I like “focus on making the existing better” approach
W2 408 Dyno results today !
- Thread starter mbaird
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Oh yea! There’s a bit more in there to get a hold of. Just keep tweaking it out! I’m looking forward to the tests and thanks for sharing this. Very cool of you.
justinp61
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Can you post the complete engine build?
I wonder how the relatively low compression is affecting the power? If it has a out of the box Victor there will be some power from port matching it. My Victor was horrible and took a few hours with a burr to make it useable.
I wonder how the relatively low compression is affecting the power? If it has a out of the box Victor there will be some power from port matching it. My Victor was horrible and took a few hours with a burr to make it useable.
MOPAROFFICIAL
Oogliboogli
I'm thinking the 1st, Chevrolet syndrome. Lol
MOPAROFFICIAL
Oogliboogli
They are horribly misaligned and misshapen.
PRH
Well-Known Member
I see there are some fuel flow numbers on one of the sheets, but no bsfc numbers on that sheet.
And I don’t think the sheet that has the bsfc numbers is the same run as the sheet with the fuel flow.
But, “assuming” the bsfc numbers are somewhat close between the pulls, looks like there was roughly 50hp in correction.
Which doesn’t seem unreasonable at all if the dyno is really at 2500’ elevation.
Unfortunately....... without being able to compare the numbers to a similar combo tested on the same dyno........ looking at sheets from other dynos is just “racing dynos”.
My experience has been that the 4” stroke combos can absorb some cam duration.......and if you’re looking for “the big number”........ 246/250 is kind of small.
Cam for what you’re doing with the car....... and the hp number just iwii.
In my mind, the numbers seem on the low side....... and the bsfc numbers are high.
But....... without being able to quantify the numbers against some other builds from the same dyno...... they’re just numbers.
Might be the dyno is stingy, might be issues with the room causing low numbers, etc.
On the dyno here........breaking 500/500 from a 408/416 combo isn’t that hard to do........ and I’d have expected to see that out of your combo of parts.
And I don’t think the sheet that has the bsfc numbers is the same run as the sheet with the fuel flow.
But, “assuming” the bsfc numbers are somewhat close between the pulls, looks like there was roughly 50hp in correction.
Which doesn’t seem unreasonable at all if the dyno is really at 2500’ elevation.
Unfortunately....... without being able to compare the numbers to a similar combo tested on the same dyno........ looking at sheets from other dynos is just “racing dynos”.
My experience has been that the 4” stroke combos can absorb some cam duration.......and if you’re looking for “the big number”........ 246/250 is kind of small.
Cam for what you’re doing with the car....... and the hp number just iwii.
In my mind, the numbers seem on the low side....... and the bsfc numbers are high.
But....... without being able to quantify the numbers against some other builds from the same dyno...... they’re just numbers.
Might be the dyno is stingy, might be issues with the room causing low numbers, etc.
On the dyno here........breaking 500/500 from a 408/416 combo isn’t that hard to do........ and I’d have expected to see that out of your combo of parts.
PRH
Well-Known Member
The sheet I posted is from 18 years ago, so the exact details are a bit fuzzy.
The cam was something like 262/266-108, using lobes that were easy on parts.
.630-ish with the 1.5HS rockers.
I will say that as it was on that sheet it had the 3450lb Challenger running 10.60’s.
The next year I put in bigger intake valves(2.055), and sold him a cam with a bit more aggressive lobes.
264/268-108 as I recall...... .645 lift if I’m remembering the lobe family correctly.
The short block got freshened, but not re-dyno tested.
The car picked up a couple tenths(10.40’s).
If you look at the air flow numbers on the sheet, you’ll see they level off after 6700, and the power starts to drop off a bit quicker from there up.
That’s the valve springs starting to lose control.
The cam was something like 262/266-108, using lobes that were easy on parts.
.630-ish with the 1.5HS rockers.
I will say that as it was on that sheet it had the 3450lb Challenger running 10.60’s.
The next year I put in bigger intake valves(2.055), and sold him a cam with a bit more aggressive lobes.
264/268-108 as I recall...... .645 lift if I’m remembering the lobe family correctly.
The short block got freshened, but not re-dyno tested.
The car picked up a couple tenths(10.40’s).
If you look at the air flow numbers on the sheet, you’ll see they level off after 6700, and the power starts to drop off a bit quicker from there up.
That’s the valve springs starting to lose control.
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I thought I had but here it is again .
4" forged Scat kit
W2 heads ported
9.8 : 1
246/250 108 .648 cam
Victor intake
TTI 1 7/8 headers
Pro Systems custom carb DP
Harland Sharp 1.6 rockers .
PRH
Well-Known Member
Frankly, I would have thought 500/500 would be a slam dunk for that combo, with probably another 20 or so on the table with more cam duration.
The heads on the motor for the sheet I posted flowed about 280.
