EGT/Pyrometer Probe ? doesn't it restrict air flow?
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Tuned
Joined: Aug 2005
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From: Brew City, USA New Berlin
EGT/Pyrometer Probe ? doesn't it restrict air flow?
I drilled and tapped and installed the probe for the Pyrometer last night.
My first thought was that the exhaust manifold seems small for such a big engine?
And putting the probe at end of the manifold as indicated by all the instructions... Seems like that is the 'tightest' spot to put it. I couldn't help but think that even that small probe must block about 10% of the exit hold from the manifold to the up-tube to the turbo.
Just got me wondering... What good does a 4" exhaust do when the opening coming out of the exhaust manfold seems to me to be the tightest bottleneck on the whole exhaust system? If people wanted less back-pressure seems like a bigger exhaust manifold would be the target of opportunity?
My first thought was that the exhaust manifold seems small for such a big engine?
And putting the probe at end of the manifold as indicated by all the instructions... Seems like that is the 'tightest' spot to put it. I couldn't help but think that even that small probe must block about 10% of the exit hold from the manifold to the up-tube to the turbo.
Just got me wondering... What good does a 4" exhaust do when the opening coming out of the exhaust manfold seems to me to be the tightest bottleneck on the whole exhaust system? If people wanted less back-pressure seems like a bigger exhaust manifold would be the target of opportunity?
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From: Lake Mary, FL
Originally Posted by Milwaukee,WI
I drilled and tapped and installed the probe for the Pyrometer last night.
My first thought was that the exhaust manifold seems small for such a big engine?
And putting the probe at end of the manifold as indicated by all the instructions... Seems like that is the 'tightest' spot to put it. I couldn't help but think that even that small probe must block about 10% of the exit hold from the manifold to the up-tube to the turbo.
Just got me wondering... What good does a 4" exhaust do when the opening coming out of the exhaust manfold seems to me to be the tightest bottleneck on the whole exhaust system? If people wanted less back-pressure seems like a bigger exhaust manifold would be the target of opportunity?
My first thought was that the exhaust manifold seems small for such a big engine?
And putting the probe at end of the manifold as indicated by all the instructions... Seems like that is the 'tightest' spot to put it. I couldn't help but think that even that small probe must block about 10% of the exit hold from the manifold to the up-tube to the turbo.
Just got me wondering... What good does a 4" exhaust do when the opening coming out of the exhaust manfold seems to me to be the tightest bottleneck on the whole exhaust system? If people wanted less back-pressure seems like a bigger exhaust manifold would be the target of opportunity?
I never saw any measurable power drops on the dyno...
At this point it's like splitting hairs, and there's no need to worry.
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Tuned
Joined: Aug 2005
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From: Brew City, USA New Berlin
Cool. If it comes from Vic I can believe it! lol
One other question. Has anyone had a probe come loose? Not break off or anything, but come loose from the fitting.
I didn't want to over-tighten the fitting in the manifold, or the probe in the fitting as they warn repeatedly against it (overtightening) in the instructions.
I was tempted to want to put loc-tite on it etc. but didn't
One other question. Has anyone had a probe come loose? Not break off or anything, but come loose from the fitting.
I didn't want to over-tighten the fitting in the manifold, or the probe in the fitting as they warn repeatedly against it (overtightening) in the instructions.
I was tempted to want to put loc-tite on it etc. but didn't
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From: Lake Mary, FL
Originally Posted by Milwaukee,WI
Cool. If it comes from Vic I can believe it! lol
One other question. Has anyone had a probe come loose? Not break off or anything, but come loose from the fitting.
I didn't want to over-tighten the fitting in the manifold, or the probe in the fitting as they warn repeatedly against it (overtightening) in the instructions.
I was tempted to want to put loc-tite on it etc. but didn't
One other question. Has anyone had a probe come loose? Not break off or anything, but come loose from the fitting.
I didn't want to over-tighten the fitting in the manifold, or the probe in the fitting as they warn repeatedly against it (overtightening) in the instructions.
I was tempted to want to put loc-tite on it etc. but didn't
This works sort of like a tack weld....it holds but you can get it off if need be.
Don't get any goo on the probe!
Last edited by Vic_Ferrari; Jan 11, 2006 at 12:09 PM.
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From: Ormond Beach
Originally Posted by Milwaukee,WI
Cool. If it comes from Vic I can believe it! lol
One other question. Has anyone had a probe come loose? Not break off or anything, but come loose from the fitting.
I didn't want to over-tighten the fitting in the manifold, or the probe in the fitting as they warn repeatedly against it (overtightening) in the instructions.
