I'm slowing getting into rebuilding this C9 head and want to upgrade the guts, so to speak. For right now, I'm going to stick with stock valves as it saves me the price of machining and lets me spend elsewhere until I decide whether or not I'll eventually migrate to the CI head. I was considering upgrading the springs though. I've been through the CI literature a few times, and because I'm an engineer (albeit electrical) I like to putz around with stuff.
I've been digging through the specs on the lifters that CI has listed, the stock springs, and playing around on ye olde interwebs. Now I have a copy of the da Falcon book, unfortunately it has disappeared as my wife is rearranging things since the baby is due in a few weeks.... Anyway, I know that some 289/302 springs have been used so I've looked at a number of different p/n for these. I also noticed that CI sells what I'm assuming to be a Toyota spring, this just a guess based upon what they call the part numbers. So that got me thinking to just head out to Summit and Jegs and dig around.
Based upon the CI spec information, I see that the OEM outer diameter is 1.355", free height of 1.795", open height 1.22", closed height 1.585" with the pressure being 52/152. I started looking for something that had a similar O.D. so that I could avoid having to machine the spring seats. The most interesting dual-spring that I found was this guy:
http://www.camshaftwarehouse.com/Produc ... 8-16-.aspx
This thing has in O.D. = 1.384", I.D. = 0.804", Seat Load 117lb@1.600", and Open Load 232@1.100". First issue I see is that there no clearance for a standard umbrella seal with an O.D. of 0.81". Minor issue as I should be able to find a narrower option there.
The thing I don't fully understand is whether or not this will blow a lobe on me because of pressure. I wasn't planning on replacing the camshaft right now, but my intention was to go with the split camshaft that CI sells (264/274, 110*). Am I in danger of blowing out the old cam? I'm not 100% sure that I don't already have a bad lifter on #3? I would check but it's a pain in the ass to get my valve cover off because of the Monte Carlo bar that I have installed between the shock towers.
I mostly tried to understand O.D., I.D., and seat pressure. I can calculate the seat pressure once I find out what the actual install height is and the same with the load pressure based upon the camshaft lift and associated valve train geometry. Right now I plan on re-using the standard 1.5 non-adjustable train that came off of the thing. Unless I find something on ebay or craigslist, the cost of an adjustable valve train is potentially more then what I would spend on headers, which I would like to get here in the nearterm as well.
And a final thought, can I get away with my old retainers? I assume retainers "should" be ok as long as they sufficiently mate with the springs. I'll probably have to measure that too...
So am I all whacked out on goofballs here? Is my understanding of how this works remotely close? Have I covered everything?
Prost!
I've been digging through the specs on the lifters that CI has listed, the stock springs, and playing around on ye olde interwebs. Now I have a copy of the da Falcon book, unfortunately it has disappeared as my wife is rearranging things since the baby is due in a few weeks.... Anyway, I know that some 289/302 springs have been used so I've looked at a number of different p/n for these. I also noticed that CI sells what I'm assuming to be a Toyota spring, this just a guess based upon what they call the part numbers. So that got me thinking to just head out to Summit and Jegs and dig around.
Based upon the CI spec information, I see that the OEM outer diameter is 1.355", free height of 1.795", open height 1.22", closed height 1.585" with the pressure being 52/152. I started looking for something that had a similar O.D. so that I could avoid having to machine the spring seats. The most interesting dual-spring that I found was this guy:
http://www.camshaftwarehouse.com/Produc ... 8-16-.aspx
This thing has in O.D. = 1.384", I.D. = 0.804", Seat Load 117lb@1.600", and Open Load 232@1.100". First issue I see is that there no clearance for a standard umbrella seal with an O.D. of 0.81". Minor issue as I should be able to find a narrower option there.
The thing I don't fully understand is whether or not this will blow a lobe on me because of pressure. I wasn't planning on replacing the camshaft right now, but my intention was to go with the split camshaft that CI sells (264/274, 110*). Am I in danger of blowing out the old cam? I'm not 100% sure that I don't already have a bad lifter on #3? I would check but it's a pain in the ass to get my valve cover off because of the Monte Carlo bar that I have installed between the shock towers.
I mostly tried to understand O.D., I.D., and seat pressure. I can calculate the seat pressure once I find out what the actual install height is and the same with the load pressure based upon the camshaft lift and associated valve train geometry. Right now I plan on re-using the standard 1.5 non-adjustable train that came off of the thing. Unless I find something on ebay or craigslist, the cost of an adjustable valve train is potentially more then what I would spend on headers, which I would like to get here in the nearterm as well.
And a final thought, can I get away with my old retainers? I assume retainers "should" be ok as long as they sufficiently mate with the springs. I'll probably have to measure that too...
So am I all whacked out on goofballs here? Is my understanding of how this works remotely close? Have I covered everything?
Prost!