Good talk through the diagnostics. I think there was two separate issues that occurred at the same time. The cam was failing, probably due to failed break-in (maybe procedure, maybe parts quality, who knows). The issue I find more concerning is the cracked pistons. I would have thought that 16 thou would have been good but I guess if the parts were specific to that KB spec sheet it wasn't enough. Anyway, looks like this disaster was identified soon enough for this engine to be salvageable.
0.016 gap would be ok for a stock cast piston, but sounds like the KB hypers need a lot more. So I would say the too-tight gap is what broke the ring lands. Look at the ends of the rings closely and see if there are witness marks where they butted. The double spring pressures should be ok to run a FT cam, by I would definitely break it in with inner springs removed.
On true blue kb hyper pistons, I run .007 per inch of bore. 350 street/drag run .028. If endurance (circle track/roadrace run .009 per inch(or for nitrous).
I wouldn’t have thought it was the end gap but I didn’t realize KB needed a bunch more. I had a buddy who used cheap pistons, high compression and 87 octane that looked similar. I’m of the thought that a lot of cam failures are either due to lifter surface finish or improper convex spec. My last build I used GM replacement lifters. Made in America and have a hardened bottom friction welded on. I was careful on break in (took the inners out) and use a zinc rich oil. No problems yet 🤞
The gm lifters with the hard disks are all I use. I'm sending a used set in to be rebuilt rather than using aftermarket lifters without the hard disks. I bought several sets of new ones (hl66 or 5232720) several years ago for all my sbc engine builds.
Also when you put it back together, I have heard several guys say you should rotate the engine over by hand and see all the lifters rotate. I would like for you to try this out and show us.
@@nylegreen261wouldn’t you be wiping off the assembly lube/grease? I’ve seen guys say to not even overly prime your oil 😂. I had some “z28” valve springs installed basically factory springs that are rated up to 500” lift single springs.
Usually went the cam starts to go flat, metal gets in the bearings and imbeds in the skirts of the pistons, this is what I have seen on a tear down of the engine and gets in the oil pump...
Open spring is a little high but still exceptable. I didn't see you look at the ring end gaps. They will be shiny if they touch. How much timing was in the motor when it was run.
Open up all the ring gaps Increasng second ring more then the top ring match top oil ring with second , allows combustion gases to not be trapped between the rings Helps control ring flutter caused by trapped gasses When rings butt its all over , using this method will maximise ring seal and operation Slightly bigger gaps won't hurt
.016" ring gap is certainly not enough. If you look at the contact pattern on the cam lobes, it looks as though the cam to lifter interface is perfect, with the lifter riding the front edge of the lobes. Here lately I've been breaking in flat tappet cams with Quaker State 5w-30 full synthetic oil and have never had a problem with the correct springs for the cam installed, which for me are Competition Cams 986's. To be safe though, go ahead and break the next cam in on your LS6 springs. Also, I think you may have mis-spoke about your retainer to valve clearance as .300" isn't nearly enough. It seems as though your calipers were further apart than .300".
@nylegreen261 hi nyle. Keep the valve guide as long as possible. Many people cut them down way way to much. If I knew I was playing with different cams, clearence for the biggest. As for how much a person needs, I set mine at .050 beyond the most lift I thought I'd ever run.
Any signs of a nitrous kit having been installed? Even a 125 plate shot will crack pistons when ring gaps are tight or nitrous applied at low rpm. Id guess tight rings, bearing clearance and bad cam break in. are the chambers sooty ?
I run 150 lbs. on a flat tappet cam made by Competition Cams with no problem... .630" and .637" lift. Tirn engine at 7,000 rpm... Some of the rings must of been installed wrong, upside down? How are the valve guides?
