I thought it might be due to the piston speed with a 4" arm but it dropped so fast . I figure it might taper off.
W2 408 Dyno results today !
- Thread starter mbaird
- Start date
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I thought it might be due to the piston speed with a 4" arm but it dropped so fast . I figure it might taper off.
Krooser
Building Chinese Free Engines since 1959...
It’s likely the cam gave up… my buddies run 440” at 9,000 rpm with a 4.125 stroke. Not Mopars but the crank doesn’t know what block it is in…
SwedishViking
Well-Known Member
MAPS
Well-Known Member
I can't say much but because I went to hell and back with my six pack this summer (like every other summer) we finally got it running "better" not perfect but better, but I see you AFR are a little low, NO ?
Figured you should be in the 14 zone, if Im wrong sorry...
MAPS
Figured you should be in the 14 zone, if Im wrong sorry...
MAPS
I'm sorry, but the stroke is not the cause here. My personal 408 makes power through 7400. Dyno tested and confirmed, and My heads only flow 285. This is cam, cam degree, carb cfm, or intake manifold choke.
Heck, the BluePrint 408, with a much smaller hyd roller cam makes hp through 6400 or so. With as cast, edelbrock heads and an airgap.
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RAMM
Well-Known Member
Would you be so kind and share those 2 dyno sheets please? J.Rob
RAMM
Well-Known Member
I was asking JohnnyMac for the BP example and his personal 408-but thanks. While we're at it do you have the uncorrected or "raw" numbers? mbaird J.Rob
I will get the actual printouts next week when I pick up the engine .
These were random pics I took thru out the day .
512Stroker
We are all here because we are not all there.
Those cam numbers look very healthy to me.
It could be a valve opening /closing timing issue making the power fall off.
Cam timing to far advanced @ +4* ?
What do the cranking speed cylinder pressures look like?
Can’t remember what this is going in and it’s intended use? Considering the cam with those @.050” duration numbers making peak HP at 6200 it seems spot on.
Overall I’d think you’d be quite chuffed with it, I know I would be!
RAMM
Well-Known Member
Just looked back on the component list and you have some very nice parts listed. What was the compression again? Did you guys use the air turbine? The engine on paper should be better than that up to about 6200-6300 rpm. J.Rob
Havent checked the cranking pressure yet .
Compression is 9.8:1
Can’t remember what this is going in and it’s intended use? Considering the cam with those @.050” duration numbers making peak HP at 6200 it seems spot on.
Overall I’d think you’d be quite chuffed with it, I know I would be!
69 4speed Swinger mostly street driving with maybe 2-3 days at the track .
Gotta make a liar outta me
Idk how clear it is, but mine noses at 72-7300. Guess my memory was of a touch. Peak was 608. It carries around 580 through 7200.
Not sure which one you are more interested in for comparison sake. But I would think OP's engine should be similar to the attached sheet. I uploaded my cam card for gigs also. I have a touch more duration, but he has more lift, and more head flow. Maybe not enough spring?
You got me on the BPE. Looks like we shut them off at 6000. I swore we turned them a little harder, but again those are street engines made to live forever. I don't have the "real" one handy on a Sunday. Just the one on the website.
EDIT: Sorry...those pics are crap.
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Knowledge is power!!
Gotta make a liar outta me
Idk how clear it is, but mine noses at 72-7300. Guess my memory was of a touch. Peak was 608. It carries around 580 through 7200.
Not sure which one you are more interested in for comparison sake. But I would think OP's engine should be similar to the attached sheet. I uploaded my cam card for gigs also. I have a touch more duration, but he has more lift, and more head flow. Maybe not enough spring?
You got me on the BPE. Looks like we shut them off at 6000. I swore we turned them a little harder, but again those are street engines made to live forever. I don't have the "real" one handy on a Sunday. Just the one on the website.
View attachment 1715816635
View attachment 1715816655
EDIT: Sorry...those pics are crap.
Thats closer to what I was hoping for out of mine . Impressive #s !
The extra 15* of intake duration is significant though .
tubbedamx
Location Boise, Idaho
Any idea what the weather corrected to yesterday.
Nampa is probably around 2500ft plus the humidity was pretty high. My air density gauge was reading 90 most of the day.
Nampa is probably around 2500ft plus the humidity was pretty high. My air density gauge was reading 90 most of the day.
3800 at mid day . 3400 at around 6:00
SLOPAR72
Well-Known Member
Well you may have been looking for something a little bigger but that's a good number. Street driver, you won't need to run Premium and no leaks. Adding that 3rd pedal to the equation will make it a blast to drive.
If you ever put it on a Chassis dyno you will see firsthand how much power is not lost by having no Converter. BTW- I bet your Dyno guy is a hoot. Older guy with more knowledge than most will ever know. That trailer full of headers pretty much sums up his history....
JW
If you ever put it on a Chassis dyno you will see firsthand how much power is not lost by having no Converter. BTW- I bet your Dyno guy is a hoot. Older guy with more knowledge than most will ever know. That trailer full of headers pretty much sums up his history....
JW
MOPAROFFICIAL
Oogliboogli
Looking at the numbers..
Probably cam n heads are mismatched.
Lemme see what heads you have on post 1....brb
Oh boy... what are .200-.500 numbers on those w2's and the header is too much imo.
Narrow power band r kinda indicative of more exh than intake charge. But I'm no expert and dont own a dyno. That intake manifold without any work only flows 'on my bench' around 245cfm.
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Shouldnt be ... this is a custom grind ordered by Ryan when he ported the heads .
I do realize this is a comprimise cam .
I wanted a hot driver . If this was a pure race car peak numbers would be higher. That being said I believe there is another 40-50 horses that can be squeezed out of it. But I can live with a meager 492 hp for now .
Should work well with 3.55s
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