valve spring change necessary?
 

Hi again,

since my last thread about the old faithful cam was closed, I have to start a new one.

It's now clear that I will swap the XE276HR for a Butler "OF" cam with LS at 114°.
My mechanic wants to keep the old valve springs and I need to know, if this will work and be safe. I have these springs at the moment:

https://www.summitracing.com/parts/lun-73100-16

I won't go past 6000rpm.
If we need new springs, I will need a tool to change them with the engine in car and heads still in place. Not sure if this is easy to do, since we only have a tool to change springs with the heads off.

Thanks a lot for your opinion on that.
Chris

i cant confirm the springs are ok... but removing the springs while in the car is easy & can probably use the same tool you have if there is clearance, otherwise auto parts stores rent valve spring compressors that will fit with engine in the car.

all you need is one of the spark plug adapters to connect an air line to it that keep pressure on the valves so they dont drop out while changing the springs.

A Moroso spring compressor makes it a breeze!
https://www.moroso.com/stud-mount-va...mpressor62370/

Good to know which tools will do the trick. I cannot find these tools where I live, so $ 133 translates to at least $ 200 until I have it with shipping and taxes and I will only use it once (probably).

The other tool we have will not work with heads on the engine.

Would be a lot cheaper and easier to keep the Lunati valve springs...
( 135 for springs, 133 for the tool plus 70 shipping plus 25% extra = $ 422 for new valve springs)

You will want about 150 on the seats.Check to be sure.Tom

I think someone copied that tool and it is cheaper. But the time fighting springs with one of the lever types it is worth it. It locks in place when compressed.

Bar type take less room to operate. Especially needed when AC box and brake boosters are in the way.

Be easy enough to fabricate one if you have to. Think my first one started life as a lawn mower blade.

https://www.grainger.com/product/1UB...B&gclsrc=aw.ds

Clay

Those springs are for a Aluminum aftermarket head with about a 1.800"to 1.850" installed height.

Are your heads aftermarket?

New Valvespings are a real good decision for rpms over 5,000.

I rarely, if ever renewed my valvesprings.

Sorry forgot to mention.. I have 72cc E-Heads (d-port).

Most times on the track I did not rev over about 5400 since it makes not much sense. But the car is mainly steet driven (99%) and the engine will not spend too much time at very high rpms.
I just want it to be safe, if occasionally I will rev to a max of 6000.

We monitor the valve springs with a LSM brand on the head valvespring pressure checker, there are other brands but that is a good one.
Just be aware these types type of testers can vary considerably compared to a bench tester like a Rimac machine.

In all instances our LSM checker measures less with installed springs vs the springs tested prior to installation with the Rimac tester. It can be as much as 10-20 pounds less !
Therefore the on the head spring tester is used only for us to monitor the springs with use over time. I use a solid roller cam set up and we check the valve springs once a year when the lash is checked.


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Chris, please stop being so vague and tell us which part number Cam from Butler you will be using?

Thanks in advance!

This cam: https://butlerperformance.com/i-2936...tegory:1272239

# CCA-BP8031SP

They say it's the same as this cam, but with wide lobe sep. https://www.summitracing.com/parts/c...1/make/pontiac

engine is a 462cui, 1.5 roller rockers, 72cc edelbrock d-port heads, rpm intake, 10.25:1 CR and Sniper EFI

Spring specs are: Lunati Dual Springs 140 @ 1.800, 330 @ 1.250, 1.100 Coil Bind

Those D port heads can be had in a flat tappet version with springs hood for.575” lift before coil bind and shipped set up for 120 psi on the seat, the version of the heads set up for hydro roller use is shipped With springs that can handle the same .575” lift before coil bind , but shipped with 140 psi on the seat.

Since it sounds like you have already run these heads I would say you need the new springs and here‘s why.
To use the springs the heads where shipped with I would want you to add a .030” shim to make up for lost seat pressure .
With the .540” lift exh lift of your new cam adding the needed shim would you take you up to .570” when those as shipped springs are rated to coil bind at .575”.

In short, yes get the new springs and set them up for 150 psi on the seat and then go and have fun!

Thanks a lot!
But I got the heads with flat tappet springs and later (2000 miles ago) I changed to a HR cam, so I needed new valve springs, which are the Lunati that I mentioned. Does this change anything or still better use new springs?
Butler uses these springs if you buy a set: https://butlerperformance.com/i-3123...%3DEDL-5845%2B

I posted yes to you installing the new springs.

You do need to have any springs double checked. The Crane springs SD uses for HR were a little soft at 1.800 when I checked them(bought a Rimac years ago). So they got a shim to get them to 150 and a little less IH.

Got it, but my "old" springs are rather new and they are not the springs the heads were shipped with as you assumed (probably not much pressure lost). Could change the result of your recommendation I thought.