For that cam, there is no reason at all to run that high of spring pressure! 112-115 closed is plenty! And for those Keith Black Hyper pistons, you HAVE TO use the recommended ring gap or more to be safe! I have heard of many, many guys destroying those pistons because they didn't want to listen to the manufacturers recommendations. Live and learn, I guess.
except when it comes to iron cylinder Harley pistons, then don't set wall clearence near as tight as KB recommends. The previous builder dissed the instructions and went with the typical Hastings 3.5-4 thou per inch. Never saw a good shot at the domes to see if any detonation was going on. Hyper pistons don't like that at all. Now , what pistins will you go back with??
ring gap break in oil stop using hyper pistons after the first half dozen failures because of similar issues i quit using them in the early 2000s in truck apps towing heavy loads i would find piston parts the size of a quarter in the pan and not hurt any thing else
Nice I will look into it. I always enjoy your work and testing. I have taken the last month off from cars. I have been active with my kids activities lately.
Were the pistons cast or forged? I bought a short block and he said the pistons were forged, eventually I lost all compression on #7. When I tore it down the #7 piston was cast and the ring lands were broken like yours, the other pistons were forged and looked fine.
They require a larger top end gap because of their thermal expansion and the top ring begin close to the top of the piston. It’s the only thing i see wrong there. They do list the 2nd end gap at 0.004” x bore so 0.016” should be ok there. On the other issue I don’t think the springs would cause issues on brake in IF the cam was broken in with the outer spring only. But since you didn’t assemble it there’s no way of saying it was done correctly. P.s. is this engine going in your Nova for a Drag test after it’s been fixed up ?
Not sure if you are asking what went wrong or if you want the audience to find the problem. Either way it clearly states 0.026 gap. And you have 0.016 That gap needs opened up about 37%. Hope that puts the small amount into perspective.
Yup, Top ring gap too tight. That's for sure. I probably have the same pistons, KB Claimer UEM but 4.030" Instructions are very clear. You'll pop the top off once the rings expand with heat. It needs the extra few thou they recommend. Too bad. Quite a bit of money gone.
Use alcohol to fill up ports and check for leaks. The surface tension of alcohol is MUCH less than antifreeze, and will leak out at the slightest gap. The antifreeze may not.
It appears the engine was bored? I saw the formula for setting ring end gaps. I would suggest following the formula sir. Seems with busted lands on the pistons. Is it possible the engine was pre-ignition issues?
That engine was dirty when it fired up. The ring gap was the big culprit. There have been some significant issues with lifters lately. It very well could be due to the lifters.
@nylegreen261 from what I have learned, Johnson lifters have been good lately. I think you can get most cams in decent shape. It's just the lifters that are an issue.
This surprised me. It has been 15 years since I have file fitted a set of rings. I have used .004 per inch bore in the past. Ran fine for a couple of years n/a. Sold engine. New owner put a 150 shot of nitrous on it and broke a piston.
I'm thinking if the consensus is 16 thousandths is too little gap, how much worse it will be on a 150 shot. Did exactly this myself a few years back. Motor ran excellent until nitrous. Same damage afterward. I probably had the same marginal gap until nitrous exposed it. Good luck, sir.
Ahhhhh NOS……. Definitely need bigger gaps for power adders and how much timing did they retard the timing for NOS or just bang it in😱😱. Detonation will destroy ring lands also👍. Loving ya vids man. Keep up the great work 👍👍
There was a time when Chevrolet built good engines, like the 350. Rebuild it stock, and then just drive it. No oil leaks, no oil consumption. If it ain’t broke, don’t fix it.
I don't mess with flat tappet cams any more. I go roller, yes they're expensive but they don't go flat and the cost and time of replacing flat tappet cams far out weight the extra cost of a roller.
