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Post by racket on Nov 8, 2016 17:59:33 GMT -5
Hi Anders
Yep , a snowmobile engine is sounding more like it :-)
Cheers John
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Post by smithy1 on Nov 8, 2016 19:20:01 GMT -5
Yep...some of those snowmobile engines have huge hp for their size. Good choice.
Cheers, Smithy.
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gidge348
Senior Member
Joined: September 2010
Posts: 426
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Post by gidge348 on Nov 10, 2016 4:34:45 GMT -5
Another option may be a Motor Bike IC engine???
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Post by Johansson on Nov 23, 2016 17:22:34 GMT -5
Hopefully the starter problem is solved for good now, I have found an original Viper 301 starter in the US and after some dealmaking I payed for it this morning! I won´t yell hooray until I have it in front of me, but it feels like I´ve solved the puzzle now. Cheers! /Anders
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Post by racket on Nov 24, 2016 3:58:35 GMT -5
Hi Anders
Nice :-)
Cheers John
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rpwp
Member
Joined: March 2016
Posts: 48
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Post by rpwp on Nov 25, 2016 18:07:26 GMT -5
Hi Anders, I've got a 601 and decided in the end to buy the original starter/gen after following your trials. There is in fact 3 separate parts to the assembly which are starter/gen assy, adapter housing and V band clamp. Have you got the adapter housing as well? fortunately I was able to get one with mine but not the clamp band which I eventually tracked down to a wreckers yard in Florida. I hope to get my 601 running in the next month or so and must update my thread...will be watching your progress with much interest..good luck! Cheers Rene
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Post by Johansson on Nov 26, 2016 9:48:42 GMT -5
Hi Rene,
Yeah, the whole business with building a one of a kind starter just felt like too big a deal. A 2-stroke engine starter with a one way clutch would in the end cost about the same as an original starter motor, so why go through all of the trouble?
I would love to hear more about your work to get the 601 up and running!
Cheers! /Anders
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rpwp
Member
Joined: March 2016
Posts: 48
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Post by rpwp on Nov 28, 2016 21:24:34 GMT -5
Hi Anders, My 601 needed a little work on the compressor as a few blades had light fod damage. Our major stumbling block was not getting the S/G with it and whether to buy or make a starter in the end deciding to pay the money and hopefully ensure success.
We have the original loom and have acquired suitable gauges for egt, oil pressure and temp and are currently wiring those in. We are also currently wiring in the S/G via a 1000A aircraft relay along with fuel solenoid/ignitors etc. As we don't have the timing unit that normally starts these engines it will be a full manual start using a stopwatch or similar to monitor the start cycle.
We have an APU that will assist the start and should keep a constant voltage/current supply to the Viper which is essential for a clean start. I'm currently debating as to whether we can connect the APU generator output via the contactor direct to the Viper starter/gen or whether we must have a start battery in circuit as well...any thoughts?
Using a 60ltr drum gravity feed for first start as we only plan for idle (40%) at this stage. Need to prime the fuel and oil system then we are getting close to a start hopefull during the xmas break.
