The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-14-2014, 10:10 PM   #1
Mike_The_Grad
Senior Member
 
Mike_The_Grad's Avatar
 
Join Date: Oct 2013
Location: Santa Paula, CA
Posts: 635
Re: Mike The Grad's Coolant Splat

So after a crazy weekend, I was able to find out some interesting news. I cleaned up the head surface of the drivers side where I had the gasket blowout on cylinder #7. I wasn't able to see any blatant cracking or warpage. I used a straight edge and flat feeler gauge with .003 indicator along with a background light source. I measured vertically and horizontally across the entire head to block mating surface, not to sure how to measure diagonally across combustion chambers... There is no doubt in my mind and also my Buddy's that this thing is flat. My friend recommended his ex-bosses opinion. This guy has been racing and building dragsters since the late 60's early 70's. Also the fact that my friend has a certain negative opinion about him as a employer, but acknowledges his mechanical ability speaks to me. He confirmed I have 2.02 heads. He felt that no internal damage had been done to the heads themselves. He HIGHLY recommends that I pull the engine and place it on a stand, so I can pull crankshaft and pistons to replace rings and main bearings. Then he can inspect cam, lifters, and cylinder walls. He said if everything checks out, do a light hone by hand and replace valve guide seals then put it back together. All in all I think its good news. Considering it still will be a few weeks til its back on the road. After I told him the truck was sitting for about 8 yrs. In my driveway,with just water no coolant in it, and no hood or even tarp for about the last two of those years that that's exactly why this happend. Live and learn is what I'm gathering from all of this...
Pictures: head gasket with failure, some type of scratch on number #7 cylinder above piston tdc that is pretty close to where the gasket failed
Attached Images
    
__________________
1972 C/10 LWB - Mine
1964 C/10 LWB - My Dad's
Mike_The_Grad is offline   Reply With Quote
Old 10-15-2014, 03:02 AM   #2
mechanicalman
Registered User
 
Join Date: Jun 2014
Location: Glendale, Arizna
Posts: 1,642
Re: Mike The Grad's Coolant Splat

Quote:
Originally Posted by Mike_The_Grad View Post
So after a crazy weekend, I was able to find out some interesting news. I cleaned up the head surface of the drivers side where I had the gasket blowout on cylinder #7. I wasn't able to see any blatant cracking or warpage. I used a straight edge and flat feeler gauge with .003 indicator along with a background light source. I measured vertically and horizontally across the entire head to block mating surface, not to sure how to measure diagonally across combustion chambers... There is no doubt in my mind and also my Buddy's that this thing is flat. My friend recommended his ex-bosses opinion. This guy has been racing and building dragsters since the late 60's early 70's. Also the fact that my friend has a certain negative opinion about him as a employer, but acknowledges his mechanical ability speaks to me. He confirmed I have 2.02 heads. He felt that no internal damage had been done to the heads themselves. He HIGHLY recommends that I pull the engine and place it on a stand, so I can pull crankshaft and pistons to replace rings and main bearings. Then he can inspect cam, lifters, and cylinder walls. He said if everything checks out, do a light hone by hand and replace valve guide seals then put it back together. All in all I think its good news. Considering it still will be a few weeks til its back on the road. After I told him the truck was sitting for about 8 yrs. In my driveway,with just water no coolant in it, and no hood or even tarp for about the last two of those years that that's exactly why this happend. Live and learn is what I'm gathering from all of this...
Pictures: head gasket with failure, some type of scratch on number #7 cylinder above piston tdc that is pretty close to where the gasket failed
Hey Mike The Grad: Is the picture posted by magwakeenercew2jh of the cracked valve seats a picture of your head?
mechanicalman is offline   Reply With Quote
Old 10-15-2014, 03:14 AM   #3
Mike_The_Grad
Senior Member
 
Mike_The_Grad's Avatar
 
Join Date: Oct 2013
Location: Santa Paula, CA
Posts: 635
Re: Mike The Grad's Coolant Splat

Mechanicalman: yes it is a picture of my passenger side head. But I think what may appear to be a crack might actually be carbon build up stuck on there from me cleaning the head. I only really had time to clean the driver side this past weekend. On Friday I will clean the passenger side up and post pics.
__________________
1972 C/10 LWB - Mine
1964 C/10 LWB - My Dad's
Mike_The_Grad is offline   Reply With Quote
Old 10-15-2014, 03:45 AM   #4
mechanicalman
Registered User
 
Join Date: Jun 2014
Location: Glendale, Arizna
Posts: 1,642
Re: Mike The Grad's Coolant Splat

Quote:
Originally Posted by Mike_The_Grad View Post
Mechanicalman: yes it is a picture of my passenger side head. But I think what may appear to be a crack might actually be carbon build up stuck on there from me cleaning the head. I only really had time to clean the driver side this past weekend. On Friday I will clean the passenger side up and post pics.
Might be a good idea to take the heads to a good machine shop for a steam clean and a magna-flux just to be sure.

Make sure you inspect the lifters, and make sure they don't get mixed up as to what hole they came out of. Post us a picture of the worst one.

That "scratch" on the upper part of the cyl wall just below the deck is likely the result of coolant dis-lodging a piece of carbon and the carbon getting suck between the top of the piston on the side above the top ring and the cyl wall. You should be able to visualize the top ring if not spray with penetrating oil, blow it out and clean it out if nec. The piston ring needs to be free and floating in order to seal. Don't scrape or wire wheel the pistons (you can jam the extra carbon onto the rings into the grooves and stick them), just spray them with penetrating oil or douse them with top engine cleaner and let them soak. Wipe it out before you install the heads then the pistons will self-clean when you start the engine.

