[Gach]

Will I hope it works out for you and Bullet is able to regrind your cam and make it usable again. Sorry it got side tracked with the intake choke discussion.

[rolling money pits]

In the case of valve spring weight, and pressures, I assume it’s being discussed based on standard springs, either single ( if there is such a thing ), dual, or trips…

Are beehive springs not an option for Pontiac heads? If using “regular” valves, a beehive spring with say titanium retainers/keepers would knock off weight from that side?

I ask out of curiosity.

[Steve C.]

In an effort to run a less aggressive solid roller profile and to lessen the spring pressure I worked with Tim at Bullet Racing. He suggested a UltraDyne .4176 series lobe. It was lobe number R10 with the duration numbers mentioned in my post 72 here. Tim stated years ago they used to run it with a typical Small Block Chevy valvetrain mass with around 190 lbs seat pressure, in a Big Block Chevy at around 220 lbs.

( Those numbers do not represent an endorsement involving any specific Pontiac valvetrain mass. They were offered for general interest only )



.

[slowbird]

Originally Posted by rolling money pits

In the case of valve spring weight, and pressures, I assume it’s being discussed based on standard springs, either single ( if there is such a thing ), dual, or trips…

Are beehive springs not an option for Pontiac heads? If using “regular” valves, a beehive spring with say titanium retainers/keepers would knock off weight from that side?

I ask out of curiosity.

I'm running beehive springs, working great for me.

[Jay S]

Tim once ground a .4176” profile for me in Pontiac that the cam was set up for working around some existing valve springs that had about 195-200 seat and a 456 spring rate. I think the new CNC versions of the .3883” and .4176” receive some small tweaks and are a little smoother profile and don’t quite need as much spring pressure as they once did. That is where I am pulling the 190 from, I recall 190 was the minimum, and small block valve terrain went down to 170. IRC the .3883 and the .4176 have identical accelerations except the .4176 has more lift.

I’ve run Bullet .3823” profiles and 1.65 rockers with 170 seat and 354 spring rate, and also 160 and a 413 spring rate. At .2” duration those profiles have more duration for the same .050” as a .3883”, but has less negative acceleration over the nose so it doesn’t require near as much spring pressure. Their .3823” works well as a tight lash SR or or HR.

From what I recall a beehive spring will control the valve terrain another 400 RPM to the top end RPMs against an equivalent standard dual spring, and do it with less spring rate.

[Half-Inch Stud]

About a decade more ago i poo-pooed the behive springs out of ignorance for the cascade of reduced weights they enable. A significant rpm benefit.

The Retainer weight reduction, the upper spring weight reduction, and so forth, that now i'd like to see the old iron PMD heads gets an LS-kit including valve stem dia, guides and seals.

[Steve C.]

One issue from the past with the beehive design for a traditional Pontiac head was the tall installed height affecting the choice.


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[Jack Ferris]

Been there

[Jay S]

The lighter spring example I made for a .4176” was for a 1.5 rocker and not a 1.65…..makes some difference, worth mentioning if comparing.

I can’t think of much for beehives available for a SR cam on a Pontiac. There are some conical options. A compcams 7256 conical spring is nice spring for a .3883” and 1.65s for a bracket engine. I think it takes a +.050” keeper to make it work on 1.80” IH heads, makes the IH 1.85”.

Another is a PAC-1421 conical but would require some care setting it up for a .3883” and 1.65s. It needs to be set up from coil bind to max out the seat pressure and needed lift. The 1421 is a very nice street spring on the the smaller less aggressive Bullet .3707” profiles with bigger rockers. That combo would be my pick over a .3883” for a lot of street use.



Beehive lack the seat pressure needed for solid rollers, if they are heavy enough then the IH is to tall, just like Steve mentioned, usually takes a hydrualic roller to make them work.

[jerry455]

I am using a conical spring with a smaller retainer on my hydraulic roller. It is not running yet but my friend, who is building the motor, has used these springs on other motors with great results.

[Cliff R]

"Cliff,
Did both of those engines use the SAME HR CAM?

Stan"

Not the same cam but both used Comp XFI lobes. Both of these engines still went on to lead a great life in the vehicle they were installed in. Neither engine was cammed to make power much past 5500rpms so having issues around 5800rpm's wasn't really a problem. At that time there were others who claimed no issues to and past 6500rpms with HR set-ups. Even so when I built the next engine for my car I topped the cam with CROWER HIPPO solid roller lifters and that engine would rev right to and past 6500rpm's and never acted like it was even thinking of having an issue.

I didn't want to muddy up this thread by getting too far off topic. Running high RPM's with retro-fit HR lifters is another subject with widely varying results and opinions, and a host of variables in the equation.....