DO STIFFER VALVE SPRINGS COST POWER? LS3 SPRING TEST!!
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- Опубліковано 30 лип 2024
- DOES YOUR LS VALVE SPRING UPGRADE ACTUALLY HURT POWER? WHEN YOU PERFORM A CAM UPGRADE ON YOUR LS, IT USUALLY REQUIRES A VALVE-SPRING UPGRADE. THE QUESTION IS, DOES INCREASING THE VALVE SPRING RATE COST POWER? CHECK OUT THIS TEST COMPARING THE STOCK LS3 VALVE SPRINGS TO A SET OF COMP BEEHIVE 26918 SPRINGS, THEN THE COMP BEEHIVE SPRINGS COMPARED TO A SET OF DUAL, PLATINUM .660 SPRINGS FROM BRIAN TOOLEY RACING. DO STIFFER SPRINGS COST POWER-THE ANSWER IS HERE!
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This man answers all the unanswered questions nobody has ever asked
haha very true!!
Just like too little pressure causes valve float the reverse causes force losses , cool vid .
He answers the questions we neglect to ask.
I’ve always wondered this
As I've learnt in Aus, there's more to the story. Higher spring pressures do add friction, and because of this they do transmit more heat into the oil raising oil temps, might not be noticeable for a 7 second straight line warrior car, but go circuit racing where the engine has to actually work for 15-60 minutes straight, up and down the revs, actually accelerating the weight of the car constantly out of corners and this shows its head. Also higher spring pressures are far more savage on lifters push-rods and the cam itself, I know with our race engines we cant idle the engines below 1500 rpm on solid rollers, if we do it just chews up the cams and lifters as all that spring pressure grinds the roller lifter into the cam, at higher speeds this isn't an issue at all as the time in which the roller lifter makes contact with the cam is reduced and therefore so are the the loads
From months of watching you its clear that the intake manifold is the major player in where your engine makes power
Definitely the shorter runner causes the drop in torque.
Well, and judging by the fact that both the long and short aftermarket manifolds showed almost identical lower RPM performance, it's also possible (probable) that the Holley runners have a larger cross sectional area that is hurting inertial mixture velocity in comparison to the stock unit.
I can't help thinking that the results may have been quite different, if the test had been performed on a 400+ cubic inch engine that could make efficient use of the additional airflow...
Don't know why but I expected to see equivalent power drop between dual spring & beehive as between stock & beehive , thanks Richard , this ones been nagging at me for a long time , and thanks for ALL of your great videos & sense of humor !
Dead on what I figured. Awesome test Richard. I did a dyno test comparing stock heads to a set of ported heads on my LS3 with the little Lingenfelter GT1 cam. Gained 15rwhp but I also had stock springs on the stock heads and BTR duals on the ported ones. Figured 5hp was the cost of the springs at the most. Awesome for testing this.
Good stuff. This goes to show that modern factory engines are built much better than the older ones. I recently upgraded my 5.0 Fox Mustang with the Trick Flow kit (2500100).
The think I learned from Steve Morrison is that they try to bring the springs as close to coil bind as possible to reduce harmonics at high rpm. Shims add more pressure but is worth the added protection for uncontrolled valves.
WE USUALLY SHOOT FOR AROUND .030 TO COIL BIND
The short runner length is what killed the torque. You won't get 100% of the energy used to open the spring back. Friction losses will take most, and there are a few little things like some gets converted to heat in the spring when it is compressed.
You would want a spring that is
- made out of a material with nearly 100% elasticity
- coated in the same stuff billiard balls are coated with
- using opposing magnets at each end to provide an extra pushback
Or some other nonsense like that.
I had a flashback to Robin Williams playing Mr. Rogers... "Can you say Entropy?" ... I've always been a little fascinated that cams work at all, particularly flat tappets. I guess I would have expected the beehives to make more power, being conditioned like I am from marketing. Like you say, though, that's why we test. Great work, thank you.
And the factory ls3 is a very good intake manifold to start with love the tests Richard
Hope the clover leaf test happens with Eric. That would definitely be a cool test.
