Valve spring pressure

Took the car out for a test and tune day at the dragstrip today. Last week it ran 5.98. I didn't do anything to it thus week other than new tires and wheels all around and locked the distributor at 34 degrees. Went to make the first pass today, it popped and farted all the way down track. Pulled the valve cover and found two broke outer springs. I'm running a lunati shelf cam solid roller with .735 lift exhaust and intake. What kind of seat pressure should I be in the ballpark of? Max rpm is 7000.

#230@1.950"

Lunati Grind #51601 cam.

Is your top end oiling right?

51606 cam. Everything seems to be oiling fine

That's the base Lunati spring for that cam. They show a heavier spring for it also that is over #300 on the seat@2.1".

I thought this was a new engine?

Better do a compression/leak down test on those cylinders. Hope they come out good.

Yea it's a new motor with 4 passes on it so far. The heads are used but were fresh from machine shop. I'm hoping there wasn't any contact inside.

so i did a compression check this morning, everything is between 205-210 so all is good. I did find one more broke spring. Now i'm on the search for a set of new springs. My installed height is 1.94 with a .060 spring locator and a Plus .050 lock set. Anyone have a part number for a set? cam is 735 lift , current spring is 1.64 OD but retainers measure 1.55 OD they are titanium.

This is what Comp. Cams shows for the solid rollers like yours, in the old parts book, 991-16 only.

https://www.cspracing.com/comp-cams-991-16-valve-springs-1-625in-chr-sil/comp-991-16/

You can look through the PAC catalog, they seem to run higher pressures for like springs.

https://www.racingsprings.com/media/wysiwyg/2020_Master_Catalog_FINAL_Web.pdf

Glad your valves are OK. I would check around during the week and see what the builders recommend.

Make sure you get the right retainers for the springs. That inner spring needs the retainer to locate it.

And these Comp 998's or very close also. The book lists 1.950 installed height.

https://www.summitracing.com/parts/cca-998-16?seid=srese1&gclid=CjwKCAiAmJGgBhAZEiwA1JZollQ_yePuyy6oWOIqOwu9ePKOKz-Oh8MVAsOChEkQGNuhK0kLJLyBvBoCsG8QAvD_BwE

Your cam is a 276/284, actually, not that it makes a lot of difference, when picking springs but, just in case.

Here is a more complete PAC Catalog. the 1944 and maybe 1948 springs are in a comparable range.

https://performancewholesale.com/catalogs/pac/PAC2014CAT.PDF

supervel45 wrote:This is what Comp. Cams shows for the solid rollers like yours, in the old parts book, 991-16 only.

https://www.cspracing.com/comp-cams-991-16-valve-springs-1-625in-chr-sil/comp-991-16/

You can look through the PAC catalog, they seem to run higher pressures for like springs.

https://www.racingsprings.com/media/wysiwyg/2020_Master_Catalog_FINAL_Web.pdf

Glad your valves are OK. I would check around during the week and see what the builders recommend.

Make sure you get the right retainers for the springs. That inner spring needs the retainer to locate it.

And these Comp 998's or very close also. The book lists 1.950 installed height.

https://www.summitracing.com/parts/cca-998-16?seid=srese1&gclid=CjwKCAiAmJGgBhAZEiwA1JZollQ_yePuyy6oWOIqOwu9ePKOKz-Oh8MVAsOChEkQGNuhK0kLJLyBvBoCsG8QAvD_BwE

Your cam is a 276/284, actually, not that it makes a lot of difference, when picking springs but, just in case.

Here is a more complete PAC Catalog. the 1944 and maybe 1948 springs are in a comparable range.

https://performancewholesale.com/catalogs/pac/PAC2014CAT.PDF

FWIW He said he has a Lunati Cam not a Comp Cam!!

On the big solid roller cams the Lunati and Comp. spring recomendations are about the same and the PAC 1944 is right with them.

Here is the springs Lunati spec.s. for that cam.

https://www.summitracing.com/parts/lun-74660-16

It looks like the Comp. Cams 998 H-11 tool steel is the only thing Summit has now out of the ones mentioned. No PAC 1944's.

https://www.summitracing.com/parts/rsc-pac-1944-16

Hopefully Lem has something in stock.

What are the inner retainer step diameters?

...

fordmonsta wrote:so i did a compression check this morning, everything is between 205-210 so all is good. I did find one more broke spring. Now i'm on the search for a set of new springs. My installed height is 1.94 with a .060 spring locator and a Plus .050 lock set. Anyone have a part number for a set? cam is 735 lift , current spring is 1.64 OD but retainers measure 1.55 OD they are titanium.

If spring diameter is 1.64" I hope that the pocket spot faces in the heads are larger. What heads are they?

Dave De wrote:

fordmonsta wrote:so i did a compression check this morning, everything is between 205-210 so all is good. I did find one more broke spring. Now i'm on the search for a set of new springs. My installed height is 1.94 with a .060 spring locator and a Plus .050 lock set. Anyone have a part number for a set? cam is 735 lift , current spring is 1.64 OD but retainers measure 1.55 OD they are titanium.

If spring diameter is 1.64" I hope that the pocket spot faces in the heads are larger. What heads are they?

