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400 SBC heads and cam recommendation

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400 SBC heads and cam recommendation

Postby Winston Wolf » Sat Apr 24, 2010 12:06 pm

I am thinking of swaping the heads on my .040 over small block Chevy 400. The bottom end is pretty good. Eagle crank, 6" rods with Mahle pistons (11.8:1 with 64cc) New last year, 500 miles or so on it.

I am currently running Gen 1 Trick Flow Twisted Wedge heads (64cc, 180cc intake runner) and a Comp Cams Magnum 292 Hyd cam (.501/.501 244 deg/244 deg @.050) I will be sticking with an Edelbrock performer RPM intake and AVS 800 carb.

It has worked well but the heads have 1.25" springs that never seem to hold up. I'm getting valve float again so I was going to switch out springs, but I'm thinking that I may just move to something more modern (heads are from 1997) that I don't have to worry about so much.

The car is a 1970 Monte, about 3700 with me in it. 4.56 gears and 3500 stall, I currently cross the line at around 63-6500 rpms.

The car is a street strip ride, and I don't get too concerned about streetability. I don't need to run faster than 11.50's in it because I won't install a roll cage. The car did 378tq/365hp on a chassis dyno last year, but I've done some tuning and the carb switch this spring and picked up a bunch from that (comparing old/vs this years timeslips took off 3 tenths and 4 mph)

I was thinking maybe some of the AFR Eliminator Race heads, but don't know a ton about them. I need lots of torque to get this big car moving, but it can take the revs, so I'm not afraid of that. I'm thinking 500 HP should be enough? With the cost of new heads I'm not sure if I will also be able to go to a roller cam, perhaps solid lifters would be ok?


I liked the twisted wedge heads, but I'm limited on cam choice with them and I think that is hurting me, plus all the monkeying around. I just put new Pro Magnum roller rockers on it, so I would re-use the 8 standard ones if I can. Maybe just a head switch is all I need and keep the current cam? I want to be somewhat budget conscience.



Thanks in advance.
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Re: 400 SBC heads and cam recommendation

Postby F1Fever » Sat Apr 24, 2010 12:10 pm

might look here, sounds like it's right up your alley:
viewtopic.php?f=14&t=21404
http://www.1320techtalk.com/viewtopic.php?t=1586
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Re: 400 SBC heads and cam recommendation

Postby Tokyo Torquer » Sat Apr 24, 2010 1:29 pm

If this is a serious street/ strip, I would recommend AFR 210 eliminators. You might also get a little more performance on the cheap and deal with your valve float problems at the same time by going to a solid FT cam.

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1973 RS Z28: 401ci Dart Little M, Littlefield 8-71 supercharger @14lbs boost, Callies Magnum crank, Lunati rods, JE pistons, 7.8:1, AFR 227 Comp heads, T&D 1.6 shaft rockers. Reed solid FT cam (240/250@.050-.523/.542 lift-112 LSA), QFT 750 carbs
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Re: 400 SBC heads and cam recommendation

Postby F-BIRD'88 » Sat Apr 24, 2010 3:52 pm

Brodix IK200's (70cc chamber) and a Isky cams mechanical cam pn#201534
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Re: 400 SBC heads and cam recommendation

Postby trmnatr » Sat Apr 24, 2010 3:56 pm

Winston Wolf wrote:I am thinking of swaping the heads on my .040 over small block Chevy 400. The bottom end is pretty good. Eagle crank, 6" rods with Mahle pistons (11.8:1 with 64cc) New last year, 500 miles or so on it.

I am currently running Gen 1 Trick Flow Twisted Wedge heads (64cc, 180cc intake runner) and a Comp Cams Magnum 292 Hyd cam (.501/.501 244 deg/244 deg @.050) I will be sticking with an Edelbrock performer RPM intake and AVS 800 carb.

It has worked well but the heads have 1.25" springs that never seem to hold up. I'm getting valve float again so I was going to switch out springs, but I'm thinking that I may just move to something more modern (heads are from 1997) that I don't have to worry about so much.

The car is a 1970 Monte, about 3700 with me in it. 4.56 gears and 3500 stall, I currently cross the line at around 63-6500 rpms.

The car is a street strip ride, and I don't get too concerned about streetability. I don't need to run faster than 11.50's in it because I won't install a roll cage. The car did 378tq/365hp on a chassis dyno last year, but I've done some tuning and the carb switch this spring and picked up a bunch from that (comparing old/vs this years timeslips took off 3 tenths and 4 mph)

I was thinking maybe some of the AFR Eliminator Race heads, but don't know a ton about them. I need lots of torque to get this big car moving, but it can take the revs, so I'm not afraid of that. I'm thinking 500 HP should be enough? With the cost of new heads I'm not sure if I will also be able to go to a roller cam, perhaps solid lifters would be ok?


