The Twin Screw Thread
12-16-2005, 09:41 AM
#212
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Bill,
>Do I need the DUAL 400 watt smoke machine
Only if you want to do 2 928s at once :-) That was just one I picked at random..
> or can I get by with the 450 watt El Cheapo version? It includes a wired remote.
That will work.
>Just how do you get the smoke into the intake with one of these things?
Most of them have flanges that you can attach hoses to, then attach the hose to your throttle body (make sure it is open) or other inlet to manifold, etc.
>Do I need the DUAL 400 watt smoke machine
Only if you want to do 2 928s at once :-) That was just one I picked at random..
> or can I get by with the 450 watt El Cheapo version? It includes a wired remote.
That will work.
>Just how do you get the smoke into the intake with one of these things?
Most of them have flanges that you can attach hoses to, then attach the hose to your throttle body (make sure it is open) or other inlet to manifold, etc.
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12-16-2005, 10:43 AM
#213
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Will this smoke generator only indicate relatively significant leaks in the intake manifold area, or does it create enough indicatior to demonstrate leaks in smaller and more remote components like vacuum pots or switches in things like the HVAC unit, vacuum accumulator, or cruise control unit?
12-16-2005, 10:51 AM
#214
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Daryl,
Thanks, it's working out pretty good!
I think you are wanting a SC'd motor to test and I don't have either one of my SC's on right now. I was considering installing one this week end but I am not going to be able to
.
Thanks, it's working out pretty good!
I think you are wanting a SC'd motor to test and I don't have either one of my SC's on right now. I was considering installing one this week end but I am not going to be able to
.
Originally Posted by Daryl
Jim,
Thank you for starting this thread!
I am down to figuring out this slightly rough idle Bill, Tony and I are experiencing. How is your car running? Could you do a simple check? Short out each cylinder one at a time and see what difference it makes to the idle of the engine. It’s really easy at the distributors. On my car when I short number 6 there is very little change to the idle speed. On Bills car there is no change when he shorts cylinder number 7.
On the air filter, don’t forget the horns bolt on under the filter. The picture is at a rough in state. I ended up positing the filter so the end of the filter rests on that tab you see sticking up just behind the filter. When I tightened every thing down it was very solid and secure in that position. I was able to remove a filler piece in the spoiler to allow more air in. I tried to show that in one of the pictures but the angle is very awkward.
Thank you for starting this thread!
I am down to figuring out this slightly rough idle Bill, Tony and I are experiencing. How is your car running? Could you do a simple check? Short out each cylinder one at a time and see what difference it makes to the idle of the engine. It’s really easy at the distributors. On my car when I short number 6 there is very little change to the idle speed. On Bills car there is no change when he shorts cylinder number 7.
On the air filter, don’t forget the horns bolt on under the filter. The picture is at a rough in state. I ended up positing the filter so the end of the filter rests on that tab you see sticking up just behind the filter. When I tightened every thing down it was very solid and secure in that position. I was able to remove a filler piece in the spoiler to allow more air in. I tried to show that in one of the pictures but the angle is very awkward.
12-16-2005, 10:54 AM
#215
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Hi Brian,
>Will this smoke generator only indicate relatively significant leaks in the intake manifold area, or >does it create enough indicatior to demonstrate leaks in smaller and more remote components like >vacuum pots or switches in things like the HVAC unit, vacuum accumulator, or cruise control unit?
If you use a small booster "duct fan" (or the "air out" of a shop vac) to build more pressure I have seen even small leaks around the throttle plate shaft seals.
There is an easier and quicker way to check for leaks. Cut a section out of a rubber inner tube with the valve in the middle and clamp it over your throttle body (again make sure Throttle is open), mass flow sensor, etc. and use an air chuck to pressure it up to about 5 psi. Then use a spray bottle with a mild soap solution to spray on the suspect areas, just like looking for a leak on a tire you will see bubbles where the leak is.
>Will this smoke generator only indicate relatively significant leaks in the intake manifold area, or >does it create enough indicatior to demonstrate leaks in smaller and more remote components like >vacuum pots or switches in things like the HVAC unit, vacuum accumulator, or cruise control unit?
If you use a small booster "duct fan" (or the "air out" of a shop vac) to build more pressure I have seen even small leaks around the throttle plate shaft seals.
There is an easier and quicker way to check for leaks. Cut a section out of a rubber inner tube with the valve in the middle and clamp it over your throttle body (again make sure Throttle is open), mass flow sensor, etc. and use an air chuck to pressure it up to about 5 psi. Then use a spray bottle with a mild soap solution to spray on the suspect areas, just like looking for a leak on a tire you will see bubbles where the leak is.
12-16-2005, 11:48 AM
#216
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Originally Posted by Bill Ball
Just how do you get the smoke into the intake with one of these things? Is that where the disco pants come in?
12-16-2005, 12:00 PM
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Originally Posted by DR
There is an easier and quicker way to check for leaks. Cut a section out of a rubber inner tube with the valve in the middle and clamp it over your throttle body (again make sure Throttle is open), mass flow sensor, etc. and use an air chuck to pressure it up to about 5 psi. Then use a spray bottle with a mild soap solution to spray on the suspect areas, just like looking for a leak on a tire you will see bubbles where the leak is.
my guess its the 45' mark where you set it to remove the belt. At this point are the valves shut or is Porsche just saying they wont make contact or cause damage when the belt is removed?
