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supaninja
Samba Member
Joined: July 03, 2010
Posts: 4020
Location: houston
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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 Posted: Wed Feb 02, 2011 8:35 pm Post subject: |
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| supaninja wrote: |
| Just squirt it then you can get away with more cam/injector choices since you'll have a lot more tuning capability. |
If I were going to go that far from stock, I would go Subaru turbo swap. But I'm not in to that. |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22413
Location: Kimball, Mi
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| Posted: Wed Feb 02, 2011 8:43 pm Post subject: |
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| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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| Posted: Wed Feb 02, 2011 9:41 pm Post subject: |
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| Bobnotch wrote: |
| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam. |
But will it run well? Do you run out of air due to the intake, or the cam? A single FI intake runner is about equivalent to a single port intake. With larger displacement, couldn't you run a cam with more lift, or more duration to compensate for the extra displacement?
I was thinking of 1745. 85.5 bore, 76 stroke. Would like to figure out how to set up a stroker. |
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JSMskater
Samba Grease Gorilla
Joined: February 01, 2006
Posts: 5362
Location: Murrieta California
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| Posted: Wed Feb 02, 2011 11:05 pm Post subject: |
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| rosevillain wrote: |
| Bobnotch wrote: |
| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam. |
But will it run well? Do you run out of air due to the intake, or the cam? A single FI intake runner is about equivalent to a single port intake. With larger displacement, couldn't you run a cam with more lift, or more duration to compensate for the extra displacement?
I was thinking of 1745. 85.5 bore, 76 stroke. Would like to figure out how to set up a stroker. |
its a little more complicated than that rose- you run out of air from the intake yes, but the cam dictates manifold pressure, and if you deviate from stock then the MAP starts getting weird readings that the analog computer just doesn't know how to deal with.
I have to agree with supa on this one, if you're gonna go with a performance motor while retaining most, if not all, of the stock FI components, you need a MAP and an ECU that you can tune to it. I don't think its really that much more complicated (or expensive) than the issues you'll run into with a non-stock cam. limiting yourself to the stock cam isn't gonna wake up the motor, all other mods considered.
Megasquirt is pretty user friendly, I think even a newb can handle it thanks to the ability to use your own laptop to tune it with.
_________________
71 Squareback-FI -- 73 Bay (subaru powered)
TOOB Member #3
I make D-jet FI connectors |
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Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22711
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
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| Posted: Wed Feb 02, 2011 11:33 pm Post subject: |
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| JSMskater wrote: |
| rosevillain wrote: |
| Bobnotch wrote: |
| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam. |
But will it run well? Do you run out of air due to the intake, or the cam? A single FI intake runner is about equivalent to a single port intake. With larger displacement, couldn't you run a cam with more lift, or more duration to compensate for the extra displacement?
I was thinking of 1745. 85.5 bore, 76 stroke. Would like to figure out how to set up a stroker. |
its a little more complicated than that rose- you run out of air from the intake yes, but the cam dictates manifold pressure, and if you deviate from stock then the MAP starts getting weird readings that the analog computer just doesn't know how to deal with.
I have to agree with supa on this one, if you're gonna go with a performance motor while retaining most, if not all, of the stock FI components, you need a MAP and an ECU that you can tune to it. I don't think its really that much more complicated (or expensive) than the issues you'll run into with a non-stock cam. limiting yourself to the stock cam isn't gonna wake up the motor, all other mods considered.
Megasquirt is pretty user friendly, I think even a newb can handle it thanks to the ability to use your own laptop to tune it with. |
So, you Einsteins aren't even talking D-Jet anymore?  
_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
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JSMskater
Samba Grease Gorilla
Joined: February 01, 2006
Posts: 5362
Location: Murrieta California
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| Posted: Wed Feb 02, 2011 11:46 pm Post subject: |
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| Tram wrote: |
| JSMskater wrote: |
| rosevillain wrote: |
| Bobnotch wrote: |
| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam. |
But will it run well? Do you run out of air due to the intake, or the cam? A single FI intake runner is about equivalent to a single port intake. With larger displacement, couldn't you run a cam with more lift, or more duration to compensate for the extra displacement?
