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Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277860] Fri, 15 May 2015 09:22 Go to next message
BobDunahugh is currently offline  BobDunahugh   United States
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Getting oil to drain back to the pan has nothing to do with the oil pump delivery system. Yes, getting that oil back to the pan is important. But for our application in a motor home engine that's running at under 3200 RPM. That isn't an issue. Running in the 6 to 7000 RPM range. That another story. As to the .055 hole in the galley. That's too big. .008, to .011 is the general size in some applications. That is done. And I've done it in track cars that run at high RPM's with vary radical cam profiles. That's a high load application.. Guy's that have heard of the galley hole idea. So then do it. Just get the smallest drill they have. Most don't have the proper size drill bit. When I checked my bearing clearance in my 403 with about 125,000 miles on it. My timing chain was in great shape. And that was without any hole in the galley plug. Our engine's really run under close to ideal condition's for a long, and healthy life. They don't get subjected to vary much cold run ti
mes. We get in them, and drive for long distances at normal operating temps. My 403 is at 153,000. In this application. I see no reason to add a hole in the galley plug. As to what harm it does. That's really the wrong term to use. I'll explain that tonight. Bob Dunahugh









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Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277868 is a reply to message #277860] Fri, 15 May 2015 12:02 Go to previous messageGo to next message
Harry is currently offline  Harry   Canada
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On the old flathead Fords, we would paint the inside of the block with Glyptal to get the oil moving back down.
Those old castings were rough.
Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277895 is a reply to message #277860] Fri, 15 May 2015 21:39 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
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As to what harm a HV pump does. That's really the wrong term to use. A better question is. Of what benefit is a high volume to my mostly stock 403, or 455 Olds engine. Guy's on this site talk about the use of syntactic lubes to make components run cooler, and with less friction. Friction / heat can be measured in the amount of HP that is required to do a measured amount of work. And in reality. Any amount of extra work that is done to move our GMC down the road. Affects MPG's. So we spend the extra money on syntactic lube's in our GMC's to reduce friction, and heat. The stock pump delivers 3.9 GPM at 38 PSI with an engine speed of 800 RPM's. That means the pump is at 400 RPM's. Most V8's of our type need around 1.3 GPM to be properly lubed. That means that you already have 1.6 GPM's going back to the oil pan by way of the relief valve. Remember. This is in a good condition engine. Main, and rod bearing clearance in a 455 are, rods, .0004 to .0033. mains are .0005
to .0021. That's a wide range for both. GM designed the oil pump to work well within this clearance range.HV pumps range in size from 23% to 50 % larger then stock. That extra oil that your pumping directly back to the oil pan. And you get absolutely no lubrication benefit from that oil. The loss of having a pump that's too large is that it puts extra load on the pump drive. Create more engine heat, and load on the engine. The stock pump uses about 3.5 HP to run. The HV pump can take 5 HP. That takes fuel. There'shere's no one way to improve mileage. Just alot of little way's to get the job done.Oil pressure numbers are like your own blood pressure readings. Those numbers indicate how you, or your engine are doing. I've heard of guy's saying that their rebuilt engine uses more oil, and has lower oil pressure then they expected. If an engine builder checks the bearing clearances. And finds them right at the factory limits. As listed above. Most will not turn the cran
kshaft. The end result well be an engine that will burn oil. And have premature oil pressure decline. My 403 with 153,000 mile. The rod bearings were at .0008 clearance. The mains were at .0009. That is on the absolute limit for me in a street engine. For track use. NO WAY. ( Or in my GMC. ) And that has been with standard 10/30 oil. The factory limits of .002 to .003 are not in my book. I AM NOT saying that any of the GMC engine builds do this. But many engine builds put HV pumps in all engines to cover up that the bearing clearance are already at the factory limits.I DO NOT care if you want to use HV pumps. They can cover up a multitude of sins, or errors. And they can help get some more miles out of a power plant that could use a rebuild. And I'm not interested in getting anyone to use standard oils. I just hope I shed some light on the topic of HV oil pumps. And not have them use them for the wrong reason of it's got to be better then stock.


