Head cc for SB 427

[Osmiumfoot]

I assembled a SB 427 with a Dart Little M 4 1/8 bore. It has 10.5 CR if I use 64 cc chambers. The cam is a 630 lift, 260 duration roller. I have a set of Dart Conquest 200 cc heads sitting around unused. My goal is to put this setup into a 3800 lb car with 4:10 gears and a converter that stalls at 3500 when used with a built SB 400, and run 11.5 in the 1/4. My question concerns the dimunitive heads combined with the large displacement. Do you think they are too small to meet my goal, or do you think I can push this pig to mid 11s without winding it past 6k?

[lun40119]

Not sure if you are asking for reiforcement on what you are doing or if you really are wondering if you can do it. Plain and simple the airspeed in those heads with that cam and cube is going to be rediculous. It will be done by 6000-6200.

Butchy has a tiny set of heads on a 400 and seems to be successful with a smaller lift cam. If you were going to use those heads I would recommend that. Sorry for the delay, just had to think about this one for awhile. Good luck fella.

[Osmiumfoot]

I was wondering, and I really appreciate the input. You gave me some more advice on Smokemup, which I also really appreciate. The thrust of what I'm hearing is that if I want to keep the rpm low, the car is too heavy to run 11.5, and the heads are too small to rpm the car to 11.5. I also have a set of AFR 210s, so I suppose I could strip that engine down and try them.

[Trmnatr]

I was wondering, and I really appreciate the input. You gave me some more advice on Smokemup, which I also really appreciate. The thrust of what I'm hearing is that if I want to keep the rpm low, the car is too heavy to run 11.5, and the heads are too small to rpm the car to 11.5. I also have a set of AFR 210s, so I suppose I could strip that engine down and try them.

We have a set of GM Camel Hump heads on a 12.38:1 406 showing ~530hp, the heads are bowl ported, exhaust runners ported just to smooth with no re shaping and polished with 2.02/1.6 valves installed. Best ET @ 2,850 pounds race weight (with more in the bag you will see this spring) 10.19 @132.28mph with 1.42 60' (and we usually 60' faster)

The cam will look funky and all cam grinders will tell you its wrong but the track will tell you its right,, Let me look at it later today and i will give you a few more opinion in the event you want to use your heads

One key thing will be a good dual valve spring, we are 155seat with an old school solid flat tappet.

You will need to post your transmission, converter, gearing, tires, usage, what ET or power you wish, car type, race weight

What size valves? 2.02 Model?

Is 6500rpm ok with you with say 6200rpm shifts? Do you recall, does that head have the small exhaust port that was like 70cc or 75cc? Conquests have been TOO LONG AGO TO REMEMBER nut they will make power

AFR is a virus here lol :D

[Awesome Bill]

You can easily do that with no problems. You will be making a ton of torqe ofcourse and that is where I would rethink a loose converter and will get looser with more car weight versus tire size and gear ratio. The 6000 rpm figure is about right and @ 3800lb, you only need 450 or so hp to put your right there. Your answer is an uneqivacal yes! Need any help, let me know.

[Osmiumfoot]

You are awesome, Bill!

[Trmnatr]

I assembled a SB 427 with a Dart Little M 4 1/8 bore. It has 10.5 CR if I use 64 cc chambers. The cam is a 630 lift, 260 duration roller. I have a set of Dart Conquest 200 cc heads sitting around unused. My goal is to put this setup into a 3800 lb car with 4:10 gears and a converter that stalls at 3500 when used with a built SB 400, and run 11.5 in the 1/4. My question concerns the dimunitive heads combined with the large displacement. Do you think they are too small to meet my goal, or do you think I can push this pig to mid 11s without winding it past 6k?

I didnt get an application so im gonna assume its a Chevelle/Camaro etc, You will need a 4500rpm stall with a 3 speed automatic and that is VERY drivable if you get an ATI (IMO the best converter available for you)

I would look at this Crane Solid Roller,
290/306 @.020"
260/268 @.050"
.670"/.625"
106° lobe center

You will want to shift about 6000-6200 and run that or a few more rpm past the lights

IMO it will run faster than your saying you want IF properly set up

[Osmiumfoot]

We have a set of GM Camel Hump heads on a 12.38:1 406 showing ~530hp, the heads are bowl ported, exhaust runners ported just to smooth with no re shaping and polished with 2.02/1.6 valves installed. Best ET @ 2,850 pounds race weight (with more in the bag you will see this spring) 10.19 @132.28mph with 1.42 60' (and we usually 60' faster)

The cam will look funky and all cam grinders will tell you its wrong but the track will tell you its right,, Let me look at it later today and i will give you a few more opinion in the event you want to use your heads

One key thing will be a good dual valve spring, we are 155seat with an old school solid flat tappet.

You will need to post your transmission, converter, gearing, tires, usage, what ET or power you wish, car type, race weight

What size valves? 2.02 Model?