I was thinking of 1745. 85.5 bore, 76 stroke. Would like to figure out how to set up a stroker. |
its a little more complicated than that rose- you run out of air from the intake yes, but the cam dictates manifold pressure, and if you deviate from stock then the MAP starts getting weird readings that the analog computer just doesn't know how to deal with.
I have to agree with supa on this one, if you're gonna go with a performance motor while retaining most, if not all, of the stock FI components, you need a MAP and an ECU that you can tune to it. I don't think its really that much more complicated (or expensive) than the issues you'll run into with a non-stock cam. limiting yourself to the stock cam isn't gonna wake up the motor, all other mods considered.
Megasquirt is pretty user friendly, I think even a newb can handle it thanks to the ability to use your own laptop to tune it with. |
So, you Einsteins aren't even talking D-Jet anymore? |
lol you do have a point
OK -- lets say just for the sanctity of this thread -- how would we go about keeping the stock D-jet while going larger
the critical aspect, is cam TIMING. if the overall lift is bigger, ok, but if the duration changes, then you run into problems. I think. Ray/Tram would know better than I.
assuming you can find a non-stock cam with STOCK duration, then theoretically all you'd have to do is bump up the fuel pressure, OR get larger flow injectors, until of course the intake doesn't have enough volume to keep up. Though as Bob mentioned a 1776 is sort of the upper limit.
I can tell you for example that Brian's engine, IIRC, is a 1776 with a non-stock cam, and his FI runs just fine. it was built by a shop in LA, whose name right now escapes me. maybe he'll chime in...
_________________
71 Squareback-FI -- 73 Bay (subaru powered)
TOOB Member #3
I make D-jet FI connectors |
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Adriel Rowley
Samba Member
Joined: October 12, 2006
Posts: 4748
Location: Mesa, Arizona
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| Posted: Thu Feb 03, 2011 2:23 pm Post subject: |
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| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I see the Web 107i cam for type 4 fuel injection, but there is no equivalent cam for type 1. The Web 86 opens the intake 4.5 degrees sooner has 9 degrees more duration, and about .070" less lift. The Web 111 is even bigger. Engle and CB cams are much larger yet. All of them are built on 108 deg lobe centers (maybe CB are on 107). Engle will custom grind a cam on 112 lobe centers that will retain manifold vacuum with lift and duration.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
I did a lot of research, and found the Web 111 was the closest to stock duration. What matters the most is intake. If you do run this camshaft, I found out after building the engine, it is best to sleeve the lifter bores do to the high amount of lift.
If you wait until Easter Break, I will get the exhaust analyzed and let you know exactly where I stand with it. So far, nothing really strange is happening, a bit loader, and possibly running a tad lean. But, idle is stable once the A.A.R. is plugged, and the one time I drove it out of tune, it felt like it had a lot of potential.
In short, if you can wait, do so, and you can learn from my mistakes.  If you are adventurous, then by all means try it, and let us know how it turns out. I figure with any engine I build, I have to accept it as experimental until I have enough experience to know what the outcomes will be, and that is not for hopefully a long time.
I do agree the added torque should in theory help with the mileage, as it will help get it going sooner. I found a big engine if treated just right can get good numbers. I drove the most powerful version of a '85 Buick Reviara and on average was in the high twenties, at one point it got 34 m.p.g. ! 
| JSMskater wrote: |
| Tram wrote: |
| JSMskater wrote: |
| rosevillain wrote: |
| Bobnotch wrote: |
| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam. |
But will it run well? Do you run out of air due to the intake, or the cam? A single FI intake runner is about equivalent to a single port intake. With larger displacement, couldn't you run a cam with more lift, or more duration to compensate for the extra displacement?