I was tempted to want to put loc-tite on it etc. but didn't
One other question. Has anyone had a probe come loose? Not break off or anything, but come loose from the fitting.
I didn't want to over-tighten the fitting in the manifold, or the probe in the fitting as they warn repeatedly against it (overtightening) in the instructions.
I was tempted to want to put loc-tite on it etc. but didn't
BTW - you do not want to bottom out the housing or probe. The tip of the probe needs to be in the center of the exhause gas path. Take your probe and look how far it extends beyond the threaded housing. Then you can judge how far you want to thread the housing. You do NOT what the housing to bottom out on the manifold. In fact most will look like the nut portion of the housing is sticking up about 1/4 of an inch. This will allow for the proper depth of the probe and allow the housing to properly seal.
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Tuned
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From: Brew City, USA New Berlin
Originally Posted by DougD
BTW - you do not want to bottom out the housing or probe. The tip of the probe needs to be in the center of the exhause gas path. Take your probe and look how far it extends beyond the threaded housing. Then you can judge how far you want to thread the housing. You do NOT what the housing to bottom out on the manifold. In fact most will look like the nut portion of the housing is sticking up about 1/4 of an inch. This will allow for the proper depth of the probe and allow the housing to properly seal.
And my housing is sticking up out from the surface of the manifold approx. 1/8" to 1/4"
So I'll assume that its where it should be.
I was a little unsure of if it was in the center of the exhaust flow or not... But
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From: Lake Mary, FL
Originally Posted by Milwaukee,WI
I drilled and tapped a hole exactly where the pictures on the various sites showed (diesel manor) etc.
And my housing is sticking up out from the surface of the manifold approx. 1/8" to 1/4"
So I'll assume that its where it should be.
I was a little unsure of if it was in the center of the exhaust flow or not... But
And my housing is sticking up out from the surface of the manifold approx. 1/8" to 1/4"
So I'll assume that its where it should be.
I was a little unsure of if it was in the center of the exhaust flow or not... But
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My dad's boat wasn't reding correctly on one of the engines and found out the probe had broken off pre turbo. It had to hit the turbo fan blades many times before blowing out but didn't really do any damage to the blades.
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From: Lake Mary, FL
Originally Posted by Banshee Ben
My dad's boat wasn't reding correctly on one of the engines and found out the probe had broken off pre turbo. It had to hit the turbo fan blades many times before blowing out but didn't really do any damage to the blades.
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He was lucky, it is a huge turbo but still, there are 100k rpms going on. A more impressive one was at a drag race event a crew took the air cleaner off and was reving it when wing nut that had been screwed on temporarily vibrated quickly off and was sucked into the reving race engine, the crew was pissed, one of the spectators behind the car felt something hit his leg and it was the wing nut. lol lucky sobs
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Tuned
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From: Brew City, USA New Berlin
Ok, need advice...
I went and did some measurements. I removed the probe, and stuck a plastic straw in the hole till it bottomed out on the far side of the manifold. Made a mark at the end of the housing on the straw. Pulled it out and placed it next to the Probe. I am DEFINITELY not bottomed out with the probe, but The probe is just over 1/4" away from the far side of the manifold. (Looking back, I should have taken a little different angle when I drilled into the manifold.)
Oh well.
Anyway.. To make a long story short. I know ideal is to have the tip of the probe centered in the manifold.
But its not. Should I:
Weld the hole shut and re-drill and re-tap?
Or
Leave it as it is... yeah, its not perfect, but not a big enough of a deal to re-drill and re-tap for???
or any other suggestions?
Thanks
I went and did some measurements. I removed the probe, and stuck a plastic straw in the hole till it bottomed out on the far side of the manifold. Made a mark at the end of the housing on the straw. Pulled it out and placed it next to the Probe. I am DEFINITELY not bottomed out with the probe, but The probe is just over 1/4" away from the far side of the manifold. (Looking back, I should have taken a little different angle when I drilled into the manifold.)
Oh well.
Anyway.. To make a long story short. I know ideal is to have the tip of the probe centered in the manifold.
But its not. Should I:
Weld the hole shut and re-drill and re-tap?
Or
Leave it as it is... yeah, its not perfect, but not a big enough of a deal to re-drill and re-tap for???
or any other suggestions?
Thanks
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i am putting on my egt gauge this weekend and i will use my shops bore scope to center the tip in manifold i am removing my manifold so i will be able to use the scope
to get an exact fit we use are scope to inspect cylinder walls for scoring
to get an exact fit we use are scope to inspect cylinder walls for scoring