Here’s one from a few years ago.
410, 10:1, pump gas, mild rpm heads(flow 270), gasket matched Victor, 1-3/4 > 1-7/8 headers, ootb QFT SQ-850, 251/259-108 roller, .600/.600, Mancini 1.5’s.
I wasn’t the one running this engine......... there was power left on the table with the jetting.
The carb was way rich, and the bsfc numbers weren’t good.
The target for this build was to be around 525hp.
Sometimes it ends up that you look like you know what you’re doing.
The heads on the motor for the sheet I posted flowed about 280.
Here’s one from a few years ago.
410, 10:1, pump gas, mild rpm heads(flow 270), gasket matched Victor, 1-3/4 > 1-7/8 headers, ootb QFT SQ-850, 251/259-108 roller, .600/.600, Mancini 1.5’s.
I wasn’t the one running this engine......... there was power left on the table with the jetting.
The carb was way rich, and the bsfc numbers weren’t good.
The target for this build was to be around 525hp.
Sometimes it ends up that you look like you know what you’re doing.
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PRH
Well-Known Member
That’s like trying to get your car into the tens and running 11.01.
It’s just not as satisfying as a 10.99
justinp61
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. So close but still not a 9. 
tubbedamx
Location Boise, Idaho
Haha, If drag racing was your focus run up it to woodburn, Oregon in September
At least 5 tenths quicker and 7-10 mph
but your right one shot at firebird
Yeah ... I love Woodburn . You can literally feel your car go faster !
PRH
Well-Known Member
On the plus side...... the front/rear fuel flow balance really looks good on the carb.
When you get the print outs, hopefully you’ll get all the sheets for a run where you pulled it to 7k.
When you get the print outs, hopefully you’ll get all the sheets for a run where you pulled it to 7k.
My peon opinion is, it's runnin outta cam. That's a relatively small one for W2 heads.
Having said that, it'll be extremely reliable and probably never "break stuff".
Having said that, it'll be extremely reliable and probably never "break stuff".
I'm not knowledgeable enough to know all the ins and outs of the dyno sheets and the values on them as far as fuel consumption and minute details. I don't however believe the hp numbers are a reflection of the cam being too small. With a very similar w2 build and a smaller hydraulic roller cam I made 50 more hp and 60 more ft/lbs at lower rpms. This was also done on a dyno known to be conservative.
You may well be right. I could be pissin in a fan.
And I certainly am not trying to be a know it all, because I don't. I was actually hesitant to post on this thread as I do not wish to come across as bragging about my build, anything but. My point being something does not seem to add up on this build and the numbers based upon experiences with mine. I would have thought this engine would have ended up with similar numbers as mine, and besting mine on top end due to more cam.
Actually that very thought ran thru my head . In a way I was relieved when I saw it peak at 6k . Lol
Idle quality is really good and the exhaust note is not much more radical than a stock 340. I was aiming for a sleeper build when I started this project.
PRH
Well-Known Member
At least you can now bolt it back into the car knowing it’s good to go
You’ll probably find that in the car the motor will easily pull past 6500.
You’ll probably find that in the car the motor will easily pull past 6500.
No offense taken on my part. I agree with what you stated . And I feel there is still some some tweeking to do . But now I know its not leaking or knocking and its running smooth down low. That is harder to acheive than WFO performance. And since 99.9% of its operation will be on the street at RPMs under 4k it should work well for me. If I decide I want a full time race car I would swap the cam to something closer to a 270ish duration and run the TR with 2 Holleys.
This combo should work great with the 4sp. Much more duration and I would be fighting the pulses at low speed and/or be forced to run 4.10s + in the rear.
PRH
Well-Known Member
It’s easy to lose track of the intent of the car and get caught in chasing dyno numbers.
You now have a nice baseline to work from.
If you decide to step it up, you can bring an updated combo back to that same dyno and see how it measures up.
You now have a nice baseline to work from.
If you decide to step it up, you can bring an updated combo back to that same dyno and see how it measures up.
I agree 100% we are now splitting hairs on HP numbers that will likely never, or rarely be needed based on intended usage. A good running leak free engine is an excellent secondary result of dyno. I know this will bring a smile to your face every time you drive it. I know how many times I have actually run mine in a manner where I utilized all she had through all 4 gears, rare indeed. Since mine sees mostly open road use I have actually considered putting on the W2 dual plane I have instead of the Victor W2. Still as it is, it will get 3rd gear rubber with 3.23 gears and 28" tires. One change I made this summer that netted nice results for driveability, was pulling the 950cfm 4150 style carb for an 800 AVS2. For ease of use on a driver it was a nice trade off. The output of my engine far exceeds how I ended up using the car, I think this is a path many of us go down. I'm not complaining though. As stated, an engine that rarely sees North of 6000rpm should live a long happy life.
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