6.2 breaking valve springs
Dec 6, 2011 | 07:45 AM
#1
6.2 breaking valve springs
I gotta 05 gmc pickup with a 6.2 engine with l92 heads and it has a broke valve spring for the 2nd time. The first the engine had a tsp 220/220 cam with prc dual valve springs. I didnt do the work but the owner of the truck claimed the tech had told him he broke 3 different springs. The tech replace all the lifters and springs with ls7 lifters and a dif brand of dual valve springs (he dont remember the brand). He then drove for about 2k miles and I put a mid 230s with .620 lift cam in it. We got it retuned and he drove it for another 7k miles and now it broke a valve spring on the intake valve. The valve is completely loose in the guide so Im not sure what all is broke. Im going to remove the head tonight. Anybody heard or have a 6.2 break valve springs this often? any help is appricieted.
Dec 6, 2011 | 08:19 AM
#2
Ive had patriot extreme springs on my motor for 11-12k and ive spun it to 6800 a ton of times. Ive never had any issues with mine. LS7 lifters, new trays, stock head gaskets, heads decked .020" i run 7.4" pushrods.
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Dec 7, 2011 | 11:54 AM
#8
well I removed the head and found this. The guide completely came out of the head. one picture is of another intake guide that has started to move. The piston got hit a little but i think it should be fine. I think ill just replace the head instead of fixing it.
Dec 7, 2011 | 01:32 PM
#9
Who did the Extensive port work on those heads??? I wouldn't be suprised if the valve/ spring heights were not set up correctly. I also would not be surprised if the Valvetrain geometry was not correct.... I would have the other head inspected too... You might find and issue with the guides. If there loose and the valve is bounceing around it can cause other damage. Also inspect the rockers for excessive wear or possible deffects
