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Posted by Wayne on April 26, 2008, 8:13 pm
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> Wayne wrote:
>> On Fri, 25 Apr 2008 18:57:13 -0500, David R Brooks
>>
>>> Wayne wrote:
>>>> Since I'm going to be tapping into a big buck part and don't
>>>> really have any experience tapping cast iron, I figure I'll
>>>> just ask a few stupid questions.
>>>> I'm tapping a 1/4 NPT hole into the exhaust section of a
>>>> turbocharger. An EGT sensor will be put in there. The part
>>>> is cast iron, about 1/4 thick. The directions are to remove
>>>> the turbocharger, drill a 7/16 hole, then tap. The part
>>>> that screws into the hole has a shoulder which is
>>>> supposed to rest against the turbocharger.
>>>> Alternately they say I can drill and tap the hole
>>>> with the engine running. Once the drill bit goes
>>>> goes through, the exhaust pressure is supposed to
>>>> push any particles out. When drilling cast iron
>>>> they say it is supposed to turn to dust. I'd
>>>> be drilling from the top down.
>>>> I have to get a tap since I don't have one that size.
>>>> I assume HSS will be ok?
>>>> It's supposed to be a pain to get the turbocharger out.
>>>> But if it was out, I could finish the hole with a
>>>> 7/16 HSS end mill. That I think, would give me a more
>>>> round hole than drilling by hand under the hood.
>>>> So I would think it would seal better that way.
>> I think I'd feel most comfortable with it removed. I'd just have to
>> work
>> up the patience (oxymoron) to do it.
>> Wayne D.
>>
>
> This is downstream from the turbine housing correct? If so just coat the
> bit with heavy grease to catch most of the chips. Then do the same with
> the tap. Step drill it so you get a nice hole. Any swarf you lose into
> the hole will just get blown downstream into the catalytic converter and
> not be a problem. This is a common thing to do when you add EGT sensors
> or do an EFI conversion and need to drill the manifold or the head pipe.
> I wold make VERY sure of the turbines position before you drill, some
> of them extend down a bit into the outer end of the scroll.
>
I don't actually have the directions yet, just the info the sales person
gave me. I'll get that in the middle of next week. So I don't know if it
goes in pre or post turbo. Just looking at it, it would appear to go right
on the turbo housing just where the it connects to the exhaust manifold.
I'd have to guess that the exhaust coming out of the main pushes down on
the blades, then turns and goes to the back of the truck. The scroll
is in front of that. How some of it works is starting to make sense.
Thanks, I'll have to check that I don't hit anything on the inside.
Wayne D.
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Posted by RAM³ on April 25, 2008, 8:52 pm
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> Since I'm going to be tapping into a big buck part and don't
> really have any experience tapping cast iron, I figure I'll
> just ask a few stupid questions.
>
> I'm tapping a 1/4 NPT hole into the exhaust section of a
> turbocharger. An EGT sensor will be put in there. The part
> is cast iron, about 1/4 thick. The directions are to remove
> the turbocharger, drill a 7/16 hole, then tap. The part
> that screws into the hole has a shoulder which is
> supposed to rest against the turbocharger.
>
> Alternately they say I can drill and tap the hole
> with the engine running. Once the drill bit goes
> goes through, the exhaust pressure is supposed to
> push any particles out. When drilling cast iron
> they say it is supposed to turn to dust. I'd
> be drilling from the top down.
>
> I have to get a tap since I don't have one that size.
> I assume HSS will be ok?
>
> It's supposed to be a pain to get the turbocharger out.
> But if it was out, I could finish the hole with a
> 7/16 HSS end mill. That I think, would give me a more
> round hole than drilling by hand under the hood.
> So I would think it would seal better that way.
>
> Any thoughts?
>
> Wayne D.
Since it's post-turbo, the only issue you'd have would be getting the swarf
caught in your engine's muffler or catalytic converter.
If you're trying to work on it when it's hot you'll have to consider the
change in hole/thread dimensions caused by thermal expansion.
If I were you, I'd take a good look at just how difficult it'd be to get the
turbo off and, as you stated, do the job with your mill.
Otherwise, I'd see if it'd be possible to pull the plumbing off the turbo's
exhaust and stuff a rag in the hole to catch the swarf.
If I were to be installing an EGT sensor on my Cummins I'd go pre-turbo and
go through the exhaust manifold so as to have a better idea of just _when_
the turbo was about to get fried. <grin>
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Posted by Wayne on April 26, 2008, 8:16 pm
Please log in for more thread options wrote:
>> Since I'm going to be tapping into a big buck part and don't
>> really have any experience tapping cast iron, I figure I'll
>> just ask a few stupid questions.
>>
>> I'm tapping a 1/4 NPT hole into the exhaust section of a
>> turbocharger. An EGT sensor will be put in there. The part
>> is cast iron, about 1/4 thick. The directions are to remove
>> the turbocharger, drill a 7/16 hole, then tap. The part
>> that screws into the hole has a shoulder which is
>> supposed to rest against the turbocharger.
