Author Topic: Cutting valve spring pockets for dual valve springs  (Read 880 times)

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AlanCasida

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Cutting valve spring pockets for dual valve springs
« on: July 20, 2026, 04:45:56 PM »
I have pretty much decided to get a hydraulic roller cam for my 428CJ motor but the heads have not been cut for dual valve springs. I see there are tools to do  this with just a drill. Is this something I should try myself or just bite the bullet and have a machine shop do it? My machine shop is a 4 1/2 hr drive one way so if I can do this myself it would be nice, but I don't want to screw the heads up either. 

chilly460

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Re: Cutting valve spring pockets for dual valve springs
« Reply #1 on: July 20, 2026, 05:01:41 PM »
Just an option, Alex's Parts sells drop in hydraulic roller valvesprings that may avoid cutting the valve pockets.  Not sure if you specifically wanted to run duals, but this is an option https://alexsparts.com/new-max-output-ii-drop-in-style-high-lift-beehive-valve-spring-kit-for-fe-ford-w-hyd-roller-vsk9p20-q5b/

AlanCasida

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Re: Cutting valve spring pockets for dual valve springs
« Reply #2 on: July 20, 2026, 05:14:31 PM »
Just an option, Alex's Parts sells drop in hydraulic roller valvesprings that may avoid cutting the valve pockets.  Not sure if you specifically wanted to run duals, but this is an option https://alexsparts.com/new-max-output-ii-drop-in-style-high-lift-beehive-valve-spring-kit-for-fe-ford-w-hyd-roller-vsk9p20-q5b/
That just might do the trick. I had no idea such a thing was available. Thanks!

blykins

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Re: Cutting valve spring pockets for dual valve springs
« Reply #3 on: July 21, 2026, 04:32:13 AM »
Those springs will be too light for an FE hydraulic roller.   

Contrary to their ad, there are other beehive spring options if you absolutely just can't machine the heads, but if the heads are off the vehicle, I'd do it right and have the steps cut down around the guides and swap to a modern Viton valve seal size. 

If that step is not removed, you're stuck with having to find a conical/beehive spring to fit (narrows down the spring choice and you may be finding a cam to fit the spring, which is not optimal) and also a hardened shim to keep the spring from chewing on the head.  A spring locator will not sit down flush.

If you have a mill, you can do this yourself with a pilot-guided cutter that cuts both the guide and the step down.  Otherwise, I'd have a shop do it.  It's a quick job, maybe if you called them ahead of time, you can have them do it while you're there.



« Last Edit: July 21, 2026, 06:40:03 AM by blykins »
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
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My427stang

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Re: Cutting valve spring pockets for dual valve springs
« Reply #4 on: July 21, 2026, 07:50:13 AM »
I am with Brent on all points

Recommend you get a retainer to seal clearance too and while you are at it, make more if needed and cut seal surface of to .531. .500 is good too but with a 3/8 I usually stay bigger

Last if it hasn’t been discussed make sure you know which locator you plan to use and leave enough step for some shim along with OD

Easy work if you plan all the dimensions
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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

Barry_R

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Re: Cutting valve spring pockets for dual valve springs
« Reply #5 on: July 23, 2026, 07:15:16 AM »
A PAC 1220 beehive will fit nicely on that OEM step, and with a .030 shim and the appropriate retainer and keeper combination should get you around 140ish on the seat.  Not race car stuff but given the light weight of the retainer it should be perfectly fine for a street hydraulic roller deal.  I am not normally a big fan of single springs (like the beehive), but this is a case where they are the best solution for the problem and I have done many using this combination without any issues at all.

67xr7cat

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Re: Cutting valve spring pockets for dual valve springs
« Reply #6 on: July 25, 2026, 03:03:23 AM »
Is no problem cutting down that step. I did it on a set of C1AE heads with nothing but a hand drill.  Yes a drill press or mill is nice, but you're just removing the step so you stop when the step has been leveled out.  If you are cutting a pocket deeper a drill press or mill is helpful as you can easily measure cut depth.  I have both a drill press and mill, but used a hand drill as it was easier and faster, and does just as good a job. Setting stuff up in a mill take time.  A head machine is nice to have.

The cutter uses a pilot that locates into the guide. They run about $100. Shops have been doing this this way for 50+ years.  If you need guide seal clearance there are cutters to reduce the guide outer diameter to use a PC type seal too, that tool is about $100.  Why this all can matter well if you use a Dual spring you usually will not have much clearance to the valve seal and will need to use a metal clad PC type seal and then you still have to make sure the spring does not move around which the best way to do that is with a inside ID spring locator.  Keeps the spring properly located so no chance if spring to seal contact and it keeps from loading the valve against the guide. 

Now if you are doing the job right you need tools to make measurements for installed height and for the spring loads at seat and full lift. The springs you get don't always match the spec in the ad. For time and memorial people have been putting springs on heads and have no idea if they are right or not. I'm fixing a set of Mopar 440 Stealth heads right now where the cam spec'd a dual spring and whoever did it just took off the old springs and put on the new.