I was thinking of 1745. 85.5 bore, 76 stroke. Would like to figure out how to set up a stroker. |
its a little more complicated than that rose- you run out of air from the intake yes, but the cam dictates manifold pressure, and if you deviate from stock then the MAP starts getting weird readings that the analog computer just doesn't know how to deal with.
I have to agree with supa on this one, if you're gonna go with a performance motor while retaining most, if not all, of the stock FI components, you need a MAP and an ECU that you can tune to it. I don't think its really that much more complicated (or expensive) than the issues you'll run into with a non-stock cam. limiting yourself to the stock cam isn't gonna wake up the motor, all other mods considered.
Megasquirt is pretty user friendly, I think even a newb can handle it thanks to the ability to use your own laptop to tune it with. |
So, you Einsteins aren't even talking D-Jet anymore? |
lol you do have a point
OK -- lets say just for the sanctity of this thread -- how would we go about keeping the stock D-jet while going larger
the critical aspect, is cam TIMING. if the overall lift is bigger, ok, but if the duration changes, then you run into problems. I think. Ray/Tram would know better than I.
assuming you can find a non-stock cam with STOCK duration, then theoretically all you'd have to do is bump up the fuel pressure, OR get larger flow injectors, until of course the intake doesn't have enough volume to keep up. Though as Bob mentioned a 1776 is sort of the upper limit.
I can tell you for example that Brian's engine, IIRC, is a 1776 with a non-stock cam, and his FI runs just fine. it was built by a shop in LA, whose name right now escapes me. maybe he'll chime in... |
How does lift not affect it? Is is not adding more air?
Sounds like the Web 111 is a good choice if you sleeve and you like a good amount of torque.
The name also escapes me too.
| Tram wrote: |
| JSMskater wrote: |
| rosevillain wrote: |
| Bobnotch wrote: |
| rosevillain wrote: |
It engine rebuild time for me.
I've heard that a bigger engine can be had by simply increasing the fuel pressure, and maybe a MAP adjustment.
I would like more than stock, as I'm pretty sure that better fuel economy and fun can be had by a little more torque.
My question is, who is running a bigger than stock, possibly cammier(?) engine while retaining the stock fuel injection? |
How much larger are you looking to go? A 1776 is about the limit with the stock intake manifold(runs out of air above that engine size). If you're looking at keeping the stock FI, then you're stuck with the stock cam. |
But will it run well? Do you run out of air due to the intake, or the cam? A single FI intake runner is about equivalent to a single port intake. With larger displacement, couldn't you run a cam with more lift, or more duration to compensate for the extra displacement?
I was thinking of 1745. 85.5 bore, 76 stroke. Would like to figure out how to set up a stroker. |
its a little more complicated than that rose- you run out of air from the intake yes, but the cam dictates manifold pressure, and if you deviate from stock then the MAP starts getting weird readings that the analog computer just doesn't know how to deal with.
I have to agree with supa on this one, if you're gonna go with a performance motor while retaining most, if not all, of the stock FI components, you need a MAP and an ECU that you can tune to it. I don't think its really that much more complicated (or expensive) than the issues you'll run into with a non-stock cam. limiting yourself to the stock cam isn't gonna wake up the motor, all other mods considered.
Megasquirt is pretty user friendly, I think even a newb can handle it thanks to the ability to use your own laptop to tune it with. |
So, you Einsteins aren't even talking D-Jet anymore? |
Georg, I am going to stick with it, as I like a real good challenge. Ever since I ran this engine, I have an itch to learn how to build a stroker; nothing wild though.
I am finding D-Jetronic is real simple, and might be able to push it more than we thought. It was not long ago that we thought we could not use a stock camshaft, and Ray blew that one away with the Web 73. Then, Brian went a little wild, and the World still turns.
_________________
Please consider I am Autistic, so I process information differently and still working on social skills. Thanks.
