Jason99T/A

iTrader: (21)

Joe/Chris, where would draw the line as to the most seat/open pressure you would run in a daily driver? My ISKY springs setup around 210 on the seat and 500 open. I figured this was a little on the edge for the street, but I knew I could get many miles of it. I'm curious as to what you guys think on the matter.

Fireball

iTrader: (21)

I'm curious as well <img src="gr_stretch.gif" border="0">

Joe Kizzire

Like Chris said... it depends on the lobe, the spring manufacture, the installed height.
Jason the numbers I gave are the specs on my springs and it's the same specs on the other 375in motor from the shop that did my heads.

Jason think about it... Have you ever seen or heard my valves float????

Geoff

iTrader: (3)

My .02 cents on spring pressure: The cam in Jason's setup wasn't designed to turn 7500+ RPM. The ramps were VERY agressive, IMHO agressive ramps are the greatest thing in the world for a RPM limited application where you are trying to build 'area under the curve' and aren't trying to spin the motor to the moon. With that, we had also installed valves with 11/32" stems and used a conventional jumbo 10 degree lock with a 1.550" retainer. All of these parts are very heavy compared to the stock style LS1 valvetrain parts. With the combination of heavy valvetrain parts and agressive ramps a good bit of spring pressure was needed to control valvefloat. I also felt that because of Jason's agressive driving I would rather err on the side of having a little too much spring pressure than too little.

Jason's motor was the first try for us doing a solid roller LS1, we have definitely learned a few things about valvetrain weight to improve future efforts, but I don't feel comfortable backing off on spring pressure.

Also FWIW Jason's motor is still being daily driven with the monster springs in Paul's car.

Geoff

ChrisB

I would feel comfortable with a little less spring pressure as long as a rev kit were used. around 170-180 seat lbs and 450-475 total. But without a rev kit I probably would have gone with similar spring pressures to what Jason used. Could you have got away with less? Probably. Would I want to find out the hard way? No.


Chris

Jason99T/A

iTrader: (21)

Brian, a 5.3l head and a 5.7l LS1 head will flow pretty much the same. They have nearly identical intake/exhaust ports. Only major differences in "stock" form is the smaller combustion chambers and valve size.

Like I told you in the email, I think the solid roller setups are just as reliable, if not more than doing a hydraulic setup. You will have a bullet proof valvetrain (shaftmount rockers, bad-*** valvesprings,etc.). You no longer have to worry about breaking a rocker arm, etc.. There were 3 cases locally where guys broke the stock rocker arms, causing a ton of needle bearings to find a new home inside the motor. <img src="gr_eek2.gif" border="0">

Only problem I can see driving the car everyday with a very aggressive cam that will require a ton of seat/open pressure is valve seat wear. You will slamming the valve open and closed very hard and this will wear the seats out over time. How long will this take? Probably quite awhile, but it will happen sooner than if you were running a B1,etc.

Checking valvelash on my car took exactly one hour. We checked it after initial startup and they had moved a little bit (very normal). We readjusted them and I drove it almost 5k miles before putting it in Paul's car. We checked them again then and they hadn't moved at all.

If you have the money and want to push the envelope a little more, then solid roller is the way to go. <img src="gr_stretch.gif" border="0">

[ January 06, 2002: Message edited by: Jason99T/A ]</p>