Author Topic: Is my engine dead?  (Read 4294 times)

Offline MIKE S

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Re: Is my engine dead?
« Reply #45 on: February 17, 2020, 04:48:11 PM »
Just for future reference, oem heads from about 76 or so and up to 86 will crack on the slightest overheat. They lightened up the castings and they will crack between the valves. Almost impossible to see with the naked eye. need to be hot tanked and cleaned and use a magna flux tool. Used to have them drilled and pinned if small enough. some will hold, some will not. use pre 76 or vortec heads. You can usually tell by looking at the spark plug cooling hole on the combustion side. Good heads will have to small holes drilled in the cooling slot. bad heads will be wide open. If you had both heads side by side you could really see the difference. All in the name of fuel economy. A few pounds here and there would help your mileage .0000001 mpg.

Offline VileZambonie

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Re: Is my engine dead?
« Reply #46 on: February 17, 2020, 06:33:17 PM »
Why do you think he was lying? Did you get new heads?
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Offline MIKE S

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Re: Is my engine dead?
« Reply #47 on: February 17, 2020, 09:42:27 PM »
No I certainly was not trying to say he was lying. Im sorry if I came off that way. I was simply trying to pass on some knowledge that I had from working extensively on GM engines from the70s until around 2005. I took care of a fleet of about 30 trucks on our farm. Most were square bodies. I ran into a lot of cracked heads and was just passing on what I had learned. I did a lot of rebuilding and repairing of these so I thought I might be able to help.

Online bigben5054

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Re: Is my engine dead?
« Reply #48 on: February 17, 2020, 10:06:11 PM »
Mike, I think he was asking me why I thought the machine shop was lying. I went to a local machine shop (not the one that did block work) to get some pricing on rebuilding the stock heads.  Numbers really added up and I told him I might as well buy some Vortecs. He said he had some ready to go in the back and brought them out. I looked at them but they werent the 062 or 906. They didnt have the heart shaped combustion chambers either. I asked him several times if they were Vortecs and he said yes. I took a pic of the casting number and told him Id get back to him. I left my heads there. I did my research and he was trying to sell me TBI swirl port heads. Meanwhile I found a set of actual Vortecs pretty cheap. Called the machine shop to tell him I was going a different direction and he said he had $100 in shop time in my heads and they were both cracked. (Which made no sense that he would have been working on mine since he was waiting for my decision).  We argued and finally I told him to just pitch them then.

Offline MIKE S

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Re: Is my engine dead?
« Reply #49 on: February 17, 2020, 10:40:04 PM »
My bad. Im glad you able to get your engine together. Back in the day I did a lot of head swapping with older models as they were plentiful. A lot harder to find now today. Most of my repairs were strictly to keep them reliable and not to increase performance. I had propane conversions on all of them so power was not priority but reliability was. Vortecs are a good choice. I had a new set for years that I was intending to put on a Chevelle I had but never did. I think I sold the pair for maybe 400 dollars about 6 years ago. Thought I would never do another project again but I got the bug.
« Last Edit: February 17, 2020, 10:44:33 PM by MIKE S »

Offline VileZambonie

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Re: Is my engine dead?
« Reply #50 on: February 18, 2020, 07:45:11 AM »
Any decent machine shop should be able to show you where the cracks were or which chamber didn't hold pressure. The fact that he tried selling you tbi heads as vortec heads says a lot as well. Sounds like you made the right choice.
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Offline JohnnyPopper

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Re: Is my engine dead?
« Reply #51 on: February 20, 2020, 07:48:50 PM »
I hope you didn't pay him...

I'd have said: do we have a contract, i.e. a signed estimate where you were authorized to spend my money?

'the world is full of imposters' comes to mind.
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