The problem is nobody around here has tools to check the springs, so I need to trust the manufacturer a little bit more than you would. Didn't check the last springs as well.... but if they are like new, they should have about 140, which is less than you would want them to be (but not far less...).

You can buy one of the cheap in vice testers and a dial caliper to get you a ballpark.
https://www.summitracing.com/search/...spring-testers
They also have the copy of the Moroso compressor for about half the cost too.

So no machine shops that build high performance engines there? Valve spring testers are kind of generic.

You are in somewhat of a dilemma regarding checking valve springs. I've repeated it many times, do not trust the specifications listed in a catalog for spring pressures.

Here is one personal example from years ago with a set of Lunati valve springs. I bought a set of their #74500 springs that were rated at 200lbs seat pressure at 1.850" installed height at the time.
They ended up installed at about 1.920" with 219-220 pounds seat pressure. Isolated case? No, I called the source I bought them from and they pulled two sets of the same springs off their shelf and tested those. They were about 230 lbs at 1.900"

Now think of the pressure if installed at their rated 1.850" installed height !

I was given the name and contact for a spring engineer at Lunati from my source. When I called he was VERY surprised and then said the springs must of been mis-labeled !

.

So if I understand correctly you only have 2000 miles on these Lunati springs, which have 140 lbs seat, 360+ spring rate, 1.1 coil bind. If it was able to control the valves with the smaller 423, the new cam is a variation of a 433. Which is only one step bigger from the same cam family for shelf grinds. My opinion is you really shouldn’t need to do anything but switch cams. Switching springs at 2000 miles seem recreational to me. Should go 20K before loosing any spring pressure on that mild spring. Be nice to know the actual pressures for the springs, what Steve C said.and fwiw…looking at the Lunati spring specs, I would have put a .030” shim under the springs with either cam.

That new cam your looking at is a much better choice. Get it done.

The problem is, we have absolutely no expert on such engines where I live and I don't want to go hundrets of miles to a shop in Germany.
I did that once... a engine builder (big shop) built my 428... it was expensive, needed much time and failed after 1,5 years. After that I descided to do everything by myself with the help of a friend who has a shop here (he mainly repairs domestic cars like VW, BMW and also Asian cars which are popular here).
The engine was build to 462cui with the components I listed. I got everything from Butler and trusted them with everything. Runs really good without issues, but my cam choice at the time was not the best.

Long story short... I don't even trust the bigger shops around here and I may just use the Edelbrock springs Butler sells with their kits. I'll ask them on their experience with these springs (I guess they check them if they build an engine).

On the other hand I have some opinions like what Jay S said... that the almost new Lunati springs will work as well which will safe me hours of work and hundrets of dollars.

Chris, just get the73100 springs and install them as they come out of the box if you have to.

You will then have atleast the seat pressure you have now and a spring installed that does not reach coil bind when installed at 1.800" until .700" lift, instead of .570" lift like you have with your springs now.

You will also gain the extended life of a far better made spring then what the E heads ship with!

The 73100 springs are what is installed at the moment. I also talked to Butler now and they say the 73100 will technically work, but he cannot say if there may be a problem with valve float. They recommend the Edelbrock 5845 and I guess I will buy these springs with a spring compressor tool (from Proform). Don't want to risk more than necessary.
I hope the tool works well with the heads on.... good news is we already have a 14mm plug for compressed air :)

I wish I had the options and opportunities you have (and the prices). But in the end we will achieve our goals. Glad you help me out and share your experience with me. Maybe one day I'll get everything sold and move to the US... gets more and more complicated and expensive over here...

The Edelbrock is a single coil spring !

Like Jay suggested add a shim under your existing springs and make the cam change.

I'm very VERY surprised your friend who has a shop there does not have a bench tester to check valve springs.

.

Wouldn't be very accurate but could have your own reference numbers and a way to keep up with and compare spring pressures.

Hang a fish scale on the end of the handle of a stud mount spring compressor.

Clay

On their page they say "dual"
https://butlerperformance.com/i-3123...3Fq%3DEDL-5845
Valve Springs, Hyd Roller, Dual, 1.460 in. O.D., 150 psi @ 1.800 inst. height, 1.150 in. Coil Bind Height

I was also surprised.. he said he does not do such "repairs" and ne need for these tools. Last time we had the heads off and changed the stock E-head springs to the Lunati with a tool that almost cracked under the pressure. I guess the Proform will be a lot better... I ordered this one: https://www.summitracing.com/parts/pro-66784

Butler has the edelbrock springs listed incorrectly. They are single springs, they have very high spring rate to dampen harmonics because they are a single spring. The only thing good about them is they cheapen the spring and cam, or complete head kit up to make them look cheaper.

The 73100 are pretty weak. Only a 333lb spring rate. Doesn’t seem like that matches up with what you post earlier which were said to be in the engines??

Ship the springs to a shop? If the new cam won't get you too near coil bind you can do the math and shim what you have to increase seat pressure. What I had to do with the Crane springs, and why I'm not using 1.65 rockers.

