Author Topic: temp fix for pinhole in injector line.  (Read 10773 times)

Reply #15August 08, 2013, 08:51:02 pm

libbydiesel

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Re: temp fix for pinhole in injector line.
« Reply #15 on: August 08, 2013, 08:51:02 pm »
Consider 2000psi... how many pinholes in a sq-in...?  100x100?  maybe more.... say it's 2000.
That's 1lb of pressure, if you are sealing the area of just the pinhole.

Yes, it's only 1lb of pressure, but it's only acting on a pin sized area.  To make a very apt analogy, just imagine setting a 1lb weight on top of a pin poking into a rubber hose and then removing it and then setting it back on the pin 1,500 times per minute.  How long before that pin pokes through the piece of rubber?
« Last Edit: August 08, 2013, 08:53:12 pm by libbydiesel »

Reply #16August 09, 2013, 06:26:30 am

TylerDurden

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Re: temp fix for pinhole in injector line.
« Reply #16 on: August 09, 2013, 06:26:30 am »
Yes, it's only 1lb of pressure, but it's only acting on a pin sized area.  To make a very apt analogy, just imagine setting a 1lb weight on top of a pin poking into a rubber hose and then removing it and then setting it back on the pin 1,500 times per minute.  
I'm not convinced that's a very apt analogy...

Line pressure does not return to zero due to the delivery valves, and as the rubber deflects from fluid pressure rise, the fluid surface area spreads (as opposed to a metal pin).


 Rubber fuel injection hose is rated @ 100 psi or so.  That means that a pinhole location that is 1/2000th of a sq-in may only be producing 1psi, but the rubber fuel injection hose is only rated to withstand 0.05psi / 1/2000th of an in^2...  It just as under-rated as if you tried to run rubber fuel injection hose the whole way.
With a band clamp around the hose at the point of the pinhole, I'd wager the hose's burst rating does not directly apply.

Reply #17August 09, 2013, 07:05:10 am

theman53

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Re: temp fix for pinhole in injector line.
« Reply #17 on: August 09, 2013, 07:05:10 am »
I think it won't hold well. I think the best bet is to try it and see. Better than nothing for at least a few miles. Since it is junk anyhow unless you are welding it I would JB weld over it and that will probably work better.

Reply #18August 09, 2013, 08:32:32 am

homerj1

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Re: temp fix for pinhole in injector line.
« Reply #18 on: August 09, 2013, 08:32:32 am »
Thanks for all the advice.

I actually hooked up with Caveman, and he fixed me up.  :)

Aivars

Reply #19August 09, 2013, 09:18:52 am

libbydiesel

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Re: temp fix for pinhole in injector line.
« Reply #19 on: August 09, 2013, 09:18:52 am »
Yes, it's only 1lb of pressure, but it's only acting on a pin sized area.  To make a very apt analogy, just imagine setting a 1lb weight on top of a pin poking into a rubber hose and then removing it and then setting it back on the pin 1,500 times per minute.  
I'm not convinced that's a very apt analogy...

Line pressure does not return to zero due to the delivery valves, and as the rubber deflects from fluid pressure rise, the fluid surface area spreads (as opposed to a metal pin).


Rubber fuel injection hose is rated @ 100 psi or so.  That means that a pinhole location that is 1/2000th of a sq-in may only be producing 1psi, but the rubber fuel injection hose is only rated to withstand 0.05psi / 1/2000th of an in^2...  It just as under-rated as if you tried to run rubber fuel injection hose the whole way.
With a band clamp around the hose at the point of the pinhole, I'd wager the hose's burst rating does not directly apply.

Now I want someone to try...  An apt analogy is always going to be somewhat different from the actual situation...  You are correct, line pressure does not return to zero.  Yes rubber will deform and as you say, the surface area will spread but that won't reduce the force, it will multiply the pounds of force applied by the added area.  It would reduce the misting in the engine compartment but I'm convinced it wouldn't hold back the leak.  

Reply #20September 23, 2013, 10:00:46 am

Toby

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Re: temp fix for pinhole in injector line.
« Reply #20 on: September 23, 2013, 10:00:46 am »
Rubber fuel injection hose is rated @ 100 psi or so.  That means that a pinhole location that is 1/2000th of a sq-in may only be producing 1psi, but the rubber fuel injection hose is only rated to withstand 0.05psi / 1/2000th of an in^2...  It just as under-rated as if you tried to run rubber fuel injection hose the whole way.

You guts need to brush up on your physics. 2000 psi is 2000 psi no matter how large an area it is acting upon. The pressure does not go down when you are applying it to a small area. Its still 2000 psi.