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Discussion Starter #1
Well I kept having a problem with my car I couldn't explain or fix and it slowly got worst. I was having a steam/ oil problem out of my valve cover breathers but never could figure out what was wrong. Also i was also always being told my car should run better than it was. Well this weekend I took a vid of my car because it got worst and it showed the bubbling in the radiator that would say a bad head gasket.. So I took the top end off and found even more....Seems when I was building the engine I made a small error that turned big. It had been a few years since I built an engine and when I did my valve adjustment I did all of the them the correct way with exhaust close adjust intake and then intake open adjust exhaust. well on piston 2 I accidently did both of them when the vavles were open causing my intake rocker to come loose and fall off. Well I didn't no at the time but my piston must have kissed the valve...Hence the oil/steam that slowly got worst as I drove it....

So now I have to buy another piston and ring set, along with gaskets set...What fun always...

Here is a tell tale look at it....



 

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That sucks...I was wondering what you might find during teardown after watching the video you posted the other day.
Now build it better, stronger & faster :yes:
 

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Ok so here is my question. Maybe i misread it. If you adjusted the valves with them open, yes when they cam let the pushrod come back down youwould have like some awesome lash. I could see the rocker coming off. BUT that means the valve just is not opening as far, so if you had proper valve cleareance with it opening the whole way, how would the piston have hit the valve if it wasn't opening fully?
 

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Discussion Starter #5
Ok so here is my question. Maybe i misread it. If you adjusted the valves with them open, yes when they cam let the pushrod come back down youwould have like some awesome lash. I could see the rocker coming off. BUT that means the valve just is not opening as far, so if you had proper valve cleareance with it opening the whole way, how would the piston have hit the valve if it wasn't opening fully?
the rocker didn't come off right away it got banged around along with the pushrod until the nut got loose enough for it to fall off. The car drove kind of fine for a while like that before it lost the rocker, then it started popping do to the dead cylinder...Put the rocker on correctly and it seemed to run fine, but the damage was done and just got worst with use....All I can come up with...

everything must have happened just perfect for the loose rocker to cause the pushrod and valve to get stuck and let it kiss the piston...

I don't know or it was bad piston and let go on its own...

no nitrous, don't remeber any backfires that would have caused it..only thing I could think of that went wrong since it was built...
 

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the rocker didn't come off right away it got banged around along with the pushrod until the nut got loose enough for it to fall off. The car drove kind of fine for a while like that before it lost the rocker, then it started popping do to the dead cylinder...Put the rocker on correctly and it seemed to run fine, but the damage was done and just got worst with use....All I can come up with...

everything must have happened just perfect for the loose rocker to cause the pushrod and valve to get stuck and let it kiss the piston...

I don't know or it was bad piston and let go on its own...

no nitrous, don't remeber any backfires that would have caused it..only thing I could think of that went wrong since it was built...
Nope..... My bet is the top ring gap was too tight and lifted the top of the piston.:yes: Seen it MANY times. Bad lash is just a coincidence.
What kind of pistons and rings? What ring gaps?
KB's Hypereutectic's are notorious for it. They typically require a bit more top and second gap.:yes:
 

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KB's Hypereutectic's are notorious for it.
They only do it when you don't follow the instructions--the required extra gap is more than just "a bit". When gapped properly, KB's work great..I'd bet 99% of KB failures are related to incorrect ring gaps.
 

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1. They only do it when you don't follow the instructions--the required extra gap is more than just "a bit". 2. When gapped properly, KB's work great..I'd bet 99% of KB failures are related to incorrect ring gaps.
That's with ANY piston.:rolleyes:
Agreed.:yes:
However, they changed their literature just a few years ago to reflect the need for the added ring gaps. LOTS of pistons met their demise before then:yes:and left a bad taste in the mouth of a LOT of builders.:rolleyes: Couple that need with a LOT of builders that used the pregapped, non-file fit rings and you can QUICKLY see where a bunch of problems can come from.