Ok, obviously the gap was too tight. But what about piston/bore clearance? Or the cam going houdini messing up oil spray on the underside of the piston? Run too lean? Im gonna bet on "gap too tight, but crowns got a bit too summery too". Aftermarket flat tappets are iffy at best these days, even previously reputable hi-po ones. Since you're gonna build her anyway, retrofit rollers might save you significant grief. Flats are "dinosaur stuff" as far as manufacturers are concerned, as all modern pushrod motors run rollers now. Gonna be less incentive to invest in tooling for flatties. That equals stretching tool life quite a bit beyond what used to be accepted. Like the other guy said, if youre gonna run flats, pony up for the oem bowtie hard faced ones, even if the aftermarket "race" ones make your bank account happier, lol.
Hmm, that's odd.. Doesn't look like the pistons were too tight in the bore. The skirts aren't all scuffed up bad. Strange that they ALL broke in the middle ring land area. He MUST have had the second ring gap too tight. The cam? Well, thats most likely a wrong break-in procedure, extended cranking before it started due to other issues, and/or the wrong oil used. No zinc or use of regular off the shelf oil. The scratches all over the pistons say that it was assembled dirty also.. Not enough fucks were given when putting this thing together. Edit: He MAY have installed the rings right out of the box, and never even filed them.... 🤷🏻
Too much for break in, use 100# less for first 1000 miles, and then go back to the LS springs!.. need to seat it properly without killing the cam, or just step up to a solid Roller…
end gap was too tight. Proper break in for the cam was not followed. You should run the springs @.050 from coil bind, the coils dampen ea. other and you will it more stable. Not a fan of flat tappet cams will never run one again personally
Gaping was wrong and i don't know why your cam like that but if it has big lift it would not matter just need adjustment who ever built it was a complete amateur😂😂😂😂❤❤
Good talk through the diagnostics. I think there was two separate issues that occurred at the same time. The cam was failing, probably due to failed break-in (maybe procedure, maybe parts quality, who knows). The issue I find more concerning is the cracked pistons. I would have thought that 16 thou would have been good but I guess if the parts were specific to that KB spec sheet it wasn't enough. Anyway, looks like this disaster was identified soon enough for this engine to be salvageable.
Thanks for the input. Yes I think I can get it back together on a budget. I didn't think it would be a problem either at first.
0.016 gap would be ok for a stock cast piston, but sounds like the KB hypers need a lot more. So I would say the too-tight gap is what broke the ring lands. Look at the ends of the rings closely and see if there are witness marks where they butted. The double spring pressures should be ok to run a FT cam, by I would definitely break it in with inner springs removed.
Nice thank you. The ring ends did look like they were hitting. They have wear marks on them.
On true blue kb hyper pistons, I run .007 per inch of bore. 350 street/drag run .028. If endurance (circle track/roadrace run .009 per inch(or for nitrous).
Nice balanced forged steel crank she has :) I concur on not enough ring gap and second scraper rings put in upside down.
Nice thank you. I thought the same thing on the second ring. They were in correctly with the top marks up.
I wouldn’t have thought it was the end gap but I didn’t realize KB needed a bunch more. I had a buddy who used cheap pistons, high compression and 87 octane that looked similar. I’m of the thought that a lot of cam failures are either due to lifter surface finish or improper convex spec. My last build I used GM replacement lifters. Made in America and have a hardened bottom friction welded on. I was careful on break in (took the inners out) and use a zinc rich oil. No problems yet 🤞
Nice thank you for the input. I will look into the gm lifters.
The gm lifters with the hard disks are all I use. I'm sending a used set in to be rebuilt rather than using aftermarket lifters without the hard disks. I bought several sets of new ones (hl66 or 5232720) several years ago for all my sbc engine builds.
When are you making a new video? I watched this over a month ago!!!
I have a few in the works. Thanks for watching.
Also when you put it back together, I have heard several guys say you should rotate the engine over by hand and see all the lifters rotate. I would like for you to try this out and show us.
I like it. Thank you.
Yep. Rotate it 3 times. Slap the valve cover and say. “That baby is gonna scream”. Hasn’t failed me yet. I barely hardly ever blow up my engines.
