Just got a little faster! But how much????

Received my stealth heads back from Modern today. Bob was good to work with and everything went as planned and looks good. I realize this is pretty mundane stuff by this boards standards, but I’m pretty jacked up to see what this does for my 451 Satellite combo.

Question is: how much will it pick up?

My combo has been listed here many times over the years, but here it is again for reference:

400 block .040 over
Factory RB crank
Iconn flattops with 4.5cc reliefs at zero deck
Engle custom grind: 252* @ .050 / .573 lift on a 109* cl (square)
1000cfm Holley annular HP
Eddy RPM with a 1/2” open spacer
MSD Digital 6+ box & Mallory mag pickup dizzy
1-7/8” Hooker Comps
9-1/2” Dynamic converter (flashes to about 4K)
Pretty basic manual 727
Full Calvert suspension (springs, bars, & shocks)
4.10’s & 28x9 slicks
Car has weighed 3820

Previous best is in my sig below. In the heat of the summer it was typically in the 11.52 - 11.56 range.

Changes: the heads you see here were previously OTB with as cast 84cc (??) chambers, good for 10.42:1. Heads are now are a verified 82 cc’s, good for 10.62:1.
Adding a mild steel 6 pt bar. Probably about 60 lbs (??)




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Were they flowed before port work?

Are these later castings?

No, they were never flowed previous. These are earlier castings. I believe they were some of the last of the 84cc versions.

So we can probably assume, they flowed in the 260 to 270 @.600 range?

Your combo is very close to my 470, except intake 😃 and I have a roller. If it doesn't go. 10.5X. (With a Thumperized Dommy) I'll be really irritated.

Yeah. That’s what Ive seen in various flow tests. Source claims 290, but most here agree that’s a happy bench. My logic tells me that now my cam is the choke point.

My 440ci with sft 258@050 - .520 net lift with otb stealths went 10.998 once, mostly 11 low teens . Went to cnc stealths car went best 10.88 mostly high 10.90s /11.00s . Engine was not altered , pinch more comp ended at 10.8
I had more stall , 5000 . And just under 3700lbs . Eddy victor intake
All through street exhaust and mufflers dumping at diff , same 1 7/8 hookers .
So around 2/10s or so .

Tex

Isn't the cam a kv/hv3 grind, or at least lobes.? I have the same cam, but on a 106. Pretty fast lobes.

Yes! It is a KV-3 on a 109 cl

The head porting likely added around 60cfm...... With a radius plate on the port opening.
The RPM is a bit of a flow restriction, so with that in place...... And depending on which manifold runner you're testing....... The gain would be more like 30-40cfm.

Usually it comes down to this......... If the flow of the heads/intake manifold were the major restrictions to the performance of the car, then improving them will yield big gains.
If you dont see the kind of pick up you're expecting....... Then they weren't holding you back as much as you thought.

With the RPM intake, on that combo........ I'm going to say a 40-50-ish hp improvement.
So, if you get that much improvement in power, and make the best use of it, at the current performance level of your car........ 4mph and .4 ET.

My gut feeling is more like 2.5-3 for both ET and speed.
Maybe more with some tweaking.

Cough cough....😎

and he already has an annular carb, do a manifold swap at the track and tell us what you gain or lose !!!

Happy bench?
More like...... No bench.

As I recall, their flow numbers were exactly the same as the numbers for Edelbrock RPM heads.

I would like to see the results before you add the cage

HaHa! Touché, and score one point for Von.

I'd like to see that as well, unfortunately I won't be able to pull it off. Bar is being installed right now, track won't be open until late March at the earliest, and I need the car to be legal at seasons open.

My mild steel 8-point bar added about 100#, FWIW.

I, too, think the Performer RPM is the next choke point. Got the hood clearance to try a tall(er) single-plain intake like a Trick Flow?

Did you ever state your performance goals?

How did that one piston look when you pulled the heads back off?

I think 11.teens @ 120, maybe a dip into the 11.0s

Adding weight by adding a roll bar to your car may help more than hurt by stiffening up the chassis. As far as gained cfm who knows as he didn’t provide before and after numbers. I had 4 sets of the Source heads on my flowbench and they all averaged 267 cfm out of the box. Bolting on any untouched intake manifold is going to kill power but easily fixed during your next upgrade. Good luck and have fun.

Hard to say, you've added weight but also gained a little comp. Question is does your combo need more CFM airflow from the heads. Could probably benefit from a little more.

Your combo is running pretty good for its 3820#,s The RPM might be a little choke up top , but the spacer does give it a little more cushion. But with your 252* cam and 4000 stall vert @ 3820# you Want that RPM intake, choking or not. Its whats helping you move that car below its torque peak which is around 4500 with that cam.

Its going to be faster for sure, but only by maybe a tenth or two at most IMO... With your car being so heavy, I think advancing the cam to around 104/105 ICL would help too, verses being straight up on a 109 icl.

Nice combo.

I assume you’re talking about the piston tops (2 & 3) that seemed fuel washed, cleaner than the others, last time I removed the heads? They were similar but not nearly as bad. Fuel distribution is the issue, I’m sure. I’ve changed carburetors and added the spacer since then. All the spark plugs look identical. So, still don’t really know what to make of it (???).