It looks like he has the A-429 Aluminum Cj Heads

Mark Miller wrote:

Dave De wrote:

fordmonsta wrote:so i did a compression check this morning, everything is between 205-210 so all is good. I did find one more broke spring. Now i'm on the search for a set of new springs. My installed height is 1.94 with a .060 spring locator and a Plus .050 lock set. Anyone have a part number for a set? cam is 735 lift , current spring is 1.64 OD but retainers measure 1.55 OD they are titanium.

If spring diameter is 1.64" I hope that the pocket spot faces in the heads are larger. What heads are they?

It looks like he has the A-429 Aluminum Cj Heads

Isnt that pocket 1.500" diameter? I know that D0OE heads are 1.500" diameter. I would also verify that those retainers are capable with those springs.
I'm no expert but if the spring contacts the edge of the pocket bore which is most likely when compressed. The spring will not be happy. Likewise using a small retainer that cannot control the spring is not good either.

^ I would think his .060" spring locator cup would prevent that. He said the heads were completely worked in another thread, I would assume the pockets were opened up.

Totally agree on getting new springs that fit his keepers, or new keepers for new springs, if he can't match a set of springs to them. Also in checking the fit of the old keepers and springs to see if that may have been a cause.

It's interesting that Comp Cams lists the 733-16 retainers for 1.625" springs and they are 1.5" diameter. It seems screwed up to me also.

https://www.cspracing.com/comp-cams-733-16-titanium-retainers-super-lock/comp-733-16/

supervel45 wrote:^ I would think his .060" spring locator cup would prevent that. He said the heads were completely worked in another thread, I would assume the pockets were opened up.

Totally agree on getting new springs that fit his keepers, or new keepers for new springs, if he can't match a set of springs to them. Also in checking the fit of the old keepers and springs to see if that may have been a cause.

It's interesting that Comp Cams lists the 733-16 retainers for 1.625" springs and they are 1.5" diameter. It seems screwed up to me also.

https://www.cspracing.com/comp-cams-733-16-titanium-retainers-super-lock/comp-733-16/

More and more I think less of Comp Cams. How can a retainer work well for springs that are an 1/8th inch different unless the inner diameter is closer meaning that the wire size is larger? I'm probably more critical of my valve parts matching but I've never dropped a valve either.
Maybe Mr. Monsta can shoot us a few photos.

^Yea it's interesting on the Comp. retainer bit. I looked at all of the PAC retainers and they only show one 1.550" for dual valve springs and one at 1.620" for triple springs. I never much paid attention to it but, it maybe an industry wide thing.

The Manley Ti retainers that I use on 1.640" dual springs......23640-16 is but 1.500" dia.

the heads are a429 heads, the pockets measure 1.76 diameter. the retainers i have a titanium 1.500 outside diameter, the springs that are currently on it measure 1.64 outside diameter. the ID of the inner spring is .765. pretty sure they are manley nextec springs but not for sure. the locks are steel 10 degree with +.050 istalled height. With no shim or locator the installed height is right at 2.000 inch. best i can figure is used a .050 spring locator and end up with a 1.95 installed, Ive called comp, lunati, and pac and they all kinda shy away from a 1.95 height with a 735 lift cam. I found some Kmotion springs i think will work, but I havent been able to find any in stock anywhere. I am wondering if they are even still in business.

What about NexTek 221443-16? 610 pounds open should be good enough for 7,000 rpm.

Manley NexTec 221443-16. Actual page 70 in the link. They show it at 1.950" and .730" lift. it's a 1.580" diameter with a .832" ID.

http://www.manleyperformance.com/dl/cat/catalog.pdf

Dave you typed at the same time, LoL.

Summits out but multiable listings for them on FleeBay.

Looks like the K-Motion K-1000 is close and they are gone gone.

And I don't know what the phone answerers are talking about, all their catalog springs reccomended for their solid roller cams in that lift area show 1.950" for spring installed height.

fordmonsta wrote:the heads are a429 heads, the pockets measure 1.76 diameter. the retainers i have a titanium 1.500 outside diameter, the springs that are currently on it measure 1.64 outside diameter. the ID of the inner spring is .765. pretty sure they are manley nextec springs but not for sure. the locks are steel 10 degree with +.050 istalled height. With no shim or locator the installed height is right at 2.000 inch. best i can figure is used a .050 spring locator and end up with a 1.95 installed, Ive called comp, lunati, and pac and they all kinda shy away from a 1.95 height with a 735 lift cam. I found some Kmotion springs i think will work, but I havent been able to find any in stock anywhere. I am wondering if they are even still in business.

Check out what K-Motion says about minimum installed height on the bottom of page 6. It also has two phone numbers you can try.

https://speierracingheads.com/uploads/3/5/3/2/35322810/211856-k-motion-brochure.pdf

The K-900 and K-1650 ARE IN THE RANGE YOU ARE LOOKING FOR ALSO. They are both 1.550"'s though. If you run the pressures on the spring chart on page 7 at 1.950" and 1.250" it makes it easy to compare. When you take out lash your cam should be at .710" lift and likely less with push rod angle and deflection as Kasse has mentioned, so keep that in mind.

You may run across some of these K-Motion springs NOS.

Comp.Cams lists 8 different retainers that are 1.5" diameter for their various 1.5" to 1.625" springs with different step diameters.

Form what I have seen the steps are usually .009" to .010" larger then the spring ID it fits.

If you want to reuse your titanium retainers you need to make sure they will fit properly.