Dynon.
Fact: The VDO senders were known to failure.
Fact: Flying RV12s are starting to see the Honeywell senders Fail and a history of failures is still being collected. We as owners may not ever see this data so if yours fail post it here on this thread so we can keep track.
Fact: The reason that Rotax went to the Honeywell Sending Units was because the Manufacture of the older VDO Units was bought out by a new company who no longer wish to have their Units in Airplanes.
Fact: Honeywell steps up with new Digital Sender. Rotax switches over to this new sender in late 2008 or early2009.
Fact: In order to get warranty service on your new Rotax you must register it with one of the 3 dealers in the USA with the paper work that comes with the engine. Then buy a new part at retail price to replace the broken part, then fill out the appropriate paper work that comes with the new part and send the old part back with this paper work. Then wait several months for a refund.
Kit from Lockwood Aivation to move your sender back to the firewall:
Male 1/8 pipe thread with restrictor in it:
Current factory location of Oil pressure Sender:
New hose screwed in where sender used to be:
Sender moved to firewall: