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Old 01-04-2006, 10:37 PM
Too Damn Slow
 
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flow numbers and camshaft selection

I am quite disappointed in my cylinder heads. They are worked over Edelbrock TBI oval port heads that have been angle milled and ported out to rectagular ports.

http://www.cardomain.com/ride/753520/8

I bought these heads off of www.racingjunk.com from a guy who supposedly had them in a 3300# Nova with a flat top equipped 496 and a pretty hairy solid roller that he said ran 6.20's in the 1/8. The machine shop where they were worked on said it made 730HP with a Victor Jr. and a 950HP. (Which now I SERIOUSLY doubt)

The machine shop that did the work on them told me they flow 370/240 @ .800 and had 90cc chambers. I got them flowed on a 4.25 bore fixture without a pipe since my local race engine shop didn't have one as small as my 1.75 headers.

Here are the numbers on #3 cylinder("bad" runner) with 28" test pressure
Lift Int Exh
.100 70.1 63.6
.200 147.8 118.3
.300 211.8 140.9
.400 258.0 173.3
.500 285.0 192.8
.600 297.0 207.4
.700 308.9 220.3
.800 318.4 232.0

they also CC'd the #6 chamber at 94cc which puts me at about 9.5:1 static CR.

Now here are the million dollar questions...

they originally were Edelbrock ROVAL

Now they are Rect 2 13/32 x 1 27/32 or 1 25/32 depending on if it is the good port or bad port

how does this compare to other rect heads?

Are these worth trying to go fast with?

What cam should I select?

Here are some of the recommendations from major cam companies...

Comp Cams
Solid Roller CB4874-4875R110-14
242/248@.050
646/653 lift
110/106

Isky
Hydraulic Roller 696294/305-10
245/258@.050
608/617 lift
110 LSA

Lunati
Hydralic Roller Voodoo 60623
292/300 advertised
241/249@.050
625/625 lift
110/106

Crane Cams
Hydraulic Roller 16HR00083
240/248@.050
621/632 lift
110 LSA

Crower
Hydraulic Roller 01404LM
292/302 advertised
236/245@.050
586/612 lift
110 LSA

What do you guys think? Remember this is a 454 in a S-10 Blazer. It weighs about 3600#. TH350/Currie 9" w/ 4.11 gears and 26" slicks at the track. I plan on street driving it as much as I can. I still haven't picked an intake either, but it will have a Holley 0-9380 carb on it.

Did I get seriously screwed over on this deal? Pretty much everyone has told me that I am the stupidest person on earth and I should get rid of these on ebay and start over, They aren't even worth their weight in scrap aluminum.

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Old 01-05-2006, 05:39 AM
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Flow does look low, but one and three quarter on a RAT? start at 2 inch and move up, my small block tow car is going together with 1.75 pipe.
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Old 01-05-2006, 05:58 AM
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heads

Those flow numbers look a little funny to me on the intake side... Do you know what typ of bench you had them flowed on???? I sure would have checked more then one chamber on each head....

My personal opinion,,, for what it looks like you are trying to do with them i would not want any bigger numbers out of them anyway. Probably in your application a smaller / or the orginal runner would probably have made a better low end engine....

What i would do since you have them and they are paid for i would run them. The thing about flow numbers is everybody gets all wacked out about them and the fact of the matter is they are just numbers.... You really need to get the heads on your combination and try them out....

I think a better place to look would be to run the correct cam for your application...If you want a off the shelf cam i would run that crower you have listed. Not anything bigger @.050

If you want a good cam but it's going to cost you call this guy

http://www.camshaftinnovations.com/

Look at my web site ( www.kstarautomotive.com ) under customer rides, Those sbc heads on that 427 chevy only went 280 cfm @.600 lift and it made over 525 hp on pump gas..

So i am not sure what you are really after out of this engine but i would think with the correct cam it should go around 600 real world hp,, not desk-top-dyno!!!

If you were to step it up to 10.5 /11.0:1 and run a more aggressive solid roller 675/700 should be a easy mark..

Even if those heads only go 318 then you should still be able to pull close to 700 hp out if it with a correct tune and cam combo.

remember if you want to run it on the street with little maintenance you will need to go light on the cam....