If the lifters went in the bores nice, and weren't tight, they WILL rotate. There's no point in trying to watch for it... 🤷🏻
@@nylegreen261wouldn’t you be wiping off the assembly lube/grease? I’ve seen guys say to not even overly prime your oil 😂. I had some “z28” valve springs installed basically factory springs that are rated up to 500” lift single springs.
Before you took it apart, my initial guess was some or all of the rings were upside down.
Sounds reasonable to me. It would make sense for the oil burning.
Usually went the cam starts to go flat, metal gets in the bearings and imbeds in the skirts of the pistons, this is what I have seen on a tear down of the engine and gets in the oil pump...
Thank you. I appreciate the input.
Open spring is a little high but still exceptable. I didn't see you look at the ring end gaps. They will be shiny if they touch. How much timing was in the motor when it was run.
I'm not sure on the timing. Yes the ring ends were shiny.
Open up all the ring gaps
Increasng second ring more then the top ring match top oil ring with second , allows combustion gases to not be trapped between the rings
Helps control ring flutter caused by trapped gasses
When rings butt its all over , using this method will maximise ring seal and operation
Slightly bigger gaps won't hurt
I like it thank you.
You are correct.
I watch to learn..hope to find out issue before I put my failure back together. 🙄
Nice I hope everything goes well.
.016" ring gap is certainly not enough.
If you look at the contact pattern on the cam lobes, it looks as though the cam to lifter interface is perfect, with the lifter riding the front edge of the lobes. Here lately I've been breaking in flat tappet cams with Quaker State 5w-30 full synthetic oil and have never had a problem with the correct springs for the cam installed, which for me are Competition Cams 986's. To be safe though, go ahead and break the next cam in on your LS6 springs.
Also, I think you may have mis-spoke about your retainer to valve clearance as .300" isn't nearly enough. It seems as though your calipers were further apart than .300".
Nice thank you for the input. Caliper was at .950. Installed height 1.75. Cam lift a was .510.
@nylegreen261 hi nyle. Keep the valve guide as long as possible. Many people cut them down way way to much. If I knew I was playing with different cams, clearence for the biggest. As for how much a person needs, I set mine at .050 beyond the most lift I thought I'd ever run.
Any signs of a nitrous kit having been installed?
Even a 125 plate shot will crack pistons when ring gaps are tight or nitrous applied at low rpm.
Id guess tight rings, bearing clearance and bad cam break in. are the chambers sooty ?
@shoelessb4515 Yes, sooty Chambers. No I don't think nitrous kit was on it.
I run 150 lbs. on a flat tappet cam made by Competition Cams with no problem... .630" and .637" lift. Tirn engine at 7,000 rpm... Some of the rings must of been installed wrong, upside down? How are the valve guides?
I checked the rings and they were installed correctly. Whats the best way to check the valve guides. Thank you.
For that cam, there is no reason at all to run that high of spring pressure! 112-115 closed is plenty!
And for those Keith Black Hyper pistons, you HAVE TO use the recommended ring gap or more to be safe! I have heard of many, many guys destroying those pistons because they didn't want to listen to the manufacturers recommendations. Live and learn, I guess.
except when it comes to iron cylinder Harley pistons, then don't set wall clearence near as tight as KB recommends.
The previous builder dissed the instructions and went with the typical Hastings 3.5-4 thou per inch.
Never saw a good shot at the domes to see if any detonation was going on. Hyper pistons don't like that at all.
Now , what pistins will you go back with??
140 lbs seat pressure for a flat tappet is way too much. 110-115 is about right
Nice thank you for the input
Still shouldn't have wiped the cam... it's made out of the same material that a larger cam is.
ring gap break in oil stop using hyper pistons after the first half dozen failures because of similar issues i quit using them in the early 2000s in truck apps towing heavy loads i would find piston parts the size of a quarter in the pan and not hurt any thing else
I'm curious if that was from detonation. Thanks for the input.
probably with factor hei distributor the curved in them will go to almost 50 degrees if you dont limitmthem@@nylegreen261
Nyle-did you like my L98 350 drag test on Speedtalk?
