Indy Heads back from porting, Guess on HP/ET Gain?

Just got my Indy 440-1 heads back from Larry Smith. Awesome work! They look great. Started with OOTB 15 year old 440-1's. New Manley Severe Duty valves, opened the intake ports up to 572-13 openings to smooth out manifold transition, fresh valve job.
What kind of HP/ET gain should I expect going from a box stock 440-1 to fully ported? He's showing 390 CFM @ .700 lift.
Car specs:
68 cuda tube chassis 2950 w/driver
446 cid 13.5:1
284*/284* .704 lift Roller w/1.6 rockers
1050 Dom
4800 stall
4.30 gear 14x32 slicks
6700 shift
Previous best 9.80 @ 137mph / 6.20@110mph

Intake Pic's

Larry's Pic's

Are you only changing the heads but leaving the cam, carb and shortblock the same? Looks like you were around 600 hp on the Moroso slide rule before since that is what it takes to push 3000 lbs to 9.8 @ 137. I'd think those heads would pick up 100 hp even with the same cam and carb so that puts you at 9.30 @ 145. But who knows, at some point another cork shows up in the system. The cork could be the cam or the exhaust or the carb. You'll just have to get it back together and see how she runs. The heads look good, they should support more than 800 hp if everything else is up to the task.

Depending on how much money is in the budget you might consider a different cam. Talk to Dwayne about what type of lobes would work with your existing valve train but could pick up some power for you. I don't think a 284/284 single pattern grind is what I'd be using with those heads but see what Dwayne has to say.

I had Larry do my heads with basicly the same figures. At 455 cubes my cam is 290@50 & i have a 1200 cfm Dominator but use a 5800 converter, same 32x14 slicks, but 4.88 gears & I rev to 8000 rpm in a 2900lb car, I was able to run 9.2@142mph. I think you need to rev harder but with your combo I'm thinking 9.5's.

Probably slow down.........lol

Definitely needs more gear, and convertor.

I think the port work will really wake up that motor.
I second the idea that higher stall speed, maybe 5600 rpm would go with that combo.

2-3 tenths with everything staying the same........

That thought crossed my mind too.. Gonna need more gear and RPM now.....

How many cc's do those intake ports end up when you do that?

I would have never bet my 15-1 572 with a 3 speed 727 would need 6000 stall. It woke it up more than any other single change made in the last 8 years.
Doug

One thing I've noticed about Larry's work, not only are the ports super-pretty and beautiful appearing,
but he always seems to sand the exterior surfaces with a DA.

Ever heard the saying "you eat with your eyes"? Same idea if the customers first impression is WOW then that is what we are hunting for....I have been using Larry for years. Always good stuff. Work like that just takes time. Todd

Larry did our 360-1s on my small block. Couldn't be happier with his workmanship. He was really sick back then and still got my parts back to me. Heck of a guy and he does quality work..

More stall might be a good idea but the stall speed will increase naturally from the extra torque so I'd try it first. The car will have more power so the MPH will go up so I'm not sure it will need more gear. The trap RPM will probably increase from 6700 to 7000 just with the additional power and speed. Might not want anymore RPM than that depending on what parts are in the engine.

This is good advise.

Hahahaha

I agree with the trend, so the converter company will make use of the extra data. But I still think that "small 446" CID and long 284 deg @.050 duration will want high 5 grand stall speed for best perf.

Now I am coming from 500+ CID experience...

I am at 3012 lbs, torqueflite, 4.56 gears and 33 tall slicks. Stall is 6200 and the motor was 550 cubes, fully ported 440-1, 3x intake and alky injected. Still sorting out suspension settings. Best 60 ft 1.24 best mph 154. I mention all this because with the right cam i believe you will need to shift at 7600 and recovery needs to be 6600 because your best average hp will be in that range. I shift my 550 at 7450 rpm, recorded on a data logger. Peak hp on the dyno was 926 hp at 7200 and was still climbing.

They look great but I have no idea what you'll gain.

I certainly hope they make you happy.

I agree with you but I'm wondering if that 446 engine really needs 284 duration. My guess is that the car would be faster with a smaller cam. The OP might not want to spin that 446 high enough to make use of the 284. If I was building a 446 with those heads and a solid roller I'd probably be 10 degrees smaller if not more. My 470 ran best with 264/268 and that was with MW heads and a ported intake. I didn't have as much compression so with more compression the cam can be a bit bigger. If the cam was smaller then the torque converter might be okay as is.

I just ran a 565 inch BB Chevy on the dyno with a 284 cam. It was a full race setup with 14:1 compression, CNC heads, Dart block, etc. It made 900 hp at 6500 rpm. Makes me think the OP's cam is too big.....