Keith

Last edited by k-star; 01-05-2006 at 06:04 AM.
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Old 01-05-2006, 07:20 AM
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I guess my first thoughts after reading your post is where in the port was all this work done. Just changing the port entry from an oval to rectangular isn't going to change much from a flow standpoint as the choke point for those heads is at the valve and short turn and not at the port entrance. The numbers you're seeing are pretty much what are seen with the stock Edelbrock RPM's. I agree with Keith on the cam with the one thing to keep in mind would be in keeping the camshaft duration in the 240@.05 range because of the lower compression. Also keep in mind that max lift for those heads with the stock valves is only around .700
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Old 01-05-2006, 08:07 AM
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The floors of the ports were welded and completely reshaped. That is why I am disappointed in the flow numbers. If you look at the pictures on my cardomain page you can kind of see how much was done to the ports.


The heads are equipped with new longer valves and DelWest TI retainers and Chromoly locks. Right now they have Comp 944 springs which will be too stiff for any cam I plan on using. The previous owner had a 268/278@.050 .748 lift cam in the 496 with these heads.
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Old 01-05-2006, 08:20 AM
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If the guy you bought them from had them flowed on a 4.5 bore fixture flow bench, that will make a big difference. I dont know if it would be as large as 50 cfm, but that could be a reason why they flowed less for you.

Adam
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Old 01-05-2006, 01:30 PM
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Slow, one of the major issues you could be having with that head is simply due to the chamber being cut so much. That can shroud the valves significantly impacting flow in the lower to mid lift ranges.

On a properly ported head the "bad" to "good" cylinders should not show more than "a few" CFM difference in flow, as an FYI.
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Old 01-05-2006, 04:05 PM
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I talked to the machine shop where tthey were done again and yes they were originally flowed on a 4.5" bore fixture and my flow numbers are on a 4.25" bore. I guess I will just have to hope for the best and get a cam to go with my combo.

I talked to Kirk at Bullet Cams today and he recommends a Hydraulic roller as well.

296/302 advertised
242/248 @ .050
600/600 lift
110/108

w/ 130#-150# seat and 325-375# open spring pressures.

He said it should be good for right around 600hp and fairly streetable with a Vic Jr. intake and 3500 stall converter.

He also finally gave me a definate answer that the stock type lifters can handle up to 612 lift.
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Old 01-05-2006, 08:35 PM
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I'm not as optimistic though. I'm guessing 475HP.
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Old 01-22-2006, 07:16 PM
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Well I've decided on the Lunati Voodoo 60622 hydraulic roller.
282/290 adv dur
231/239 @.050
.600/.600 lift
110/106

My DCR will still be rediculously low at 7.4, but I can't do much about that now. I'll definately be able to run 87 in it.

I am looking at using Comp 914 springs so I can use my TI retainers. If I install them at 1.860" it will give me 146 on the seat and 372 over the nose. Will this be ok for factory hydraulic roller lifters?

I also think I'm going with a Vic Jr for intake with the gear change to 4.11's

DD2000 tells me 513hp @ 5500 and 543lb-ft @ 4500 using the flow numbers listed earlier. I'm hoping that translates to 400hp at the rear tires.

Now I need to pick a converter. I'd like something pretty tight in the 3000-3500 range. I like my Hughes GM25 converter since it only has about 3% slip at the big end on the track and doesn't create much heat when cruising. I am also thinking I need to go with a smaller diameter converter to reduce the rotating mass of the drivetrain.

What do you guys think?
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Old 01-22-2006, 07:27 PM
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What was the basis for deciding on a cam other then what the grinder called for? I must of missed something.
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Old 01-22-2006, 09:20 PM
Too Damn Slow
 
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Quote:
Originally Posted by 56Maynard
What was the basis for deciding on a cam other then what the grinder called for? I must of missed something.
After talking to all of the cam companies I was a bit confused. I talked with Harold Berkshire who used to own Ultradyne and designed the Voodoo cams for Lunati. I wanted to stay with a hyd roller and under .612 lift so didn't have to get new lifters. He recommended either an older Ultradyne solid or the Voodoo.

I could go with either a single plane or a dual plane. DD2000 says the single plane will give me more area under the curve and I'll just select a converter to go with it.
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