Me too, I am excited about it.
I was actually surprised we didn't see a change between the beehive and dual spring. Very cool test in my opinion, thank you very much. I would think the return energy, during valve closing would be reduced at high revs because the spring is being used to push all the valve train back to close position. At low speed, I suppose it would push the cam forward quite a bit, possibly enough to return the cost of compressing the spring in the first place. , but if you get closer to valve float, there would be no energy pushing the cam forward. The test didn't really confirm that logic.. but I was thankful for the content. Keep up the good work, you're the man.
Both maintained control, so that was good. Wear on components? Might be a different story.
I put the 26918 on my Vortec headed small block and picked up 400 rpm on the top end and a couple horsepower. I suspect my old springs were not up to the task at hand. Also I find my idle is better. Thanks Richard for that tip I bought the same springs for my turbo engine as well.
Anyone else impressed with the consistency of the Dyno here? Those two graphs were almost exact overlays
I’m not impressed
Engine Dyno is always pretty accurate to itself as you'd expect. As long as things like oil temp are the same then should be exactly like he shows here.
You'd be surprised how much things like transmission/diff temp and tire pressure makes on a standard roller Dyno
Now spin it to 9,000rpm and see if there is a difference.
That's what I was thinking.
Lol he will lose power very quickly but not in the way he was hoping
Very interesting test! Thanks for sharing!
I love these. Blessings Richard 💪
The higher spring rate definitely increases friction in the assembly. Just think of all the forces on the rocker bushings and roller lifter as well as across the valve tip. The question is, will this difference in friction be noticeable? In some cases it will, as you saw with the stock cam. In others it will not, likely because the difference in friction between the Beehives and the Duals was fairly small.
I would’ve liked to have seen you spin both spring setups up and see where they start to loose stability. The beehive should have an advantage there.
Always love your videos
Awesome video as always 👍🏽
Friction being a factor in any machine with moving parts, you don't get as much energy back out of compressing valve springs as you do when they close the valves, but it is very close. A camshaft is a very efficient thing, even more so when you have roller cam followers. When the major manufacturers went to roller lifters in the late-80's, they reported a 2% fuel economy increase. When I worked at Cummins, engine familiarization training covered teardown test results, and they said at full power, a heavy duty diesel camshaft only takes ~2 HP to drive.
Energy recovery from valve springs is something that is making it very difficult for camless engines to get on the market. Whether the energy for actuating the valves comes from hydraulics, pneumatics, or electricity, there has to be a pump, compressor, or generator to create the power to lift the valves. Then the parasitic power loss offsets the benefit received from the fully variable valve timing.
I would agree with what you said. I do believe you would get some energy loss from heat during spring compression also, but would be very little. I thing pressure variation between the strokes of the cycle would probably play a larger part. Particularly during exhaust valve opening against high (sorta) exhaust gases versus the low pressure when the intake valve opens. Obviously boost changes the effect.
Well no machine is 100% efficient, and even compressing a spring will cost power the stiffer the spring the more it will cost. Conversely if the spring isn't phisically strong enough to close the valve at higher rpms it will cost you way more power than the stiffer spring will. Basically you want enough spring to do the job and maybe a tad bit of safety factor for maximum power. But that's splitting hairs, just get whatever spring you can find that will do the job without having to pawn your wife's engagement ring..
Screw it, pawn the ring. If she understands, she’s a keeper. If she doesn’t, dump her ass because you know something like this will happen in the future if you’re a gearhead!! Lol.
I like this because I can relate I went with the double spring for my 243 heads that are ported and milled by my local guy 😁 and also had the short block done through him. Just a 5.3 but hope to see good power 😅.
An older guy told me that heavy springs will cost power.. well, guess he was right
I was going to say camshaft, damn. I was wrong
They cost power in THAT situation.