A good trick is to coat the cyl walls with grease, then rotate the engine and the rings will push the grease to the top carrying the dirt off the top of the rings with it then simply wipe it out with the piston down.

I wouldn't pull the engine out just yet if you don't think you put it in a hydraulic lock and the #7 top ring is free (the piston should move independent of the ring and the ring should stay against the cyl wall). Looks like the piston is stamped "30"? Probably been re-bored.

I'd be more optimistic of the bottom end than I would be of the heads, but hope you get away with just a pair of head gaskets.
mechanicalman is offline   Reply With Quote
Old 10-15-2014, 08:43 AM   #5
Mike_The_Grad
Senior Member
 
Mike_The_Grad's Avatar
 
Join Date: Oct 2013
Location: Santa Paula, CA
Posts: 635
Re: Mike The Grad's Coolant Splat

Mechanical man: yes the engine has been totally rebuilt. I think in '92. At the 300k mark. And its got 74k on the rebuild. The work was done by my ex's grandfather. He had a shop here in town for quit a while. From what I hear he has a damn good reputation. I don't doubt any of the work he's done on any car. I know the crank is .10 under. My financial situation may change here shortly, so I'm thinking of taking advantage of the situation and do a little more than just change gaskets. The only true thing that's hurting me is being without a vehicle. And the more I send to the shop the longer the turn around is...
__________________
1972 C/10 LWB - Mine
1964 C/10 LWB - My Dad's
Mike_The_Grad is offline   Reply With Quote
Old 10-15-2014, 02:59 PM   #6
mechanicalman
Registered User
 
Join Date: Jun 2014
Location: Glendale, Arizna
Posts: 1,642
Re: Mike The Grad's Coolant Splat

Quote:
Originally Posted by Mike_The_Grad View Post
Mechanical man: yes the engine has been totally rebuilt. I think in '92. At the 300k mark. And its got 74k on the rebuild. The work was done by my ex's grandfather. He had a shop here in town for quit a while. From what I hear he has a damn good reputation. I don't doubt any of the work he's done on any car. I know the crank is .10 under. My financial situation may change here shortly, so I'm thinking of taking advantage of the situation and do a little more than just change gaskets. The only true thing that's hurting me is being without a vehicle. And the more I send to the shop the longer the turn around is...
No reason to believe the bearings are bad, the oil didn't get much water for very long at all, make sure the rings are free on # 7. Turn the heads upside down and pour some trans oil into the ports onto the underside of the valves to check for leaky valves before you take them apart.

Any chance anything on the valve seats looks remotely like a crack, send the heads to the shop. Valve seals, for sure; I'd put the "umbrella" seals on it along with the stock "o-ring" on the intake only. Don't put the o-rings on the exhaust valve if you are using the umbrellas, they stop the oil flow to the umbrella and it gets too hot. Same reason the o-ring burns up on the exhaust and fails, but if the umbrella gets the oil over it, it will last a long time. The stock exhaust valve faces are way too thick next to the stem and retain too much heat.

No advantage to replacing rings and honing unless the rings are stuck, and then I'd just do it on #7 ONLY if it needed it, it just increases piston to cylinder wall clearance and will decrease the life of the engine.

Because you have the intake off, do what I said for the lifters, it's too easy. After sitting outside for years with no tarp, a lifter could have gotten sticky and might be on it's way out. You don't want to take it apart again after you do the head gaskets. You don't want to see bad lifters/cam, but if you have a bad lifter/cam, you want to see it.

If the heads are cracked, replace them. Don't let the shop talk you into a crack repair.

If you think the heads need magnaflux test, they pass, and if your g-dad in law put new valve guides in it, have the shop grind the seats and put a "head improvement kit" in it, you can do it yourself if you have or can get a valve spring compressor. Very reasonable, come with everything you need, come in both valve sizes. Measure the valves first, I think you have the 1.94 but measure to be sure. Get the cheapest head kit in your valve size, you don't need higher pressure valve springs and if the cam is stock you don't want to shim the springs.

http://www.competitionproducts.com/H.../#.VD6_V010wu4

http://www.competitionproducts.com/C...s/products/27/

If you use a head improvement kit, you won't need or be able to put the o-rings on the intake valves.

New head bolts, 1094 head gaskets.

It is what it is. I'm telling you the cheapest, fastest way to fix right. Feel free to ask me anything.
mechanicalman is offline   Reply With Quote
Old 10-15-2014, 04:11 PM   #7
Mike_The_Grad
Senior Member
 
Mike_The_Grad's Avatar
 
Join Date: Oct 2013
Location: Santa Paula, CA
Posts: 635
Re: Mike The Grad's Coolant Splat

Mechanicalman: I definitely appreciate your input. The way I look at it is, the more information available to me will help me make the correct choices. Everyone isn't right, and everyone isn't wrong. I will pass along the opinion and see what I hear in return. And yes, I agree with you about doing this again in the near future. I don't want to! It seems as though everything I've done up til this point I've already had to redo. But that's the fun about learning right?! Pfff.... I'm about getting it done right the first time. But that can't always be when I try and do everything myself for the first time. I love to learn, just not at the price of doing everything twice. It is what it is, and I'm much smarter now than I was 6 months ago.
__________________
1972 C/10 LWB - Mine
1964 C/10 LWB - My Dad's
Mike_The_Grad is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:10 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 1997-2025 67-72chevytrucks.com