Dad's 1964 Beetle purchased September 1968.
https://www.thesamba.com/vw/forum/viewtopic.php?p=9252810#9252810
1971 Sunroof Squareback with Fuel Injection
http://www.thesamba.com/vw/forum/viewtopic.php?t=219811&highlight=squareback+rejuvenation |
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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| Posted: Thu Feb 03, 2011 5:54 pm Post subject: |
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I jumped in with both feet. 1776, stock heads(?), 69mm DPR counterweighted crank.
Found a guy that grinds Porsche cams. He lists a 914 FI cam, much like the Web 107i. Spoke with him on the phone, he's done D-jet engines, and he recommended a custom ground cam close to the specs of his 914 cams, 8.5:1 compression, and ratio rockers if I choose.
Here we go... |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22413
Location: Kimball, Mi
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| Posted: Thu Feb 03, 2011 7:06 pm Post subject: |
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| rosevillain wrote: |
I jumped in with both feet. 1776, stock heads(?), 69mm DPR counterweighted crank.
Found a guy that grinds Porsche cams. He lists a 914 FI cam, much like the Web 107i. Spoke with him on the phone, he's done D-jet engines, and he recommended a custom ground cam close to the specs of his 914 cams, 8.5:1 compression, and ratio rockers if I choose.
Here we go... |
Actually the cam you want him to duplicate the grind for is the Web 86. That grind is a very good replacement grind for FI use in a t-4 engine. I know Ray will cough up the real info on it, but it's a good cam. Even Jake recommends it for FI t-4 engines.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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| Posted: Thu Feb 03, 2011 7:23 pm Post subject: |
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Web sells an 86 for the type 1. Cam guy says that anything with more than 255 duration won't idle well. I was actually thinking about the 86, but the 18 degrees of overlap looked daunting. I was comparing to the 107i, as it is the Web recommended FI cam.
86 works? |
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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| Posted: Thu Feb 03, 2011 7:29 pm Post subject: |
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| Now I see a Web 73, for solid lifters with FI. |
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JSMskater
Samba Grease Gorilla
Joined: February 01, 2006
Posts: 5362
Location: Murrieta California
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| Posted: Thu Feb 03, 2011 11:36 pm Post subject: |
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| rosevillain wrote: |
| Now I see a Web 73, for solid lifters with FI. |
IIRC the 73 is the "safe" bet while still getting more performance. I myself haven't done much research on the differences between the cams, so I like the conversation we're having.
Adriel -- I never said anything regarding the lift and more air, but yes lift of the cam does allow more air into the cylinder -- however remember, the volume of air from the intake at some point reaches an upper limit, and no amount of larger opening of the valves is going to increase that. That was the point I was making. Furthermore, more lift, more air, etc, can all be matched by increased fuel flow -- however the TIMING of WHEN the valves open and close, the duration, can't deviate too far from stock or else the valves will either stay open too long or close too early for when the injectors fire --- which is separately dictated by the cam lobe on the DISTRIBUTOR which you cannot change. Finally, the timing/duration of the cam will also affect manifold pressure (since the valves will presumably be open longer) and so if that signal from the MAP to the ecu LASTS too long, then the injectors will pulse far too much fuel for the available air, or far too little, at certain rpm ranges and such -- it just complicates an already delicate balance and without an O2 sensor or very many simple methods of adjusting the MAP (I know ray disagrees -- but often his more complex procedure is beyond the skills or toolset of a novice/ shadetree mech -- I know I dont have an exhaust sniffer!) then the motor will simply never run right and cook itself.
_________________
71 Squareback-FI -- 73 Bay (subaru powered)
TOOB Member #3
I make D-jet FI connectors |
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JSMskater
Samba Grease Gorilla
Joined: February 01, 2006
Posts: 5362
Location: Murrieta California
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| Posted: Thu Feb 03, 2011 11:37 pm Post subject: |
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| rosevillain wrote: |
I jumped in with both feet. 1776, stock heads(?), 69mm DPR counterweighted crank.