Depends if you have valve float
I think the heavier spring corrected just the tiniest bit of valve float that was allowing the motor to breath better… could have had one slightly weak stock spring … there was a large gap between the beehive spring and the dual spring and it clearly showed there was no loss in power adding spring pressure
An old timer was probably talking about a non roller motor a roller motor is not going to lose any power from friction as no parts are actually touching
David Vizard rates beehives and conical springs as the best options. Clearly the best option for the bigger cam in this test as there is less load on the valve train for the same output.
Needed to run the rpm higher to see valve float as well and if there is a power separation higher in the rpm. Run a different cam setup if you need to for a high rpm test north of 7,000rpm. Also, run a titanium retainer on the beehive just like the titanium retainer on the duals. Throw the Comp Conical 7228 spring into the mix as well. Also weigh each spring and retainer setup to show the weight difference of each setup as well. Obviously the beehive spring was way too much spring for the stock cam so it is going to hurt if you run more spring and seat pressure than you need too. Were these valves stock solid valves or hollow stem intake valves? Less valve weight to keep stable can be done with less spring.
Good video Richard and thanks from Australia 🇦🇺
Very welcome
Part of a spring upgrade is to lessen the possibility of valve float. That was a problem I had with my air cooled VWs. Start building more power with those and you're likely to swallow a valve.
Awesome! Always wondered about spring power cost at low rpm vs gain in rpm
Makes me wanna see a test of the same duration cams with different lifts. One using stock springs, and one using a stiffer spring to see how much the difference is!
spec numbers mean nothing between different cams. too many variables in cam grinds
Great test!!!!!!I learned a lot,hope I can find the specs on the 232 crane cam.I guess 232 intake so 598 or so lift think I can figure it out. Looks like a great 6.0 street cam.I watche the comp cam 1.72 video too,crazy how the power feel off with a stock cam 🥴love the 918 springs 😃
Cool test
Just in time for my lunch break 😎💪🏼
💩😀
Thanks Richard.
I love Richards vids very good info
I just commented on freiburger instagram a couple weeks ago asking for this test wondering if the stiffer spring affected low speed power thanks I always wondered this!
I chose the btr springs simply because I chose a btr cam. Great video.
Good choice!
If you only need to upgrade your spring for cam lift it doesn't matter if it looses a bit of power because the stock spring wouldn't work with the upgraded cam. So...
Exactly use the right spring for the right job, don’t needlessly get heavier springs if ya don’t need them for the valve to function right lol.
I love these kinds of tests. I had a friend that raced Pontiacs for years. His combination was a mix of mostly factory parts including the cam. But he had tested every little thing and for every one thing that picked up 5 horsepower here of 8 horsepower there he had a very quick car. His '71 LeMans wagon ran well into the low 12's back in the 90's and he was well into the 11's by the 2000's when he had a stroke and quit racing. One test I would love to see you do is a timing chain test. I read a test by Roush Racing many years ago on a 500hp ish SBF and they tested stock butt link, double roller, timing gears, a timing belt and a high performance butt link called a Hyvo I think? Anyway, it's amazing how much less power was made with the oh so popular double roller compared with a stock style timing chain. I'd love to see this repeated if you ever have the time.
YES !
Are you talking about the legendary Pontiac KCIR Jim Hand?
@@GasserNorm Yes. He was a great guy to race with and always a great guy off the track too.
@@1967davethewave I knew Jim as well. He helped me with my 1980 Firebird. He was a great guy.
@@GasserNorm Yeah, he walked up to my 69 GTO back in about 91. I was running high 13's. He looked under the hood, shook his head and said, "If you ever want to go fast come talk to me." I did that night and I was running in the 12's by the next season.
Hey Richard, can do a video on a vacuum pump on stock motors? See if it makes a difference?
Good stuff, thank you.
Now put a cam in that raises that rpm ceiling by 1000 and see which springs yield better results.
Valve springs, how I've been taught and experienced.
90lbs is 90lbs out because the cam has phases there is "90lbs of resistance"
When assembling an engine i have a habbit of setting my main caps, pistons, wristpins, and every moving part in free spin, which even one part "slightly" off can add a TON of drag.
After about 3-4h of setting everything, CLEAN I add a few drops, a high-speed ceramic bearing lube, and free spin my engine.