Nice I will look into it. I always enjoy your work and testing. I have taken the last month off from cars. I have been active with my kids activities lately.
Were the pistons cast or forged? I bought a short block and he said the pistons were forged, eventually I lost all compression on #7. When I tore it down the #7 piston was cast and the ring lands were broken like yours, the other pistons were forged and looked fine.
Looks like a typical KB piston with not enough ring gap!
I wouldn't of thought a ring gap of
.016 would cause problems. I have changed my mind.
@@nylegreen261 Guy after guy after guy has done this, people just don't learn!! Manufacturer recommends their own specs for a reason.
They require a larger top end gap because of their thermal expansion and the top ring begin close to the top of the piston. It’s the only thing i see wrong there. They do list the 2nd end gap at 0.004” x bore so 0.016” should be ok there.
On the other issue I don’t think the springs would cause issues on brake in IF the cam was broken in with the outer spring only. But since you didn’t assemble it there’s no way of saying it was done correctly.
P.s. is this engine going in your Nova for a Drag test after it’s been fixed up ?
Not sure if you are asking what went wrong or if you want the audience to find the problem. Either way it clearly states 0.026 gap. And you have 0.016 That gap needs opened up about 37%. Hope that puts the small amount into perspective.
Yup, Top ring gap too tight. That's for sure. I probably have the same pistons, KB Claimer UEM but 4.030"
Instructions are very clear. You'll pop the top off once the rings expand with heat. It needs the extra few thou they recommend.
Too bad. Quite a bit of money gone.
Use alcohol to fill up ports and check for leaks. The surface tension of alcohol is MUCH less than antifreeze, and will leak out at the slightest gap. The antifreeze may not.
I am curious about compression ratio and timing. Spring pressures sound good. Ring gap seems a bit tight. Spark plugs have any dust on them?
Looks like compression was around 10:1. With around .065 of quench. I will take a look at the plugs.
It appears the engine was bored?
I saw the formula for setting ring end gaps.
I would suggest following the formula sir.
Seems with busted lands on the pistons. Is it possible the engine was pre-ignition issues?
Yes it has a 4.040 bore. Will follow the formula on the next set of pistons. Pre-ignition is possible. I will check the plugs over.
That engine was dirty when it fired up. The ring gap was the big culprit. There have been some significant issues with lifters lately. It very well could be due to the lifters.
Thanks for the input. Im going to do some research on lifters and try to get a good set.
@nylegreen261 from what I have learned, Johnson lifters have been good lately. I think you can get most cams in decent shape. It's just the lifters that are an issue.
Muppet should have stuck to building briggs n strattons.. 🤣🤣🤣
Ring end gap was set at 4 thou instead of the required 6.25 thou. Simple as that
This surprised me. It has been 15 years since I have file fitted a set of rings. I have used .004 per inch bore in the past. Ran fine for a couple of years n/a. Sold engine. New owner put a 150 shot of nitrous on it and broke a piston.
I'm thinking if the consensus is 16 thousandths is too little gap, how much worse it will be on a 150 shot. Did exactly this myself a few years back. Motor ran excellent until nitrous. Same damage afterward. I probably had the same marginal gap until nitrous exposed it. Good luck, sir.
Ahhhhh NOS……. Definitely need bigger gaps for power adders and how much timing did they retard the timing for NOS or just bang it in😱😱. Detonation will destroy ring lands also👍. Loving ya vids man. Keep up the great work 👍👍
There was a time when Chevrolet built good engines, like the 350. Rebuild it stock, and then just drive it. No oil leaks, no oil consumption. If it ain’t broke, don’t fix it.
Nice, nothing wrong with that.
BAd back yard rebuild.
I'm not sure if it was a backyard build. But it definitely had problems.
I don't mess with flat tappet cams any more. I go roller, yes they're expensive but they don't go flat and the cost and time of replacing flat tappet cams far out weight the extra cost of a roller.