Found a guy that grinds Porsche cams. He lists a 914 FI cam, much like the Web 107i. Spoke with him on the phone, he's done D-jet engines, and he recommended a custom ground cam close to the specs of his 914 cams, 8.5:1 compression, and ratio rockers if I choose.
Here we go... |
you're going to LOVE the DPR crank. Jose does incredible work and I'd recommend him to anyone.
_________________
71 Squareback-FI -- 73 Bay (subaru powered)
TOOB Member #3
I make D-jet FI connectors |
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Adriel Rowley
Samba Member
Joined: October 12, 2006
Posts: 4748
Location: Mesa, Arizona
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| Posted: Fri Feb 04, 2011 2:30 pm Post subject: |
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| JSMskater wrote: |
| rosevillain wrote: |
| Now I see a Web 73, for solid lifters with FI. |
IIRC the 73 is the "safe" bet while still getting more performance. I myself haven't done much research on the differences between the cams, so I like the conversation we're having.
Adriel -- I never said anything regarding the lift and more air, but yes lift of the cam does allow more air into the cylinder -- however remember, the volume of air from the intake at some point reaches an upper limit, and no amount of larger opening of the valves is going to increase that. That was the point I was making. Furthermore, more lift, more air, etc, can all be matched by increased fuel flow -- however the TIMING of WHEN the valves open and close, the duration, can't deviate too far from stock or else the valves will either stay open too long or close too early for when the injectors fire --- which is separately dictated by the cam lobe on the DISTRIBUTOR which you cannot change. Finally, the timing/duration of the cam will also affect manifold pressure (since the valves will presumably be open longer) and so if that signal from the MAP to the ecu LASTS too long, then the injectors will pulse far too much fuel for the available air, or far too little, at certain rpm ranges and such -- it just complicates an already delicate balance and without an O2 sensor or very many simple methods of adjusting the MAP (I know ray disagrees -- but often his more complex procedure is beyond the skills or toolset of a novice/ shadetree mech -- I know I dont have an exhaust sniffer!) then the motor will simply never run right and cook itself. |
Joe, thank you for confirming! You know why I am asking, right? So, now I know what I need to do.
As for exhaust analyzer, there are ways around using one. However, to get one just have to look. I have to remember to now, as I know I am not in the right range it seems.
Has anyone found the actual volume limit to the manifold? Somewhere I remember seeing the formula to calculate it, but now where it is escapes me. I however do not believe its volume has to do anything with lift. What matters is how well it flows, which I think it is better than we give it credit, but probably could be improved on. Though, for some reason, some air restriction moves the torque band down the R.P.M. range.
_________________
Please consider I am Autistic, so I process information differently and still working on social skills. Thanks.
Dad's 1964 Beetle purchased September 1968.
https://www.thesamba.com/vw/forum/viewtopic.php?p=9252810#9252810
1971 Sunroof Squareback with Fuel Injection
http://www.thesamba.com/vw/forum/viewtopic.php?t=219811&highlight=squareback+rejuvenation |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22413
Location: Kimball, Mi
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| Posted: Fri Feb 04, 2011 2:41 pm Post subject: |
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| Adriel Rowley wrote: |
| What matters is how well it flows, which I think it is better than we give it credit, but probably could be improved on. Though, for some reason, some air restriction moves the torque band down the R.P.M. range. |
I believe Ray, and possibly Jim have said that a foil ("V" shaped) on the front IAD plate could improve air flow inside the IAD. It would straighten the air some, and not have that flat plate daming up air into the airstream. The idea behind moving the torque lower, is to make it more usable. Most times, torque comes in right away, then as the rpms rise, torque falls off. About that same time, you're shifting into another gear. However, IF you changed the camshaft, you could also move the torque up higher into the rpm band. While good for top end running, it justs kills "off the line" response. This is why some cams work great for carbs, and not for FI.  It's also the reason cam selection is so important.