A short block should almost THROW the wrench and freely spin.
Add heads without plugs or rockers and it still spins but WOOSHES!
GO ONE STEP farther and add rockers and feel HOW MUCH DRAG springs give the engine.
Ive been told by old hot rodders that the N/A guys are WAY over valve springing their engines, losing and robbing TONS of free rev and parasitic drag.
And that the boosted guys need to do math based on their valve face to boost ratio giving them what valve spring is perfect for operation with again "not having too much" spring.
Which aparently is a thing!
Make a low compression 5.3l LM7 with stock cam and spin her up with .660 btr springs... that 440lbsish of pressure is going to really bog that N/A down.
you choose springs for the cam lift and desired operation, I have a valve spring dyno test up-it is not much of a change in power from stiffer springs
I think you'd have to put those upgraded springs in a motor with a stock can in order to notice slower drop, if any at all. Because you are upgrading the cam whatever penalty you pay for more seat pressure is offset by lift and duration provided by the bump stick.
In endurance racing run it for 8 hours and see how much less fuel was used. Your first test showed the results. Of over spring.
Thank-you Richard from Aus. for your tireless testing! How do you fit all this stuff in? I struggle to find time to check my tire pressures regularly. There could have been a slight loss in power from increased friction with the 26918 springs, very hard to measure. I would hazard to guess some of the slight power drop may be due to lifter bleed down at the higher RPM where some duration and valve lift is lost. One of the secrets to power is seating the valves firmly at all RPM's . The big challenge with valve trains is to run the least amount of spring to do that.
depends on modulus of elasticity of spring alloy chosen and if it simply has a blunt surface on follower instead of roller ball bearing at the end of valve stem then yes there will be power sapping taking place. :) :)
I really like tests like these. I'd really like to see a test on various windage trays and the power savings they provide.
It would be pretty difficult to test a windage tray on a Dyno. Think carefully about what a windage tray does.... If your crank is sloshing through oil while its sitting on a stand, you have bigger fish to fry.
a windage tray does add power on the dyno-but works even better when subjecting the engine to g loads on a track
@@richardholdener1727 Interesting. Is that because of properly managing oil being slung off the bearings?
@@richardholdener1727 Thanks for the reply and correcting me. Did some research. Conclusion: Dry sump always wins, except for $$$$.
Heavier spring WILL ACCELERATE valve train wear, lifters,pushrods,rocker arms,valve stem, keepers,etc
And the timing chain.
With today's parts, if your wearing out that stuff you got problems with the setup.
@@unclegeorgesspeedandfeed I agree. I’ve never seen an ls timing chain fail. Now other OHV engines definitely have issues. Also the only ls heads that would see valve guide wear seem to be the ls7 heads. But I think that has something to do with the 1.8:1 rockers.
Well, that would only be true if the lighter springs in your comparison were also able to adequately control the valve train. If not, the opposite would result.
@@michaelangelo8001 yeah it's a fine line of control and Chaos. As rpm rises the line gets exponentially smaller.
As I’ve found out, stiffer springs cost rockers and pushrods . I had wear where they meet
Any cam wear? I'm always afraid....
Good point , thanks.......
@@youcanbesmartaskhow3857
Nope. Cam and lifters were perfect! I was surprised as it was making a racket
The roller lifters and rockers help reduce the frictional losses from the stronger springs.
They take more spring and have more weight on the wrong side of the rocker
I would love to see an engine assembled with just the cam and valves in place to see the drag of just a roller cam and rocker assembly working against the springs. How much power is needed to drive that? Is there always a compressed spring helping to advance the cam?
Kool physics behind the returning energy from a compressed spring. I would think it comes down to the efficiency of the spring it's self. the stock spring should in theory be more efficient at the given pressures based of the results. as force goes up I'd bet efficiency goes down. So the two aftermarket springs were the same do to them having a similar efficiency probably partly from the increase in pressure numbers with the large cam which would make the open and seat pressure difference a smaller percentage change compared to the small cam with a larger change.
