Low Hp but high Nm?
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Registered: 11/16/2017 Posts: 20 |
Hello,
Last year we testid our new 12mm p7100 pump. We used 3000rpm, p-7100 on 500cc, 5x0.6mm nozzles, holset hx40 super, 6 degrees of timing (I didn't realised that pump is advancing 10 degrees timing in full rack travel, but we weren't using so much fueling, max fueling is 600+cc.) Here is dyno run, we got only 300hp and 2000Nm This is our friend tractor using 4.75 litre engine. Turbo is Hx40 super, we broke it on next run in 4 bar of boost. Is it possible that retarded timing causing so high Nm but low Hp? |
Re: Low Hp but high Nm?
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Registered: 12/01/2018 Posts: 108 |
I’m not familiar with a ford engine, but on a 466 ih engine I had a 12mm p7100, 5x22 injectors, stock 3lm466 turbo. 3000rpm made just over 600hp. Pump timing was set with timing light at 33*. I hope this helps you some. |
Re: Low Hp but high Nm?
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Puller
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Is there much pulling over in Estonia? I googled it, you’re right beside Russia. |
Re: Low Hp but high Nm?
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Registered: 11/16/2017 Posts: 20 |
Some years ago we tried to make 4 pulling events in year but there isn't enough interest of this here. With this tractor we are planning to go compete in Finland. |
Re: Low Hp but high Nm?
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Moderator Registered: 03/27/2008 Posts: 1,152 |
Running a diesel with late timing is a little bit compareable to running a late ignition timing. So it's "correct" at low rpm but the combustion happens too late for higher rpms.
Your set up should be more like 28 - 35 degrees. Depends a little on how fast your pump is, gear ratio etc. Floating Finish - the German Tractor Pulling Web Show and EU Live Streams: [www.youtube.com] |
Re: Low Hp but high Nm?
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Registered: 11/16/2017 Posts: 20 |
Many thanks for advice.
This is Russian tractor, it is very similar to Ford. Factory timing setting for 2400 rpm are something like 24 degrees with stock inline injector pump. But stock pump are making much less injection pressure and 6 times less fuel. But with this timing it was really hard to start engine, it was kicking back. Is there any easy way to figure out a way to what is best timing? My first idea was to set timing on something like 16 degrees and when full power there are flame out from exhaust then put some more degrees etc. |
Re: Low Hp but high Nm?
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Registered: 11/16/2017 Posts: 20 |
Tractor in my first post was my fiend tractor, we were just testing P7100.
We can use only stock cam 242/254 degrees of lift at 0, overlap is 36 degrees. But we are allowed to use adjustable cam sprocket. We are going to use hx52 11cm2 This p7100 are using uper helix/higher noches on the plunger. |
Re: Low Hp but high Nm?
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Registered: 11/16/2017 Posts: 20 |
Early in this spring when we were working on our new engine cylinder head we discovered that nozzles are spraying against the cylinder head. We lowered injectors 3mm to get injector height right.
Injector what we are using now have 150 degrees on spray pathern, original had 115 degrees. At Least now I know why we made so little Hp when we were testing pump and nozzles. |
Re: Low Hp but high Nm?
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Moderator Registered: 03/27/2008 Posts: 1,152 |
Hi!
If you want help with your Belrus tractor, there are several guys in the Netherlands and Eastern Germany running them - and quite well! [www.facebook.com] check this guy on FB. That's the "Belarus tuning heaven"... Floating Finish - the German Tractor Pulling Web Show and EU Live Streams: [www.youtube.com] |
Re: Low Hp but high Nm?
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Registered: 03/17/2019 Posts: 65 |
Fast timing will start hard and run more rpms slow timing will start easier and make more exhaust temperature. Be careful with slower timing. Turbo go boom haha |
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