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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Bobnotch
Samba Member
Joined: July 06, 2003
Posts: 22413
Location: Kimball, Mi
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| Posted: Fri Feb 04, 2011 2:46 pm Post subject: |
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| Adriel Rowley wrote: |
Has anyone found the actual volume limit to the manifold? |
I think over on STF, Ray has a way of figuring out the size of the plenum, and it's runners. It'll probably be in the FI section, or possibly the type4um. I know there's a lot of techincal info on it there (STF).
_________________
Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
| Tram wrote: |
| "Friends are God's way of apologizing for relatives." |
| Tram wrote: |
| People keep confusing "restored" and "restroyed". |
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JSMskater
Samba Grease Gorilla
Joined: February 01, 2006
Posts: 5362
Location: Murrieta California
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| Posted: Fri Feb 04, 2011 4:40 pm Post subject: |
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| Bobnotch wrote: |
| Adriel Rowley wrote: |
Has anyone found the actual volume limit to the manifold? |
I think over on STF, Ray has a way of figuring out the size of the plenum, and it's runners. It'll probably be in the FI section, or possibly the type4um. I know there's a lot of techincal info on it there (STF). |
I'm taking a fluid dynamics class right now, so I wouldn't claim to know the particulars (this is largely a theoretical shot in the dark) but the way I would do it is to take a set of runners and IAD and then block off the bottoms, fill it with water, and then pour it into a graduated cylinder or two. Thats your static volume.
then, you would use a "steady state" type fluids eqn -- under the general assumption that at any given time the amount of air flowing through the intake cannot exceed the static volume. you would then use the pressure and density of air at standard atmosphere to find the mass flow through the intake.
I'm sure Ray will come in and make that more legitimate, but if I was trying to figure it out thats how I'd start.
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71 Squareback-FI -- 73 Bay (subaru powered)
TOOB Member #3
I make D-jet FI connectors |
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rosevillain
Samba Member
Joined: December 28, 2005
Posts: 1290
Location: roseville, ca
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| Posted: Fri Feb 04, 2011 5:11 pm Post subject: |
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| JSMskater wrote: |
| Bobnotch wrote: |
| Adriel Rowley wrote: |
Has anyone found the actual volume limit to the manifold? |
I think over on STF, Ray has a way of figuring out the size of the plenum, and it's runners. It'll probably be in the FI section, or possibly the type4um. I know there's a lot of techincal info on it there (STF). |
I'm taking a fluid dynamics class right now, so I wouldn't claim to know the particulars (this is largely a theoretical shot in the dark) but the way I would do it is to take a set of runners and IAD and then block off the bottoms, fill it with water, and then pour it into a graduated cylinder or two. Thats your static volume.
then, you would use a "steady state" type fluids eqn -- under the general assumption that at any given time the amount of air flowing through the intake cannot exceed the static volume. you would then use the pressure and density of air at standard atmosphere to find the mass flow through the intake.
I'm sure Ray will come in and make that more legitimate, but if I was trying to figure it out thats how I'd start. |
The crude way that I did it was to fill a runner with water, then I poured it into a bowl that had been tared on a scale. 280 grams. 1 gram = 1 cubic centimeter. The plenum was 580 grams. I did not use distilled water, and I had been drinking, so my numbers will not be exact, but I think close.
The calculators that I have found are mostly concerned with runner area, not volume. To some degree, small runner to engine displacement will provide higher intake velocities which equals more torque. At some point, that will limit RPM's. I think that the volume discussion is vacuum signature related.