The locator is wrong, the inner spring is stuck to the valve seal which has caused the valve stems to wear in spots so now it needs all that fixed and a new set of valves. Somehow the guides survived. This is all on a set of heads with less than 1,000 miles on them.  In addition, since stock on these heads is a installed height of 1.875" and a spring that should nominally be set up at 1.900" (really 1.920" after measuring them)  The valve open pressures range from 315 to 330 lbs.  which for a HFT is more than it needs and just wearing out parts.  Just an FYI if none of the valves have a shim you know nothing was checked. If they all have the same thickness shim you know one valve was checked and they made them all the same.  Saves a lot of time not checking spring pressures and installed heights 16 times over! 

Unless you want to invest in the tools and invest the time to determine the right parts and set them up right just have a shop do them. Only issue there is finding a good shop that will do the job right.

67xr7cat

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Re: Cutting valve spring pockets for dual valve springs
« Reply #7 on: July 25, 2026, 03:09:36 AM »
A PAC 1220 beehive will fit nicely on that OEM step, and with a .030 shim and the appropriate retainer and keeper combination should get you around 140ish on the seat.  Not race car stuff but given the light weight of the retainer it should be perfectly fine for a street hydraulic roller deal.  I am not normally a big fan of single springs (like the beehive), but this is a case where they are the best solution for the problem and I have done many using this combination without any issues at all.
Just wondering how you can recommend a spring when the OP never mentioned the valve open lift?

My427stang

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Re: Cutting valve spring pockets for dual valve springs
« Reply #8 on: July 25, 2026, 10:05:21 PM »
A PAC 1220 beehive will fit nicely on that OEM step, and with a .030 shim and the appropriate retainer and keeper combination should get you around 140ish on the seat.  Not race car stuff but given the light weight of the retainer it should be perfectly fine for a street hydraulic roller deal.  I am not normally a big fan of single springs (like the beehive), but this is a case where they are the best solution for the problem and I have done many using this combination without any issues at all.
Just wondering how you can recommend a spring when the OP never mentioned the valve open lift?

I don't love 140 seat, I'd like to see 10lbs more on a hyd roller and a 45 degree seat FE intake, and maybe 10 more than that on a 30, but open pressure means much less on these hydraulic rollers especially with a lightweight retainer.  Anywhere from 390-425 will run hard. and likely could go less depending on the lobe intensity.

Not that you shouldn't know open pressure, but the PAC is a good start to fit the head, let the builder determine the next step.
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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

67xr7cat

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Re: Cutting valve spring pockets for dual valve springs
« Reply #9 on: July 26, 2026, 01:07:45 AM »
A PAC 1220 beehive will fit nicely on that OEM step, and with a .030 shim and the appropriate retainer and keeper combination should get you around 140ish on the seat.  Not race car stuff but given the light weight of the retainer it should be perfectly fine for a street hydraulic roller deal.  I am not normally a big fan of single springs (like the beehive), but this is a case where they are the best solution for the problem and I have done many using this combination without any issues at all.
Just wondering how you can recommend a spring when the OP never mentioned the valve open lift?

I don't love 140 seat, I'd like to see 10lbs more on a hyd roller and a 45 degree seat FE intake, and maybe 10 more than that on a 30, but open pressure means much less on these hydraulic rollers especially with a lightweight retainer.  Anywhere from 390-425 will run hard. and likely could go less depending on the lobe intensity.

Not that you shouldn't know open pressure, but the PAC is a good start to fit the head, let the builder determine the next step.

"Not that you shouldn't know open pressure, but the PAC is a good start to fit the head, "
I don't agree with this.
"let the builder determine the next step."
Yeah like when he tells the customer you wasted $250 on the wrong spring...

This is what how I see it... seat pressure you just need enough so the valve does not bounce when closed. A big part of that is dictated by the cam geometry along with the mass of the valve assembly and RPM.  Over the nose has to be enough or you will have valve float or loft the valve.  Again cam geometry and valve assembly mass determine this. Also a higher valve lift means a greater valve velocity and the associated acceleration/Deceleration to deal with and usually needs more spring.  Hydraulic roller cams can have .530" lift or .660" lift.  I know better than to believe an extra .130" of lift does not matter both in needed open pressure as well as what is going to be the right spring rate.

I don't know how you figure out the right spring, but how I do it is determine what the pressures are needed for seat and full lift.  Then find a spring that has the seat pressure needed at a installed height that will work. Then multiply the spring rate by the lift and add that to the seat pressure. When that number is right I have my spring. I see builders who will over spring stuff because it is easier and if the valvetrain don't float or bounce nobody notices much, but all you are doing is wearing out parts more than is needed and you may be loosing lift from more deflection and lifter collapse too.

Now lets look at the PAC-1220 and yes it is a quality spring. It is spec'd for 155 lbs at an installed height of 1.88".  Now if the OP's cam has a lift of .530 he will have 351 lbs at full lift.  Even at it's rated .600 lift it is at 377 lbs. For under .600" lift something with a higher spring rate would be better if we use the numbers you like to see.

