Author Topic: super charging a diesel  (Read 5951 times)

Reply #15January 22, 2009, 10:22:15 am

arb

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super charging a diesel
« Reply #15 on: January 22, 2009, 10:22:15 am »
Sure would be interesting to rework a VW diesel to be 2 stroke !!  The guys putting a mazda rotary in aircraft punch 2" holes in the rotor housing and TIG weld a S.S. tube for what they call "P port". They easily get 300 hp out of an 2.6L twin rotor without turbo or blowers.

http://rotaryeng.net/

Reply #16January 22, 2009, 10:33:19 am

truckinwagen

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super charging a diesel
« Reply #16 on: January 22, 2009, 10:33:19 am »
rotary motors are sweet, I almost got a 13B to put into my beetle based buggy, but a buddy ended up with it and put it into a triumph spitfire, crazy fast!

the two stroke diesels have a intake port in the cylinder wall and exhaust valves in the head, I suppose one could retrofit a four stroke to be two stroke, lots of work, but could be fun.
83 Opel Kadett Diesel

Reply #17January 22, 2009, 10:47:39 am

arb

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super charging a diesel
« Reply #17 on: January 22, 2009, 10:47:39 am »
Quote from: "truckinwagen"
rotary motors are sweet, I almost got a 13B to put into my beetle based buggy, but a buddy ended up with it and put it into a triumph spitfire, crazy fast!

the two stroke diesels have a intake port in the cylinder wall and exhaust valves in the head, I suppose one could retrofit a four stroke to be two stroke, lots of work, but could be fun.


Yeah, Mazda calls them a 1.3L engine...

The side ports in the diesel would be the same engineering challenge as the side ports they are putting in the rotary. They have not had one fail yet and aircraft engines run at 100% hp for 5 minutes and them 75% - 100% the rest of the time. Unless you are in Germany, or don't care about speed limits, we never abuse our engines like that.

Yes, a custom cam shaft would be needed with double lobes for all valves unless you wanted to change the cam belt to gear set - the cam puts quite a load on the belt at 2:1, I would not trust 1:1 for the cam on a belt.




Reply #18January 22, 2009, 10:53:04 am

truckinwagen

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super charging a diesel
« Reply #18 on: January 22, 2009, 10:53:04 am »
honestly I think the biggest challenge of the two stroke design(damn you, now I want to build one!) would be the injection, it would need to inject into two cylinders at a time every 180* of crank rotation.

maybe a injection pump from a large two cylinder industrial motor could be used and just tee the injection lines?

the hardest part of the intake ports would be finding a location on the block that you could cut through and not interfere with the water jacket or oiling system, what does the back of the block look like, there are no accessories there.
83 Opel Kadett Diesel

Reply #19January 22, 2009, 11:00:42 am

arb

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super charging a diesel
« Reply #19 on: January 22, 2009, 11:00:42 am »
Quote from: "truckinwagen"
honestly I think the biggest challenge of the two stroke design(damn you, now I want to build one!) would be the injection, it would need to inject into two cylinders at a time every 180* of crank rotation.

maybe a injection pump from a large two cylinder industrial motor could be used and just tee the injection lines?

the hardest part of the intake ports would be finding a location on the block that you could cut through and not interfere with the water jacket or oiling system, what does the back of the block look like, there are no accessories there.


_big grim_ - ME TOO !!!

Injection would be real easy with our pump, but with a 1:1 drive not 2:1. Some of the small diesels out there use gear drive... no worries about breaking a belt then. ;-)

Another approach would be to slap the common rail setup all the new diesels are using. You'd probably want to use the TDI block and head, though.

On the ports, that is the easiest - like the rotary P-port, punch through the side including the water jacket. Tig weld inside the bore, and seal the outside with either TIG welding or JB-weld like many have done. Yes, I think the back of the block is ideal for this.

Reply #20January 22, 2009, 11:27:10 am

Turbinepowered

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super charging a diesel
« Reply #20 on: January 22, 2009, 11:27:10 am »
Quote from: "truckinwagen"
rotary motors are sweet, I almost got a 13B to put into my beetle based buggy, but a buddy ended up with it and put it into a triumph spitfire, crazy fast!

the two stroke diesels have a intake port in the cylinder wall and exhaust valves in the head, I suppose one could retrofit a four stroke to be two stroke, lots of work, but could be fun.


Need to do some flow dynamics too, to get proper scavenging. TDI head on an AAZ block would be a better candidate for this than an IDI head, since your volumetric efficiency is likely to go down you would need the decreased surface area of the DI design.

But you would definitely have a better breathing exhaust!

Reply #21January 22, 2009, 11:47:41 am

truckinwagen

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« Reply #21 on: January 22, 2009, 11:47:41 am »
there is another issue, two stroke diesels cover the intake port with the piston skirt when at TDC to keep boost out of the block, with our fairly long stroke and short piston, I'm not sure if it would.

I think a chain drive would be easier than making a gear drive for the cam and the pump.
83 Opel Kadett Diesel

Reply #22January 22, 2009, 11:55:22 am

arb

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super charging a diesel
« Reply #22 on: January 22, 2009, 11:55:22 am »
Quote from: "truckinwagen"
there is another issue, two stroke diesels cover the intake port with the piston skirt when at TDC to keep boost out of the block, with our fairly long stroke and short piston, I'm not sure if it would.

I think a chain drive would be easier than making a gear drive for the cam and the pump.


2 stroke gassers charge the crank case. Maybe this would not be a problem for us if we are not looking for big boost.

Reply #23January 22, 2009, 12:35:39 pm

truckinwagen

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« Reply #23 on: January 22, 2009, 12:35:39 pm »
yes, but two stroke gassers don't have a separate oiling system, and their seals are built for it, if we pressurized our crankcase we would loose lots of oil past all of the shaft seals.
83 Opel Kadett Diesel

Reply #24January 25, 2009, 04:14:40 pm

Baixo

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super charging a diesel
« Reply #24 on: January 25, 2009, 04:14:40 pm »
rotary engines are 4 stroke. its just that a rotary goes through a 4 phases in one revolution.

its efficient design of only 3 rotating parts, and 4 phases per one revolution is also what makes the rotarys need lot of fuel......

i miss my RX7........ :(

the purpose of the peripheral port is oviously to get even more air in, but it replaces the side ports.....

its like taking your stock haed and doing a complete race job...port/polish and big ass cam.....