Sbc 350 big crack on block under intake - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bridgeman57 · 09-04-2022, 12:50 AM

pulled the intake off to replace the gasket and found a nice crack on #3 side. Very small amount of coolant in lifter bay when I pulled intake off. I’m sure I spilled some also. Oil has seemed to be fine. Any cause of how it cracked? Possibly got to cold at some point in its life. Over heated? JB weld her up and see what happens or junk it?

mr.mud1 · 09-04-2022, 06:44 AM

well if it was mine,i'd be replacing it.that crack is right at the deck,it must've frozen at some point?you certainly don't want antifreeze in the oil,that'll kill bearings for sure,a band-aid might be to J-B Weld it up if you had to get it home but long term,even if you got it stopped up,i'd never trust it?

**Grumpy old man** · 09-04-2022, 07:07 AM

Junk it , it's not worth the time to even attempt to repair it . And JB weld will do nothing for it . Sometimes things just aren't worth trying to repair . it's done .

They'll be plenty of comments on how someone fixed one with JB weld or using Belzona but repairs like that don't last and may work for awhile on a farm truck or tractor where if it does get worse you'll just have to tow it to the barn , It's not like it's a numbers matching rare engine , And I'd have a hard time driving it anywhere knowing it had an issue that one day may leave you seriously stranded on the side of the road .

**special-K** · 09-04-2022, 07:43 AM

Not worth taking chances. I'd junk it. I'm curious what engine it is. Original or?

Bigdav160 · 09-04-2022, 09:09 AM

Freeze damage.

I've seen it many times.

Bridgeman57 · 09-04-2022, 10:34 AM

It’s a 70’s someone put in my 61. I’m thinking freeze damage as well. I’ll be throwing in another 350 I have done here shortly. Canada block. #6 push rod is ready to snap in half as well. Glad I pulled the intake when I did and not out driving with the wife lol.
BLOCK #’s
3970010
V0599800

Accelo · 09-04-2022, 10:48 AM

Yes, it is freeze damage. I had a block in the garage one cold winter, without a water pump installed, and it cracked in the same area.
It's junk in my opinion. Let me rephrase that. The amount of effort to install it isn't worth the risk.
Yes, it may be possible to fix it. Unless it's a rare block I would start over.

**chevy71super** · 09-04-2022, 12:25 PM

Yes. Frozen block. In had a similar issue. Went to have the engine rebuilt and magnaflux revealed a crack on both sides in the same area. Signs were there. Oil cap had the tell tale foam. The truck was out of Northern Idaho. Back in those days a 4 bolt main block was only $150.

Amazingly I drove the truck 2 years like that. I don’t recommend doing it . . . I changed the oil enough to prevent the bearings from getting scored. (PS. I have a 2015 Ford Escape sucking antifreeze. Probably a bad head gasket. POS. I put in stop leak. It slowed the loss of antifreeze significantly. I’m still driving it until I can afford a new car.)

**YellowK5** · 09-04-2022, 01:33 PM

Its a sign of over heating! I just scrapped my 72 blazer block for the same reason..Granted I was rebuilding it any way at the time...

**truckster** · 09-04-2022, 04:01 PM

That block isn't junk...

**Sheepdip** · 09-04-2022, 05:09 PM

Quote:

Originally Posted by Grumpy old man

Junk it , it's not worth the time to even attempt to repair it . And JB weld will do nothing for it . Sometimes things just aren't worth trying to repair . it's done .

They'll be plenty of comments on how someone fixed one with JB weld or using Belzona but repairs like that don't last and may work for awhile on a farm truck or tractor where if it does get worse you'll just have to tow it to the barn , It's not like it's a numbers matching rare engine , And I'd have a hard time driving it anywhere knowing it had an issue that one day may leave you seriously stranded on the side of the road .

I agree with Grumpy...it's history.

**AussieinNC** · 09-04-2022, 05:51 PM

Quote:

Originally Posted by truckster

That block isn't junk...

I would end up in divorce court

jumpsoffrock · 09-04-2022, 10:12 PM

Quote:

Originally Posted by AussieinNC

I would end up in divorce court

But you'd have a mighty nice table!!

Accelo · 09-05-2022, 01:18 AM

Very expensive table.

**Seanext** · 09-05-2022, 08:18 AM

As my Dad would say " I can get you going but don't drive any further from the house than you are willing to walk back"

streetstar · 09-07-2022, 07:36 PM

Quote:

Originally Posted by Accelo

Very expensive table.

I wish i could get out that cheap OTOH

Ever price anything Amish built for the home?