Thats what I said I have, which are the 73100 springs.
I changed the stock e-head springs with the Lunati 73100 for the XE276HR cam (heads first came with springs for flat tappet).

I'm not too sure about that... Jegs also lists them as "spring type - double"
https://www.jegs.com/i/Edelbrock/350/5845/10002/-1

I could ask Butler to check them before shipping.... I don't trust the 2 shops I know in the region who might have the tools.

Yes you are correct the edelbrock’s 5845s are a dual spring. I looked at the wrong column, springs per cylinder.

A compcams 978-16 spring would be a better choice than the 5845s. 400 lb/in spring rate versus the 460+ lb/in of the edelbrocks. Ideally you should be 370-400 on your spring rate for the new cam, 150 seat. The 5845’s have quite a bit higher spring rate than you need. Over 130+ higher spring rate than what you have now. Like killing a fly with a hammer. Collapsed lifter waiting to happen.

I just got mail from Butler and they confirm they are dual springs.
A little bit much, but the good side may be that they can weaken over time and still will not cause valve float :)

I have the lifters Butler sold me with the other HR cam... don't know which part number they are, but they were not cheap. (I didn't buy a set at the time)

When changing valve springs with heads on, how do you do it?
Should I just bring the piston to TDC and change springs or should I use compressed air? I saw a guy who put a rope into the spark plug hole... not sure which way is safe and best.

I'll get my tool and cam/springs by end of this week, so I'm about to make some plans on how to swap things without issues.

i run the butler e-heads with 73100 springs and a 3318/3319 comp cam on a 106 lsa 1.7 intake rockers and 1.65 exhaust
no problems
cam is done about 5700 anyway, so any rpms past that isn't a big deal for me
i am chipped to 6200, have gone to 6400, but can tell after 57-5800 cam is done (should say my combo is done with peaking/increasing power as Rpms go up) (its "windmilling")
i dont experience any valve floating issue
if i go more lift i'll need to change springs
but supposedly these springs are good for hdy/flat/hyd rollers
mine are 10+ years old now

Yes bring cylinder to TDC Depending on deck height and valve notches you may or may not has to use air or the rope trick, but one or the other helps.

Sounds like it should work for my combination as well... Butler said they would recommend going with the stiffer Edelbrock 5845. Still I'm not to happy to change the springs, but better now than later. I guess my cam will have power up to 6000 or maybe just a little bit more.. But however, I'll keep my limiter at 6000rpm or maybe go up 100-200rpm depending how it feels on the strip.

If on TDC, is there still a chance the valve will fall down? Deck height is stock and valve notches are maybe a little bigger than standard because I had to get the compression down a little with 462cui and 72cc heads. Still they are not massive... I think the pistons have -12cc or something like that.

The rope seems to be a good idea, since air pressure would force the piston down.

Even with a dished piston, but with a 72 CC chamber size the valve should not drop out at TDC.

Thats good news. The pistons are -15cc.
The only number I have not is the deck clearance, but it should be around .020 since the block was stock and we didn't zero deck it. So I should be around 10.4:1 and 10.6:1 CR. (10.24-6.80-2.125-1.295 = 0.02 deck clearance)

Would be pretty bad if a valve drops since I only bought the spring compressor tool to avoid removing the heads.

As Steve said generally they will not drop in most cases.

the air psi needed to hold the vale up will definitely not push the piston down. the main benefit to using air is it holds the valve all the way up nice & tight & makes adding the locks & new spring while using the spring compressor tool much easier.

im sure the rope works ok but the air is quick & easy & wont even budge the piston.

the air psi needed to hold the vale up will definitely not push the piston down. the main benefit to using air is it holds the valve all the way up nice & tight & makes adding the locks & new spring while using the spring compressor tool much easier.

I agree. Sometimes the seal holds it good sometimes it slips down getting the locks back on is a pain.

Sounds like I will have a lot of fun changing the valve springs :rolleyes:
But I'll use compressed air and get the pistons on top just in case something happens.
Hope I can feel the difference when it's all done :)

I changed from SFT to SR springs in the car. 72cc E heads. Did get harder to rotate as more cylinders got the stiffer springs!

You may not notice any difference until 20K miles down the road when the springs are still doing there job just fine!

So I did it... it wasn't just a cam and spring change in the end... I did:

- changed the xe276hr to the OF cam from Butler
- replaced valve springs (with Edelbrock 5845.) using the Proform 66784 tool.. wasn't too hard with engine in the car
- replaced valve seals
- gasket matched the RPM intake
- build new wires and connectors for the EFI

Because of bad weather I couldn't do much testing, but it clearly feels stronger and it runs really nice...idling at 800rpm without any issue and no problem with vacuum.

If anyone with a 455 is wondering, if the old faithfull cam is too big... don't worry... I'm pretty sure a tighter LSA would also be streetable.. mine has 236/242/114.