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#30
by
theman53
on 24 Aug, 2012 08:54
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There is quite a bit on this that I didn't write about, like that radius, as I really don't know about it. BUT the machinist with the flow bench does. That is a Dual plenum design mine will be single. I don't know if the pipe will be tapered or not to feed. My machinist with the flow bench is getting back to me on that, but he seems to think with the sausage funnels in the middle of the pipe it will not be as big of a deal as the air will have to turn to head down. Also, the intake valves close, which changes flow and is the reason for the specific length runners. He has a neat little thing that he can shoot die into the air and watch it with camera to see what it is doing. Like I said, I am a "wanna be" intake builder not a real one, but with the info I have I will have an intake that will provide better air than stock.
The biggest deal with performance from what the machinist tells me is Velocity. Flow is OK, but if you can get the air moving really fast into the cylinder to fill it, when the piston starts up, the cylinder will still be filling with air. IF you have good velocity with the incoming air charge. To open the head ports bigger is not a good goal, but shaping them so the air doesn't slow down or have to turn much is great. That is the idea with this intake, the air will only turn 2 times Also, the .8L displacement of the plenum is 1/2 the engine volume. From his many times around the intake making he has found that 1/2 the engine displacement will give the best throttle response with almost no negative affect to high rpm flow...especially on a small diesel that doesn't rev to 8,000rpm. Larger creates more "lag" and smaller it will starve the engine on the higher RPMs.
I will have it done sometime, but I maybe running the engine with the stock intake for a bit. Since you have that flow program, do you know what length the runner should end up. My machinist hasn't told me yet, but said he thought it was 9" from another he built before...there is a harmonic in the air flow and I am trying to find it for more low RPM. The gasser intakes and the D24 runners measure pretty much exactly 8" at the centerline, but I am not going to be running as much rpm and want more bottom end. If you know that would be great
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#31
by
Gizmoman
on 24 Aug, 2012 09:12
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#32
by
keaton
on 24 Aug, 2012 17:36
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That is nicely modelled, with the CFD, did you simply put the airflow onto the inlet and let it work itself out regarding the passing over the fins or did you stipulate that the air had to flow equally over the fins?
I only ask because if you simply told the system that there was an airflow at the inlet on both then it proves categorically that the fins are required.
Cheers
nathan
when I originally started playing with this design I was only concerned with even flow. I could change the runner length and diameter to pick peak Tq.
that CFD calculations are a far cry from accurate IMO. I still need to learn how to tell the program how the valves open and close (in order). that CFD is calculating 60lbs/min, ~2bar @ 100F
There is quite a bit on this that I didn't write about, like that radius, as I really don't know about it. BUT the machinist with the flow bench does. That is a Dual plenum design mine will be single. I don't know if the pipe will be tapered or not to feed. My machinist with the flow bench is getting back to me on that, but he seems to think with the sausage funnels in the middle of the pipe it will not be as big of a deal as the air will have to turn to head down. Also, the intake valves close, which changes flow and is the reason for the specific length runners. He has a neat little thing that he can shoot die into the air and watch it with camera to see what it is doing. Like I said, I am a "wanna be" intake builder not a real one, but with the info I have I will have an intake that will provide better air than stock.
The biggest deal with performance from what the machinist tells me is Velocity. Flow is OK, but if you can get the air moving really fast into the cylinder to fill it, when the piston starts up, the cylinder will still be filling with air. IF you have good velocity with the incoming air charge. To open the head ports bigger is not a good goal, but shaping them so the air doesn't slow down or have to turn much is great. That is the idea with this intake, the air will only turn 2 times Also, the .8L displacement of the plenum is 1/2 the engine volume. From his many times around the intake making he has found that 1/2 the engine displacement will give the best throttle response with almost no negative affect to high rpm flow...especially on a small diesel that doesn't rev to 8,000rpm. Larger creates more "lag" and smaller it will starve the engine on the higher RPMs.
I will have it done sometime, but I maybe running the engine with the stock intake for a bit. Since you have that flow program, do you know what length the runner should end up. My machinist hasn't told me yet, but said he thought it was 9" from another he built before...there is a harmonic in the air flow and I am trying to find it for more low RPM. The gasser intakes and the D24 runners measure pretty much exactly 8" at the centerline, but I am not going to be running as much rpm and want more bottom end. If you know that would be great
I would have to look up the runner length for you, its been a while. i know you want about ~3.5degree tapper from Velocity stack to valve.
off the top of my head: 85,000 / tuned rpm = runner length (1st harmonic iirc)
again i need to find my book and look it up, also got some FSAE cod to look through as well....
