additional threaded hole? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

shelby987 · 11-15-2005, 09:57 AM

I was looking over the built 250 I bought the other day, and I noticed that there is an 'extra' tapped hole that my current 250 doesn't have.....on the back of the engine, right below the pushrod covers, there is one hole on my current 250, right below the last bolt that holds on this cover, on the new one, that same hole is there (believe its where the oil pressure sender threads into)....but there is a second, looks to be larger hole right between the second and third bolt that hold this cover one.....anyone know what its for? I will try to post pics when I get a chance.

sneakysnake · 11-15-2005, 11:08 AM

right here?

shelby987 · 11-15-2005, 12:10 PM

is that the pic you meant to post? The hole I am talking about would be just infront of the oil pressure sender at the far right of your pic.....your pic. doesn't show the location I am talking about.

phlegm · 11-15-2005, 12:45 PM

I have some on my 350 I think. My friend who rebuilds chevy engines in spare time said he usually bolts down the grounding straps there. currently my straps run from the firewall to my valve covers.

shifty · 11-15-2005, 12:53 PM

That pic above just shows the sending unit for oil and the connector is hanging (that's one of my pics from my 250's

)

Here are a couple of "better" pictures of that side of the engine on both of my 250's:

The hand points to the sending unit hole. Are you talking about the other hole near the dipstick?

http://satellitehead.com/images/68ch...swap%20019.jpg

Next, here's a link of the newer 250 I put in the truck. Some holes were different - like the water temp sensor, etc. Is the hole in this pic?

http://satellitehead.com/images/68ch...swap%20018.jpg

shelby987 · 11-15-2005, 01:35 PM

I tried to show the location of the hole in your pic, but your files are too large, and I can't compress them enough to post....but the hole is in the second ridge to the right, between the 2nd and 3rd bolts that hold on the pushrod covers

shifty · 11-15-2005, 06:00 PM

mark it in one of these two smaller pictures - they should end up being small enough to post! (right-click the photo and "save as")

shelby987 · 11-16-2005, 08:37 AM

Done....any ideas?

shifty · 11-16-2005, 12:18 PM

Not a clue. If they're threaded the same, My guess is simple: One would be used for a dummy gauge (which is shown being held in that picture) and the other for an real gauge w/needle (VDO?)

**tnblazerk5** · 11-16-2005, 12:44 PM

i got see if my 6 banger has it in a few mins

shelby987 · 11-16-2005, 12:48 PM

not sure if it matters, but the block was out of a nova from the information I have received.....not a truck.

**tnblazerk5** · 11-16-2005, 01:12 PM

mine dont have it but i got a 6banger out of a 70 nove at my buddys house i will get pics of it too
heres a pic of the one here in my jimmy

**CPNE** · 11-16-2005, 02:04 PM

Quote:

Originally Posted by shelby987

Done....any ideas?

To mount a starter support bracket to the block? That's my guess. I've see support brackets on later model V8's that support the front of the starter. You didn't say what year block you had.

shelby987 · 11-16-2005, 02:36 PM

The guy I bought it from took it out of a 77 nova......he said it was original to the car.

**CPNE** · 11-16-2005, 03:34 PM

Quote:

Originally Posted by shelby987

The guy I bought it from took it out of a 77 nova......he said it was original to the car.

That's makes my guess even more likely to be accurate

shelby987 · 11-16-2005, 03:51 PM

so basically thread a bolt in there to plug the hole (because it goes through the casting) and call it good?
Why would a bolt hole to secure a starter go through the casting?

sneakysnake · 11-16-2005, 04:29 PM

Are the threads pipe (NPT) or bolt (SAE)?
The sender should be 1/8th in. pipe thread.
A bolt will be 3/8th or 7/16ths.
How deep is the hole? is it tapped into the journal so oil will come out, or just bottom out?

11-15-2005, 09:57 AM	#1
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	additional threaded hole? I was looking over the built 250 I bought the other day, and I noticed that there is an 'extra' tapped hole that my current 250 doesn't have.....on the back of the engine, right below the pushrod covers, there is one hole on my current 250, right below the last bolt that holds on this cover, on the new one, that same hole is there (believe its where the oil pressure sender threads into)....but there is a second, looks to be larger hole right between the second and third bolt that hold this cover one.....anyone know what its for? I will try to post pics when I get a chance.