The power it take going up the lobe vs what it gives back going down the lobe will be rpm dependent. When you turn it over by hand it will be the same, you don’t even notice any drag from the valve trane. But there will come a point where you could spin it so fast the lifter would not even touch the lobe on return side, then you would loose 100% of that energy.
As the seat Pressure is increased Also is the resistance think of it like a stamp rocker vs roller the roller reduces resistance same difference
I think the stock valve spring had the tiniest bit of float off the peak of the cam lobe allowing the motor to breath just a little better and when they went with a heavier spring it fixed it… or maybe the new springs were heavier and the increased inertia from compressing and decompressing the spring was responsible for the power loss … but if that was the case why didn’t the dual spring lose power… two springs are surly heavier than one
Richard Holdener how are ya brother. Have u seen these sbc hybrid LS motors ?? Very cool imo. New longblock 454 BB 86 C10 Silverado. # 14081045 heads. Thinking cam n turbo thinking 1000Hp. Will my 045 heads flow enough ? Guess easy 7-800 hp maybe stretch to 1000hp. What ya think ? Thanks brother.
I was also wondering if tightening/over tightening your v belt or serpentine belt would lose power
There was actually a slight loss in power going from stock cam with stock spring to upgrade spring.
So that's pretty cool. The higher spring pressures work great for higher lift or higher RPM on a stock cam.
I thought it would be cool to run a lighter than stock spring with a stock cam in order to gain gas mileage and a little power. No RPM bump allowed with the engine I had in mind.
the stock high-mileage springs had already lost spring rate
26918 is drop in spring? Advantage because of the use of stock retainers and locks.
Of course the power isn’t the same or springs would not heat up on their own. It’s obviously pretty close though. 😎
But does it add stability? Reduce float? Reduce bounce? ( asked rhetorically before watching video )
What have I learned? I never know for sure what I'm going to learn until after I watch a Richard Holdener video.
Crazy that Crane beat the stock cam across the board. The Short runner intake shifted the torque peak to the right around 1500 RPM.
Great test Richard!!! Keep up the good work!!
I would be interested in a in depth valvespring / retainer test ... Beehive vs dual , steel retainer vs titanium or lightweight etc etc
Please do a ebay valve spring test. I blew up my ls6 motor using ebay 1218 valve springs. I thought they were pac 1218 but they weren't. There are many different companies selling 1218 springs claiming they're 600 lift. Please and thank you
@richard holdener i would say they engine is always lifting a couple of the springs at whatever (lbs) force it took to set the cams in place (compressed springs already got a head start).
Imagine two 2” springs, side by side. It takes 200lbs of force to compress one of them all the way down to 1”. While compressing one of them, i mount it directly on top of the other (uncompressed) spring so they now
measure 3” in height. When i allow the two springs to interact, the force of the compressed spring will overcome the totally uncompressed spring and they will both be partially compressed (under pressure) and meeting in the middle. Even though the springs are identical and now under the same load, would take EXTRA force to move the meeting point of the 2 springs, either up or down. Whatever lbs of pressure this is, (i would say) is the amount of force it takes to rotate the cams at any given point of time. Id say its easier to rotate the crank WITHOUT the springs mounted? Could be wrong just thinking out loud here lol
stiffer springs cost power
This one helps me A LOT - THANKS... In my quest to get more power, EFFICIENTLY, I don't want to do mods which will cost me any power(& hence efficiency) - so now I know to keep any cam\RPM mods within the capabilities of my stock springs... Thanks Again... =] PS: I don't understand why there wasn't a further decrease in power with the even stiffer, dual springs - could there be some sort of hidden threshold? O.O PPS: Who knew cam springs add parasitic losses... o.O
Love your videos u are my go to for advice and videos. Did notice anymore valve train noise
I DID NOT BUT WE CAN'T REALLY HEAR THAT IN THE DYNO
@@richardholdener1727 i had a btr stage 2 came and behive spring upgrade and that sounded good valve train noise wise. The next engine was the btr truck norris cam with dual springs and that sounds like a sewing machine. At first I was thinking lobe separation maybe or springs, but u said no to lobe separation for making noise between the two. It would be interest test sometime to see if their in a noise differance between different spring combinations oise wise. Thank you for responding keep up the good work.
