[oldworldnewtoys]

hay guys im flip flopping on how i want to proceed with establishing proper installed spring height on my vortecs i all ready have a new set of valves with a height of 4.911 placing the spring installed height around 1.685 my new springs have a installed spec of 1.750 my question is do i get different valves as close to the right height (about +.050) as i can and cut the rest out of the seat (about .015) or do i get +.050 keepers and is that likely to cause problems with the roller tip rocker i have with the retainer and yes i know about the retainer to seal issue

thanks for the thoughts and wisdom you guys and this site are the best!!!!

 

[ap72]

go have your spring seats and guides cut down and run the parts you have. You can also switch to .530" seals which means you'll have a better selection.

 

[engineczar]

There are also several options depending on what type cam you're running. What style cam do you have? Solid, hyd, roller. What spring are you trying to squeeze in and how much seat pressure do you need? Also what are the actual measured spring pressures at the two different heights 1.75 and 1.685. Often the springs measure out different than what is advertised.

 

[MouseFink]

The V6/V8 Vortec heads have valve spring pockets that are thinner than older heads. I would avoid cutting those seats any amount and make up the difference with longer valves. Machine Vortec spring pocket depth at you own risk.

Your set up may vary but my 4.3L V6 engine as-built spec. would be a good guideline:

Used Manley 1.94" #11860-1 int. and 1.600" #11863-1 exh. valves x 4.951" long, 11/32" stems, with a .290" tip length for extra .020" clearance (total of .040") between the locks and the self-aligning roller rocker arm rails. Stock Vortec valves have .289" tips.

Used standard Comp Cam 613 locks on the exhaust valves and 614 + .050" locks on the intake valves.

Used Alex's Parts 1.255" OD x .875" ID shims to achieve 1.750" +/- .010" assembled height for 144 lb. seat pressure. Different shim stacks were required on the exh. and int. seats after eliminating the exhaust valve rotators.

Used a Comp Cams #4721 seat cutter to enlarge the spring pockets to 1.350" OD seat x 0.775" OD spring locator boss to fit 1.310" OD x .885" ID Comp Cams #26918 beehive valve springs.

Used Comp Cams #4726 guide cutter to cut intake and exhaust valve guide from .562" OD to .530" OD to fit Comp Cams 518 Viton .530" ID x .575" OD seals.

Reduced valve guide height by .200" with fitted .060" between the Viton seal and the lower spring locator boss. .

 

[lmsport]

Use the +.050 locks, UNLESS, you are using rail rockers.

 

[ap72]

The V6/V8 Vortec heads have valve spring pockets that are thinner than older heads. I would avoid cutting those seats any amount and make up the difference with longer valves. Machine Vortec spring pocket depth at you own risk.

Your set up may vary but my 4.3L V6 engine as-built spec. would be a good guideline:

Used Manley 1.94" #11860-1 int. and 1.600" #11863-1 exh. valves x 4.951" long, 11/32" stems, with a .290" tip length for extra .020" clearance (total of .040") between the locks and the self-aligning roller rocker arm rails. Stock Vortec valves have .289" tips.

Used standard Comp Cam 613 locks on the exhaust valves and 614 + .050" locks on the intake valves.

Used Alex's Parts 1.255" OD x .875" ID shims to achieve 1.750" +/- .010" assembled height for 144 lb. seat pressure. Different shim stacks were required on the exh. and int. seats after eliminating the exhaust valve rotators.

Used a Comp Cams #4721 seat cutter to enlarge the spring pockets to 1.350" OD seat x 0.775" OD spring locator boss to fit 1.310" OD x .885" ID Comp Cams #26918 beehive valve springs.

Used Comp Cams #4726 guide cutter to cut intake and exhaust valve guide from .562" OD to .530" OD to fit Comp Cams 518 Viton .530" ID x .575" OD seals.

Reduced valve guide height by .200" with fitted .060" between the Viton seal and the lower spring locator boss. .

I take it you get your valve train parts for free? Obviously cost isn't a concern.

 

[engineczar]

Yes Vortecs can run Beehives and work well for higher rpm's if you need to run a single due to the lighter weight of the retainers as well as the reduced mass of the spring itself. Also the variable spring rate helps with harmonics.

The downfall is that they're roughly double the price of a comparable conventional spring, that along with the cost of the mating retainers.

