Crazy95Z

So I'm finally in the beginning stages of putting my new motor back together. Last night, we mocked up one cylinder becuase my builder wanted to test piston to valve clearance. Well, when doing this, we discovered that my new beehives was nearly coil-binding by just turning the motor over by hand. 2 coils was completly touching and between the others, there was no more than .003" of clearance between the rest. We think something is not right here. I had the springs put on by a local reputable machine shop and they knew all the specs on the new engine and even had me trade down to the 915's instead of the 918's, claiming the seat pressure was going to be too much.

Cam Specs: .356" intake / .360" exhaust
or
.570" intake / .576" exhaust with 1.6 RR

Comp R Lifters
Hardened Pushrods
Pro-Mag 1.6 Rocker Rollers
Guide Plates
7/16" Studs
Beehive 26915 Springs
New seats, locks, reatainers, and valve seals
Install height of the springs is 1 11/16" (atleast I think thats what my builder said, I'll double check tomorrow)


The shop did all the work on the heads and even milled them down some and while the valves were out, did a 3-angle valve job to help the valves seat a little better. Any help is appreciated.

It was my understanding that these springs was good up the .625" of lift so why are they so close to binding? Thanks for any help

MaxLean

I *believe* that the nature of the beehives is that the lower larger coils are designed to stack as the spring compreses.

Grimpala

Check out this site, all kinds of good info on the beehives

http://www.babcox.com/editorial/ar/eb50354.htm

One question, are you running stock heads, and what seat pressure did the shop say the 915's had. I'm about to put these same springs on my impala and am curious if the 918's will be too much.

Spinner

918s are fine, they do need the comp R lifters though. There should be at least .030 clearance on the top two coils on a beehive, .050 preferable.

.003 is unacceptable, you need some +.050 installed height locks because the springs will heat up, expand, and bind/self destruct if thats the clearance your seeing

Crazy95Z

I'm sry, I had a typo. I meant .030" of clearance not .003".. So I guess I'm right at the limit huh? Anyone suggest to not run it right at the limit? Either way, I'm still going to see if I can't get the shop I had put them in to redo them becuase I don't feel real safe running them that tight.

SStrokerAce

With that lift you could have them setup as small of a installed height as 1.725" which it's probably close too. A +.050 lock helps if they are stock length valves.

The 918 and 915 don't have to use Comp R lifters but then again they don't hurt.

The coils do stack as the lift is increased so you are ok there.

As for getting close to coil bing .050 is about as close as you need to go, the best way to get that is to know the springs coil bing height (1.085" if I remember right on a 915) and the installed height minus the lift at the valve, that will tell you the clearance.

Bret

Grimpala

So the 918 with the +.050" lock, stock length valves and say a Harland Sharpe 1.6 rocker shoudl be ok? Gonna be ruinning the cc306 so that would be .544/.576 at the valve. I think the +.050 retainers give you a height of 1.760?? SO at 1.184 with that setup shoudl be well within the specs.

Also, anyone know if the 918 will go into the head without machining?

truedualws6

I have stock heads with the 26918 springs. Using the +.050" super locks
794-16 retainers and .062" spring seats results in an installed height of
about 1.75". If you do the math that is .665" to coil bind. This gives you
.089" safety factor. Pretty good if you ask me. The springs are designed to
stack the lower coils as they become closed.

If you use the 7* hardware you will be in the 1.72" installed height range.
This is still OK as you have a .059" safety factor, however, your closed
pressure will be very high.

Comp also makes a spring seat. I think the number is 4705-16 but you should
call to verify. Here are the other parts:

795-16 steel retainers, or
794-16 titanium retainers
614-16 locks (+.050), 1.75" installed height w/.062" spring seats

Grimpala

So what kind of machine work did you have to have done to get the springs to fit?