11-15-2005, 11:08 AM	#2
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	Re: additional threaded hole? right here? Attached Images

11-15-2005, 12:10 PM	#3
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: additional threaded hole? is that the pic you meant to post? The hole I am talking about would be just infront of the oil pressure sender at the far right of your pic.....your pic. doesn't show the location I am talking about.

11-15-2005, 12:45 PM	#4
phlegm Still Green but learning Join Date: Nov 2004 Location: Central NC Posts: 1,895	Re: additional threaded hole? I have some on my 350 I think. My friend who rebuilds chevy engines in spare time said he usually bolts down the grounding straps there. currently my straps run from the firewall to my valve covers. __________________ -- Cory 71 Cheyenne 10 - SWB, 350, "3 on the tree" AC cab 07 Suburban LTZ 4x4 2010 Acura TL 98 Mastercraft "FrankenStar" 225 27253 UPS/USPS IIOY....nope never was Last edited by phlegm; 11-15-2005 at 12:46 PM.

11-15-2005, 12:53 PM	#5
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: additional threaded hole? That pic above just shows the sending unit for oil and the connector is hanging (that's one of my pics from my 250's ) Here are a couple of "better" pictures of that side of the engine on both of my 250's: The hand points to the sending unit hole. Are you talking about the other hole near the dipstick? http://satellitehead.com/images/68ch...swap%20019.jpg Next, here's a link of the newer 250 I put in the truck. Some holes were different - like the water temp sensor, etc. Is the hole in this pic? http://satellitehead.com/images/68ch...swap%20018.jpg __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

11-15-2005, 01:35 PM	#6
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: additional threaded hole? I tried to show the location of the hole in your pic, but your files are too large, and I can't compress them enough to post....but the hole is in the second ridge to the right, between the 2nd and 3rd bolts that hold on the pushrod covers

11-15-2005, 06:00 PM	#7
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: additional threaded hole? mark it in one of these two smaller pictures - they should end up being small enough to post! (right-click the photo and "save as") __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM. Last edited by shifty; 11-15-2005 at 06:00 PM.

11-16-2005, 08:37 AM	#8
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: additional threaded hole? Done....any ideas? Attached Images

11-16-2005, 12:18 PM	#9
shifty Questionable Join Date: Mar 2005 Location: Atlanta Posts: 13,376	Re: additional threaded hole? Not a clue. If they're threaded the same, My guess is simple: One would be used for a dummy gauge (which is shown being held in that picture) and the other for an real gauge w/needle (VDO?) __________________ If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.

11-16-2005, 12:44 PM	#10
tnblazerk5 User #12137 Join Date: Apr 2004 Location: kingsport,upper east tenn Posts: 11,598	Re: additional threaded hole? i got see if my 6 banger has it in a few mins

11-16-2005, 12:48 PM	#11
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: additional threaded hole? not sure if it matters, but the block was out of a nova from the information I have received.....not a truck.

11-16-2005, 01:12 PM	#12
tnblazerk5 User #12137 Join Date: Apr 2004 Location: kingsport,upper east tenn Posts: 11,598	Re: additional threaded hole? mine dont have it but i got a 6banger out of a 70 nove at my buddys house i will get pics of it too heres a pic of the one here in my jimmy

11-16-2005, 02:36 PM	#14
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: additional threaded hole? The guy I bought it from took it out of a 77 nova......he said it was original to the car.

11-16-2005, 03:51 PM	#16
shelby987 Registered User Join Date: Mar 2005 Location: Just outside Durham, NC Posts: 894	Re: additional threaded hole? so basically thread a bolt in there to plug the hole (because it goes through the casting) and call it good? Why would a bolt hole to secure a starter go through the casting?

11-16-2005, 04:29 PM	#17
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	Re: additional threaded hole? Are the threads pipe (NPT) or bolt (SAE)? The sender should be 1/8th in. pipe thread. A bolt will be 3/8th or 7/16ths. How deep is the hole? is it tapped into the journal so oil will come out, or just bottom out?



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