 

[MouseFink]

ok this is a question i get a lot but never have an answer cause i rarely use stock castings.

Can't vortech heads use beehive springs? I always see the cam mfg. suggest two types of springs and they always have there heavy dual springs listed first. But I have used beehive type springs and they work good for many applications.

Sorry not trying to hijack your post. I got a feeling beehives are your answer. It seems like they probably sell a set that are direct fit. but nto sure figured someone on here already has it figured out.

Beehive valve springs or dual standard valve springs will not fit a Vortec heads without machine work. The Vortec valve springs are 1.241" OD and the Vortec heads have spring pockets that are 1.248" OD with a inside spring locator boss that is .750" OD - .775" OD. Beehive valve springs are 1.310"" OD x .885" and require a pocket that is machined to 1.350" OD x .775" ID with the seat cutters that are available. Dual valve springs are at least 1.300" OD in order to accommodate the inner spring.

Most beehive valve spring failures can be traced back to the bottom coil because they were fitted on Vortec heads with re-sizing the spring pockets.

 

[engineczar]

CompCams 26981-16 will fit with no machine work.

 

[MouseFink]

CompCams 26981-16 will fit with no machine work.

My error....those Comp Cams beehive valve springs fit will Vortec heads without machine work. They would be good to use with a milder camshaft with less than .460" valve lift.

The Comp Cams 26981 valve springs are the ones I used on my first set of 1993 L35 4.3L V6 heads two years ago. . My fresh heads are 1995 L35 heads and are being finished now have Comp Cams 26918 valve springs. I up graded to 344 lb. open pressure at .500" valve lift.

 

[ap72]

Beehive valve springs or dual standard valve springs will not fit a Vortec heads without machine work. The Vortec valve springs are 1.241" OD and the Vortec heads have spring pockets that are 1.248" OD with a inside spring locator boss that is .750" OD - .775" OD. Beehive valve springs are 1.310"" OD x .885" and require a pocket that is machined to 1.350" OD x .775" ID with the seat cutters that are available. Dual valve springs are at least 1.300" OD in order to accommodate the inner spring.

Most beehive valve spring failures can be traced back to the bottom coil because they were fitted on Vortec heads with re-sizing the spring pockets.

There are MANY different beehive springs out there, some will fit, some are too large in diameter for stock seats, and some require a different installed height. Like any other spring you need to check the info for each different part number.

 

[oldworldnewtoys]

There are also several options depending on what type cam you're running. What style cam do you have? Solid, hyd, roller. What spring are you trying to squeeze in and how much seat pressure do you need? Also what are the actual measured spring pressures at the two different heights 1.75 and 1.685. Often the springs measure out different than what is advertised.

you guys might hate me but im building this block around this cam and on the cheep so my options are slightly limited. but im a machinist so free machining!!
I have a lunati 60103 flat hyd cam. add durr of 268/276. at .050" of 227/233 with a lift of .489" and .504". i recently got all my parts and there sitting in my closet lol. i have not checked the actual spring rate. i went with the spring they recommended for the cam. spring number 73943 they stopped making it after i ordered them. that kinda worried me. it has a closed pressure of 108# and an open height at 1.250" and 339#. coil bind at 1.060". inside dimensions (with wire damper) .765" and outside of 1.266"

 

[cobalt327]

CompCams 26981-16 will fit with no machine work.

Sure will. There are other drop in springs for the Vortec heads that allow more lift w/o any machining needed, despite what you may read.

Two beehive springs from Comp are p/n 26915 and p/n 26918.

Another spring that works w/o machining and is recommended by GM is the Crane Cam p/n 10309-1 drop-in valve spring/retainer kit which is good for .550” lift (this allows about 0.025" between the retainer and seal).

More here.

 

[oldworldnewtoys]

I think I will give em a call. Thanks!

 

[MouseFink]

Beehive valve spring must be fitted to the head precisely because that spring is the only one you have and if it fails, it may take the engine with it. Poor fitting valve springs will over-stress the lower coils.

The critical area for fitting beehive springs is the spring pocket. The outer edge of the spring pocket and the valve guide boss locate the valve spring on the head. The locators are very important in order to prevent the spring from oscillating around the spring pocket. That is why it is risky to use "drop in" beehive valve springs. I prefer valve spring pockets that are .010"- .020" larger OD than the valve spring and valve guide boss that is .010" - .020" smaller than the ID of the valve spring. That is difficult to achieve since the valve spring seat and guide cutters may not be available for a perfect fit, depending on which valve spring you use.

