Max lift with stock valve length?

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Bewy said:
The Comp 26918 Beehive will do nicely. Coil binds @ 1.100". Normally installed @ 1.800" with 125 lb seat. With your valve lift, you could reduce this to about 1.750" to increase the seat pressure to about 140. Beehives require less tension because of their lower weight & design.
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Thats not enough spring load for even a mild solid roller.

200 on the seat would be the very MINIMUM ago use, especially with steel valves.

More roller lifters have died a quick death from too little spring load than too much.

That a slow idle speed. Or cranking the engine over with the ignition off to build oil pressure. That will kill a roller lifter right quick.
 
For example...

230seat/580open on a .660 net lift street roller cam (2.14I/1.81E, 1.5 rocker) 6500rpm max engine speed

280 seat/720 open on a .740 net lift endurance roller cam (2.20/1.81, 1.7 rocker) 7500rpm max engine speed

From this data you can see that increasing component mass (bigger valve etc), rpm and rocker ratio will necessitate an increase in valve spring psi requirements as well as attenuating service intervals.

A smaller diameter (wire), higher quality valve spring will help things tremendously by having less mass for a given spring rate. Isky, PAC, PSI, and Manley are good brands to investigate.

Use a +.50 lock in combination with a +.050 tool steel retainer to get 1.800IH and you will find that the LS and G3 Hemi spring offerings might work. The newer v8 engines use typically use 1.800-1.850IH springs which has opened up our short valve spring options.
 
Bewy said:
The Comp 26918 Beehive will do nicely. Coil binds @ 1.100". Normally installed @ 1.800" with 125 lb seat. With your valve lift, you could reduce this to about 1.750" to increase the seat pressure to about 140. Beehives require less tension because of their lower weight & design.
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That pointed at the original question or Copperhead's roller question?
The person I got the cam from said he was running a beehive but didn't know the number or specs.
 
I was referring to you. And this is a FT cam, not a roller correct?


What the instruction sheet says with my last box of 26918 springs: for use with hyd & roller cams...&n for aggressive cam designs.
 
If you have a spring tester, you cam measure the loads & spring dimensions & that will tell you which springs you have.
 
Jeremiah said:
For example...

230seat/580open on a .660 net lift street roller cam (2.14I/1.81E, 1.5 rocker) 6500rpm max engine speed

280 seat/720 open on a .740 net lift endurance roller cam (2.20/1.81, 1.7 rocker) 7500rpm max engine speed
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Would really like to know where data like this comes from? Your own testing, or..? I’ve tried searching for specifics like this and apparently don’t know how to Google. Maybe there’s a calc or software package for it? I know the old lb/.001” lift rule of thumb (basically what my cam came with from comp), but would love something more accurate, especially when using the thinner wire with higher frequencies and such. Thanks!
 
I could be wrong and altho I havent looked at Jeremiah's math. I just use the mfg spring rate per inch and calculate it accordingly. But this is new stuff to me lol
dusterbing the peace said:
Would really like to know where data like this comes from? Your own testing, or..? I’ve tried searching for specifics like this and apparently don’t know how to Google. Maybe there’s a calc or software package for it? I know the old lb/.001” lift rule of thumb (basically what my cam came with from comp), but would love something more accurate, especially when using the thinner wire with higher frequencies and such. Thanks!
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Minimum? Depends on the lobe & rpm..similar really. How much cushion do you want and what's the needed service life..all goes into your parts selection as much as anything else.
I use KMOTION K800 double with a small .575 lift @1.5 street solid roller and have turned it to 7000rpm many times, on average about 6400rpm. [email protected] installed height and using a comp cams 740 retainer...it sits @220- 225 lbs seat and around 480lbs [email protected]
2.02 11/32 valves. I would not run less than that. Chevy guys get away with running less pressure because they don't have things like 3/8 valves, big retainers, heavy 2-3 groove locks and 59° lifter banks.... they have 11/32 valves, little retainers, 1-2 groove locks, smaller lifters and 'iirr' 44° lifter banks, skinny shorter push rods n yadda yadda.
 
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gzig5 said:
Correct
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stock valves? I wouldnt put more than 280-300 lbs on them. Close to .600 lift max. It's not about lift as it is pressure theyll break at.
I haven't used a stock 2.02 in almost 30 yrs. Last I did it was with a purple.557.
Those valve faces were hammered when the heads came apart and I went mancini stainless '$150 dollar a set specials'.
Those lasted 2 builds. Still have them in a box somewhere. Stock valves are too soft , heavy..and will break...and if they dont.. they will hammer themselves and start to leak.
 
To tell the truth, I'm not sure if they are stock valves or not. I haven't pulled the heads apart yet, but it was sporting OEM lifters and orange/red stripe 340 springs on a original 340 lift cam. I do know that the motor was worked on at some point in it's life so anything is possible. I won't be running these heads for too very long or especially hard before I go to the next head/cam/intake configuration, but I really want to see how they do.
 
There is always someone that pops up who runs them in the danger zone. One's luck can be better than anothers.
Too many ingredients for issues and being heavy means more spring, but being cautious makes for a chance of float..and that's a double edge sword.
 
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