Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
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Joined: Feb 2004
Posts: 2,182
From: Moore OK
Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
I have the gm847 and some cm 612 springs. My machine shop said that shimmed they would be fine for this cam.
HAHAH, valve float comes on @ 5500 rpms.
I am trying to find the right spring, which looks like it will be expensive.
Whats the max OD that will fit the stock seats? I have read you need them machined for the 1.46 springs, but everyone says the K-800s fit fine. They are a 1.46 OD spring, so how do they fit?
Will any 1.46 OD spring fit?
Is there something close to stock that will work?
Clicky
The Crane single coil spring looks close. Then I could reuse my CMS locks/retainers to save money. My springs now are 1.26 OD and the Crane springs are 1.255, should fit.
I know I can run some springs with locators, by trimming the locator to fit on the stock seat, again I end up buying springs, locators, locks, retainers... so a bit expensive.
HAHAH, valve float comes on @ 5500 rpms.
I am trying to find the right spring, which looks like it will be expensive.
Whats the max OD that will fit the stock seats? I have read you need them machined for the 1.46 springs, but everyone says the K-800s fit fine. They are a 1.46 OD spring, so how do they fit?
Will any 1.46 OD spring fit?
Is there something close to stock that will work?
Clicky
The Crane single coil spring looks close. Then I could reuse my CMS locks/retainers to save money. My springs now are 1.26 OD and the Crane springs are 1.255, should fit.
I know I can run some springs with locators, by trimming the locator to fit on the stock seat, again I end up buying springs, locators, locks, retainers... so a bit expensive.
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Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
Re: Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
If you have the head off have the seat machined for 1.50s and have it sunk .050.
If the head is on buy some K-800s and a proper seat , remove stock seat and seal, add new seat and new seal, Install spring with a +.050 keeper. Shim to 1.90.
I have been using these springs on several cars (mine and freinds) with the 847.
I started with mine installed at 1.83 on my AFRs with the regular keepers (most height I could get) but it was wearing lifters and breaking the 3/8th studs. After I moved the height up to 1.90 with a new set I can rev freely to 7000 (by the factory tach) and keep my studs in place.
If the head is on buy some K-800s and a proper seat , remove stock seat and seal, add new seat and new seal, Install spring with a +.050 keeper. Shim to 1.90.
I have been using these springs on several cars (mine and freinds) with the 847.
I started with mine installed at 1.83 on my AFRs with the regular keepers (most height I could get) but it was wearing lifters and breaking the 3/8th studs. After I moved the height up to 1.90 with a new set I can rev freely to 7000 (by the factory tach) and keep my studs in place.
Thread Starter
Registered User
Joined: Feb 2004
Posts: 2,182
From: Moore OK
Re: Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
Hmmm,
I have the 7/16 studs so that will help. What retainers are you using on these?
Looks like either way I am going to be coughing up some change.
Looks like K800s, retainers, locks, seals, seats are going to set me back a good $250.
*Edit Hello Perry, small world.
I have the 7/16 studs so that will help. What retainers are you using on these?
Looks like either way I am going to be coughing up some change.
Looks like K800s, retainers, locks, seals, seats are going to set me back a good $250.
*Edit Hello Perry, small world.
Registered User
Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
Re: Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
Lol yeah it is...lol
I am using the Titanium retainers that came with my AFR heads.
I will be at the track this Friday, were you planning on coming by (COFBA thing).
I am using the Titanium retainers that came with my AFR heads.
I will be at the track this Friday, were you planning on coming by (COFBA thing).
Thread Starter
Registered User
Joined: Feb 2004
Posts: 2,182
From: Moore OK
Re: Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
Depends on a lot of things, lol. Shortshifting the 847 @ 5k won't be much fun.
Crane told me to use these, CRN-11309-1
its their single spring kit... said it would be plenty.
Crane told me to use these, CRN-11309-1
its their single spring kit... said it would be plenty.
Registered User
Joined: Dec 2003
Posts: 2,724
From: Oklahoma where trees are made of wood.
Re: Trying to figure this valve spring thing out. What will/won't fit. Valve float on 847
I used the same kit before on my old 93 with the CC305 and 1.6s. They worked good with that cam revving to 6300. But you have just a tad more lift with the 847 (lol) I used them for about 3 years without any trouble.
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