In related news, barrels are at the machine shop with the case and heads, and cams are at the cam grinder. |
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Adriel Rowley
Samba Member
Joined: October 12, 2006
Posts: 4748
Location: Mesa, Arizona
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| Posted: Fri Feb 04, 2011 5:40 pm Post subject: |
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|
| Bobnotch wrote: |
| Adriel Rowley wrote: |
Has anyone found the actual volume limit to the manifold? |
I think over on STF, Ray has a way of figuring out the size of the plenum, and it's runners. It'll probably be in the FI section, or possibly the type4um. I know there's a lot of techincal info on it there (STF). |
I think this is what I was thinking of, if not, it still should be linked here:
http://www.thesamba.com/vw/forum/viewtopic.php?t=4...vol+volume
| JSMskater wrote: |
| Bobnotch wrote: |
| Adriel Rowley wrote: |
Has anyone found the actual volume limit to the manifold? |
I think over on STF, Ray has a way of figuring out the size of the plenum, and it's runners. It'll probably be in the FI section, or possibly the type4um. I know there's a lot of techincal info on it there (STF). |
I'm taking a fluid dynamics class right now, so I wouldn't claim to know the particulars (this is largely a theoretical shot in the dark) but the way I would do it is to take a set of runners and IAD and then block off the bottoms, fill it with water, and then pour it into a graduated cylinder or two. Thats your static volume.
then, you would use a "steady state" type fluids eqn -- under the general assumption that at any given time the amount of air flowing through the intake cannot exceed the static volume. you would then use the pressure and density of air at standard atmosphere to find the mass flow through the intake.
I'm sure Ray will come in and make that more legitimate, but if I was trying to figure it out thats how I'd start. |
That is how I would do it. And to dismay Jack, I would use duct tape.
| rosevillain wrote: |
| JSMskater wrote: |
| Bobnotch wrote: |
| Adriel Rowley wrote: |
Has anyone found the actual volume limit to the manifold? |
I think over on STF, Ray has a way of figuring out the size of the plenum, and it's runners. It'll probably be in the FI section, or possibly the type4um. I know there's a lot of techincal info on it there (STF). |
I'm taking a fluid dynamics class right now, so I wouldn't claim to know the particulars (this is largely a theoretical shot in the dark) but the way I would do it is to take a set of runners and IAD and then block off the bottoms, fill it with water, and then pour it into a graduated cylinder or two. Thats your static volume.
then, you would use a "steady state" type fluids eqn -- under the general assumption that at any given time the amount of air flowing through the intake cannot exceed the static volume. you would then use the pressure and density of air at standard atmosphere to find the mass flow through the intake.
I'm sure Ray will come in and make that more legitimate, but if I was trying to figure it out thats how I'd start. |
The crude way that I did it was to fill a runner with water, then I poured it into a bowl that had been tared on a scale. 280 grams. 1 gram = 1 cubic centimeter. The plenum was 580 grams. I did not use distilled water, and I had been drinking, so my numbers will not be exact, but I think close.
The calculators that I have found are mostly concerned with runner area, not volume. To some degree, small runner to engine displacement will provide higher intake velocities which equals more torque. At some point, that will limit RPM's. I think that the volume discussion is vacuum signature related.
In related news, barrels are at the machine shop with the case and heads, and cams are at the cam grinder. |
Well, there we have it: 250c.c. per each runner tube and 550c.c., for a total of 1550c.c.. This is interesting for the fact the engine is about 1584c.c..
I did some calculating of cylinder volume. 1600c.c engine is 396c.c., 74mm stroke 1699c.c. engine has a cylinder volume of 425c.c., 76mm stoke 1744c.c. engine has a cylinder volume of 436c.c., the famous 1776c.c. engine has a cylinder volume of 444c.c., and 78.4mm 1779c.c. engine has a cylinder volume of 450c.c.. The intake holds 800c.c of air per a cylinder. This might be the reason up to the 1776 works, as there is enough air to comfortably fill the cylinder and not create high intake air velocity.
The 1776c.c. increases the cylinder volume by 12 percent and 1779c.c. is a 14 percent increase, which to me just be right on the edge of being acceptable, but we probably not going to find out.
_________________
Please consider I am Autistic, so I process information differently and still working on social skills. Thanks.
Dad's 1964 Beetle purchased September 1968.
https://www.thesamba.com/vw/forum/viewtopic.php?p=9252810#9252810
1971 Sunroof Squareback with Fuel Injection
http://www.thesamba.com/vw/forum/viewtopic.php?t=219811&highlight=squareback+rejuvenation |
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