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+--- Thread: Combustion chamber air swirl (/showthread.php?tid=3671)
Combustion chamber air swirl - Hercules - 05-21-2012
Doing head modification on 617 eng.1985yr.,combustion chamber side.
QUESTION; for increased performance would more air swirl be best or just direct air more towards pre-combustion chamber . In a DI engine fuel is sprayed directly into combustion chamber,increased air swirl is an advantage,(helps mix and ignite fuel). What is needed in a IDI engine?
Fuel is sprayed into pre-combustion chamber,mixing with some air,ignited
and flame exits into main combustion chamber where more air is available to
continue burn.
RE: Combustion chamber air swirl - larsalan - 05-21-2012
People modified the prechambers so they are giving more power. I thought it was a tried and tested improvement but, I might be mistakin.
http://www.superturbodiesel.com/std/thread-2169.html
is this only for super pumps? I dunno some one maybe chime in on that.
Is that even the thread I am thinking of?
RE: Combustion chamber air swirl - Hercules - 05-21-2012
Thanks Larsalan for the reply.Looking to understand air movement in the main combustion chamber.If swril is better or more towards pre-combustion chamber. Should be a good 20-25 h.p.here with very little mod.time or cost if head is off. For all pumps including stock. No need to add more fuel,more H.P.if more fuel added. Increase efficiency,increase performance with out additional fuel.
RE: Combustion chamber air swirl - sassparilla_kid - 05-21-2012
This has me very intrigued, I would definitely like to see the outcome. It seems like anything to get the fuel to be distributed more evenly and more efficiently would yield a power increase. I have a feeling though that this may help somewhat. Another thought, not sure if it would make much of a difference or not, is what about polishing all of the surfaces of the pre-chambers? If I remember correctly I read somewhere about people getting the insides of the injectors polished somehow, to help fuel flow and what not
RE: Combustion chamber air swirl - Hercules - 05-22-2012
Modified Prechambers do work,was pleased with increase,use 85yr ones are the best,no further mods need be done, unless flame holes increased small amount.Any 80-85 yr 617 prechambers will work,just update hole sizes.
Polishing inside of prechamber,could work,will try,Thanks
Polished inside of injectors (8) of them,always lost quality of spray,lost buzz, need very close tolerances to maintain.This buzz
is needed to have good idle and less smoking at low rpm. Larger tolerances do provide more fuel.
Sassparilla_Kid your correct,if fuel and air is mixed and distributed more evenly a higher efficiency should occur.
Have already TESTED, the results are in .More power with less fuel.( Higher efficiency) Would like to POST the best way to do this mod.if can find an answer to my question.
RE: Combustion chamber air swirl - ConnClark - 05-22-2012
Mercedes Benz got a patent on changing the impingement pin to induce prechamber swirl. I believe they used it on the OM603s. I would be possible to do it on an OM617 too but figuring out the right angle would be trial and error.
RE: Combustion chamber air swirl - Hercules - 05-22-2012
Thanks,ConClark. Have not tryed this yet! I have heard that there is some gain here. Have three extra sets of prechambers.Will experiment soon. There was a change in injector angle of 5 degrees at the same to make this work the best.
Things known: Do not increase prechamber neck hole size,more smoke.
Use 85yr prechamber,injection nozzle moved 1mm closer to dispersion ball,improved atomization.
Use 1980 hole sizes in prechamber,also used again in 1985 (was NOT noted in books).
Follow MBZ changes up through the years.Up date as much as possible
Follow the knowledge of others.
Enjoy!!!.
RE: Combustion chamber air swirl - sassparilla_kid - 05-22-2012
What size should the holes be enlarged to for the best performance? Or, what size are the 1980 and 1985 prechamber hole sizes?
RE: Combustion chamber air swirl - Hercules - 05-22-2012
These are mbz sizes,others have commented that a small amount larger worked well.See post #2 above for link. Although,I would not suggest enlarging hole in tip end more than Mbz.