Rebel, are you spinning that 455 to 8000 with a stock block? I've been trying to keep the rpm under 7000 to make the tall fill,Hughes girdled stock 440 live.

Andy, I was running the OORB 440-1's with an old Reed 271/274 .625 lift roller for 3 seasons until I lost a lifter and scored the cam. I had the Comp 284* .660 lift roller sitting on the shelf for 30 years from my old Stage 6 446 motor so I threw that in with the old Crane rollers to get me back on the track.
The car ran the exact same ET and MPH with both cams shifting at 6500,6700,6800 and 6900.I tried 1.6 rockers and it lost half a tenth.I figured the cam was too big but it kept me racing and the car sounded a lot meaner. I tried 4.86 gears when it had the smaller cam but the car ran the Exact same ET and picked up 2 MPH while pushing it through the traps at 7400. Rather than work the stock block filled/girdled 440 any harder for little gain I swapped the 4.30's back in. I could always try the 4.86's again with the ported heads.
The car has always liked leaving on the brake at 4800 for a 1.37 60ft. If I lowered the launch to 4200 or 3800 it lost 0.15 to 0.20 ET and 60ft was in the 1.40's. I was Leary about running more than 36* timing with 13,5 comp but my reaction times were all over the place, mostly red. I bumped the timing up to 38* then 40* and was able to launch at 4200 with a good rt and run the same ET.
Wong story short, I sent the old Reed cam out to Bullet and had it reground wit 276*/279* dur .670 lift with 1.6 rocker ratio. Do you think that cam would perform better in this combo or will the ported heads like the 284 cam.

PS: My plan was to use the ported heads with the 284* cam on a 14.5 comp 493 that I was piecing together but the crank is .020 under and the only narrow bearings I can find listed are Kings and they have been on backorder for 6 months so it looks like the 446 will be going back in

No, I'm using a low deck Maxx block. I have a 512 with a stock block I rev to 7k, but has a BCR girdle kit to keep it together.

I'm pretty sure that the 284 is too big for your engine in terms of making best power but based on your testing it might be a good match for your chassis. In other words, if you put a smaller cam in it then perhaps the extra torque will set off a domino effect and it might take you a bunch of work with springs and shocks to get back to a good 60 ft time. Same thing with your timing test. I'd never recommend adding timing like that to solve a reaction time issue but if it works for you then go for it. Seems like playing with fire though. That is a lot of timing for a high compression wedge headed engine. I'd never run 40 degrees of timing in a high compression BB Mopar engine.

I hate to say change too many things at once (heads and cam), but since you want to keep the RPM below 7000; I think the 276*/279* dur .670 lift would be a better fit.
More torque to improve the sixty foot time and work with the existing "low" stall converter better.
Still think a high 5k converter is the right thing to have at the end of the day (month, year, etc.). It has been a long time since I raced less than 493 CID, but that sixty foot seems slow for a 2950 lb car with a 3-speed transmission.
Or is it a PG with 1.76/1.80 first gear?

Quite simply, I wouldn't do a thing. I'd go run the car, get a timeslip, then, the incrementals on that slip, will tell you everything you want/need to know. You can then adjust with data. This is the old ask 100 people, and you'll get 130 answers.I am sure you will need to make changes, but I wouldn't just guess.

I agree 100%. I personally don't see the need for more converter or more gear. It's a bracket car, no sense in killing the motor with rpm that you don't have to. I am sure it will run quite well.

A buddy of mine runs a 499 or 500" wedge in a tube chassis bracket car, smallish solid roller with good springs. It runs 5.70's or so shifting at 6400 and lives long trouble free lives.

Exactly. The 528 in my Omni-Charger went 5.65-5.70 shifting at the same rpm. It has -1's, bowl ported (330@ .700), .693 roller, 1.76 Glide, and a 4.10 gear. Car is 2500 with me in it. I can't remember the Duration or Cam CL, but it is a fairly mild grind.

Guys,
He can't do nothing and just run it. He already ported the heads.
This is the time to make changes. But not too many.
I prefer one at a time. But taking the entire engine apart to change things is not in everybodys desire.

I’d put it back together with the Bullet cam.

I built a RB451 several years ago.......
13:1, SR heads with MW openings that flowed in the 340’s, port matched 440-3, 272@.050/.650 lift cam, 1.5 rockers.
Made peak tq at 5500, peak hp at 7200.

I'd put it back together and run it. See what the heads pick you up and that will give you a better idea of what if any other changes may need to be made. Right now it's a guessing game as what COULD help it until you get on track data.