Can LS6 valve springs work??

[buttonfly]

I will be running the comp 206/206 roller...question being it looks like the 918's are reccomended, but the question lies can I run stock LS6 springs? I work at a chevrolet dealership and I can buy a set of these my cost is around 40.00 for a set of 16. I searched and searched but could not find a difinative answer as to "if" they would work. I do know a lot of LS guys running pac 1218 or 1518 springs, but they are running cams well above .575 lift. Thank you in advance for any and all information....thank you

I am just curious as if it was even worth the time.

 

[bison]

26918's are about the minimum id be using if i was looking for 125+mph. There is no point in comparing a soft LS lobe that is used in a naturally aspirated application to a fast ramp high boost application. If you can get around 140 on the seat and about 400 open and not coil bind you will be ok up to about 30psi and 5700 rpm on the typical lobes out there. If youre running the most aggressive lobes you will need more pressure. There is no point in chasing spring pressure. A little extra does no harm. Too little will leave you scratching your head. Ive used comp 941, comp 26918, comp 26120, and PAC 1203 with great success over 135mph and boost in the high 20's. Ive gone to 33psi/6300 rpm with the PAC springs. If youre looking for 140mph you need to look a little closer at the springs. I woudlnt use anything that was less than 165 on the seat and 420 open with the hyd grinds out there. Im currently running about 200 seat and a little over 500 open on the engine in my black car. 885 lifters required. Ive got over 3000 street miles on this setup. Beyond that you should just consider a solid lobe. Dont try and run a lot of spring pressure on non 885 hyd lifters. The problem installing any spring with any nut on a buick head with the standard valves is that the installed height becomes an issue once you start getting into the .580 lift range. You just cant throw any double spring on there because you will coil bind.

 

[buttonfly]

26918's are about the minimum id be using if i was looking for 125+mph. There is no point in comparing a soft LS lobe that is used in a naturally aspirated application to a fast ramp high boost application. If you can get around 140 on the seat and about 400 open and not coil bind you will be ok up to about 30psi and 5700 rpm on the typical lobes out there. If youre running the most aggressive lobes you will need more pressure. There is no point in chasing spring pressure. A little extra does no harm. Too little will leave you scratching your head. Ive used comp 941, comp 26918, comp 26120, and PAC 1203 with great success over 135mph and boost in the high 20's. Ive gone to 33psi/6300 rpm with the PAC springs. If youre looking for 140mph you need to look a little closer at the springs. I woudlnt use anything that was less than 165 on the seat and 420 open with the hyd grinds out there. Im currently running about 200 seat and a little over 500 open on the engine in my black car. 885 lifters required. Ive got over 3000 street miles on this setup. Beyond that you should just consider a solid lobe. Dont try and run a lot of spring pressure on non 885 hyd lifters. The problem installing any spring with any nut on a buick head with the standard valves is that the installed height becomes an issue once you start getting into the .580 lift range. You just cant throw any double spring on there because you will coil bind.

Thank you as always, I truely appreciate the info Bison. That gives me a target for the springs. I should have said I am looking for mid 120 trap speed, upper 20's on boost, possible on E85, and I would like to do it on the 6152. I do think to do this I will need to get the big boy pants on and buy a 9.5 ptc.

 

[bison]

The 26918's would easily cover that. You'd need to ck the pressures on the GM springs. They might have you covered. You can run them conical springs really tight. Like .030 from theoretical coil bind no problem. The 6152 will gave you covered and the ptc 9.5" will make a huge difference. If you start hitting backpressure I could convert that 6152 into a 6176p and you would be good till you run it out of compressor. The gt35r comp wheel is superior to the 60-1 especially if you are running over 2.5:1 pressure ratio. The t350 turbine spools well but will hit some backpressure around 55lbs/min. The 76p will had you covered till the comp wheel is out of breath. The difference in spool with a proper 9.5" ptc would be hardly noticeable

 

[buttonfly]

Did I understand you to say you could convert the 6152 to a 6176?? I am very interested in that conversion, PM me a cost to convert....thanks