well, i found out why oil pressure was low..... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**'70_402** · 03-21-2008, 07:20 AM

it was my main bearings... i guess they were mis-marked/packaged... they were standard bearings instead of 10-10's our fault for not checking.... but easy fix... don't even have to pull the motor.... sucks.. but better than a tear down..... i am just so releived to find the issue...

slammed1 · 03-21-2008, 07:21 AM

Glad you caught that..........and that mistake wont haunt you ever again........or it well shouldnt!!

**El Jay** · 03-21-2008, 07:46 AM

I'm guessing you learned about "plastigage", regardless of what the supplier said.

Not a "put down", to be sure. I just have a basic distrust in parts suppliers.

So I just "check, check, check!"

lyrikz · 03-21-2008, 08:07 AM

Quote:

Originally Posted by slammed1

Glad you caught that..........and that mistake wont haunt you ever again........or it well shouldnt!!

Ya, that wont haunt you, but if you didnt even plastiguage the motor, what other things did you skip??

**special-K** · 03-21-2008, 01:47 PM

Glad to hear.No big deal and now you can be sure.

cdowns · 03-21-2008, 02:38 PM

building a motor that lives is all in the details. some people luck out with off the shelf out of the box who needs to measure type of assembly procedures most dont

i'd be worrying about the camshaft

lyrikz · 03-21-2008, 06:19 PM

Quote:

Originally Posted by cdowns

building a motor that lives is all in the details. some people luck out with off the shelf out of the box who needs to measure type of assembly procedures most dont

i'd be worrying about the camshaft

That is my concern. I mean, if you put in the wrong bearings that went the other way, you would have a destroyed crank. To tight it grinds all up.. I wasnt meaning to sound like a dick, just a concerned big brother...

67ChevyRedneck · 03-21-2008, 07:14 PM

I hope you get it all fixed proper and all figured out!!!

This is why I stick to crate engines!

chris71 · 03-21-2008, 07:57 PM

Quote:

Originally Posted by 67ChevyRedneck

I hope you get it all fixed proper and all figured out!!!

This is why I stick to crate engines!

Even with crate engines you are not totaly safe, i have seen the GM 502's have problems with incorrect main bearings. and have heard a couple other 502's have the same issue. a guy i used to work with was an engine builder and i saw him take a brand new 502, take a cap off and use plastigauge and sure enough, he had to order new bearings. the good news is i havent heard of this with the other gm crate motors

*Billla* · 03-21-2008, 08:05 PM

Quote:

Originally Posted by 70'_402

it was my main bearings... i guess they were mis-marked/packaged... they were standard bearings instead of 10-10's our fault for not checking.... but easy fix... don't even have to pull the motor.... sucks.. but better than a tear down..... i am just so releived to find the issue...

Were the actual bearings mis-marked? They're stamped on the back with the undersize. I can't think of what an .012/.013 clearance might do

I have to admit - I would pull it down just to be sure there's no damage - and that the rod bearings aren't similarly incorrect. The diagnosis is based on looking at the box the bearings came in?

I also check bearing clearance during mock-up; I use a bore gauge but Plastigauge works fine - and is way better than nothing.

All part of learning about building engines. The very first engine I did, a 327 (1978...a long time ago), I put in the crank and it wouldn't turn. .002 interference fit. I assumed that the machine work was correct....and it wasn't.

stllookn · 03-21-2008, 08:50 PM

When I raced bikes we would completely disassemble a showroom bike and motor to double check every clearance and tolerance. Most racers thought we were nuts but we never had a problem with "infant mortalities".

**70STOVEBOLT** · 03-21-2008, 10:25 PM

I work in the parts dept. of a heavy diesel rebuilder and we find this quite a bit. Even the OEM"s have this problem sometimes, I've found. We plastigage every engine we build and use a dial-bore gauge on cylinders after the liners are installed to make sure there are no rolled o-rings on the liners.