Tip-end (K) 2.0mm/0.079" Middle front(L) 3.5mm/0.138" Sides front(N) 3.2mm/0.126" Rear (M) 2.5mm 0.098"
RE: Combustion chamber air swirl - DeliveryValve - 05-22-2012
Here is a link to our past discussions on this subject.
http://www.superturbodiesel.com/std/thread-1544.html
The prechamber info you provided is good stuff. I'll have to investigate this.
.
RE: Combustion chamber air swirl - ConnClark - 05-22-2012
here is the patent I was talking about before
US Patent 4,347,814
RE: Combustion chamber air swirl - Hercules - 05-22-2012
Thanks for the patent number. DeliveryValve thanks,for the post link( missed that one), have read and studied that article a number of times on the web. Just finished doing a variation of this on the combustion side.
RE: Combustion chamber air swirl - sassparilla_kid - 05-23-2012
Do the precombustion chambers share a common part number throughout the whole 617.95x line, or are they different? If they are different it would definitely make it easier to get an '85 specific set
RE: Combustion chamber air swirl - Hercules - 05-23-2012
Up dated prechambers MBz starting in 1984 California version start of model yr.Will be gradually phased-in on Federal version
engines.(missed that by 1yr.)
What to look for to tell diff. Bore in upper half enlarged From 8mm to14 mm (hole located under seal ring,under injector)
Will ck if numbered and post.
RE: Combustion chamber air swirl - Captain America - 05-23-2012
Here is the page on prechamber changes
RE: Combustion chamber air swirl - winmutt - 05-23-2012
(05-21-2012, 03:41 PM)Hercules Fuel is sprayed into pre-combustion chamber,mixing with some air,ignited
and flame exits into main combustion chamber where more air is available to
continue burn.
If that happened then everyone one of us would be blowing our prechamber tips. Ignition is in cylinder. Preignition in the prechamber means things go boom!
RE: Combustion chamber air swirl - Hercules - 05-23-2012
What is the purpose of the glow plug?(to ignite the fuel during cold starting).Where is the glow plug located?(prechamber) Where does the burn Start?? If my thoughts are incorrect please explain, Thanks
RE: Combustion chamber air swirl - willbhere4u - 05-23-2012
Since there is no source of oxygen in the prechamber it just heats the fuel up and it ignites as it being sprayed out of the tip
RE: Combustion chamber air swirl - DeliveryValve - 05-23-2012
.
RE: Combustion chamber air swirl - Hercules - 05-23-2012
Would pictures help? Go to u-tube, IDI diesel theory,(view) next see Direct& Indirect Injection, on page already (view)should clear up any questions.
Thanks DelveryValve,you beat me there. All here to learn & share.
Found an answer to my Question Will post performance upgrade results.
RE: Combustion chamber air swirl - willbhere4u - 05-23-2012
In the Mercedes there is a ball at the end of the prechamber that glows red hot that ignites the fuel as it exits the tip
RE: Combustion chamber air swirl - erling66 - 05-23-2012
No reason to discuss this. IGNITION STARTS IN THE PRECHAMBER
Ever heard of melted injectors? Take a guess why they melt
RE: Combustion chamber air swirl - winmutt - 05-23-2012
(05-23-2012, 10:44 AM)Hercules What is the purpose of the glow plug?(to ignite the fuel during cold starting).Where is the glow plug located?(prechamber) Where does the burn Start?? If my thoughts are incorrect please explain, Thanks
This was a good video http://www.youtube.com/watch?v=-ww7VIoftk4&feature=autoplay&list=PLE8E56324ED7AF54A&index=5&playnext=3
The gp does not ignite the fuel during cold starting. I stand corrected on where the ignition starts, that is news to me and contradictory to what Lance preached on about in the past (not surprisingly). More discussion!
RE: Combustion chamber air swirl - yankneck696 - 05-23-2012
(05-23-2012, 06:10 PM)winmutt(05-23-2012, 10:44 AM)Hercules What is the purpose of the glow plug?(to ignite the fuel during cold starting).Where is the glow plug located?(prechamber) Where does the burn Start?? If my thoughts are incorrect please explain, Thanks
This was a good video http://www.youtube.com/watch?v=-ww7VIoftk4&feature=autoplay&list=PLE8E56324ED7AF54A&index=5&playnext=3
The gp does not ignite the fuel during cold starting. I stand corrected on where the ignition starts, that is news to me and contradictory to what Lance preached on about in the past (not surprisingly). More discussion!