09-04-2022, 12:50 AM	#1
Bridgeman57 Registered User Join Date: Nov 2018 Location: Yuba city, California Posts: 86	Sbc 350 big crack on block under intake pulled the intake off to replace the gasket and found a nice crack on #3 side. Very small amount of coolant in lifter bay when I pulled intake off. I’m sure I spilled some also. Oil has seemed to be fine. Any cause of how it cracked? Possibly got to cold at some point in its life. Over heated? JB weld her up and see what happens or junk it? Attached Images

09-04-2022, 06:44 AM	#2
mr.mud1 Registered User Join Date: Dec 2020 Location: Joggins Nova Scotia Posts: 1,599	Re: Sbc 350 big crack on block under intake well if it was mine,i'd be replacing it.that crack is right at the deck,it must've frozen at some point?you certainly don't want antifreeze in the oil,that'll kill bearings for sure,a band-aid might be to J-B Weld it up if you had to get it home but long term,even if you got it stopped up,i'd never trust it?

09-04-2022, 07:43 AM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: Sbc 350 big crack on block under intake Not worth taking chances. I'd junk it. I'm curious what engine it is. Original or? __________________ "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 ~

09-04-2022, 09:09 AM	#5
Bigdav160 Registered User Join Date: Apr 2011 Location: Klein Texas Posts: 3,852	Re: Sbc 350 big crack on block under intake Freeze damage. I've seen it many times. __________________ My Classics: '72 K20 Suburban + '65 Dodge Town Wagon '72 Corvette Roadster +'67 Corvette Roadster '73 Z-28 Camaro '63 Ford SWB Uni Pickup '50 Ford Coupe

09-04-2022, 10:48 AM	#7
Accelo Registered User Join Date: Mar 2015 Location: washington Posts: 2,162	Re: Sbc 350 big crack on block under intake Yes, it is freeze damage. I had a block in the garage one cold winter, without a water pump installed, and it cracked in the same area. It's junk in my opinion. Let me rephrase that. The amount of effort to install it isn't worth the risk. Yes, it may be possible to fix it. Unless it's a rare block I would start over. Last edited by Accelo; 09-04-2022 at 04:00 PM.

09-04-2022, 07:07 AM	#3
Grumpy old man Senior Member Join Date: Dec 2013 Location: Gods country East,Tn Posts: 8,545	Re: Sbc 350 big crack on block under intake Junk it , it's not worth the time to even attempt to repair it . And JB weld will do nothing for it . Sometimes things just aren't worth trying to repair . it's done . They'll be plenty of comments on how someone fixed one with JB weld or using Belzona but repairs like that don't last and may work for awhile on a farm truck or tractor where if it does get worse you'll just have to tow it to the barn , It's not like it's a numbers matching rare engine , And I'd have a hard time driving it anywhere knowing it had an issue that one day may leave you seriously stranded on the side of the road . __________________ 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop

09-04-2022, 10:34 AM	#6
Bridgeman57 Registered User Join Date: Nov 2018 Location: Yuba city, California Posts: 86	Re: Sbc 350 big crack on block under intake It’s a 70’s someone put in my 61. I’m thinking freeze damage as well. I’ll be throwing in another 350 I have done here shortly. Canada block. #6 push rod is ready to snap in half as well. Glad I pulled the intake when I did and not out driving with the wife lol. BLOCK #’s 3970010 V0599800

09-04-2022, 12:25 PM	#8
chevy71super Registered User Join Date: Jan 2002 Location: So Cal Posts: 658	Re: Sbc 350 big crack on block under intake Yes. Frozen block. In had a similar issue. Went to have the engine rebuilt and magnaflux revealed a crack on both sides in the same area. Signs were there. Oil cap had the tell tale foam. The truck was out of Northern Idaho. Back in those days a 4 bolt main block was only $150. Amazingly I drove the truck 2 years like that. I don’t recommend doing it . . . I changed the oil enough to prevent the bearings from getting scored. (PS. I have a 2015 Ford Escape sucking antifreeze. Probably a bad head gasket. POS. I put in stop leak. It slowed the loss of antifreeze significantly. I’m still driving it until I can afford a new car.) __________________ 71 Cheyenne Super 4X4 SB 72 Cheyenne Super 4X4 SB 72 Cheyenne 4X4 SB

09-04-2022, 01:33 PM	#9
YellowK5 Active Member Join Date: Jun 2021 Location: Rancho Cucamonga California Posts: 170	Re: Sbc 350 big crack on block under intake Its a sign of over heating! I just scrapped my 72 blazer block for the same reason..Granted I was rebuilding it any way at the time...

09-04-2022, 04:01 PM	#10
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,798	Re: Sbc 350 big crack on block under intake That block isn't junk... Attached Images __________________ I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson

09-05-2022, 01:18 AM	#14
Accelo Registered User Join Date: Mar 2015 Location: washington Posts: 2,162	Re: Sbc 350 big crack on block under intake Very expensive table.

09-05-2022, 08:18 AM	#15
Seanext Senior Member Join Date: Mar 2013 Location: Dallas NC Posts: 586	Re: Sbc 350 big crack on block under intake As my Dad would say " I can get you going but don't drive any further from the house than you are willing to walk back"



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