How much of a rebuild is needed on this 350? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**desert-rat** · 07-08-2023, 02:25 PM

I picked up this engine from a person who said it was rebuilt. It was fully assembled and running. So yeah, the pistons read 030. The pistons were dirty so I cleaned them off. I still see cross hatches but one bore shows rust. Maybe it sat too long?? Should I completely disassembled the block and have a shop deep clean and inspect it??

**desert-rat** · 07-08-2023, 02:29 PM

One more

**Steeveedee** · 07-08-2023, 03:12 PM

Can you measure the height of the ring ridge? That alone could dictate another bore job; once you're that far in might as well do it all. If you just want to ring & hone, you'll need to remove that ridge. Plus, you're going to get some blow-by on the rusted cylinder.

**Accelo** · 07-17-2023, 11:00 AM

I personally see no reason not to run it as is.
Cheers

**special-K** · 07-17-2023, 11:15 AM

First of all, a rebuild means go all the way, new pistons and all. Anything less is an overhaul. I'd either run yours as is and use it up or bore and re-ring. If bigger pistons are needed it's go all the way for me

**Ironangel** · 07-17-2023, 05:08 PM

Appearance wise it dont look bad except for that one rusty hole. If you dont have a bore gauge to measure the holes then I would at least run a ball hone down that rusty hole to clean it up. Lay a paper towel on top of the piston at BDC squirt some WD-40 in the hole and give it a few quick strokes with a ball hone. Slap it together and run it if all the valve seats look good.

54blackhornet · 07-20-2023, 07:11 PM

Could you give that rusty cylinder a clean up with some wet 1000 grit paper ? Looks like it’s just sitting on the surface.

**kwmech** · 07-20-2023, 10:01 PM

Quote:

Originally Posted by 54blackhornet

Could you give that rusty cylinder a clean up with some wet 1000 grit paper ? Looks like it’s just sitting on the surface.

That or try some scotch-brite with some WD-40 and see what happens. I'd probably polish it up some and run it

**HO455** · 07-21-2023, 01:16 PM

What are your plans for the engine? That is the big decider with what I see in the photos.

Pulling the base plate on the oil pump and inspecting the pumps internals will give you a idea as to the condition of the bearings. That may help you determine the course to steer.

schovil69 · 07-25-2023, 01:30 PM

Run it.

MARKDTN · 07-25-2023, 03:28 PM

That does not look like a fresh build-too much stuff at the top. That said I would probably try to clean the rust with a scotchbrite pad and run it. You may lose some compression in that one and the other one with a mark in it, but I'd roll the dice and try it.

**desert-rat** · 07-26-2023, 12:37 AM

Yeah, I threw in the towel. Decided to take the block to a shop for cleaning, decking, machining, etc.

07-08-2023, 02:25 PM	#1
desert-rat Senior Member Join Date: Jan 2013 Location: 3,018 feet above the SoCal/Mojave Desert region. Posts: 357	How much of a rebuild is needed on this 350? I picked up this engine from a person who said it was rebuilt. It was fully assembled and running. So yeah, the pistons read 030. The pistons were dirty so I cleaned them off. I still see cross hatches but one bore shows rust. Maybe it sat too long?? Should I completely disassembled the block and have a shop deep clean and inspect it?? Attached Images

07-08-2023, 02:29 PM	#2
desert-rat Senior Member Join Date: Jan 2013 Location: 3,018 feet above the SoCal/Mojave Desert region. Posts: 357	Re: How much of a rebuild is needed on this 350? One more Attached Images

07-08-2023, 03:12 PM	#3
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,209	Re: How much of a rebuild is needed on this 350? Can you measure the height of the ring ridge? That alone could dictate another bore job; once you're that far in might as well do it all. If you just want to ring & hone, you'll need to remove that ridge. Plus, you're going to get some blow-by on the rusted cylinder. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

07-17-2023, 11:00 AM	#4
Accelo Senior Member Join Date: Mar 2015 Location: washington Posts: 2,198	Re: How much of a rebuild is needed on this 350? I personally see no reason not to run it as is. Cheers

07-17-2023, 11:15 AM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,862	Re: How much of a rebuild is needed on this 350? First of all, a rebuild means go all the way, new pistons and all. Anything less is an overhaul. I'd either run yours as is and use it up or bore and re-ring. If bigger pistons are needed it's go all the way for me __________________ "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 ~

07-17-2023, 05:08 PM	#6
Ironangel Senior Member Join Date: Feb 2010 Location: Falls City, Nebraska "100 Miles From Nowhere" Posts: 2,219	Re: How much of a rebuild is needed on this 350? Appearance wise it dont look bad except for that one rusty hole. If you dont have a bore gauge to measure the holes then I would at least run a ball hone down that rusty hole to clean it up. Lay a paper towel on top of the piston at BDC squirt some WD-40 in the hole and give it a few quick strokes with a ball hone. Slap it together and run it if all the valve seats look good. __________________ Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American"

07-20-2023, 07:11 PM	#7
54blackhornet Registered User Join Date: Jul 2008 Location: Eastern Oregon Posts: 2,283	Re: How much of a rebuild is needed on this 350? Could you give that rusty cylinder a clean up with some wet 1000 grit paper ? Looks like it’s just sitting on the surface. __________________ 71 C-20 07 Magnum RT AWD

07-21-2023, 01:16 PM	#9
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 10,925	Re: How much of a rebuild is needed on this 350? What are your plans for the engine? That is the big decider with what I see in the photos. Pulling the base plate on the oil pump and inspecting the pumps internals will give you a idea as to the condition of the bearings. That may help you determine the course to steer. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

07-25-2023, 01:30 PM	#10
schovil69 Registered User Join Date: Oct 2013 Location: Lincoln, NE Posts: 115	Re: How much of a rebuild is needed on this 350? Run it.

07-25-2023, 03:28 PM	#11
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,141	Re: How much of a rebuild is needed on this 350? That does not look like a fresh build-too much stuff at the top. That said I would probably try to clean the rust with a scotchbrite pad and run it. You may lose some compression in that one and the other one with a mark in it, but I'd roll the dice and try it. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

07-26-2023, 12:37 AM	#12
desert-rat Senior Member Join Date: Jan 2013 Location: 3,018 feet above the SoCal/Mojave Desert region. Posts: 357	Re: How much of a rebuild is needed on this 350? Yeah, I threw in the towel. Decided to take the block to a shop for cleaning, decking, machining, etc.



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