Hydraulic Roller Seat Pressure

[lordmikef]

About to install a new hydraulic roller and the new bee hive springs are producing about 175 pounds at the seat. I am presently using the stock rocker arms and was wondering if they would be able to handle this. Has anyone run that much pressure without roller rockers?

 

[BlackBandit]

That's too much. It should be around 130-135 on the seat. What springs, locks retainers are you using? Also, what is the lift on the cam and what installed height is producing that pressure? I only ask because I'm curious what your open pressure will be.

 

[lordmikef]

Going to be using bee hive springs from comp, crane lifters. Open pressure is going to be 325.

 

[johnnyttype]

r u sure that its 175? open 325 would make me think that the springs should be 120's closed. i have 125's installed at 1.75" i believe, open was about 330 i think?!

 

[BlackBandit]

r u sure that its 175? open 325 would make me think that the springs should be 120's closed. i have 125's installed at 1.75" i believe, open was about 330 i think?!

That's why I asked what he was using as far as parts go. Lordmikef, it sounds like your math is off. If you tell us what you're using (p/n's not parts) then I'm sure several here would be willing to double check.

 

[lordmikef]

I am using a comp cams 212-212 .504 lift installed at 1.70 coming up with 175# on the seat and 325# open comp cams roller lifters 885-12 1.65 rockers

 

[BlackBandit]

If that's the 264HR grind then your total lift will be .5365 inches of lift with 1.65 rockers. Without the P/N for the springs I can't verify any pressures.

EDIT: If you're using the comp 995 beehives then your installed height at 1.7 will yield 137 pounds on the seat and with that cam and rockers would give you 287 open. It would also leave .1485" before coil bind.

 

[Blown&Injected]

that is about the same TOTAL lift I have and I recall my Behive springs being 138 closed and 303 open so unless the rate is different on the Behives, it does seem that some math is off.

 

[Blown&Injected]

I am using a comp cams 212-212 .504 lift installed at 1.70 coming up with 175# on the seat and 325# open comp cams roller lifters 885-12 1.65 rockers

It has been a while but i thought 1.725 to about 1.740 is a good range for those springs - maybe try some 10* locks

 

[johnnyttype]

what equation do u guys use when calculating this stuff? my numbers were from my fuzzy memory of 1.5 years ago using a tool that compressed the spring to a calibrated height. plus im not using beehives, i have comp 941's:smile:

 

[BlackBandit]

that is about the same TOTAL lift I have and I recall my Behive springs being 138 closed and 303 open so unless the rate is different on the Behives, it does seem that some math is off.

Well, I'm just doing the math based on spec'd installed height and spec'd spring rate. Things tend to not be exactly as advertised.

johnyttype, It's all basic math. Just addition, subtraction, devision, and multiplication. Also, the beehives have a lower spring rate because they need less pressure to control the valve.

 

[Blown&Injected]

It has been a while so ... well I can just search my threads from about 2 years ago and I bet I can find my math - I was working on trying to get it just right back then.

Are you using just math or are you actually measuring the spring pressure?

 

[bison]

About to install a new hydraulic roller and the new bee hive springs are producing about 175 pounds at the seat. I am presently using the stock rocker arms and was wondering if they would be able to handle this. Has anyone run that much pressure without roller rockers?

What is you total valve lift? Those numbers dont sound right for spring pressures. You must have the wrong application. No need for more than 140 lbs at 1.700. Especially with the beehives. The required pressure over the nose is less with those too. I have 941's and they are around 145 on the seat and that is about the limit with a hydraulic. I would think twice about running the stock rockers and especially the stock shafts. They will break if the engine is run to its potential with that cam. Mine goes over 6000 in 3rd with to clear the traps. I shift at 5800. My net lift is .496 and the 941's i have have about 8000 miles on them. Not many of them were very easy miles either HTH

 

[lordmikef]

I apologize. I said that wrong. The rocker ratio is 1.55 which puts the lift at .504. The cam grind is the 264HR. I don't know why we are measuring 175 in the seat and only 325 at 1.7 I would think that with 175 at the seat, open would be much more.

 

[bison]

I apologize. I said that wrong. The rocker ratio is 1.55 which puts the lift at .504. The cam grind is the 264HR. I don't know why we are measuring 175 in the seat and only 325 at 1.7 I would think that with 175 at the seat, open would be much more.

175 at the seat is too much for a hydraulic.

 

[BlackBandit]

I apologize. I said that wrong. The rocker ratio is 1.55 which puts the lift at .504. The cam grind is the 264HR. I don't know why we are measuring 175 in the seat and only 325 at 1.7 I would think that with 175 at the seat, open would be much more.

Do you happen to know the p/n of the spring you are using? Like I said in my previous post, if you have the 995's and you have the spring at 1.7 then you'll have ~137. If you have 175# at 1.7 then you have the wrong spring. The spring rate your seeing is consistent with the beehives. Your seat pressure is just too high. How are you measuring your installed height?

 

[lordmikef]

Comp Cams recommended the 99831 beehive spring and that is what they sent. 167# on the seat is what they came up with and we measured at 172#

 

[BlackBandit]

I can't find that P/N in the comp catalog and the only summit number I can find that's close is a solid flat tappet lifter.

 

[lordmikef]

Very strange. That's what it says on the cam card that came with the set-up. I'll see what I can dig up. When I talked to them, I was told it was a new beehive they have been working on and that it may act a little different.

 

[BlackBandit]

Well, maybe it's not in the catalog yet. It sounds like it's doing what it's supposed to based on what you say. I would call their tech line and verify the seat pressure is ok. If they say it is then I guess they're the cam guys.