427 SBF

BOSS#1540 said:
For a low rpm tire burner I think he already had what he needed with the afr's etc.
I've always said the 1st rip of the year in the spring feels like holy fuckin shit, by the end of the summer I'm pretty sure this thing is down a cylinder 😆
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What would peak HP be with that 243/255 HR cam?
I'll take an uneducated guess and say around 6600.
 
Steve439 said:
What would peak HP be with that 243/255 HR cam?
I'll take an uneducated guess and say around 6600.
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No idea!
Cylinder pressure, valve events ? , with some advance. Valve weights? Idk.

I've dynoed a few Clevelands and rpm'd them all, looking for the mythical high rpm power. All done before 7000 rpm, cams from 258° to 276° @ 50. More to it than just the cam is all I can say, lol.

New one is to spin 8600, similar duration to last one that was done at 7000 (268/276, 636 lift, 108 lsa in on 104 icl vs 278/284, 837/796 lift, 112/113 lsa, 109 icl) BUT Darin has the heads and intake set up properly now.

Edit: the last engine with the 636 lift cam was 12.8:1 with 220 psi cranking pressure, as far as cylinder pressure vs rpm, still done before 7000
 
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Steve439 said:
Give some serious thought to it and decide:

What percent of the driving will be done on the street?
What percent of the time on the street will be at full throttle?
What percent of the time, including full throttle, will be done over 5000 RPM?

Think about all that and then decide if a single plane would actually be part of the perfect combo for your circumstances.
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This is the reason I can't justify more money into larger, better, or different parts.

98% street driving
10% full throttle for a gear or two
15% of the time shifting over 5k

At the track as it is currently built I'll shift at 6500 (or 6200 if it rolls over sooner). Guess that's TBD but that's the plan anyways
 
I was trying to get 500 at the wheels.
 
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You bought the ProMaxx 210s?
They flow over 300 and you have enough displacement and cam to take advantage of a lot of that.
500 sounds low.
 
89 Fox 427 said:
I was trying to get 500 at the wheels.

Looks like I'll be more like 500 at the flywheel. Disappointing to say the least
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Don't worry about what you have at the wheels. It's a tuning device. My brother's car and niece's car were almost the same # on the chassis dyno, he runs 12.1 @111mph, she ran 14.1 @ 98 or some shit.
Mine dynoed 583hp (flywheel), maybe 600 after a few changes, ran 125+ mph, should've been good for 10's
I don't have a hp or et goal (800hp and 9's 🤫), my goal was to get what I could out these old parts and still drive it on the street.
What is YOUR goal ?
 
Steve439 said:
You bought the ProMaxx 210s?
They flow over 300 and you have enough displacement and cam to take advantage of a lot of that.
500 sounds low.
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On the flow bench

Promaxx
246 @ .400
274 @ .500
295 @ .600
303 @ .700

Afr 220
253 @ .400
287 @ .500
306 @ .600
317 @ .700
 
BOSS#1540 said:
What is YOUR goal ?
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Unrealistic.

I see brand new cars with a/c and a kids seat in the back making 600, 700, 800hp.

My ford edge ran a 12.77

My goal? Drive it to the track without issue. Put a 950 on it, change tires, run a 10.5, and drive home
 
89 Fox 427 said:
Unrealistic.

I see brand new cars with a/c and a kids seat in the back making 600, 700, 800hp.

My ford edge ran a 12.77

My goal? Drive it to the track without issue. Put a 950 on it, change tires, run a 10.5, and drive home
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A lot of these new cars have power adders, yer na.
Something wrong with lights for edge to run 12.77 😆
600hp at the flywheel will do that if the car is set up.
I drove mine on the street for over 15 years with nothing but oil changes
 
BOSS#1540 said:
A lot of these new cars have power adders, yer na.
Something wrong with lights for edge to run 12.77 😆
600hp at the flywheel will do that if the car is set up.
I drove mine on the street for over 15 years with nothing but oil changes
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Not a fuckin thing wrong with the lights.

I'm about to return all these fucking parts honestly
 
You have more displacement, bigger heads and cam, you're going to make a lot more power than the original plan.
 
BOSS#1540 said:
Why? Wtf happened that's got you disappointed?
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When I was buying heads and cam I was told 1.5hp/cube is easy and that the heads I bought would do that.

So far 2 other builders have said I definitely won't break 600.
 
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Steve439 said:
You have more displacement, bigger heads and cam, you're going to make a lot more power than the original plan.
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The original ORIGINAL plan was 450hp.

Buying the dart block the goal was 650 and a 10.5.
 
Again, I just need to breath, run it, and see what it does out there.

Maybe it'll kill me before I get to the track
 
89 Fox 427 said:
When I was buying heads and cam I was told 1.5hp/cube is easy and that the heads I bought would do that.

To me that says id hit 650hp.

But what they were LIKELY saying is those heads would support 650hp with new intake, new carb. So blame my interpretation of words I guess.

So far 2 other builders have said I definitely won't break 600. And in a recent email I was told my combo as it sits will be low 500hp
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I was at 409 cubes, 4.034" bore, 12.8:1 but cam bleeding off compression. Old unported heads that flowed 340 but not sized correct where it matters. Unported intake, truck oil pan, only 636 lift and made 583hp from 6-7000 rpm and 503 ft/lbs from the start of the dyno on basically, lol.
I think you'll be fine
 
Same 358c before that with a solid flat tappet cam with 671 lift made 452hp. The bigger duration cam with 636 lift made 2 more hp at peak but was down everywhere else.
 
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