Bob Dunahugh










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Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277945 is a reply to message #277860] Sat, 16 May 2015 23:11 Go to previous messageGo to next message
Bob de Kruyff   United States
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Registered: January 2004
Location: Chandler, AZ
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BobDunahugh wrote on Fri, 15 May 2015 08:22
Getting oil to drain back to the pan has nothing to do with the oil pump delivery system. Yes, getting that oil back to the pan is important. But for our application in a motor home engine that's running at under 3200 RPM. That isn't an issue. Running in the 6 to 7000 RPM range. That another story. As to the .055 hole in the galley. That's too big. .008, to .011 is the general size in some applications. That is done. And I've done it in track cars that run at high RPM's with vary radical cam profiles. That's a high load application.. Guy's that have heard of the galley hole idea. So then do it. Just get the smallest drill they have. Most don't have the proper size drill bit. When I checked my bearing clearance in my 403 with about 125,000 miles on it. My timing chain was in great shape. And that was without any hole in the galley plug. Our engine's really run under close to ideal condition's for a long, and healthy life. They don't get subjected to vary much cold run ti
mes. We get in them, and drive for long distances at normal operating temps. My 403 is at 153,000. In this application. I see no reason to add a hole in the galley plug. As to what harm it does. That's really the wrong term to use. I'll explain that tonight. Bob Dunahugh









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OK--got the opinion part but where are the facts?


Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277953 is a reply to message #277945] Sun, 17 May 2015 02:04 Go to previous messageGo to next message
appie is currently offline  appie   United States
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Fact: My paterson engine, now 5000 ml. With high volume pump does not loose any oil

Appie eleganza 76 "Olga" now sadly sold 6 wheel discbrake Quadrabags Springfield stage 2 462 olds Manny tranny ( pictures at http://www.gmcmhphotos.com/photos/g6489-olga.html Fulltiming in Europe july 2014 til july 2016 Denmark
Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277963 is a reply to message #277860] Sun, 17 May 2015 10:01 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
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I'm not saying that a HV pump by it's self will cause any engine to burn more oil. But a HV pump along with crankshaft clearances that approach .0033, and be on. That's when the piston's oil ring will get over loaded. And can't do the job they are designed to do. If the crankshaft clearance's are kept under .0009. That will keep the oil that's in suspension to a controllable level. There isn't a major OEM engine manufacture that make a HV pump to be used for their stock production engines. That are used as they were designed to be used for. So why don't engine manufactures list HV pumps as an option? Isn't that saying something? HV pumps are for situations that you've added items that require additional oil that the OEM engine wasn't designed for. Or you have an engine has clearances be on stock. We do thing to get these GMC's to get better MPG's by reducing friction/heat. Synthetic lubes come to mind. Then put in a HV pump that can take 50% more HP/heat then a stock
pump. It all comes down to the crankshaft clearance. I have no idea why HV pumps are put in stock rebuilt engines. Other then remove any chance of some one saying that their oil pressure is't high enough in their opinion.
Bob Dunahugh









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Re: [GMCnet] Engine oil control. There's alot more then justopinions [message #277967 is a reply to message #277963] Sun, 17 May 2015 16:18 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
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Bob,

I would suggest at the next GMCMI Convention you get together with Dick Paterson and have a chat. He uses Melling high flow pumps on
the Olds engines he builds.

Regards,
Rob M.


-----Original Message-----
From: Bob Dunahugh

I'm not saying that a HV pump by it's self will cause any engine to burn more oil. But a HV pump along with crankshaft clearances
that approach .0033, and be on. That's when the piston's oil ring will get over loaded. And can't do the job they are designed to
do. If the crankshaft clearance's are kept under .0009. That will keep the oil that's in suspension to a controllable level.
There isn't a major OEM engine manufacture that make a HV pump to be used for their stock production engines. That are used as
they were designed to be used for. So why don't engine manufactures list HV pumps as an option? Isn't that saying something? HV
pumps are for situations that you've added items that require additional oil that the OEM engine wasn't designed for. Or you have
an engine has clearances be on stock. We do thing to get these GMC's to get better MPG's by reducing friction/heat. Synthetic lubes
come to mind. Then put in a HV pump that can take 50% more HP/heat then a stock pump. It all comes down to the crankshaft clearance.
I have no idea why HV pumps are put in stock rebuilt engines. Other then remove any chance of some one saying that their oil
pressure is't high enough in their opinion.
Bob Dunahugh









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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277972 is a reply to message #277963] Sun, 17 May 2015 23:51 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
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Dave. The oil pump in our GMC is a gear type hydraulic pump that is capable of producing high pressure that is determined by the restriction of the demand, and the relief valve. The relief valve keeps the oil pump out put pressure that's delivered to the engine in the 30 to 45 PSI. If your bearings are in good condition. You can increase your pump presure by lengthening the relief valve spring. I have seen higher pressure relief valve springs on the market. Increasing your pressure would put more oil past your bearings. A higher volume pump can not do that. That higher pressure will put more oil in suspension. And for that reason. I would not go higher then 37 PSI.It was brought up today about were's my data on oil pumps with respect to stock verses HV pumps. My information has come from reading SAE papers, and my work with engines that are being operated on dino's. It's a fair question. So were's the data that says HV pumps should be installed in engine's that wer
e just properly rebuilt? Again. I'm not going to say that HV pumps are bad, or wrong. They have their place. And I'm NOT on anyone's case. We have a good discussion going on. And isn't that's what this site is all about. Anyway. I just haven't seen anything in the way of prof, or data with respect to HV pumps. GM, Ford, and Chrysler have been in the business of building great engines for a vary long time. And with their past performance in the way of having their engines last a vary long time. I find it hard to believe that they've been installing too small of an oil pump all these years. As to the question relating to valve trains. I'd go with what the manufacture of that product suggest.
Thanks for the dialog. Bob Dunahugh












