Author Topic: Is my engine dead?  (Read 9690 times)

Offline bigben5054

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Re: Is my engine dead?
« Reply #15 on: October 15, 2018, 10:02:38 PM »
No.  I called a couple machine shops today to get a rough idea on cost to go through a set of heads and it’s around $250-$350 plus any needed parts.  Seems a bit high for some bone stock heads.  Been looking into picking up a set of Vortec heads instead.  Can find decent ones for half of what machine shop wants to redo these.

Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #16 on: October 16, 2018, 01:57:16 PM »
Doesn't look like a heavy ridge at the top of the cylinder is why I asked. Maybe low mileage, but if you have access to a micrometer it might be worth checking just how much wear there is. You've gone this far. Is the engine out of the truck?

I have to say, I have been out of the loop on modern engines, couldn't tell you what a Vortec head is if my life depended on it, but they sure sound interesting. I must investigate... 
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bigben5054

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Re: Is my engine dead?
« Reply #17 on: October 16, 2018, 02:49:46 PM »
Motor is still in truck and I don't really want to pull it.  You can barely feel anything at the top of the cylinder and these pistons are stamped 30 over, so I'm guessing it doesn't have a ton of miles on the rebuild.  Vortec heads are a pretty good bang for your buck.  Need a Vortec manifold and centerbolt valve covers, but everything is easy to find and usually pretty inexpensive.  Most articles I've read say they are worth 20-40 HP over stock.

Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #18 on: October 17, 2018, 07:26:02 PM »
Okay, sound like you're in good shape on the lower end.

Have you popped the valve out? I think I have a spring compressor, but haven't seen it for years. Curious as to why such a loss of pressure when there's no visible crack/hole.

I'm really surprised that just changing your heads can deliver that much more horsepower! Thanks for the info, now I'm really interested.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bigben5054

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Re: Is my engine dead?
« Reply #19 on: October 18, 2018, 07:05:35 AM »
I did the loan-a-tool at Autozone last night and popped out that intake valve.  It just looks covered in carbon build up.  Its clearly unable to close completely at this point because of the carbon buildup, but I still dont have an answer as to why it possibly got stuck open in the first place.  I'll take them all out and spend some time with the wire wheel this weekend.   

Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #20 on: October 18, 2018, 12:27:03 PM »
I don't know if I would pull them all out.

I think I would clean that one and take it to the machine shop (call first) and see if they have a vacuum tester. (old school) See if it is still leaking.

Strange that conditions of excess fuel and/or poor ignition would cause such a buildup that produced no pressure. But it sure looks that way.

The rest were straight up 120. did you take Vile's advice and look for a sheared lobe on the cam?
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bigben5054

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Re: Is my engine dead?
« Reply #21 on: October 18, 2018, 01:33:14 PM »
Good suggestion, thanks.  I did not look for a sheared cam lobe.  I suppose with the intake off, I can crank the engine by hand and watch the lifters.   

Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #22 on: October 18, 2018, 02:41:18 PM »
Yeah, I'd start there.

Sometime rebuilders aren't aware that the have to break in a new camshaft.

Hope it's something simple like carbon...
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bigben5054

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Re: Is my engine dead?
« Reply #23 on: October 19, 2018, 10:58:47 AM »
Last night I took off the passenger side header and pulled the valve cover (I have limited wrenching time during the week).  There was a small pool of antifreeze in the back corner of the head (above #8 cylinder).  Note from my original post that all cylinders compression tested at 120lbs except #3 (zero) and #8 (140).  Also recall that I thought the passenger side exhaust was a bit steamy.  I'll get that head pulled tonight, but I suspect I'll find some coolant in #8.  In my limited experience, this means 1) bad head gasket; 2) cracked head; 3) cracked block; 4) cracked/leaking intake.  I know that some cracks can be hard/impossible to see with the naked eye, but I'm not crazy about the idea of paying a shop to magnaflux the heads or the block (I'm still holding out hope I don't have to yank the whole engine).  What sort of things should I be looking for when I pull the head that might give me a hint as to how that water is getting in there? 