Is 6500rpm ok with you with say 6200rpm shifts? Do you recall, does that head have the small exhaust port that was like 70cc or 75cc? Conquests have been TOO LONG AGO TO REMEMBER nut they will make power

AFR is a virus here lol :D

The application is a 77 Camaro, T350, ATI 8" that stall at 3.5 k behind a built 400, 4:10 gears, 26" tires, street/strip, 3800 lbs on the tree, looking for ETs between 11.5 and 11.6. The valves in the Conquests are 2.05/1.60. I don't know what the exhaust port is on these heads, the intake is 200. You've been very helpful. Any information you can supplly would be most appreciated, and thanks for your other post.

[Osmiumfoot]

I didnt get an application so im gonna assume its a Chevelle/Camaro etc, You will need a 4500rpm stall with a 3 speed automatic and that is VERY drivable if you get an ATI (IMO the best converter available for you)

I would look at this Crane Solid Roller,
290/306 @.020"
260/268 @.050"
.670"/.625"
106° lobe center

You will want to shift about 6000-6200 and run that or a few more rpm past the lights

IMO it will run faster than your saying you want IF properly set up


Its already cammed with a Comp solid roller. 630 lift 260/266 108 LSA. Didn't Crane go out of business? Why is there such a love/hate relationship with AFR? At least I think there's some love out there, but most of what I read is that people think they're overhyped. I have a set and the machine work is lacking in quality but they move the car well.

[Trmnatr]

Its already cammed with a Comp solid roller. 630 lift 260/266 108 LSA. Didn't Crane go out of business? Why is there such a love/hate relationship with AFR? At least I think there's some love out there, but most of what I read is that people think they're overhyped. I have a set and the machine work is lacking in quality but they move the car well.

108lsa in my opinion is too wide for what your doing with the 200cc head

You need a 106, you need 8 degree or more split on that big of an engine

We run the exhaust lash tight , intake loose, just because we its junk lol

[Awesome Bill]

That roller will work very well. You do not have 3500rpm stall most likely with a 8". The 3500rpm is just where your brakes give up and the car moves, just shows you how good your brakes are. If you had a transbrake, you would see most likely 5500.

No love hat with AFR, they are a very good company and make very good products. People seem to think no else in the world can manufacture things and own CNC machines. AFR has been making heads longer than most. I never said I did not like them, I am a solid DART Warehouse and intend on staying there. I can not do better with their product over Dart or even Brodix. Tony is very knowledgeable and should not be taken lightly. What he says in everything I have read is dead on.

You have to be satisfied with customer relations, timely call backs when there are problems, and ofcourse, its got to make power.
Its already cammed with a Comp solid roller. 630 lift 260/266 108 LSA. Didn't Crane go out of business? Why is there such a love/hate relationship with AFR? At least I think there's some love out there, but most of what I read is that people think they're overhyped. I have a set and the machine work is lacking in quality but they move the car well.

[Trmnatr]

That roller will work very well. You do not have 3500rpm stall most likely with a 8". The 3500rpm is just where your brakes give up and the car moves, just shows you how good your brakes are. If you had a transbrake, you would see most likely 5500.

No love hat with AFR, they are a very good company and make very good products. People seem to think no else in the world can manufacture things and own CNC machines. AFR has been making heads longer than most. I never said I did not like them, I am a solid DART Warehouse and intend on staying there. I can not do better with their product over Dart or even Brodix. Tony is very knowledgeable and should not be taken lightly. What he says in everything I have read is dead on.

You have to be satisfied with customer relations, timely call backs when there are problems, and ofcourse, its got to make power.

DAMN Bill, Can you school me on converters??????????

A simple 1" tire change effects the converter,,, How in the HELL do you tell the man what his converter is????

We lightened the car up 200 pounds and LOST STALL RPM

On the Camaro we are 50 pounds heavier and GAINED STALL RPM

Yet by looking at the way his combo is, not knowing ALL the facts you can tell him his converter is 5500rpm

Im gonna call ATI and see if they can teach me how to do this, I guess if they cant you will

[Awesome Bill]

Its already cammed with a Comp solid roller. 630 lift 260/266 108 LSA. Didn't Crane go out of business? Why is there such a love/hate relationship with AFR? At least I think there's some love out there, but most of what I read is that people think they're overhyped. I have a set and the machine work is lacking in quality but they move the car well.

Yep, they went out of business! Your cam is fine, and you will run well. You might, and I mean might find a very little in a new cam, but your most likely to be held up somewhere else first.

People just like to say AFR, DART, BRODIX, PRO-FILER, RHS one or the other has to be better and they are all limited by 4.400 bore spacing, the same valve train, valve size, location etc. NOW when we can raise some ports and move things around, then you will see power. But, the other guys does it also. So run your stuff and have fun. Half these guys on here most likely can't even add! I would be more interested in how your car gets from point a to b and what rpm, tire, gear, converter your using and then see where I can make it better!

[3V Performance]

Not sure if you are asking for reiforcement on what you are doing or if you really are wondering if you can do it. Plain and simple the airspeed in those heads with that cam and cube is going to be rediculous. It will be done by 6000-6200.
Good luck fella.


X2 Heads are way to small for the engine size.

[Osmiumfoot]

OK, I'll flaunt my ignorance. What are X2 heads?

[want-a-be]

X2 = times two. Which means he agrees.

Don

[Osmiumfoot]

:o

[want-a-be]

:o

LOL....;)