Broken Valve Spring - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rbuckin111 · 12-15-2012, 11:06 AM

Appreciate your help on this one. I recently put in a 230 rebuild in my 64 GMC. In about 2000 miles, I have had two valve springs break. Everyone tells me springs breaking is rare, so it leads me to believe something is awry that is causing it. Do any of truck buddies have an idea what might be going on? Not looking forward to this happening 10 more times!

64-454ss · 12-15-2012, 11:49 AM

I had the same thing on my 350. I think it was exhaust valve on # 1 cylinder (very front cam lobe). Got lucky first 2 times! Not so much the 3rd.(now I have a 454) The only thing i could conclude was that it was getting some bad vibrations or something from the after market gear drive. I'm not familiar with the GMC 230, but, does it have timing gears or chain? If it is gears, just something to check out.
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cableguy0 · 12-15-2012, 12:34 PM

I could only assume new springs were used? Aside from high rpm race applications broken valve springs are definitely rare and even in racing they are somewhat rare. Coil bind is usually the only thing that will cause them to break. I would have a hard time believing that you managed to turn enough rpm in a 230 I6 to get coil bind without throwing the bottom end out on the road. I would check everything and make sure nothing is binding. Are the pushrods bent? Are the valves opening and closing freely? Its always possible you got some junk springs

crazy longhorn · 12-16-2012, 07:31 PM

Quote:

Originally Posted by cableguy0

I could only assume new springs were used? Aside from high rpm race applications broken valve springs are definitely rare and even in racing they are somewhat rare. Coil bind is usually the only thing that will cause them to break. I would have a hard time believing that you managed to turn enough rpm in a 230 I6 to get coil bind without throwing the bottom end out on the road. I would check everything and make sure nothing is binding. Are the pushrods bent? Are the valves opening and closing freely? Its always possible you got some junk springs

That would be my 1st ?....used or new on the springs? The next would be as stated....nothing binding. check for bent pushrods,& or sticky valves? I think the young man has you covered on this one

crazyL

12-15-2012, 11:06 AM	#1
rbuckin111 Registered User Join Date: Mar 2011 Location: Mesa, AZ Posts: 46	Broken Valve Spring Appreciate your help on this one. I recently put in a 230 rebuild in my 64 GMC. In about 2000 miles, I have had two valve springs break. Everyone tells me springs breaking is rare, so it leads me to believe something is awry that is causing it. Do any of truck buddies have an idea what might be going on? Not looking forward to this happening 10 more times! __________________ Lovin' my 64 GMC Fleetside Daily Driver

12-15-2012, 11:49 AM	#2
64-454ss Registered User Join Date: Nov 2012 Location: Escalon, Ca Posts: 63	Re: Broken Valve Spring I had the same thing on my 350. I think it was exhaust valve on # 1 cylinder (very front cam lobe). Got lucky first 2 times! Not so much the 3rd.(now I have a 454) The only thing i could conclude was that it was getting some bad vibrations or something from the after market gear drive. I'm not familiar with the GMC 230, but, does it have timing gears or chain? If it is gears, just something to check out. Posted via Mobile Device

12-15-2012, 12:34 PM	#3
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	Re: Broken Valve Spring I could only assume new springs were used? Aside from high rpm race applications broken valve springs are definitely rare and even in racing they are somewhat rare. Coil bind is usually the only thing that will cause them to break. I would have a hard time believing that you managed to turn enough rpm in a 230 I6 to get coil bind without throwing the bottom end out on the road. I would check everything and make sure nothing is binding. Are the pushrods bent? Are the valves opening and closing freely? Its always possible you got some junk springs __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.



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