Offline bigben5054

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Re: Is my engine dead?
« Reply #24 on: October 19, 2018, 11:12:24 AM »
Or...maybe they failed to put sealant on the head bolts when they "regasketed" this motor.  Let's hope for that one. 

Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #25 on: October 19, 2018, 02:15:30 PM »
So the puddle of anti-freeze was sitting under the valve cover, and you saw it when removed? That's troubling if true.

Sometimes it leaks into areas when you take things apart if the block wasn't drained to a point below the water pump ports, but I can't say how it got under the valve cover.

A Far reach is that the head gasket is bad, and it came in through a head bolt. Did you see any A/F in the oil?

I recall the steam question and the answers that stated somewhat normal when first getting warmed up. Did it continue steaming after reaching operating temp?

I think it points to a cracked head. You'll know if the combustion chamber is squeaky clean.

1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bigben5054

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Re: Is my engine dead?
« Reply #26 on: October 19, 2018, 02:27:43 PM »
Yes, the antifreeze was there when I pulled off the valve cover.  I shrugged it off at first because you are right, I had anti-freeze all over the place from pulling the intake and other head.  But later I was thinking about it and thought hey, how did that get in there? 

The anti-freeze in there looked like it just came out of the jug, so clearly it had not worked its way up through the oil pan, oil pump, valve train etc.  I did a few Google searches and unsealed head bolts seem like a good lead.  But, how would the antifreeze get from on top of the head into the cylinder?  It don't see how it could.

As far as the steam, it got worse the longer it ran.

Part of me is starting to believe that the prior owner knew of the problem, thought it was a head gasket so he put all new gaskets in it, but turns out that didn't fix it, so he did something to temporarily hide the problem while he dumped the truck.

Hopefully I'll get time tonight to pull the head and I'll post what I find.

Offline bigben5054

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Re: Is my engine dead?
« Reply #27 on: October 19, 2018, 10:29:08 PM »
The head doesn't look too bad.  To the naked eye anyways.  But there was a good amount of oil in #8 (the one with 20lbs more compression than all the others).  The coolant may or may not have already been in there.  I made a mess pulling the head off.  That oil pooled in there is bad news though, yeah?  Thinking piston rings.  But if the rings are that bad, why would I get such good compression?  Would the oil in there act as a sealer for the bad rings?  Ready to scrap this thing. 

Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #28 on: October 20, 2018, 08:56:20 PM »
Wow, a stumper at the moment.

Unsealed or loose headbolt may have allow it up, but it would still need to make it past the head gasket and into that bolt passage. You said the former owner changed the gaskets- do they look new?

Do you have the lower radiator hose removed? It looks like there is/was a high level of A/F that leaked into cylinder in both 6 and 8.

Can't figure the oil in 8, especially looking at the exhaust valve, it was burning better than 4 and 6.

Start with the heads and a magnaflux inspection, if they check out, take a look at the block. May as well pull it, mark the components, and inspect.

We all feel for you, are you into the truck for much $?
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline bigben5054

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Re: Is my engine dead?
« Reply #29 on: October 20, 2018, 10:52:38 PM »
I have read that the antifreeze can cling the threads and then come out under the bolt heads.  That’s how it think antifreeze got under the valve cover.  And I think more likely than not, the antifreeze you see in 6 and 8 got in there when I pulled the head.  No, didn’t remove lower hose.  Should have because it’s a mess. 

I’m more concerned about the oil I found in the cylinder.  I figure it either came down through the valve guides or blew up past the rings.  I fear the latter makes more sense given the quantity of oil.

I appreciate all the advice.  I’m not into the truck much.  Paid $2k for it.  I haven’t put a dime in it other than that.  What gives me the most pause right now is starting to pump $ into this motor.  I can find “ran great when pulled” small blocks all day long for $250-$300.  Of course, might just be buying another headache doing that.