427 SBF

Now I have to check the size of my engine. I know I have a 3.875 stroke crank and I am pretty sure it is a 4.155 bore. I thought I had a 427.
Now if your bore is 4.125 (which mine used to be) but a 4" stroke brings you up to a 427......... I thought a 4" stroke on these blocks (4.125 bore) came out to 434. Doesn't really matter......... When my engine was only a 4.125 bore with that crank it was a 414.
 
89 Fox 427 said:
When measuring from head surface to spring cup they are approximately .025 difference.


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That won't give you an accurate measurement.
 
89 Fox 427 said:
Based on this chart that came with my heads, after measuring the springs I believe I have the AFR 8020 springs in that head. A Google search says they are for maximum valve lift of .550 for use with Hydraulic flat tappet camshafts

My cam is a roller with .555 and .576 which leaves me with questions.

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Your cam should have a cam sheet, hopefully it shows recommended spring pressures and installed height. If not, call them and ask.
What do the valves weigh, what rpm do you plan on spinning? Looks like steel retainers and keepers? If you were getting at it an engine builder would want to see some cam specs to determine how aggressive the ramp is, the weight of the valves and valvetrain, usage, rpms, actual lift, and he'd determine the required spring rate then play with installed heights to fine tune.

Coil bind needs to be checked, retainer to seal, seal to inner spring clearance as well. Setting up installed height takes some talent.
Read up on it so you have a better understanding.
 
Mike Beck said:
Now I have to check the size of my engine. I know I have a 3.875 stroke crank and I am pretty sure it is a 4.155 bore. I thought I had a 427.
Now if your bore is 4.125 (which mine used to be) but a 4" stroke brings you up to a 427......... I thought a 4" stroke on these blocks (4.125 bore) came out to 434. Doesn't really matter......... When my engine was only a 4.125 bore with that crank it was a 414.
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Yers is a 420
4x4.125 is a 428 actually, rounding up, lol.
 
This car ran OE gm lifters below.. (in case anyone thinks i'm full of it) And before anyone judges this car, note that this was done decades ago now with factory ported cathedral heads.. back when LS cylinder heads were still at 325cfm, and good single plane intakes hadn't yet been made. Car below with today's LS7 heads (380+cfm) and a CID 4500 intake would easily be in the 8's n/a

2002 Camaro Z28 - Freakishly Fast - GM High Tech Performance

Coleman, itching to get back into the fast lane purchased a 2002 Camaro Z28, dropped in a fresh 404ci LS2 with LS2 heads backed by a TH350 trans along with some extras and was off to run low 9s. - GM High Tech Performance
www.motortrend.com www.motortrend.com
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And Cleveland heads flowed more in 1970 😆👍
 
As usual, I can't make a decision.. this time about lifters. Any input is welcomed

Morel 5323 (i have in my possession and can send back)

Or comp evolution 89311

Or Johnson 2212sbr

Or isky 3877

Or bam 2010
 
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89 Fox 427 said:
As usual, I can't make a decision.. this time about lifters. Any input is welcomed

Morel 5323 (i have in my possession and can send back)

Or comp evolution 89311

Or Johnson 2212sbr

Or isky 3877
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BAM solid roller with dlc bushing
 
I use Crower HIPPO lifters in my stuff.
But, they are solid roller.
For hydraulic roller, no clue..........
 
Steve439 said:
Mark O says "solid" in post #24.
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I have him flip flopping in pm's.

Called him yesterday, I think he said you can achieve your dreams with either one. I took that as stay Hydraulic.

Or I made all this up in my head
 
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