[Tim Corcoran]

I have a question regarding valve springs. I found a valve spring that is rated 125 lb. @ installed height of 1.800. It's a comp Beehive P/N 26918. If I install it at an installed height of 1.7 to get the spring pressure up to 162 on the seat and 354/359 over the nose and my distance from coil bind is .080 on the intake and . 070 on the exhaust is there any problem running the spring at .100 less than it's rated for in the catalog?

Is there a problem with using a .060 spring locator then installing a .060 and a .015 or .030 shim under the locator to achieve the 1.7 IH?

[Tim Corcoran]

I think I found a spring that may work better without as many shims and installed closer to the recommended installed height
Maybe someone with experience doing head work can check my calculations to see if I am figuring correctly.
Comp Beehive spring 26120
According to the chart in the Comp Master Catalog
155 lb. @ IH of 1.880 and 377 lb. @ 1.880 Open Pressure (Spring Rate is 370 lb./In. coil bind is 1.230)
My Cam lift .515 I and .530 E
To increase spring pressure I want to move the IH from 1.880 to 1.860 my calculations are as follows;
162 lb. @ IH of 1.860
Exhaust Lift .530 open pressure 358.5 Distance from coil bind .100
Intake Lift .515 open pressure 352 Distance from coil bind .115

Does anyone have an excel spreadsheet to make these calculations easier?

[1968GTO421]

Possibly forum member Stan Weiss could help you with this. You could PM him or hopefully he comes across your post here. Best of luck with this.

[chiphead]

I think that should be OK theoretically. As long as you can locate the ends of the spring and don't bind it or work it too hard it should be OK. Bazillions of LS engines are running out there with similar setups. This is for a street HR setup on an iron head, right?

The challenge you may find is retainers and locks to fit your valvestem, give the correct IH and provide tip clearance for the rocker arm. OH, and remember that you need enough clearance for the valve stem seal, both from the spring ID and retainer at max lift. I remember seeing a post or two about beehive spring setups and retainers, you may want to search "beehive" or "retainer" in the advance search and see what pops up. There was a deep dive into this a few months ago.

[lust4speed]

You will have to measure actual spring height for each valve because not every valve and spring seat end up the same. Then measure each spring at the intended height to see how far the box of springs are off from each other. When you get that done, you realize that it will be time to make additional adjustments with installed height to juggle each valve to the best compromise. For instance, you want to move height from 1.880 to 1.860 or 20 thousandths. Shims are .015 and .030 so even if you were really lucky and hit the 1.880, you couldn't exactly hit your goal. Things get really sloppy in the real world and .015 shims might be .018 and .030 might be .034 but the next shim you pick up might be a little thinner. Figure that some springs in the same box will be above spec and some below when measured, and the end results graphed out look more like a blind guy throwing darts at a target. Luckily spring pressures are forgiving and there is a wide range where they function well, and it's only when you go really too soft or hard that things go wrong.

[Skip Fix]

What Mick said. And do we really know with any specific cam that 155 lbs works better than 142 or worse than 162?

[Tim Corcoran]

Chiphead, yes it's a small hyd roller Lunati Voodoo 20510711 and 6X heads. I appreciate all the info Chip and Mike and I am aware of all those factors and have a spring pressure checker and installed height micrometer to measure IH for each valve and shim accordingly. Yes I plan to check pressure on every spring I would not go by what printed in the catalog. I have long valves and relatively low lift so the challenge has been to find a spring that will fit within all the parameters, IH, pressure on seat, open pressure and getting close to but not too close to coil bind but I think the Comp 26120 spring falls within all of that. And yes I will check the retainer to valve guide clearance and for any spring interference too. Paul Carter has used this same cam and he gave me spring pressure recommendations and I talked to Joe Lewis at Johnson Lifter asking about spring pressures for the lifters (2110OPR) and he also told me how much preload to use when adjusting the lifters. The spring pressures Joe gave were right on with what Paul said also what David Butler told me so I think I have that dialed in. My real concern in my post was if I was doing the calculations correct for the open and closed spring pressures because the catalog only tells you what the pressures are at a given point and you need to take the deviations from your actual IH and lift and multiply it times the spring rate to come up with your pressures. The only purpose of doing so is to find the right spring for my application and when I put it all together I will be checking every spring and every valve. Thanks again guys.

[Tim Corcoran]

And Skip the answer is no. I hope that using the lighter spring and retainer with a little reduced mass will help to stabilize the action a little better. I will be using 5/16 pushrods what do you recommend for wall thickness, .080 or .120?

[AG]

You won't have any issue with valve control with that cam unless you have excessive distance to coil bind and still it would be unlikely. That's a fairly low RPM cam.

[Tim Corcoran]

Paul Carter used the same cam in a build he did on a combo very similar to mine but I have a bigger bore and a lot more airlow in the heads and a few points more compression and the one he did stopped making power at 5800 on the dyno so mine could spin a little faster but maybe not. I just want to have a stable valve train and when it stops making power it's not because the valves are floating.

[chiphead]

Those same dyno pulls are why I chose the voodoo 231/239/110 for my 434. I used the comp 985 springs and tool steel retainers at 1.78"-1.8" IH on a set of 670s with cut spring seats and 5.1" valves. It gave 150-155lbs on the seat .

https://www.compcams.com/dual-valve-...i-d-inner.html

Get a set of the smith bros pushrods from butler in the correct length based on measurements. 5/16 by .116 wall.

[Tim Corcoran]

Chip, thanks for your comments. The hyd roller cam for a street rod has proven to make great power and maintain good streetability. The biggest drawback is how heavy the hyd roller lifter is all that inertia moving up and down so fast puts a lot of demand on that lifter. This is why I decided to go with a beehive spring and tool steel retainer to remove some weight. Yes I do plan to use the Smith Bros .116 pushrods from Butler I have them on my drag car. Tell me how does your 434 run with that combo? Did you dyno the engine? What lifters did you use and do they make any noise?

[chiphead]

I went with the hylift johnson lifter that Paul uses. I also did the lifter bore mod, so I'm hoping it helps cut down on lifter noise and helps oil supply to the top end. I also drilled a tiny hole in the front and rear galley plugs to spray a little extra oil on the chain and dizzy gears. Also paid special attention to the oil pump to keep the pressure/flow up.

I wish I could comment on how it runs, it's still triple bagged up on the stand with two socks full of charcoal. I'm still in bodywork hell while I cut out the rust. Building a hotrod with two little kids during a pandemic has been a diary of a madman TBH. Wanting to fire it keeps me motivated.

[Tim Corcoran]

I found a valve spring that I believe is the best match so far. I's a PAC-1211X beehive installed at 1.7 gives me 170 lb. on the seat 375 open and .070 from coil bind. In order to use the locator for this spring I will need to cut the valve guides from .625 to .560 if there is enough material to do this safely.