A ring would need a window in the top of the piston to escape the groove and get ontop of the piston . I don't see a window or opening.
Should have read all the way threw ...disregaurd last post Posted using the Full Custom H.A.M.B. App!
Might cut your muffler open and see if there is any pieces that it spit out. Was there any metal in the cylinder when you took the head off? OTherwise, see what is missing off your carbs.
Well, if there is any good news at this point, this is it; I pulled #8 piston and all the rings were intact and the bore seems perfectly smooth and still has a nice cross hatch to it, so I'm hoping I won't have to deal with boring / honing. I really dodged a bullet, take a look at the close up pic of the fractured ring land, it didn't touch the bore thank god. The picture of the bore sucks. My phone said the flash is disabled because the phone is too hot.
So you think the foreign object is in the exhaust pipe ? If it wasnt still in there when you pulled the head, what was continuing to make the noise that coincided with the timing light which is at 1/2 engine rpm? Interesting
Maybe it coincidentally made it through the valve as he shut it down. I was gonna suggest looking in the muffler too, but I thought, "do traditional hot rods have mufflers?"
There were a few metal bits that I picked out of the piston. Hard to tell what they were. I'll pull the valve springs later tonight to see what the valve seats look like.
If the seat material is harder than cast iron, I would thing there would be marks in the combustion chamber.
Pull the valves out of that hole and look at the bottom of the guides. I have seen shops cram guides in and splay out the top and bottom metal of the head, or if they used cast iron guides one of those may have started flaking off.
please post a picture of the head chamber too . as for the cam, the pattern is hard to follow looks ok for over the top , the Base circle has not had enough time to wear itself in . get a new set of tappets ( unless you labeled or organized them when you pulled them out they have to go back in the same exact hole as you pulled them out of and do not have to be rebroken in a little HP lube will not hurt them though ) and reuse it .( you have to rebreak in the tappets like before )
Great to finally find the culprit. Whatever it was, has obviously been spat out exhaust side. But I'm picking the continued knock will be the piston skirt collapsed, and kicking over on compression stroke. Get the piston mic'd, bet it's out of shape. At least Summit will sell you a single KB. Good luck reassembling.
Sounds like you have found the problem. I also had what I thought was an engine noise only to find out that one bolt was backing out of the flywheel plate and just starting to touch another part when the motor was running. Simple fix but one that scares the hell out you first until you start checking everything out. Jimbo
I labeled and kept all the lifters, pushrods in order. I'm kind of scared to use the cam, I don't want to pull this engine apart again. I'm pretty sure the cam is ok. If the machining costs are reasonable I'm going to get a roller cam.
CHEVY ,,, check the 2 bolts that . Hold the inspection cover bottom of trans at flywheel ... I have found that to be a problem more than once .. some times it's the little things that make you crazy ... Sent from my KFSOWI using H.A.M.B. mobile app
Greybeard, you must be clairvoyant! That's exactly what happened. The valve guide broke off and it looks like the boss is cracked. It's kind of hard to see in the pics. Think these heads are junk? At least I don't feel bad about making a mistake, I don't think this is my fault. I'm not sure if it's worth spending any more money on this engine at this point. ATTACH=full]2651111[/ATTACH]
I think this is a case where the machine shop should make this right for you. Take him all of the parts and show him what you found. They may have to put oversized guides back in and I would recommend bronze. I know a lot of people don't like bronze guides on the street, but they are a little more forgiving on the installation. I will almost bet he installed the guides with the head and guides at room temp. Best way to do cast iron guides is warm up the head and freeze the guides. As you can see, cast iron guides are brittle.
Wow sorry for all your grief on the rebuild it really sucks. I've had my own problems with machine shops over the years. And it's a royal PIA to deal with faulty workmanship after the fact. But i think you can save the build take some deep breaths and go see your head builder to stand behind his work. Ron
Hi Devin.Something else to do would be to have prints made at a place that makes prints from digital media,and put them in an album to show how the machine shop screwed the pooch on their work.Then if anyone asks why you quit using that shop,just show them the prints.Or better than an album,frame them and hang them in your shop for all to see.The shop should have to eat the cost of repairs or replacement of the damaged parts too. Good luck.Have fun.Be safe. Leo
You are right. I'm just not sure if I want to seal with them or have any more work done by them at this point. I found too many little mistakes which ultimately equalled a big one. But then again I shouldn't have to shoulder the burden.
Perhaps you should consider offering them the opportunity to pay to have another machine shop, of your choice, correctly make the repairs. Never hurts to go into these kinds of situations with a "Plan B".
exactly,some lessons are more costly than others.who was the person that attempted to port the heads after the guide work was done? Another pro bronze valve guide person here,in .500 guide they tend to get a bit pricy. As long as the finish is done with a hone and not just reamed to size and use a bore gauge to make sure they are straight,you will have years of service. Cast may have been used to keep costs down. Was this discussed with the machinist? Another possibility,something may have ingested in the cylinder,bent the valve then when the valve closed it broke the end of the guide. Kind of like the chicken or the egg was first type of thing.
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