I’m currently right against the hood with. Drop base 3” air cleaner. So anything taller than the RPM is out. I think that wile the RPM may not flow what a victor does, I think it does good things for my heavy-azz car. While I’d be willing to try an M1, I don’t think the car would be any faster, and I think I’d be shifting higher for the same ET. Could be wrong, but it currently pulls pretty good between 4500 & 5500.

Goals are to be faster with no specific ET. Im a bracket racer and I’m currently usually the slower car in the local Pro ET class, which is full of mid to high 10’s cars. I’d like to be the hunter once in a while instead of constantly being the hunted. Low 11’s will Have the race in front of me now & then. More MPH at the stripe would be nice as I feel the faster car always has better options. With that said; a 10 second time slip would be the next benchmark I’m looking at. I don’t want to get hung up on it, but it would be cool.

I agree w putting the cam in sooner. Mine is at 102 or 103, on a 108.

What are your 60s? Jw, as our et/weights are pretty close.

It’s generally in the 1.57X range on the typical 11.55 run. In good fall air last year it went a best of 1.548.

It sounds like your car would like a low first gear set

I was wondering if your car would go any faster with the Indy dual plane that I run. As far as I know the intake comes in standard port and can be opened to Max Wedge size easily. I believe it has bigger runners then the RPM and I don't think its any taller. Just a thought as that way you could still have the good low end of a dual plane and it should outflow the RPM you are using ? Just a thought ? Ron

Your comments about wanting to get into the tens make me think a bigger cam, single plane intake, bigger carb, and restalling the converter to 5,000+ is the way to go. And it sounds like you don't have a cold air system? That is leaving a lot on the table.
I would do any gear change last. Consistancy at this power and speed level come from back to back 60 ft numbers, and accurate shift rpm. When i was running 9.50s and went to an airshifter with rpm switch, i saw my times narrow by .02. Having the 1/2 shift happen further down track is a help, and once you have the cam/converter combo up well above the torque peak, the old rear gear ratio has less
Effect on ET, but good effect on cosistancy.

B series engine, Ron. I don’t think Indy makes the 2D for a B, do they? Onsidering hood clearance, the only viable options to me are the M1 or maybe a victor. But again, I like the torque curve and shift points down low where they are now.

Go to the old NASCAR trick of drawing high pressure air from the cowl area. The air cleaner assembly can be built rather easily for this. Just study the early Nascar Hemi engine and cold air assemblies. You would still keep a stock locked flat hood and fool everyone while getting pressurized mine shaft air.

Ah yes sorry as I forgot that. I have wondered how the Indy dual plane stands up to the RPM as I believe the Indy has larger runners. Good luck with it. There is also the Mopar 337 single plane that is not to tall. I hear its a pretty good intake. Ron

An old Edelbrock TM6 would clear the stock hood and work well with that combo.



Ron

Been running this cold air system for a while.

Hey Greg, the cam would likely be my next engine move. But I'm hoping I'm done under the hood for a while at least. Current cam, as outlined, is a pretty good lobe profile (Engle KV-3) topping out at grosst .573 / net .555 lift. So I'm leaving a decent amount of my heads potential on the table. Going to a 1.6 rocker, or simply more cam to make use of the heads potential up around .600 valvelift seems like it would yield results. But I realize that is only a theory. Not sure about your carb thoughts. Currently running a 1000 4150. I think this carb is plenty. Don't want more converter because I drive this car on the street regularly.
Basically, as long as I get near bottom 11's, I'll be satisfied and turn my future efforts towards shedding weight, as that would not only help it go a little faster, but also make it easier on parts.. The car currently carries every bit of its factory stuff. A nice fiberglass hood, bumper, and maybe removing the original am radio in favor of a delete plate, along with a few other tricks could negate the weight of the bar, and effectively move that weight rearward.
Can't wait for spring.....

Gary how does it run with the exhaust hooked up? Weren't you running a pretty small exhaust with Flowmasters?

Though the infamous "Silver Bullet" is more your breed, it wouldn't hurt to incorporate some of its DNA tricks to yours like you mentioned. Wheels and various suspension parts could also shed weight. Weight loss will bring results, but may have to make due of some$$.
Watch out though, weight loss can be contagious and lead to a unsound car on the street.

I believe the Nascar cowl setups reign over the grill setups in that they take advantage of the high pressure at the windshield area.

I will be following along here. I have more cubic inches, and the combo is nowhere near sorted out, but the intake aspect of this sure interests me.

That would be a great clone

Well, if you street drive it, whole new deal. More like fine honing about what you have.

It's been years since I've made a pass with the exhaust corked up. It does have a full "street car" 2-1/4" exhaust system with Flowmaster 40's that was near new when I bought it over 10 years ago. I put 3" head pipe 16" off the headers with 3" cutouts on it that I open at the track. I jet the primaries down a couple when it's corked up. I believe the exhaust would cost it 2 tenths or more.

"exhaust to cost it 2 tenths or more"
not to mention the weight with it.

Even though I feel the RPM intake is the best for this combo, the TM6 would be my second choice. Pretty hard to find though now a days.

Sounds like the consensus on my potential performance gains from the head work is 2 to 4 tenths. I’m hoping to hit the higher end of that range, obviously. I’ll report back when it’s back together on what the “butt-dyno” says, but real data won’t be available until the rain stops, which could be a while.

Thanks to all for the input and conversation.

Good luck with your new updates

.....

Seems like the answer is in his sig? Looks like he knocked off couple tenths.