@@chrisdunn2544 Why did you use dual springs with a cam that only has .552 lift?
I didn't strictlly performance did I asked the same question . I believe that were the noise is coming from I believe it's a over kill I'm going to switch next summer.
@@nowayjose596 I didn't strictlly performance did I thought it was a over kill. I hoping when I change them the sewing machine noise goes away
162 k congratulations Richard
Oh perpetual motion machine I long to find thee...
ME TOO
I though al gore figured that one out already?
I though al gore figured that one out already?
Was part of the advantage of the first set of springs from the valve train “hanging” because it couldn’t follow the cam’s closing ramps or having so much momentum at the top of the opening ramp that it kept going for a little more lift?
I was thinking the valves could be lofting with the stock springs at the higher rpm's. The increase in power mostly occurred at the upper end of the rpm range.
Intake killed it
I dont think you would see an appreciable difference in power until you up the rpms up higher. If you go high enough to get float you may eliminate it with stiffer springs. The stiffer springs wouldn't make more power just getting it back from float.
Bravo!!
Seems like heavier springs may sacrifice a little bit of power because of the additional friction.
Does new dual spring sound stiffer then stock one when I installed new 660 pac with upgrade kit for rocker arm I noticed sound like ticking on cold start but every day the sound becomes quieter what do you think guys is it normal ?!
My wife keeps telling me stiffer is always better. ;) lol
Go with the thickest pushrod 😀
Would it be the same story with the overhead cam engine?
First time subscriber long time watcher
Welcome back!
Sound Test!! I have upgraded a lot of LS engines over the years and a common complaint I get is about sound!!! The LS engine doesn’t sound as good as my old SBC!!!
1-So does firing order affect sound???
2-Will a LS lose power if it was converted to the traditional SBC firing order??
3-Will a SBC make more power with the LS firing order???
You do great work… keep it up!
i doubt firing order changes power
@@richardholdener1727 is it possible to build a modern L88 427 out of the 7.0L LS7?
Same displacement,
Same carburetor,
Same camshaft specs,
Same power???? Maybe more??
With the camshaft upgrade it is hard to tell what the valve springs hurt. Obviously with a bigger cam you need better springs but it doesn't help that you changed the camshaft while comparing the springs. I'd like to see what the dual valve springs do on the same cam as the comp springs.
THE BTR DUAL SPRINGS WERE COMPARED ON THE SAME CAM AS THE COMP 26918 SPRINGS-THOSE RESULTS WERE SHOWN
Manifold runner length has way more to do with the down low power loss
Great stuff Richard. Tangential question - 90 lbs of seat pressure on the stock spring seems super light, especially when someone runs boost on an otherwise stock engine. 15 psi would be putting ~50 lbs of pressure on the back of a 2.165" intake valve working against the spring. Ever run into any issues with that on your big bang tests?
I can't remember running boost on a stock rec-port motor with stock springs -all the big bang motors had spring upgrades
I would be interested to know, the run to failure test of the cam and valvetrain with the higher pressures.
longevity?
Why did the larger springs with the same factory cam loose power? Lifter bleed down? Deflection in the valve train? Hard to know without a spintron or swapping for some short travel lifters.
spring resistance
The question isn't whether the spring rebound energy is the same as its required compression force(because it isn't, there will always be some energy lost to friction and heat and hysteresis). We should ask which type or strength of spring will lose the least energy and be most efficient returning the potential to the downward side of the cam lobe. Generally speaking, more material means more friction more heat loss but also better stability. But in the case of double coil springs you also have the factor of the two coils interacting and those harmonic and compounded frictional losses. I suppose it's all worth considering at some point, but your test seems to have proved that at normal(sub 8krpm) engine speeds, it really doesn't matter. I wonder how fast you need to spin an LS before the patterns on spring types start to diverge.
Your answer hints at engineering sir.... a sound input, thank you.