**'70_402** · 03-23-2008, 08:34 AM

yep... the rod bearings were std. also... got em replaced and she's running like a top... just getting some miles on her now... thourouly pleased...

hvychve · 03-23-2008, 10:22 AM

Blueprint

03-21-2008, 07:20 AM	#1
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,553	well, i found out why oil pressure was low..... it was my main bearings... i guess they were mis-marked/packaged... they were standard bearings instead of 10-10's our fault for not checking.... but easy fix... don't even have to pull the motor.... sucks.. but better than a tear down..... i am just so releived to find the issue... __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

03-21-2008, 07:21 AM	#2
slammed1 1972 Chevrolet SWB Join Date: Jan 2008 Location: FT Smith AR Posts: 512	Re: well, i found out why oil pressure was low..... Glad you caught that..........and that mistake wont haunt you ever again........or it well shouldnt!! __________________ My New thread with pics (not my build thread yet.) http://67-72chevytrucks.com/vboard/s...46#post2573646 1972 Chevrolet 1/2 ton short wide bed,68 frt clip Project. 1980 Camaro Inherited when father passed,68K Miles 2003 Ford Mach1 FUN as Hell!! 2002 Dodge Ram 5-8 slam Rolling BillBoard (Gone not forgot) 2004 Dodge Ram HEMI 10" lifted on 37's and 2wd.

03-21-2008, 07:46 AM	#3
El Jay Gone to greener pastures Join Date: May 2007 Location: Gateway to the Delta Posts: 7,354	Re: well, i found out why oil pressure was low..... I'm guessing you learned about "plastigage", regardless of what the supplier said. Not a "put down", to be sure. I just have a basic distrust in parts suppliers. So I just "check, check, check!" __________________ '69 Chevy 1/2 T LWB Stepper: Daily Beater '72 GMC 3/4 T Fleet: Another Daily Beater '72 Plymouth Gran Coupe: ? "Ah women. They make the highs higher and the lows more frequent." Friedrich Nietzsche "Never kick a fresh turd on a hot day." Harry S. Truman GUN CONTROL: Never having to say, "I missed you." Always fire two warning shots into your attacker's chest area before putting a bullet between his eyes. Paraphrased from Louis Awerbuck

03-21-2008, 01:47 PM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: well, i found out why oil pressure was low..... Glad to hear.No big deal and now you can be sure. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

03-21-2008, 02:38 PM	#6
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: well, i found out why oil pressure was low..... building a motor that lives is all in the details. some people luck out with off the shelf out of the box who needs to measure type of assembly procedures most dont i'd be worrying about the camshaft __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY Last edited by cdowns; 03-21-2008 at 02:58 PM.

03-21-2008, 07:14 PM	#8
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: well, i found out why oil pressure was low..... I hope you get it all fixed proper and all figured out!!! This is why I stick to crate engines! __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

03-21-2008, 08:50 PM	#11
stllookn Saving 1 truck at a time! Join Date: Aug 2001 Location: Kent, WA Posts: 6,465	Re: well, i found out why oil pressure was low..... When I raced bikes we would completely disassemble a showroom bike and motor to double check every clearance and tolerance. Most racers thought we were nuts but we never had a problem with "infant mortalities". __________________ '68 C20 Longhorn 50th Anniversary 400/TH400 '68 C20 Longhorn 50th Anniversary 468/TH400w/buckets '72 C20 Halfhorn (Longhorn w/o cab and front clip) '69 Flxible Cruiser (look up ugly in the dictionary)

03-21-2008, 10:25 PM	#12
70STOVEBOLT Senior Member Join Date: Jun 2005 Location: Winona Lake, IN Posts: 6,424	Re: well, i found out why oil pressure was low..... I work in the parts dept. of a heavy diesel rebuilder and we find this quite a bit. Even the OEM"s have this problem sometimes, I've found. We plastigage every engine we build and use a dial-bore gauge on cylinders after the liners are installed to make sure there are no rolled o-rings on the liners. __________________ 70 C/10 SWB 402/TH400/3.73 "The Needy Beast" 200,000 Mile Club Disc Brake Club Owner installed options: Front Sway Bar Power Steering Power Brakes Cigar Lighter Courtesy Lights Deluxe Side Markers Wiper Delay Sliding Rear Window Power Windows Power Locks Sniper EFI 2015 Silverado 1500 LS 4.3/6L80/3.23 lowered 2" front & rear

03-23-2008, 08:34 AM	#13
'70_402 Senior Member Join Date: Dec 2003 Location: Pampa, Texas Posts: 1,553	Re: well, i found out why oil pressure was low..... yep... the rod bearings were std. also... got em replaced and she's running like a top... just getting some miles on her now... thourouly pleased... __________________ https://www.ebay.com/itm/29620574751...mis&media=COPY

03-23-2008, 10:22 AM	#14
hvychve To The Levy Join Date: Jan 2007 Location: california Posts: 391	Re: well, i found out why oil pressure was low..... Blueprint



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