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Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #277987 is a reply to message #277972] Mon, 18 May 2015 12:34 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
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Robert. I was thinking the samething yesterday about a talk at the GMCMI Ralley this fall. Dick and I have had talks about HV pumps. I believe his thought was that as engines get tired. In this way the pump is already installed. He has a point. But to me. Will I be alive at that point. GRIN. As my original 403., and the loads I pull. That engine still maintains it's original min bearing clearance after 153,000 miles. And 37 years later. Another topic could be on high out put coils. In my race engines that run from 6 to 8,000 RPM's. With 13.5 to 1 compression. Require 110 octane leaded fuel. I still use a stock GM ignition coil with no problems. Bob Dunahugh












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Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #278000 is a reply to message #277987] Mon, 18 May 2015 17:02 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
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BobDunahugh wrote on Mon, 18 May 2015 12:34

Robert. I was thinking the samething yesterday about a talk at the GMCMI Ralley this fall. Dick and I have had talks about HV pumps. I believe his thought was that as engines get tired. In this way the pump is already installed. He has a point. But to me. Will I be alive at that point. GRIN. As my original 403., and the loads I pull. That engine still maintains it's original min bearing clearance after 153,000 miles. And 37 years later. Another topic could be on high out put coils. In my race engines that run from 6 to 8,000 RPM's. With 13.5 to 1 compression. Require 110 octane leaded fuel. I still use a stock GM ignition coil with no problems. Bob Dunahugh


As for high output coils....please start another thread with it's own title. JWID










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Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: [GMCnet] Engine oil control. There's alot more then just opinions [message #278018 is a reply to message #277860] Mon, 18 May 2015 21:48 Go to previous message
BobDunahugh is currently offline  BobDunahugh   United States
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Here's some data. And somethings to think about if your taking your engine for a rebuild. The stock pump delivers 3.9 GPM at 38 PSI with an engine speed of 800 RPM's. That means the pump is at 400 RPM's. Most V8's of our type need around 1.3 GPM to be properly lubed. That means that you already have 1.6 GPM's going back to the oil pan by way of the relief valve. Remember. This is in a good condition engine. Main, and rod bearing clearance in a 403,and 455 are, rods, .0004 to .0033. mains are .0005 to .0021. That's a wide range for both. GM designed the oil pump to work well within this clearance range. HV pumps range in size from 23% to 50 % larger then stock. That extra oil that your pumping directly back to the oil pan. And you get absolutely no lubrication benefit from the oil that's going in at the bottom of the oil pan. The loss of having a pump that's too large is that it puts extra load on the pump drive. Create more engine heat, and load on the
engine. The stock pump uses about 3.5 HP to run. The HV pump can take 5 HP. And that takes fuel. Oil pressure numbers are like your own blood pressure readings. Those numbers indicate how you, or your engine are doing. I've heard of guy's saying that their rebuilt engine uses more oil, and has lower oil pressure then they expected. If an engine builder checks the bearing clearances. And finds them right at the factory high limits. As listed above. Most will not turn the crankshaft. The end result well be an engine that will burn oil. And have premature oil pressure decline. My 403 with 153,000 mile. The rod bearings were at .0008 clearance. The mains were at .0009. That is on the absolute limit for me in a street engine. For track use. NO WAY. ( Or in my GMC. ) And that has been with standard 10/30 oil. The factory limits of .002 to .003 are too large to use in any rebuild in my opinion. I AM NOT saying that any of the GMC engine builders do this. But many
engine builds put HV pumps in all engines to cover up that the bearing clearance are already at the factory limits. Bob Dunahugh I DO NOT care if you want to use HV pumps. They can cover up a multitude of sins, or errors. And they can help get some more miles out of a power plant that could use a rebuild. And I'm not interested in getting anyone to use standard oils. I just hope I shed some light on the topic of HV oil pumps. I just don't like to see guy's install a HV pump because it sounds like a nice idea only. Bob Dunahugh

Bob Dunahugh















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