Quick Valve Spring Question

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94f150rules
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Quick Valve Spring Question

Post #1 by 94f150rules » Wed Jul 11, 2018 6:46 am

I just ordered the crane 260 cam part number 503901 for my 4.9 build. When I was putting the order in at Summit I forgot to order valve springs and retainers, so I told the sales rep to put whatever Springs and retainers crane recommends in the order. I just review the order and it looks like he ordered me dual Springs part number CRN 99838-12 are these the dual springs that need machine work to fit? I want to know so I can quickly order the right set today and hopefully have them by Saturday. He also included CRN 99957-16 valve retainers.

pmuller9
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Re: Quick Valve Spring Question

Post #2 by pmuller9 » Wed Jul 11, 2018 8:46 am

Crane 96803-12 single spring
They will fit the 99957 retainers. Just not sure what the installed height will be with the 99957 retainer since they add .145"

You want an installed height of 1.700".

I'm assuming you are using the stock 4.75" long EFI head valves?

The Crane catalog calls for the 99838 dual spring but the spring rate (438lbs/in) is too heavy for what you are doing.
The 96803 single spring should give you around 107 lbs on the seat and 250 lbs open which is plenty for 5000 rpms.

94f150rules
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Re: Quick Valve Spring Question

Post #3 by 94f150rules » Wed Jul 11, 2018 1:33 pm

Yes I am using the stock head. I haven't modified anything.

pmuller9
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Re: Quick Valve Spring Question

Post #4 by pmuller9 » Wed Jul 11, 2018 2:59 pm

Would you please measure the installed spring height using the stock intake retainer.
Install the retainer on the valve without the spring and measure between the bottom of the retainer to the head valve spring pocket.

Also measure how much travel before the retainer touches the top of the valve guide or valve seal.
The exhaust valve lift of the Crane cam is very close to the travel limit of the stock valve.

94f150rules
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Re: Quick Valve Spring Question

Post #5 by 94f150rules » Wed Jul 11, 2018 7:47 pm

Thank you for getting back to me so fast. Im going to have to wait to check the measurements, I cant take the truck apart until Friday night after work. I was trying to have every thing here by Friday so I can get it all done by Sunday night. If they don't measure out can I use the factory springs? Or use the new springs with the stock retainers? Unfortunately I need the truck for work Monday.

pmuller9
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Re: Quick Valve Spring Question

Post #6 by pmuller9 » Wed Jul 11, 2018 11:32 pm

The Crane 503901 has an exhaust valve lift of .487" with the stock 1.6 ratio rocker and will compress the stock exhaust spring near or at coil bind.

The stock intake valve retainer will fit on the new spring but I believe the installed height is 1.640" which is tight for the new springs and will add 20 lbs to the spring pressure making the seat pressure around 127 lbs.
This is the reason I suggested checking the stock retainer height.

The exhaust retainer has a rotator as part of the assembly and will compress the new spring too much.

94f150rules
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Re: Quick Valve Spring Question

Post #7 by 94f150rules » Thu Jul 12, 2018 6:20 am

So is there a different retainer, or spring that I could order? Would a beehive spring help? I really dont want to pull the head and change the valves if I dont have to. You really know your stuff so I trust your advice.

94f150rules
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Re: Quick Valve Spring Question

Post #8 by 94f150rules » Thu Jul 12, 2018 9:32 am

I've been sneaking and reading on the forum at work trying to find an answer, and I'm just going in circles. I'm terrible at finding things on forums. But I think I read that the factory intake springs are 1.7. I tracked down a cylinder head off of a 95 4.9, and I'm thinking of just swapping the intake valve springs and retainers onto my exhaust valves to do away with the short spring and valve rotators, this should give me the height I need right? The only part thats not so great is Im using old springs but atleast it would work. Would using those retainers with my new springs work? Now it's crunch time so I'm trying to find a way to make all this work

pmuller9
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Re: Quick Valve Spring Question

Post #9 by pmuller9 » Thu Jul 12, 2018 3:54 pm

The pre 1987 carburetor heads have a 1.810" long valve and have an installed spring height of 1.700"
The EFI head has a shorter 1.750" long valve so one might assume that the installed spring height would be 1.640"?
Since you now have a spare EFI head could you check the actual installed spring height?

The other question is: Do you have a metal replacement timing gear to replace the fiber gear on the camshaft?

94f150rules
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Re: Quick Valve Spring Question

Post #10 by 94f150rules » Thu Jul 12, 2018 4:37 pm

Yes, I just got the metal gears in the mail. Along with most of my other parts. There's another box waiting on my porch I have to open when I get home.

The whole cam lift issue is driving me nuts I keep seeing people who recommend this cam for EFI and some people saying they're running it. I wish that they would mention that you need to rebuild your head to run it.... This is becoming a big mess.

pmuller9
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Re: Quick Valve Spring Question

Post #11 by pmuller9 » Thu Jul 12, 2018 9:44 pm

Since you have a spare EFI head check two things.

1.) Measure the distance between the bottom of the stock retainer and the head surface without the valve spring in the way.
2.) Measure how far the valve travels before the retainer hits the top of the valve guide with the valve stem seal in place.

Then we will know for sure what the clearances are.

The new retainers you ordered are supposed to increase the installed spring height by .145" and can be used if the stock intake retainers don't give you enough height.

94f150rules
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Re: Quick Valve Spring Question

Post #12 by 94f150rules » Thu Jul 12, 2018 10:18 pm

Paul I am so sorry, I thought you meant the design of the retainers added a thickness of .145 reducing my total lift before the retainer hits the seal/guide, not increasing it. Ive been going nuts trying to find ways to make more clearance. You have probably been reading all my posts thinking whats wrong with this guy...

pmuller9
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Re: Quick Valve Spring Question

Post #13 by pmuller9 » Thu Jul 12, 2018 11:31 pm

94f150rules wrote:Paul I am so sorry, I thought you meant the design of the retainers added a thickness of .145 reducing my total lift before the retainer hits the seal/guide, not increasing it. Ive been going nuts trying to find ways to make more clearance. You have probably been reading all my posts thinking whats wrong with this guy...


I wasn't sure what was going on LOL. No worries.

How much valve travel do you have before the retainer hits the seal/guide?

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