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#33
by
theman53
on 25 Aug, 2012 08:23
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BTW...The JD Green block is NOT an MF engine code. This is one of the 4 engines I got from Canada 2 years ago this Dec. It is a CY engine code. I have not really found it before, but I do know it has squirters *installed with sealant already* and it is a therefore a TD block I am assuming. I friend of mine said it could have been a Canada only thing. I know it came from an MK1 as it had the MK1 pass. engine bracket on it. I was thinking maybe a Vanagon or something like that, but I don't think those were ever TD engines?
If you guys know where or what it is let me know, thanks ><>
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#34
by
theman53
on 25 Aug, 2012 08:32
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Just got an update from the machinist. He said the .021" is for the bottom compression ring and it is OK. Not ideal but won't hurt anything. The lower compression ring is supposed to be more open than the top. That way when the gasses pass by the first ring the second ring it will leak by faster and not unload the first ring. He called it "flutter" if you have that issue.
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#35
by
justiz00
on 25 Aug, 2012 08:37
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The CY I have is originally from an 83 Jetta TD. That may be your source also.
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#36
by
libbydiesel
on 25 Aug, 2012 11:05
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All the 1.6TD Quantums and Audis got CY motors.
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#37
by
RabbitJockey
on 25 Aug, 2012 13:46
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Cy. Was the mkI and quantum engine code
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#38
by
theman53
on 31 Aug, 2012 21:13
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The coated pistons nestled in there bores, were in the hopes head would soon be there. --Didn't realize I got such a good pic of my left hand too--
I have some more stuff to go, bolting on the crank gear, IP, TB cover backing plate, oil pump, and water pump...but that is it. My head is still not done, so it won't run for a while.
I still need to get the runner length and make my intake. I am going to throw an old head gasket and my AAZ head on and then mock up the intake, but until then I am done for a bit.
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#39
by
Gizmoman
on 12 Sep, 2012 23:55
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Iv'e read about the piston coatings from several of your posts and visited the website as well. Do you think they can coat a piston that is scored a bit and "bring it back to life"?
My stock pistons are all in pretty good shape as are my bores and I'm having a tough time finding new ones at a decent price. Just curious as to your thoughts.
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#40
by
theman53
on 13 Sep, 2012 21:30
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No idea, I would contact them and ask as they are the ones that know that stuff.
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#41
by
theman53
on 16 Sep, 2012 21:44
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Well, I still have no head and no further progress on the intake as far as building it goes. I have been adding a room to the basement for my oldest and adding 22x15 to my shed that house the VW diesel engines I have now. I will hook in the air compressor and add a bunch of shelves in the shed. So I really wouldn't have much of an update if the head were here. I am trying to get the building done by the end of the week.
I figured out the length of the intake runners from the vavle head to the end of the runner for peak torque at 3200 rpm should be 11.45" long. I need to measure how far it is from the valve head to the flange of the intake and see if it is possible, as I can only have about 10.4" from the bolt holes to the top of the plenum. I am recessing it into the plenum, but only about an inch. It will be fun, as long as it is around 2" from that vavle head to the flange all will be good, if I can make it a pinch longer I maybe able to make the torque a little lower in the RPMs. I will let you all know as soon as I get it welded and I will take pics.
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#42
by
theman53
on 19 Sep, 2012 09:42
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I need some info. I need the measurement in a cylinder head. Ideally, from the top of the head of a closed valve to the closest/bottom part of the mating surface of the head and intake manifold. It doesn't have to be perfect or to the .001" to the nearest 1/8" would be fine. I would like it from the valve stem part closest to the mating surface. I would prefer a hydro head casting measurement but I definately need a 1.6 measured. I have an AAZ head and it measures approx 3" but I want to be sure the 1.6 hydro is the same or similar. I need this as the last piece to the intake #s so I can have the pieces cut for welding.
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#43
by
RabbitJockey
on 20 Sep, 2012 11:33
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let me know if you want solid lifter measurements, i have one sitting on my basement floor.
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#44
by
theman53
on 20 Sep, 2012 21:46
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Yeah, since I haven't recieved any response on the Hydro, measure it up. If the mech is about 3" from the valve stem closed valve to the mating surface of the head and intake them I know 2 of 3 and that will be good enough for what I am doing.