On the pair of 1995 L35, 4.3L V6 heads I am having prepared, I am using Comp Cams 26918 beehive valve springs that are 1.310" OD and the spring pockets are going to be machined to 1.350" OD for .020" clearance. Those Comp Cams valve springs are .885" ID and the valve guide boss is going to be machined to .775" OD for .055" clearance. The machinist will use a Comp Cams 4721 seat cutter and a Comp Cams 4726 guide boss cutter. Larger OD valve springs are difficult to fit because of the valve cover supports and head bolt holes. I will use ARP 12-point head bolts because a 6-point socket will not fit between the larger diameter valve springs.

IMO....larger OD valve springs provide more valve spring seat and open pressure. Economy "drop-in" valve springs should never be used with a radical roller tappet camshaft. Roller lifters are heavier than flat tappet lifters and when they are used on a camshaft with more than .480" valve lift, the valve springs should have 330 lb. - 350 lb. open pressure or the lifters may be tossed over the nose of the cam lobes at high RPM and float the valves with disastrous results. The nice thing about roller lifters is that you can safely use a high lift camshaft....providing you have adequate valve spring pressure. High valve spring pressure and hydraulic roller lifters can be a problem with eventual lifter collapse and lifter damage. It would be wise to use Comp Cams (or equal) 15850 short or 875 reduced travel roller lifters. High valve spring pressure also requires full roller rocker arms or you can burn up the rocker arm pivot balls. Full roller rocker arms MUST be used with Comp Cams short and reduced travel lifters. Full roller rockers present stud problems and valve cover clearance problems to solve especially on a 4.3L V6.

 

[ap72]

IMO....larger OD valve springs provide more valve spring seat and open pressure.

Well, this opinion is not only useless but in many cases wrong. The pressure the spring provides is the pressure it provides- the OD is irrelevant. A larger OD should be avoided if you can though because it does increase the mass of the spring.

Spring OD, ID, material, thickness, shape, height, coil count, etc. all go into making the spring's open and closed pressure. Increasing the OD is one of the last things they will do to increase the pressure though as it increases the mass which can lead to surge. People spend a LOT of money on spring material just to keep the OD down while supplying the required pressures.

 

[cobalt327]

I can't even see his posts unless someone quotes him. But to his credit he at least added 'IMO' as a qualifier instead of stating it as fact.

 

[MouseFink]

Well, this opinion is not only useless but in many cases wrong. The pressure the spring provides is the pressure it provides- the OD is irrelevant. A larger OD should be avoided if you can though because it does increase the mass of the spring.

Spring OD, ID, material, thickness, shape, height, coil count, etc. all go into making the spring's open and closed pressure. Increasing the OD is one of the last things they will do to increase the pressure though as it increases the mass which can lead to surge. People spend a LOT of money on spring material just to keep the OD down while supplying the required pressures.

Show me a valve spring that has 350 lb.open pressure and can be fitted at 1.750" and is 1.250" OD. You cannot can you. That blows you theory into the weeds.

IMO.........The wire diameter must be increased to increase the spring rate and must fit in a certain installed height AND diameter. If the wire diameter will not allow the spring to be fitted in a prescribed OD and height, the OD and height must be increased.

I added "IMO" just to make this self proclaimed forum cop happy.That seems to be a weed in his ***.

 

[engineczar]

Show me a valve spring that has 350 lb.open pressure and can be fitted at 1.750" and is 1.250" OD. You cannot can you. That blows you theory into the weeds.

Howards 98215, I use them all the time.


98215 Single with Damper 1.265 dia 115 @ 1.800 380 @ 1.200

@1.75 you have about 135#'s on the seat which works well for a solid flat tappet


There's also PAC1409's and Isky's 295D

All standard Stock Eliminator stuff.

At one point we were running 180# on the seat with Schubecks but we've backed off some.

 

[MouseFink]

Howards 98215, I use them all the time.


98215 Single with Damper 1.265 dia 115 @ 1.800 380 @ 1.200

1.250" OD and 1.750" height fits without machine work.

I agree with your example.....
Larger valve spring = higher pressure.