Lance wrong???? Please say it isn't so !!!
Ed
RE: Combustion chamber air swirl - Hercules - 05-23-2012
(05-23-2012, 12:46 AM)sassparilla_kid Do the precombustion chambers share a common part number throughout the whole 617.95x line, or are they different? If they are different it would definitely make it easier to get an '85 specific set
Pulled a prechamber from a spare 85yr. head ,the numbers are the same
as a few yrs. earlier,found on the top rim of prechamber, 617/03. Telling diff.either a 8mm hole or a 14mm hole at opening into mixing chamber( just under where Injector seal would set).
RE: Combustion chamber air swirl - DeliveryValve - 05-23-2012
(05-23-2012, 09:37 PM)Hercules(05-23-2012, 12:46 AM)sassparilla_kid Do the precombustion chambers share a common part number throughout the whole 617.95x line, or are they different? If they are different it would definitely make it easier to get an '85 specific set
Pulled a prechamber from a spare 85yr. head ,the numbers are the same
as a few yrs. earlier,found on the top rim of prechamber, 617/03. Telling diff.either a 8mm hole or a 14mm hole at opening into mixing chamber( just under where Injector seal would set).
Here is a picture I took of the difference between pre-chambers from this thread.
http://www.superturbodiesel.com/std/thread-2169-post-23897.html#pid23897
The rest of the pre-chamber mod thread.
http://www.superturbodiesel.com/std/thread-2169-post-23897.html#pid23897
.
RE: Combustion chamber air swirl - sassparilla_kid - 05-23-2012
Awesome, I guess I need to find myself a set
RE: Combustion chamber air swirl - Simpler=Better - 05-24-2012
For clarification:
RE: Combustion chamber air swirl - Hercules - 05-24-2012
(05-23-2012, 11:53 PM)sassparilla_kid Awesome, I guess I need to find myself a set
Be sure to use the 10mm seal if at all possible,helps move the heat dissipation path away from injector tip .That"s according to MBz.
Less overheating of tip. (this was effective).
RE: Combustion chamber air swirl - winmutt - 05-24-2012
(05-24-2012, 10:00 AM)Simpler=Better For clarification:
That may have been the most annoying video in history.
RE: Combustion chamber air swirl - sassparilla_kid - 05-24-2012
(05-24-2012, 04:43 PM)winmutt That may have been the most annoying video in history.
Agreed, what a goober
Just a thought, would the prechamber mod help naturally aspirated 616's and 617's as well? Or is it most beneficial on turbo engines?
RE: Combustion chamber air swirl - ronnie - 05-24-2012
Here is what I wrote about pre chamber mods on a 616 non turbo. This was posted on peachparts. I have since rebuilt the engine, added a turbo and changed to pc's from a 617a, and reamed the burn holes .010 larger.
"I reamed out the holes in the pre chambers(pc's) this week, and this does give a nice improvement. It has been talked about so I took the plunge and did it. Here are the areas of the holes in the pcs,
616 .0528 square inchs '78
616 .0498 square inchs uprated? an '83
617 .0595 square inchs turbo, '83
It is interesting to note that the uprated ones have less area. three holes are bigger(.125), but two are smaller(.090), plus the mini hole(.025) in the bottom. If i where to go .125 on all five holes in the old style pc then it comes to .0613.
I did ream to .125 diameter on all holes, they were .116.
Results, 5 mph faster on the hill climb. Egts just over 1300 at top of hill. Hill has 700ft of elevation change. Not sure of the distance, but it is steep, and starting from a stop.For general driving lower egts, and more responsive, less smoke too. Now a normal start from a light gets no visible smoke.
This is not a stock engine, changes are new manifold, advanced timing, larger exhaust, ip adjustments. So nothing radical, but not stock either."