Feel like my 440 should be faster

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What size converter would yall recommend for my setup? If I ended up going to trick flow heads one day would that same converter still be applicable? (which I believe have a smaller chamber volume and would raise my compression to about 10.2:1)

I will definitely be going to at least 3.73 or even 3.91s out back this winter.

If you’re looking for a big move in the seat of the pants feel, the TF heads and a good 9.5” or 10” converter is the right call.
 
How many miles on the engine now.

Is the carburetor opening all the way with the accelerator pedal? Need 2 people to check this.

Are the secondaries opening fully or at all? Maybe you are driving a 440-2bbl.
About 500 miles on the motor. I’ll have to check the carb this weekend. Thank you
 
The thing about the CR is………at that high of an elevation, the CR is “effectively” less.

After you do a cranking pressure test and have a real number to look at.
Use the Wallace cranking pressure calculator to see how close it is.
Then change the baro pressure to something that represents being closer to sea level.
The cranking pressure number will go up.
Now, start lowering the CR until the cranking pressure number is pretty close to what you’re seeing from the test.
Whatever CR you used to come up with that result is basically what the effective CR is at your altitude.

Edit-
So I ran the numbers on Wallace…..
Current baro reading(station pressure) at Denver airport is 24.79”.
For a 446, 9.38cr, int closing point of 67abdc, and 24.79” shows 121psi gauge pressure.
At 29.50” it would be 144.
For the gauge to read 121 at 29.50” the CR has to drop down to about 8.25:1
Thanks for running those calcs. I’m going to run a compression test this weekend
 
How fast was the car with the previous 360 engine? Was it a stock 360 or modified?
Will play a big part in your perception of what is "fast".
Not sure the details on the build, it wasn’t anything crazy. Big cam, Victor intake, stock heads, fairly “tired” motor. However in retrospect, good engine.
 
What size converter would yall recommend for my setup? If I ended up going to trick flow heads one day would that same converter still be applicable? (which I believe have a smaller chamber volume and would raise my compression to about 10.2:1)

I will definitely be going to at least 3.73 or even 3.91s out back this winter.
3.91 & at least 3000stall converter. Heads would definitely help, but rear gear first is a good idea.
 
That cam and 3.23 gears are a mismatch, either go to 3.91-4.10 or change to smaller cam for torque, and tighter converter. It all comes down to what the purpose of the car is.
 
Take it to the strip, weight and 1/4 mile mph will tell you how. The Mopar Bibles are accurate predictors for build, power to weight ratio etc. I also think you might have too much timing? Is it pinging?
 
I have two thought as to what's causing the sluggishness.

First off is the heads. Bolting a set of unported stock heads to an engine with that size cam is never going to result in decent power. The stock heads have a lot of room for improvement. Just a little bowl work will go a long way. Add in a bit of milling, maybe .025" is so, and you'll get a much better setup.

Second is the vacuum secondary carburetor. It's entirely possible that the secondaries aren't opening all the way. Make sure to check what spring is in the vacuum pod. Anything other than the second lightest available might not allow full opening on a mild build.

As for cam size, I've looked into that cam. I like it for the most part as far as creating a nice, torque oriented engine. It's just limited by the cylinder head. I've seen the 452 head untouched first hand. I would not recommend it.

The 3.23 gear is hindering you a bit for sure, but your cam is a torque cam. I would only worry about swapping gears if you want the car to be more strip than street.
 
Standup303, I feel your pain. I live near Parker, CO at 5800' and miss the power of my 340 when I lived near sea level in SoCal. I am running 10.05:1 actual compression, essentially stock 340 specs, but you lose 20-25% of your HP due to altitude. There were times at Bandimere when the indicated altitude was 8800' due to temperature and barometric pressure that day. Knocks well over 1 second of 1/4 mile times.
Understand that Bandimere will reopen in Hudson, CO.
"The family-run speedway, now led by Bandimere Jr.’s son, John “Sporty” Bandimere, hopes to have the new facility partially open by 2025, with full operations by 2026. While a partial opening may not be profitable, Bandimere Jr. emphasizes that maintaining the racing family’s legacy is the top priority: “It’s about keeping this racing family together.” Bandimeres Explore Relocation to Hudson, Colorado for New Expanded Facility | Drag Illustrated

BTW, what dyno facility were you planning on using? Not many left in CO.
 
One more thought…….

“Feel like my 440 should be faster”

Basically…….No matter how fast it is……..after 1000 miles of driving it……..that’s how you’ll feel.
 
One thing to keep in mind if you get more aggressive with your rear end gears which I believe you should. make sure your exhaust is up to it. your motor will wind up much quicker and the exhaust needs to be up to the task.
 