I liked the twisted wedge heads, but I'm limited on cam choice with them and I think that is hurting me, plus all the monkeying around. I just put new Pro Magnum roller rockers on it, so I would re-use the 8 standard ones if I can. Maybe just a head switch is all I need and keep the current cam? I want to be somewhat budget conscience.



Thanks in advance.


The Pro-Filer 210 like Bryce used will be a excellent choice, AFR's would be a good choice too. IMO you can not go wrong with Dart, Pro-Filer, AFR or Brodix. All good quality and performing heads
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Re: 400 SBC heads and cam recommendation

Postby Winston Wolf » Sat Apr 24, 2010 7:36 pm

If found a Hotrod test on the heads I am currently running.

http://www.hotrod.com/techarticles/tric ... index.html

Looks like the flow numbers they got out of them are as follows:

Lift In Ex
.100 54 60
.200 130.5 106
.300 186 139.5
.400 216 160.5
.500 222 177
.600 222 184.5

It sounds like the single pattern cam I am running was a decent choice, not too much lift at .501

I've been running this combo for 12 years now, so I'm sure cylinder head design has come a long way. I would just keep them on, but Im' having problems finding a spring that will work. I can't seem to find anything with the 1.70 installed height, 1.25" spring and the correct spring pressures. Comp Cams told me to run a 941-16, which I haven't opened yet, but I see no they call for an installed height of 1.75. If I do put these in and run keep what I have with the 1.7 installed and my .501 cam I will be at 1.199 These have a coil bind at 1.10 is this even safe to run that tight? I don't really want to wreck anything.

All these headaches makes me want to just take them off and use something normal. With the new rockers I just pumped another 350$, but I think I may be bandaiding.

If I decide on an AFR 210 Race Eliminator or 210 Pro-Filer, just how much of a gain can I expect over these old Twisted Wedge's?? Maybe I wouldn't even need to change cams to get where I need to be?
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Re: 400 SBC heads and cam recommendation

Postby BrazilianZ28Camaro » Sat Apr 24, 2010 7:50 pm

About replace the TFS valve springs, I have these # LUN-73943 in my baby 292 SBC ...7200 rpm isn't a problem with a girly XE 274 cam :mrgreen:

They have 1.26" OD and .630" max lift if memory serves me right.

They are the only ones at 1.26" OD I found that can work with .500"+ lift.

Hope this helps.
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Re: 400 SBC heads and cam recommendation

Postby gmc406 » Sat Apr 24, 2010 8:11 pm

Just outa curiosity, what did the curent setup run?
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Re: 400 SBC heads and cam recommendation

Postby Winston Wolf » Sat Apr 24, 2010 8:16 pm

BrazilianZ28Camaro wrote:About replace the TFS valve springs, I have these # LUN-73943 in my baby 292 SBC ...7200 rpm isn't a problem with a girly XE 274 cam :mrgreen:

They have 1.26" OD and .630" max lift if memory serves me right.

They are the only ones at 1.26" OD I found that can work with .500"+ lift.

Hope this helps.



The Lunati spring:
OD 1.266''
ID .883''
Installed Height 1.750''
Installed Pressure 108
Open Height 1.250''
Open Pressure 339
Coil Bind 1.060''
Max Lift 0.630''
Spring Rate 462

Comp Spring I have:

Comp Cams #249-941-16
Single Outer Valve Springs
O.D.: 1.255"
I.D.: .871"
Seat load: 130lbs @1.750"
Open load: 350lbs @1.250"
Coil bind: 1.100"
Rate: 441lbs/in
With damper

What is on the engine now and seems to be floating:

Outside Diameter of Outer Spring (in) 1.260 in.
Damper Spring Included Yes
Spring Rate (lbs/in) 358 lbs./in.
Inside Diameter of Outer Spring (in) 0.875 in.
Installed height 1.750
Recommended Camshaft Style Flat tappet hydraulic
Installed Height (in) 1.750 in.
Seat Pressure at Installed Height (lbs) 125 lbs.
Open Height (in) 1.200 in.
Open Pressure (lbs) 325 lbs.

From reading it looks like I answered my own question and the 1.7installed - .501 lift - coil bind of 1.1 is ok at .099

It looks like I'm running my current springs right at coil bind, this, I am assuming has contributed to the relatively short life of the springs (my own stupid mistake).