>>
>> Alternately they say I can drill and tap the hole
>> with the engine running. Once the drill bit goes
>> goes through, the exhaust pressure is supposed to
>> push any particles out. When drilling cast iron
>> they say it is supposed to turn to dust. I'd
>> be drilling from the top down.
>>
>> I have to get a tap since I don't have one that size.
>> I assume HSS will be ok?
>>
>> It's supposed to be a pain to get the turbocharger out.
>> But if it was out, I could finish the hole with a
>> 7/16 HSS end mill. That I think, would give me a more
>> round hole than drilling by hand under the hood.
>> So I would think it would seal better that way.
>>
>> Any thoughts?
>>
>> Wayne D.
>
> Since it's post-turbo, the only issue you'd have would be getting the
> swarf
> caught in your engine's muffler or catalytic converter.
>
> If you're trying to work on it when it's hot you'll have to consider the
> change in hole/thread dimensions caused by thermal expansion.
>
> If I were you, I'd take a good look at just how difficult it'd be to get
> the
> turbo off and, as you stated, do the job with your mill.
>
> Otherwise, I'd see if it'd be possible to pull the plumbing off the
> turbo's
> exhaust and stuff a rag in the hole to catch the swarf.
>
> If I were to be installing an EGT sensor on my Cummins I'd go pre-turbo
> and
> go through the exhaust manifold so as to have a better idea of just
> _when_
> the turbo was about to get fried. <grin>
How'd you know this was a Cummins? Looks like 4 bolts off of the exhaust
manifold, a clamp in front and back. 2 of the bolts are in the back and
have to be gotten from underneath. They said removing is difficult only
because of accessability. They probabaly mounted the turbo prior to
putting the exhaust manifold.
Wayne D.
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Posted by William Noble on April 26, 2008, 9:58 pm
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>
> How'd you know this was a Cummins? Looks like 4 bolts off of the exhaust
> manifold, a clamp in front and back. 2 of the bolts are in the back and
> have to be gotten from underneath. They said removing is difficult only
> because of accessability. They probabaly mounted the turbo prior to
> putting the exhaust manifold.
>
>
> Wayne D.
however hard it is, it can't be harder than removing the turbo from an Audi
TT - that was a real total absolue (place curse word here) nightmare -
daughter broke a timing belt - well OK, we can fix that - just pull the
head - but to get the head off you gotta remove manifold to turbo bolts and
one stripped (don't ask, removing the head is non-trivial - a motor mount
goes through the middle of the timing belt, for example) - anyway, I cut the
bolt with a air driven cutoff and got the head off, and then was so tired
that when I went to unscrew the bolt it unscrewed easily and then I dropped
it right into the turbo where no amount of fishing with a magnet would get
it out (turns out it isn't magnetic, but I didn't realize that at the
time) - taking the turbo out (with the head off) took about 2 1/2 hours -
with the head in place I just can't imagine how long and how difficult it
would be - and putting it back was worse - there is no room, the
transmisison for all wheel drive is underneath it, and there are oil AND
water lines (2 of each) going into it, plus a mounting bracket that you
can't see and have to unscrew by feel, plus ....
so, trust me - don't do what I did..... and be glad you have more
accessability than on the TT.
** Posted from http://www.teranews.com **
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Posted by RAM³ on April 27, 2008, 3:45 pm
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> How'd you know this was a Cummins? Looks like 4 bolts off of the exhaust
> manifold, a clamp in front and back. 2 of the bolts are in the back and
> have to be gotten from underneath. They said removing is difficult only
> because of accessability. They probabaly mounted the turbo prior to
> putting the exhaust manifold.
I drive an '03.5 RAM 3500 with the 305/555 HO CTD. <Grin>
If you're *not* a member of the TDR site/fora then I'd strongly suggest
that you visit their site: <http://www.turbodieselregister.com> and browse
through the fora that apply to your model.
Their quarterly magazine is full of good technical advice on all aspects of
the care and BOMBing of the Cummins ISB engines.
For the benefit of those unaware of the term, BOMB is an acronym for
"Better Off Modified, Baby!".
When a Cummins is BOMBed, especially for towing, an Exhaust Gas Temperature
gauge is extremely highly recommended lest you fry the turbocharger.
See? It's an elementary exercise in Logic. <grin>
While my preference is for a pre-turbo installation, a post-turbo
installation offers the advantage that any dust/swarf would simply be blown
out the exhaust pipe since it would not pass through the turbocharger.
Those with catalytic converters and/or particulate filters might have an
issue with "stuff" collecting there so, if yours has either or both,
disconnecting the exhaust pipe at the turbocharger before starting the
engine and letting it run for a couple of minutes will be a simple step to
clear the deritus. The pipe can, then, be re-attached as soon as it's cool
enough to handle.
BTW, while you're installing the EGT sensor and gauge, why not also install
a Boost sensor and gauge as well? <GRIN>
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