Am i missing somehting obvious or does that make sense?
12-16-2005, 12:02 PM
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Thanks for that Dave!!
That sounds somewhat safer than my original idea of hooking up a propane bottle to the induction system, for pressure, and then searching for leaks with a match!
That sounds somewhat safer than my original idea of hooking up a propane bottle to the induction system, for pressure, and then searching for leaks with a match!
Actually, if (like me) you've always wanted to share a good Cuban with your Porsche .... this may be the golden opportunity 
12-16-2005, 12:32 PM
#222
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Tony,
>Thats the route ive heard of to, but ive always wondered about the valves. During engine rotation is there actaully a time when ALL the intake valves are completley shut...
If you think about it , only 16 of the valves really need to be shut. For example if the intake valves are open on a cylinder and the exhausts are closed the air is still not gonna leak out quickly (unless you have severe ring blow-by)
I have never positioned the engine any specific way when testing this way. Maybe I have just been lucky the last hundred times I have done it over the last few months :-) I have also be able to get my completely assembled SC intakes including everything (TB, MAF, tubing, etc) but the filters to hold 20 inches of vacuum for 45 seconds or so.
If you have big enough leaks so that the intake system will not hold pressure, then attach a leak down tester to the inner tube valve and adjust the output to a constant 5psi, then use the spray trick. BUT if the leak is leaking that bad you WILL hear where it is coming from.
>Thats the route ive heard of to, but ive always wondered about the valves. During engine rotation is there actaully a time when ALL the intake valves are completley shut...
If you think about it , only 16 of the valves really need to be shut. For example if the intake valves are open on a cylinder and the exhausts are closed the air is still not gonna leak out quickly (unless you have severe ring blow-by)
I have never positioned the engine any specific way when testing this way. Maybe I have just been lucky the last hundred times I have done it over the last few months :-) I have also be able to get my completely assembled SC intakes including everything (TB, MAF, tubing, etc) but the filters to hold 20 inches of vacuum for 45 seconds or so.
If you have big enough leaks so that the intake system will not hold pressure, then attach a leak down tester to the inner tube valve and adjust the output to a constant 5psi, then use the spray trick. BUT if the leak is leaking that bad you WILL hear where it is coming from.
Last edited by DR; 12-16-2005 at 12:54 PM.
12-16-2005, 12:34 PM
#223
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Brian,
>That sounds somewhat safer than my original idea of hooking up a propane bottle to the induction system, for pressure, and then searching for leaks with a match!
PLEASE tell me you are kidding....BOOOOOMMMMM :-)
>That sounds somewhat safer than my original idea of hooking up a propane bottle to the induction system, for pressure, and then searching for leaks with a match!
PLEASE tell me you are kidding....BOOOOOMMMMM :-)
Last edited by DR; 12-16-2005 at 12:53 PM.
12-16-2005, 12:47 PM
#224
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Tony: I understand we have no valve overlap, so the manifold should be air tight. If the intake valve is open, the cylinder will fill, but that's all. No need to plug the exhaust, even if you could.
12-16-2005, 05:50 PM
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Hey What you guys smoken,
Got a few minutes to bug you guy’s.
Dave, thanks for the tip on how to apply continues air pressure. I was going crazy adding air then running around the engine listening. As well I was loosing a very little by the rings, I could hear the air through one of the vent hoses, and that added to the difficulty of holding pressure and knowing for sure I found everything. The engine had not been run for a few days. Probably a good idea to do this on a warm engine. I liked the smoke because I could just stand there and watch. I had a very small leak where the idle valve attaches, just needed to tighten the clamp. Missed that with the air pressure test. After using both methods I am certain I don’t have leaks.
Dave, are you aware of any one who has a TS car and has a slight idle roughness. My car as well as others have this problem. It’s minor and very easy to live with but I want to fix it if I can. I have some ideas as to why but I am not sure if this is a problem on all of the TS cars. If it is then we know for sure it’s inherent in all cars and when someone finds a fix we will all benefit.
What we are doing is shorting each spark plug one at a time and observing the change in idle. In my car there is very little change in number 6 and Bill has no change in number 7. We have done all of the obvious checks, compression, injectors, etc. Any thoughts you have on this? Any thoughts anyone have??
Got a few minutes to bug you guy’s.
Dave, thanks for the tip on how to apply continues air pressure. I was going crazy adding air then running around the engine listening. As well I was loosing a very little by the rings, I could hear the air through one of the vent hoses, and that added to the difficulty of holding pressure and knowing for sure I found everything. The engine had not been run for a few days. Probably a good idea to do this on a warm engine. I liked the smoke because I could just stand there and watch. I had a very small leak where the idle valve attaches, just needed to tighten the clamp. Missed that with the air pressure test. After using both methods I am certain I don’t have leaks.
Dave, are you aware of any one who has a TS car and has a slight idle roughness. My car as well as others have this problem. It’s minor and very easy to live with but I want to fix it if I can. I have some ideas as to why but I am not sure if this is a problem on all of the TS cars. If it is then we know for sure it’s inherent in all cars and when someone finds a fix we will all benefit.
What we are doing is shorting each spark plug one at a time and observing the change in idle. In my car there is very little change in number 6 and Bill has no change in number 7. We have done all of the obvious checks, compression, injectors, etc. Any thoughts you have on this? Any thoughts anyone have??