I can’t figure out why you would use stock 452 heads when 2.14/1.81 valves and some minor bowl work like un shrouding the valves can make the cam work 40 - 50hp better. That’s basic Mopar engine building 101.
 
Not sure the details on the build, it wasn’t anything crazy. Big cam, Victor intake, stock heads, fairly “tired” motor. However in retrospect, good engine.
That should have been a real pig @ 5400 ft, doesn't sound like a good combo at all and really not hard to beat with a 440.
 
Interesting. Seems like all signs are pointing to a cam change
no!, IMO, you need more cylinder pressure!
Yes an earlier closing intake would help; just not enough. IMO that 235* cam is just right for your BB, but it needs a DP at 5400ft.

But with your pistons being reasonably high , and already a thin gasket, this points to a reduction in chamber size.

3.23s will get you ~53mph at the top of First gear. IMO they are about the right gears for your streeter. You just need to stall it up to find some power..

But all this small talk could be settled with a compression test.
I did the calcs like @PRH did and came to the same conclusion
 
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Just did a 360la to 440 swap and honestly thought the 440 was going to be quicker.

Had to cancel my dyno tune appointment tomorrow due to snow. Was wondering if you all see anything that stands out as a weak spot in the build that could be hindering power?

Running 19 initial, 37 total, vac advance, have the curve setup how I want it.

Haven’t touched the carb, Quick fuel said go down 1 jet size (I believe) for every 1,000’ of altitude and I’m at 5,400’ but the plugs look good to me, medium tan color

Everything is brand new:

9.38.1 compression (calculated)
Bored .030 over with Speed Pro forged pistons and moly rings
Completely balanced
Cam and crank tunnels align honed
452 heads stock unported with Howard’s springs specs for the cam
New cam bearings
Howard’s Roller .530 lift, 235/243 dur, 103 CL
Howard’s roller lifters
440 Source roller rockers
Custom Smith Bros push rods
Aluminum 440 source water pump housing and pump
Carter street super m6903 fuel pump
Melling standard oil pump
Edelbrock Performer RPM intake
Quick Fuel Slayer 750cfm carb, vac secondaries, 1” spacer
Lokar stainless braided throttle cable
K&N air cleaner
CVF serpentine system
Stock ignition box and ballast
MSD coil
MSD spark plug wires
Schumacher Tri Y headers
Schumacher engine mounts
Pypes 2.5” stainless exhaust with Street Pro mufflers
Hughes 2500 stall converter
3.23 gears
727 reverse manual valve body
You’re fighting the Altitude. I swapped my Howard’s 238/238 0n 108Lsa 9.5:1 combo that would run 14.2 @ 101 (no traction)with street tires @ 1400’ after we ran at 4600 it wouldn't pull. You need a point of compression or 10-15* less duration. I went deeper 3.55- 4.30 and it was still winded... without more compression. The new combo has 10.8:1 and a 242/242 on 110 and only runs 13.89 in 6000' da.
 
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I’d say go back to the heads and do the valves and pocket porting you should also cut the heads down so they are 80cc.. all this will help the 440 every where with hp and tq.
 
I am no expert but few things stand out:
-Thats low comp for a built motor
-Stock heads complete waste of time doing cam etc very minimum need porting and polishing, also port match all your items you would be surprised how badly they often line up. Old heads have very small ports get an old bloke who knows mopars he will know exactly where they need a tickle
-Gears are waaaaaay off, they are hwy gears for getting fuel economy, go 3.9s. Diff gears make more difference than any other modification
-Your stall sounds way out as well, stall cam and gears all need to be working as one. I had my stall custom built to suit cam and gears
 
Big cam, low compression, smog heads, high gears, low stall.

It at least has the right intake manifold.

Option 1.
Go with a smaller cam. Talk to the cam grinder about building cylinder pressure up and working with flow limited heads.

Option 2.
Pit in a 3500 converter and 4.10 gears.
 
Thought I did pretty good. This was supposed to be a budget build (lol yeah right) I almost left the stock pistons and many people recommended bumping it up at least to 9.0. So I got the speed pros. Then I contacted many cam manufacturers. Howard’s had a good reputation and recommended this cam for my motor, street car, 9.38:1 compression, 2500 stall. Think the cars going to get 3.73 or 3.91 gears and call it a day at this point. Sick of throwing money at it.

View attachment 1716350210
Re-read this. Do you see the plus symbols?

2500 and 9:1 are the bare minimum. You need more stall and more gear. That's what I would do.
 
It’s January…….plenty of time for tweaks before car season gets underway.

Pull the heads, have them milled to 80cc and the bowls blended.

Get a 9.5” converter.

If that’s still not enough, put some gears in it.
 
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