I think in the altitude, your big cam, lower compression, and 3.23's are taking away what you hoped for. I bet with a stock magnum cam it would come to life.
Feel like my 440 should be faster
- Thread starter standup303
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That's disappointing. My low compression 360 with 3.23's and stock converter runs that without slicks and no posi....
Insert Batman slapping Robin, "It's a Sure-grip, not a posi!" Meme.
I did that absolutely on purpose
A milder cam might be the easiest solution.
@ 5400 ft you'd be lucky to run 14's. lolThat's disappointing. My low compression 360 with 3.23's and stock converter runs that without slicks and no posi....
Well that's good. One you can rest up from and the other is permanent.
That's the normal Chevy and Ford go to. 2500 is a stock converter for Chrysler.
I lived in Colorado, and drove many a classics in colorado, I know what it pulls out of them
But I'm at 600 ft now, so I'd get a 13.9 .... requiring a helmet 
standup303
Well-Known Member
Interesting. Seems like all signs are pointing to a cam change
standup303
Well-Known Member
standup303
Well-Known Member
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.
As others have stated, your combo is a little mismatched.
First place to pick up some power is in those heads. The trickflows are my go to, but the stock 516 heads are also right up there.
A thinner head gasket will also help, The Mopar performance steel shim head gasket #P4286754 is a 4.38" bore, 0.020" thick (about 5cc volume) that could be used to up the compression a bit.
I would definitely get a set of rear gears, 3:55 for all around driving maybe even some 3:91’s if you like.
Or just put on a 150 shot of nitrous and go with that..
37 total. Is this with or without the vac advance plugged in?
Newbomb Turk
Well-Known Member
I’ll start off with two simple things.
You say the timing curve is where you want it. Is that what the engine wants? I doubt that.
To that end, it’s more difficult to get the correct timing curve on a wheel dyno. If it is just an inertia dyno it’s very hard. If it’s an eddy current dyno then you can load the engine down properly and set the curve.
It’s like sausage making but it’s how you get the curve dialed in.
The other is plug color. If it’s medium tan it’s medium rich at least.
If you have enough ignition the plugs should be dull white with an .080-.120 wide ring around the bottom of the porcelain where it meets the shell of the plug.
I didn’t read any further than that.
Edit: your converter is at least 1000 rpm too tight. At least.
BSB67
Well-Known Member
Step one is to determine if what you have is performing about the way it should. None of us can know this based on the info you have given us.
Second, you really need to get clear on what exactly you want from your car. Few people actually go to the track to achieve meaningful performance results. Instead most folk seem to be happy with simply melting the tires from a 30 mph roll. The path you take for best track performance verses smokin the tires will be different.
For best track performance based on your list, the first thing I would probably do is heads/compression. Do a cranking cylinder pressure test. This information will be very useful.
If it’s a spinning the tires goal, get a smaller cam first, then maybe a gear change.
Second, you really need to get clear on what exactly you want from your car. Few people actually go to the track to achieve meaningful performance results. Instead most folk seem to be happy with simply melting the tires from a 30 mph roll. The path you take for best track performance verses smokin the tires will be different.
For best track performance based on your list, the first thing I would probably do is heads/compression. Do a cranking cylinder pressure test. This information will be very useful.
If it’s a spinning the tires goal, get a smaller cam first, then maybe a gear change.
PRH
Well-Known Member
Let’s revisit the CR-
-What part number pistons, and set at what deck clearance?
-heads were measured and the chamber volume is?
-gasket bore and thickness(or part number)?
Other thoughts…….
Unported stock heads are definitely a restriction if trying for better upper rpm power.
A [email protected] cam, With modest CR and especially at your elevation will want more stall speed(32-3500 actual flash stall).
Something like a tight 10” converter.
A better match cam wise for something that only has an actual flash stall speed of 2500+/- is going to be about 15*@.050 less.
A cranking compression test is worth doing.
Engine warm, throttle wide open, all plugs removed.
I usually look for pressure on first pump, 4 pumps, and max pressure(7-8 pumps).
My experience is that from the drivers seat, a properly tuned, appropriately sized DP carb will “feel” hotter than a VS carb………even if/when it’s not any quicker at the track.
-What part number pistons, and set at what deck clearance?
-heads were measured and the chamber volume is?
-gasket bore and thickness(or part number)?
Other thoughts…….
Unported stock heads are definitely a restriction if trying for better upper rpm power.
A [email protected] cam, With modest CR and especially at your elevation will want more stall speed(32-3500 actual flash stall).
Something like a tight 10” converter.
A better match cam wise for something that only has an actual flash stall speed of 2500+/- is going to be about 15*@.050 less.
A cranking compression test is worth doing.
Engine warm, throttle wide open, all plugs removed.
I usually look for pressure on first pump, 4 pumps, and max pressure(7-8 pumps).
My experience is that from the drivers seat, a properly tuned, appropriately sized DP carb will “feel” hotter than a VS carb………even if/when it’s not any quicker at the track.
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BSB67
Well-Known Member
Your 2500 converter is for towing. Who made that decision? . That thing must be a real pig until it gets rolling. You should be running at least a 3500 for street performance. 4500 for street/strip.
Gears do not mean anything as much as the converter for launch or acceleration from a stop.
I had cars that would sizzle the tires with 323's and a higher stall converter and others that would barely want to leave with 410's and to low of a stall.
Get a good converter for that cammed big block and your eyes will open wide.
Gears do not mean anything as much as the converter for launch or acceleration from a stop.
I had cars that would sizzle the tires with 323's and a higher stall converter and others that would barely want to leave with 410's and to low of a stall.
Get a good converter for that cammed big block and your eyes will open wide.
Not high enough compression and your heads don't flow enough.
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