Cheers Rene
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rpwp
Member
Joined: March 2016
Posts: 48
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Post by rpwp on Nov 29, 2016 4:35:28 GMT -5
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Post by Johansson on Nov 29, 2016 6:15:29 GMT -5
Hi Anders, My 601 needed a little work on the compressor as a few blades had light fod damage. Our major stumbling block was not getting the S/G with it and whether to buy or make a starter in the end deciding to pay the money and hopefully ensure success. We have the original loom and have acquired suitable gauges for egt, oil pressure and temp and are currently wiring those in. We are also currently wiring in the S/G via a 1000A aircraft relay along with fuel solenoid/ignitors etc. As we don't have the timing unit that normally starts these engines it will be a full manual start using a stopwatch or similar to monitor the start cycle. We have an APU that will assist the start and should keep a constant voltage/current supply to the Viper which is essential for a clean start. I'm currently debating as to whether we can connect the APU generator output via the contactor direct to the Viper starter/gen or whether we must have a start battery in circuit as well...any thoughts? Using a 60ltr drum gravity feed for first start as we only plan for idle (40%) at this stage. Need to prime the fuel and oil system then we are getting close to a start hopefull during the xmas break. Cheers Rene Hi Rene, Thanks for the youtube link! Really nice to have a real APU starter for the Viper, I can´t say for sure whether you need a battery bank inbetween or not but as long as the voltage output from the APU is ok I cannot see a reason why you would need any batteries. Do you have any closeup pictures of the starter adapter? When I did a test spin of my Viper with the old starter I noticed a small oil leak under the auxilliary gearbox which the starter bolts to, is the original adapter sealed so there is meant to be an oil level inside where the starter motor spline coupling is? Cheers! /Anders
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rpwp
Member
Joined: March 2016
Posts: 48
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Post by rpwp on Dec 1, 2016 4:26:08 GMT -5
Yes I do have some photos Anders but the upload image function won't work for me at present so will try later. (working now) Basically the adapter has large openings around its periphery so is not in any way oil tight. We are not sure where the oil level will end up but suspect there is no seal as such apart from maybe around the starter/gen output shaft (sealed?) bearing. Question: How are you feeding fuel to the LP filter housing? purely gravity or assisted by booster pump/diffuser pressure? Cheers Rene
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Post by Johansson on Dec 1, 2016 17:28:21 GMT -5
Thanks a lot for the pictures! Once I have the starter mounted I´l do a couple of more test spins to find out where the oil is leaking from, at least I know that the starter coupling isn´t supposed to hold any oil in.
I´ve made a 20 liter test tank with gravity feed just for the initial test runs, later I plan to make a new and larger one pressurized with a tenth of a bar or so.
Cheers! /Anders
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rpwp
Member
Joined: March 2016
Posts: 48
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Post by rpwp on Dec 4, 2016 14:14:55 GMT -5
Hi Anders,
While going thru some Viper info I have found the note below which you might find useful given you are acquiring a genuine starter/generator, might save you some problems!
This advice was given me by a guy in the US who's business is fitting RR Vipers into L29 aircraft so knows his stuff. Of particular note is the importance of applying battery voltage to the field windings during start!
Hope you find it helpful,
Cheers Rene
The initial draw on start is 800-1000 amps, which means you will need a good relay and enough battery capacity to operate it. If batteries are too small or weak to provide the proper voltage, the starter wear increases exponentially. In other words you will burn it up in a short time. What we do is series 2 12 volt truck size batteries and 1 6 volt battery of the same amperage. This will give 30 volts, which will drop 3-4 during start. If there is too low voltage, the starter will draw more amps to try to maintain the same wattage. We use this system on all our external battery carts.
One other thing about these units you should know. When in the start mode there is battery voltage applied to the field as well as the armature. This boosts the torque of the starter in your case it can go on and off with the start relay.
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Post by Johansson on Dec 4, 2016 16:15:35 GMT -5
Wow, thank you very much Rene for this information! I wouldn´t want to ruin my starter so I´ll make sure to follow these instructions to the letter. I think it will take a while before I´ll dare to start the Viper, every now and then some crucial bit of information pops up (no dry spinning of the fuel pump, rear bearing priming, these starter voltage instructions etc) so I might as well leave it be a year or two more until I feel like I have a clearer picture of what I really need to know about the engine. Building your own engines really makes life easier, you know exactly what the internals look like and you can repair everything at home in case something breaks... Cheers! /Anders
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rpwp
Member
Joined: March 2016
Posts: 48
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Post by rpwp on Dec 4, 2016 18:32:32 GMT -5
Hi Anders,
Glad it's been useful advice mate!
Yes there is a bit to think about but being an ex Viper mechanic helps a little and it's not as daunting as you think just needs a little pre-planning.
I will post the process we go thru on my thread in the near future along with the wiring layout we use. Being a hydro-mechanical fuel/oil system makes life easier cause it's old school without fancy ecu electronics to go wrong, my biggest concern is having sat un inhibited for a few years what state the myriad of internal seals are in...guess we'll find out soon enough, watch this space:)
Cheers Rene
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