99Bluz28

iTrader: (35)

The PAC 1211X Beehive springs($150) have a 370 open pressure, handle slightly more lift(.625"),and they're a direct swap for your PAC 1218 which only have a 318 open pressure.
http://www.ws6project.com/user_stor/...oducts_id=5134

99Bluz28

iTrader: (35)

FYI with you 1.75 rockers your lift is now right about .588"/.590", an your ramp rates are slightly more aggressive.

96capricemgr

iTrader: (1)

I wouldn't get so fixated on open pressure, yes the valve can get out of control at full lift but hell there are cams designed to do that. A power loss from valve float is going to be from bouncing off the seat when the valve closes, it bounces and then is open when it needs to be closed costing power.

How long have the springs been in use?
Valvesprings become a maintenance item with a aftermarket cam.
The heavy, higher ratio rockers certainly demand further consideration when choosing springs and beehives need to be setup correctly to take full advantage of them. Slap them in at any old installed height and then fail to consider they are a maintenance item and you will have issues.

IMO you should call a professional you trust and get advise from them. You already made mistakes, now you need to just contact someone you trust and do what you are told.

ejbta2

I will use a dual spring for sure and will call Jake at Texas Speed. Thanks for the info guys you confirmed what I was thinking, I just did not know how much pressure I needed, and will stay above 440. The reason I used the PAC 1218 was because I already had them on my heads. When I put the rr on my stock cam I lost valve control above 5500 rpm.

99Bluz28

iTrader: (35)

It sounds like you already knew the root cause of you issue; Heavier rockers tips and too low of a spring pressure. The PAC 1218 require a 1.8" seat height, if they're set above 1.8" your spring pressure is even lower.

96capricemgr

iTrader: (1)

Maybe the important lesson here is that at least from what little you have told us the roller rockers sound like they are a mistake from the start and you are dead set on continuing with them because you already wasted the money. Really you are throwing good money after bad.

If there was a REASON to spend the coin on aftermarket rockers you just haven't mentioned it.
Most vendors who sell aftermarket rocker would tell you to stay stock with trunnion upgrade for what you have, the additional set of spring you now have to buy cost more than the trunnion upgrade would have. The little bit of extra lift is not worth it because you could have just bought a cam with more lift.

chevybayboy

iTrader: (6)

Id go brain tooley

99Bluz28

iTrader: (35)

I wouldn't recommend that for the YellaTerra 6645s; not at all!
Furthermore, not all RRs can handle 450lbs open pressure, especially aluminum RRs, I'd verify the opening pressure they can handle before making a purchase. He shouldn't have a problem with 450lbs on his rockers since there not aluminum.

JakeFusion

iTrader: (7)

There has been some debate on what the limit is with the YTs. I've seen 420. I've seen 450. I've also seen a lot of broken YTs because they are setup incorrectly.

Like I said, you want to run as little spring pressure as you can get by with. If you have valve float or are pole vaulting the pushrods, you need more control via additional spring pressure. But you don't want so much you are collapsing the lifter, damaging the valvetip, or destroying the rocker arm.

99Bluz28

iTrader: (35)

Yeah I've seen 400, and 425 with the new version, but I still wouldn't recommend them, not anymore. I believe 450 was for the 6639 adjustable rockers.

ejbta2

I appreciate all the feedback, I would have made a mistake buying the Lunati's 73925k1 because they did not have enough pressure. I went with PRC's because they have 450 open pressure. JAKEFUSION I made my decision due to your knowledge of the subject and several parts dealers agreed with what you have said.

JakeFusion

iTrader: (7)

Those should work well with the Comp RRs. If you can run roller rockers without valve float, you'll pick up a few HP on the top end due to the decreased friction. So it's not a horrible investment at all. Just the stock GM rockers are tough to beat for their strength and light weight.

ejbta2

Thanks to everyone. I knew I needed dual springs but I didn't know how much pressure and how much spring rate. There is a difference in spring pressure between stock and roller rockers 400 on stock and 450 on roller. I did not know that before I posted this post. This is my first ls1 build, I had a few issues one was with my heads, piston to valve clearance witch I had to use a thicker head gasket(.07 cometic) and still had 10.7 compression ratio. And the other was the wrong springs (I was using what I had ). I used the PAC 1218 because the cam specs said it was beehive friendly (but not with rollers I found out) they may have worked with the stock rockers but I don't know. The car is running good now my local performance parts store had the springs. Two small issues on my first build isn't bad. Its done and I am happy, that's all that matters.

96capricemgr

iTrader: (1)

Wait a minute what am I missing here?

I thought the discussion was the YTs max out at either 420 or 450 and you went with a 450 spring? So sitting at the edge of rated durability

This is after I said that seat pressure being too low is what hurts power. Too little open pressure is often done on PURPOSE to loft the lifter gaining extra lift at high rpms. Not a great thing to do with a mild hydraulic setup but the point is lack of open pressure doesn't hurt power hell it can help it so long as it doesn't smash thing together too much when the parts do land back together.

JakeFusion

iTrader: (7)

He has the Comp RRs, not the YT. That was a side discussion.

He went with springs that have more seat pressure too. If you look at everything TSP says, they recommend higher open pressures as well to reduce valve float in the upper RPMs. Their spintron testing backs this up (as does Tooley's).

96capricemgr

iTrader: (1)

I understand the spintron thing and the little things that make big differences when analyzing things with one.

I just saw what I felt was an aweful lot of fixation on open pressure and I have seen other guys do that and not get the seat pressure right. Watched an LT1 guy go through I think 3 sets of springs because he wouldn't listen, think he has swapped the cam twice since too..

Doing things wrong over and over is hard and expensive.

JakeFusion

iTrader: (7)

I agree do it once and do it right. The seat pressures of BTR and TSP springs are 155+

Sales@Tick

iTrader: (3)

No offense, but you're totally wrong.

Platinum springs- stock rockers
Extreme Springs- stock rockers
Max Pressure- roller rockers

boostit5.3

iTrader: (3)

here it says the max pressure springs can be used with stock rockers, but reccomended for track only...

http://www.briantooleyracing.com/650...retainers.html

Sales@Tick

iTrader: (3)

I'm not going to argue with you, but that is not what you said.

I talk to Brian personally at least 4-5 times a week, I know his philosophies like the back of my hand.