I've personally ran then (KB-102's) with a 275 shot for years and well over 30 bottles without a problem until a couple 325 hits lifted a ring land.:D MAN WHAT A RIDE IT WAS THOUGH!!!! The fact that I had opened the gaps for planned nitrous use is ONE of the things that made mine last as long as it did.:yes:
 

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Discussion Starter #9
They ar srp forged pistons and I set the gap at if I remmber correct .022 for top and .02 for 2nd. The literature stated I think .020 and .018 for NA engine and other told me .022 and .020 for nitrous so that is how I set it up for future fun....I can find the paper so this is just from memory which has been wrong..All I know is that I set it up for the nitrous application per the instructions and others recomendation
 

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However, they changed their literature just a few years ago to reflect the need for the added ring gaps
It's been over 10 years since I put them in my 391, and at the time I set my gaps at .039" expecting to try a little nitrous--never got around to it, the car ran 10.25/131 on the motor, and I don't have a NHRA license.
 

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hate to see

the damage , hopefully it won't be too much to get you back in the game

I saw some KB's in a 406 take a 300 fogger and a 125 plate system for over a year ,, kept waiting for it to pop and it finally did ,,,, i think they still did pretty good considering.
 

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Discussion Starter #12
the damage , hopefully it won't be too much to get you back in the game

I saw some KB's in a 406 take a 300 fogger and a 125 plate system for over a year ,, kept waiting for it to pop and it finally did ,,,, i think they still did pretty good considering.
hopefully by the end of next month..I had to pay for my wifes college so funds are scarce right now..Everything always happens at the worst time...
 

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They ar srp forged pistons and I set the gap at if I remmber correct .022 for top and .02 for 2nd. The literature stated I think .020 and .018 for NA engine and other told me .022 and .020 for nitrous so that is how I set it up for future fun....I can find the paper so this is just from memory which has been wrong..All I know is that I set it up for the nitrous application per the instructions and others recomendation
Every manufacturer seems to recommend something different and then the ring manufacturers come in and recommend something different as well.
First off, bore size x .005 is about where I set a N/A application. Higher compression, nitrous/boost, etc and the multiplier can go as high as .008... Your gaps IMO should have been set (assuming a 4.030" bore) at .020" top and .022 second (N/A ONLY) and for MILD nitrous/boost the gaps would grow to .028" top and .030" second and continue to grow depending on the amount or nitrous.

It's been over 10 years since I put them in my 391, and at the time I set my gaps at .039" expecting to try a little nitrous--never got around to it, the car ran 10.25/131 on the motor, and I don't have a NHRA license.
Looks like a multiplier of bore size x .0095 or a little better. The added gap you used for the future nitrous use is what saved those pistons IMO..
 

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Discussion Starter #14
Every manufacturer seems to recommend something different and then the ring manufacturers come in and recommend something different as well.
First off, bore size x .005 is about where I set a N/A application. Higher compression, nitrous/boost, etc and the multiplier can go as high as .008... Your gaps IMO should have been set (assuming a 4.030" bore) at .020" top and .022 second (N/A ONLY) and for MILD nitrous/boost the gaps would grow to .028" top and .030" second and continue to grow depending on the amount or nitrous.
Hey I was at .022 top and .020 for 2nd but never ran nitrous just set it incase...Well this time I will set them all to a bigger gap..Thanks!!
 

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i almost

That'll buff out.
laughed ,, mmm ,,, i laughed pretty hard actually :devil:,,,

but on the positive side , i know where there is a 496 that dynoed close to 1000 hp on alcohol , it needs refreshed , but he only wants 4000 for it ,, aluminum rect heads , 800 lift roller , callies crank , aluminum rods ,,

could detonation have caused this ??
 

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Discussion Starter #16
laughed ,, mmm ,,, i laughed pretty hard actually :devil:,,,

but on the positive side , i know where there is a 496 that dynoed close to 1000 hp on alcohol , it needs refreshed , but he only wants 4000 for it ,, aluminum rect heads , 800 lift roller , callies crank , aluminum rods ,,

could detonation have caused this ??
I don't think so, I am at 10.7 and run 94 octane I never heard any.

I can redo that cylinder and get new rings for all cylinders and all gaskets for 325-350 and have her running again. it will just take time...
 
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