Always great content. I would like to get your opinion on how long aftermarket performance Springs and Titanium Retainers last with and aftermarket Camshaft? @.600-620 Lift
depends on the stability of the cam
Good info, especially the hit on the torque curve from the short runner intake. I’m really interested in the 20 or so hp change from a valve job and some port matching. You also mentioned a compression increase-is that info in another video somewhere? I’m trying to decide whether to replace my dished LY6 pistons with flat tops for a street build. It has 823 heads and I picked an “in between” cam (225° intake) that might make 535-ish peak hp in a 6.2, but the lower compression and 12 less cubes make it unlikely I’ll break 500. On the other hand it’ll probably be happy on 87…
A CAMMED LY6 EASILY MAKES 500 HP-WE DID 543 HP WITH A COMP 469 CAM
@@richardholdener1727 Thanks for the reply! My cam is 6° shorter-225° vs 231°. If a typical LS3 makes 575 to 585 with a 469 cam and 535-ish with the BTR stage 2 NA cam, my LY6 is unlikely to break 500, I think. That’s 20 hp for the 12 cu in and 20 for the 9.7 vs 10.7 compression. Flat top pistons could get me half of that (one of those 20’s) back. OTOH, I probably won’t have any problems leaving a stop light with a 6L90’s 4:1 first gear… Thanks for all the great info your channel continuously reports, Richard!
So, will the lower pressures of the beehive springs result in less wear and tear over the life of the engine, as opposed to the dual springs?
Yes, until a certain rpm is hit. When the lighter spring starts to loose stability at high rpm it can cause significantly more damage than a heavier spring.
Just curious do you think it hurts running? The Brian Tooley racing Springs on a factory Cam as that's what I have on my setup. I did the heads 1st and had them done and I have not installed the Cam yet being the factor cam is only a 500 lift. In my ls1 wouldn't think the pressure would be nearly as much
ITS FINE
What about stock pushrods versus comp cams pushrods .does the flex mean that much or is it a waste of money .I've always ran comps with the 918 springs
i tested stock vs .080 vs .105 wall-no change
What is the part number for that crane cam
But witch is best under boost beehive or double
Who supplied the dual springs?
I would have thought the heavier springs on a stock cam would have cost low end power. As they are harder to open. Top end power should have been the same or just a little better.
I have seen stock cams wiped in a short time when the springs were replaced with springs 20% stiffer. Fresh overhauled head onto a stock bottom end. Cam was to be upgraded in the near future which turned into a couple of weeks.
Alternativly a drag racer who had to have huge springs and wondered why he could not keep a cam in it. Crane called for 125 seat, and it had about 180. Solid flat tappet
EFI intakes seem not to make sense. Though long runner should give a bigger power spread
Richard can the ls6/ beehive springs be put on 1970 186 Double Humps that have been upgraded with 2.05 1.60 valves...pinned rocker studs and ported exhaust ports. The engine is a 80to85 stock 350 with a just above stock cam and 416 305heads....the DHumps I bought are set up for Hyd Roller and my engine is Hyd FT.....if the behives won't work can you recommend a spring that will work for me...and what rocker ratio to run.
THAT DEPENDS ON A LOT OF STUFF-CAM LIFT, DESIRED RPM, SPRING LOCATORS, GUIDE SIZE ETC...
Yes you can run them with matching retainers for your valves. You can also cut a factory ls rocker stand up and use the individual pedestals and use the rockers. Also you will need to get the heads machined for positive seals.
I wonder if throttle response is different between the beehive and dual spring. Cause ive heard many times that a beehive makes more power but is less reliable than the dual, however the dyno showed no difference. Is reliability even an issue with the beehive? With less seat pressure and using the correct spring and correct adjustment, i cant imagine one is more reliable than the other either.
the dual spring is no matter what a safer option incase a spring failure.. but your basically right really
If you can run a lower spring pressure everywhere, with no loss in power. Then this would be less wear on the needle bearings on the rockers, less wear on the valve, valve seat, spring keepers and retainers...