Without know hard facts, like what lift the stock springs can handle, I'm going with coil bind as the culprit. When you have coil bind, generally the retainer, especially stock retainers are going to be the weak link. Think about it, when it coil binds the retainer is seeing extreme loads.

 

Yes, stock head gasket to keep compression at 10-1 per s&s. I dont believe the valve floated but who knows. The retainer is snapped in half. I took a pic with my Blackberry and tryed to post it but cant seem to make it work. I didnt clay the piston/valve, really didnt think it would be necessary. Shows you what I know. Motor sure did run good for 1200...

 

I myself would be afraid to run even .575 with stock springs. I am guessing when it was on the dyno you had it running at a higher rev range then you did on the street. Were the heads 100% stock? bummer for sure.

 

yeah, I kept the heads stock.. S&S claims 583 can be run with stock springs. gota love hindsight. Bike was around 4000 RPM when retainer broke. Kinda crazy, when it died all power went out, headlight and all. Not sure if its a safety feature or what. Luckily nothing went into bottom end, oil pump or cylinders. Still gona pull oil pan just to be safe and clean out lines.

 

Pittz I hate to hear about your bad luck but to tell the truth thats one of the reasons I went with the 204 cam's. 508 lift, I think all the new higher lift cams put the stock springs right on the ragged edge and like you have stated valve float due to a weak spring is not good. I hope it's not to bad and you'll be on your way again without hitting the wallet too hard.

 

Thanks Tn. 204 is a good choice.

 

does anyone know if heads off 2012 will work on my 09? Also found a set of a 2010 but they have ACRs.

 

When you install those keepers, always tap the top of valve stem with a hard plastic hammer two or three time straight down to seat them and make sure they are seated. Hit it and watch closely that you see stem drop down about 1/8-3/8 inch on the thrid hit or so. When I do a V8 heads it not unusual to have at least one jump out of the first tap. However keep in mind that they actually will jump out if you just tap it so hard that it jumps down 1/2" or so all at once. I assumed you are talking about the two tapered keepers broke or come out or are you truely talking the spring retainer that they clip down in and the retainer that sets in the spring? Have seen some high lifts angles incorrect so rocker hit edge of retainer or was very close at cranking speed. No telling what it would do at 5500 rpm.

 

Both of those heads will work for you.

 

the acr's won't be an issue just don't wire them up if you are going to continue to use the ez starts.