« Last Edit: July 26, 2026, 01:15:07 AM by 67xr7cat »

My427stang

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Re: Cutting valve spring pockets for dual valve springs
« Reply #10 on: July 26, 2026, 08:24:54 AM »
Well, first thing I would say is don't buy parts before measuring, and moreover, if you are buying a pile of parts for your builder, you are likely both overpaying and carrying risk.  Nobody stands behind parts you brought to the table. 

Barry gave the guy a part number as example to show there are springs out there that fit an iron head, and ones he used.  FWIW, he even stated they aren't perfect but a good fit when applicable.

I am not disagreeing with you, what I am saying is that Barry didn't say "go buy that spring".  I'll also add that I would prefer to see a guy put bronze guides in, a spring cup or locator, and then have more spring choice, but there are times when guys don't want their less common iron heads cut on. 

As an example, I have a set of original Cobra Jet -J heads, customer doesn't want to cut them.  We haven't worked out the build details, but if it does turn out to be a hydraulic roller, an option is back the cam into available springs.  That 1220 would be good to go at 1.88 or a little taller with the light retainers and then pick a lobe lift based on coil bind and pressures.  I don't like doing it that way, but sometimes you have to.

As far as selecting springs, your method is tried and true, not fighting you, there are few more steps to it than just pressures, but I assume you just shortened it up for example.

As far as open pressures, I will also say that it is very common to have intake lift different than exhaust and open pressures vary, part of life unless you match lobe lift.  Which I do for the most part, but not always.  I'd also say that lobe design matters, and that if you have a lofting lobe, look at the lobe, lots of stable options out there now.  Bounce though is more common and especially a pain with a 30 degree seat if maintaining a factory valve seat angle

My point is that Barry threw an example, it's a logical example, and many of us have had good experience with beehives, and yes, I wouldn't buy the 1220 until he knew more, but it shows that there are usable springs out there without cutting (again assuming retainer to seal clearance and lobe design)


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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

67xr7cat

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Re: Cutting valve spring pockets for dual valve springs
« Reply #11 on: July 26, 2026, 10:24:07 AM »
I'm sure Barry was just trying to be helpful, but go back and read what he wrote. To someone not well versed in all this stuff it could have been taken as a spring recommendation. This is why I asked him the question I did. He hasn't come back to clarify his post and I'm not going to read into his post as to intent.

Btw some builders like when a customer supplies the parts as then they do not have to warrantee them.  Personally I never cared if they do, but if I don't like the parts I won't use them.

MeanGene

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Re: Cutting valve spring pockets for dual valve springs
« Reply #12 on: July 26, 2026, 10:42:22 AM »
Is no problem cutting down that step. I did it on a set of C1AE heads with nothing but a hand drill.  Yes a drill press or mill is nice, but you're just removing the step so you stop when the step has been leveled out.  If you are cutting a pocket deeper a drill press or mill is helpful as you can easily measure cut depth.  I have both a drill press and mill, but used a hand drill as it was easier and faster, and does just as good a job. Setting stuff up in a mill take time.  A head machine is nice to have.

The cutter uses a pilot that locates into the guide. They run about $100. Shops have been doing this this way for 50+ years. 

Any chance you have a part # for that particular cutter? I have an assortment of the cutters for cutting down the guides for seals, but not the one for cutting the seats. Thanks!

blykins

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Re: Cutting valve spring pockets for dual valve springs
« Reply #13 on: July 26, 2026, 11:14:22 AM »
I'm sure Barry was just trying to be helpful, but go back and read what he wrote. To someone not well versed in all this stuff it could have been taken as a spring recommendation. This is why I asked him the question I did. He hasn't come back to clarify his post and I'm not going to read into his post as to intent.

Btw some builders like when a customer supplies the parts as then they do not have to warrantee them.  Personally I never cared if they do, but if I don't like the parts I won't use them.

Who do you build for?
Brent Lykins
Lykins Motorsports
Custom FE Street, Drag Race, Road Race, and Pulling Truck Engines
Custom Roller & Flat Tappet Camshafts
www.lykinsmotorsports.com
brent@lykinsmotorsports.com
www.customfordcams.com
502-759-1431
Instagram:  brentlykinsmotorsports
YouTube:  Lykins Motorsports

67xr7cat

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Re: Cutting valve spring pockets for dual valve springs
« Reply #14 on: July 26, 2026, 11:34:00 AM »
I'm sure Barry was just trying to be helpful, but go back and read what he wrote. To someone not well versed in all this stuff it could have been taken as a spring recommendation. This is why I asked him the question I did. He hasn't come back to clarify his post and I'm not going to read into his post as to intent.

Btw some builders like when a customer supplies the parts as then they do not have to warrantee them.  Personally I never cared if they do, but if I don't like the parts I won't use them.

Who do you build for?

Brent what is your problem?  I work for myself. Sorry if I offend you. Nothing has changed on here. Is a shame.