Hyper pistons gap at 26 thousands per instructions
I'm on it thank you.
what's a ringing gap?
I think ringing gap. Is ring end gap sorry about that.
A ringing gap is what happens to your neck after being a smart ass and a guy's had enough of your shit!! lol
ring gap was too tight, ring ends touched, popped the side of the piston.
the bottom of the rockers is from someone tightening the rockers all the way down, bottoming out the lifters, which is what made the cam wipe.
Sounds reasonable thanks for the input.
You may have forgotten to install the piston return springs...😊
LoL nice
Maybe the muffler bearings where set to tight 🤔🤔🤔🤔🤔🤪🤪😂😂😂👍
Nyle Geeen how can I get ahold of you, I have some questions about a nova I am building…. Maybe an email?
Let me think about the best way. Give me a few.
Probably didnt help the bearings when those pistons broke. .026 thats gonna get missed. Read those instructions
Will do thank you.
No, it didn't have too much spring pressure...
Ok, obviously the gap was too tight. But what about piston/bore clearance? Or the cam going houdini messing up oil spray on the underside of the piston? Run too lean? Im gonna bet on "gap too tight, but crowns got a bit too summery too". Aftermarket flat tappets are iffy at best these days, even previously reputable hi-po ones. Since you're gonna build her anyway, retrofit rollers might save you significant grief. Flats are "dinosaur stuff" as far as manufacturers are concerned, as all modern pushrod motors run rollers now. Gonna be less incentive to invest in tooling for flatties. That equals stretching tool life quite a bit beyond what used to be accepted. Like the other guy said, if youre gonna run flats, pony up for the oem bowtie hard faced ones, even if the aftermarket "race" ones make your bank account happier, lol.
Not a bad idea. Looking into a hydraulic roller.
Hmm, that's odd..
Doesn't look like the pistons were too tight in the bore. The skirts aren't all scuffed up bad. Strange that they ALL broke in the middle ring land area. He MUST have had the second ring gap too tight.
The cam? Well, thats most likely a wrong break-in procedure, extended cranking before it started due to other issues, and/or the wrong oil used. No zinc or use of regular off the shelf oil. The scratches all over the pistons say that it was assembled dirty also..
Not enough fucks were given when putting this thing together.
Edit: He MAY have installed the rings right out of the box, and never even filed them.... 🤷🏻
Bearings look like crap don’t think they would’ve made it another 2000 miles
Agreed they were getting torn up by debris.
NOT ENOUGH RING END GAP.
Both
Grade 7 cromoly piston crower forged crank Manley aluminum rods crome piston rings crome rod bolts crome bushed wrist pin cromoly Spiro locks crome plated cylinders chrome plated brodix late-model spec head all crome plated on the inside of everything cam spec roller 224 224 680in 680ex lift 10.5 to 1 comp edlebrock 2325 intake holler custom 800cfm mech carb msd 7al box ignition chrome plated plugs windage tray copper head gaskest 4 bolt main block msd small diameter distributor chrome plated stainless steel valves ......9000rpm plus zero balanced...
Too much spring and not enough ring gap
Too much for break in, use 100# less for first 1000 miles, and then go back to the LS springs!.. need to seat it properly without killing the cam, or just step up to a solid Roller…
end gap was too tight. Proper break in for the cam was not followed. You should run the springs @.050 from coil bind, the coils dampen ea. other and you will it more stable. Not a fan of flat tappet cams will never run one again personally
@JohnMcMahon-yf5ks Yes I agree. Thanks for the input.
That's not a Keith Black piston
My research came up with uem pistons. They make kb and silvolite pistons.
Those bearings look like shit for 250 miles.... 😝
Your end gaps are way too small
Gaping was wrong and i don't know why your cam like that but if it has big lift it would not matter just need adjustment who ever built it was a complete amateur😂😂😂😂❤❤