I'm starting to think just sticking with what I have and installing these new springs with the higher spring rate will be just fine. I am a bit concerned about the seated pressure though, I don't know how much is too much for a flat tappet hyd cam.
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Re: 400 SBC heads and cam recommendation

Postby Winston Wolf » Sat Apr 24, 2010 8:22 pm

gmc406 wrote:Just outa curiosity, what did the curent setup run?



12.02 @ 114.06 with a crap 60ft of 1.778 (takes off like a turd)

I was running a 2400 stall. Ordered/waiting on a Precision Ind Vigilante 3500 stall to fix that issue. Plus I was having an issue with the car automatically shifting out of 1st at 5700 RPM's. (I think my trans had low fluid, it's a 200-4R)

I'm thinking I can get my 60ft down with the new converter and fix the short shift issue and shave at least a couple tenths off my ET.

Like I said, max for this car will be 11.50's, but I'm not even close to that yet.
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Re: 400 SBC heads and cam recommendation

Postby BrazilianZ28Camaro » Sat Apr 24, 2010 8:36 pm

Winston Wolf wrote:
The Lunati spring:
OD 1.266''
ID .883''
Installed Height 1.750''
Installed Pressure 108
Open Height 1.250''
Open Pressure 339
Coil Bind 1.060''
Max Lift 0.630''
Spring Rate 462

Comp Spring I have:

Comp Cams #249-941-16
Single Outer Valve Springs
O.D.: 1.255"
I.D.: .871"
Seat load: 130lbs @1.750"
Open load: 350lbs @1.250"
Coil bind: 1.100"
Rate: 441lbs/in
With damper

What is on the engine now and seems to be floating:

Outside Diameter of Outer Spring (in) 1.260 in.
Damper Spring Included Yes
Spring Rate (lbs/in) 358 lbs./in.
Inside Diameter of Outer Spring (in) 0.875 in.
Installed height 1.750
Recommended Camshaft Style Flat tappet hydraulic
Installed Height (in) 1.750 in.
Seat Pressure at Installed Height (lbs) 125 lbs.
Open Height (in) 1.200 in.
Open Pressure (lbs) 325 lbs.

From reading it looks like I answered my own question and the 1.7installed - .501 lift - coil bind of 1.1 is ok at .099

It looks like I'm running my current springs right at coil bind, this, I am assuming has contributed to the relatively short life of the springs (my own stupid mistake).

I'm starting to think just sticking with what I have and installing these new springs with the higher spring rate will be just fine. I am a bit concerned about the seated pressure though, I don't know how much is too much for a flat tappet hyd cam.


Yes, you are binding your actual springs since you need .03" clearance plus the max valve lift.

The Lunati springs have considerably more rate,as you can see.This can eliminate the valve float.

Mines are installed at 1.77" and cam have .523" lift w/ 1.6RR. I shift at 6500 at drags with no problems with heavy vortec 1.94/1.50 valves.

I did the break in with these springs and rockers :shock: :D

You can change the springs AND get a good head port work to beef up the flow# and intake runner cc's, IF this is cost effective to your desired hp level. :roll:
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Re: 400 SBC heads and cam recommendation

Postby bigcam406 » Sun Apr 25, 2010 9:10 am

if you did a head swap with the ones that were mentioned previously,and no other changes,you would notice a huge difference.that being said,without a cam change,you would be leaving alot on the table.id recommend the Profiler's and if your budget allows,why not go to a hydraulic roller setup?
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Re: 400 SBC heads and cam recommendation

Postby Winston Wolf » Sun Apr 25, 2010 11:38 am

bigcam406 wrote:if you did a head swap with the ones that were mentioned previously,and no other changes,you would notice a huge difference.that being said,without a cam change,you would be leaving alot on the table.id recommend the Profiler's and if your budget allows,why not go to a hydraulic roller setup?


What do you consider huge? 10HP? 50?

I know a hyd roller would probably be best, but I don't want to pump too much more money into this thing, so it would be a last resort.
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Re: 400 SBC heads and cam recommendation

Postby bigcam406 » Sun Apr 25, 2010 12:37 pm

lets just say that if you went with the Profiler 210's,theres a 70 cfm difference at .500"on the intake.put into hp perspective,you'd be into the 11 second bracket without a problem.
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Re: 400 SBC heads and cam recommendation

Postby bigcam406 » Sun Apr 25, 2010 12:49 pm

sorry,i meant to say there is a 50 cfm difference on the intake side at .500" compared to your heads,so all else being the same,cant see 11's being a problem. :)
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