400 BB Mopar dyno test

-
Brian,

I know this was more of a "what will it do" session but did you happen to test without the spacer?
 
RAMM said:
You may just not be accustomed to the DTS graph appearance. That curve when used with Superflow's WynDyn software would look much smoother. It's just an appearance thing--I am not debating the actual torque output. J.Rob
Click to expand...

Thanks Rob, but to be honest I only looked at the graphed curve initially. I understand dyno settings, the screen, printer settings, and even the camera angle can affect the resulting graph. That's why I translated and simplified the graph I posted into just numbers to illustrate apples to apples without the visual affect.
Just for clarification I was also not debating the output level reached, just the manner of that output. It is very representative of a 383/400 stock stroke set of curves and makes good power.
 
moper said:
Brian,

I know this was more of a "what will it do" session but did you happen to test without the spacer?
Click to expand...

No, but most times...especially if the combo wants some air, the spacer will add about 10HP and improve both HP and TQ curves when used on a dual plane.
I'm waiting for the OK to post our other results from the topend swap...
 
400 can make some serious power if built right. We did a 400 last year. It was made out of the following

516 heads 2.08/1.60 valves NO PORTING(rules for class)
Stock 2bbl intake no gasket match or porting
Stock Truck exhaust manifolds, ran 2 1/4 exhaust on the dyno
10.5 to 1 compression
Voodoo 60303
Stock rockers
Holly 4412 2bbl with adapter(1" spacer basically)

It made 331HP @5200rpm 475TQ @2500rpm

Plus we were able to balance the stock Cast crank internally without any heavy metal. Bob weight was >2200g
 
ou812 said:
No, but most times...especially if the combo wants some air, the spacer will add about 10HP and improve both HP and TQ curves when used on a dual plane.
I'm waiting for the OK to post our other results from the topend swap...
Click to expand...

If it was a longer stroke in relation to the port/intake I'd think that would be the case but it should not be wanting for air with that intake and carb. I'd be curious if that would have helped the low end and peak rpm.
 
Great thread, I too have a 400 and would like to install in my daily driver. Could I get the same results with a 452 head? I would like to do a budget build following your receipe. Ending result would be a horse a cube,
 
manchalk said:
Great thread, I too have a 400 and would like to install in my daily driver. Could I get the same results with a 452 head? I would like to do a budget build following your receipe. Ending result would be a horse a cube,
Click to expand...

I would think the power would be very similar between the 2 heads. And 406HP should be simple.
 
ou812 said:
We just finished a 2 part dyno session using a steel 383 crank, stock rods, stock block (.030 over), 906 heads with bowl cleanup and std size Manley valves.
We went with a Comp Thumpr cam, straight up, 9.8:1 compression, Holley 750DP, rpm intake and TTI 1 7/8 headers.
It made 427HP at 5700rpm and 443TQ at 4200rpm.

I will post the dyno sheet Monday.
Click to expand...
Wow its great that you engine builders are posting info like this, I really appreciate it. Did you go with a Thumper over say an Extreme energy because the specs better suited what you wanted or for the rough idle? I see that the thumpers have a tighter lobe separation. Also is it a roller or flat cam? One more thing, seeing that this is an A body site it would be great to see what effect Schumacher shorty tri-Y headers have on the power compared to the big race headers, especially considering the cost, compromises and flat out pain in the *** issues the big headers cause in an A-body.
 
Doosterfy said:
Wow its great that you engine builders are posting info like this, I really appreciate it. Did you go with a Thumper over say an Extreme energy because the specs better suited what you wanted or for the rough idle? I see that the thumpers have a tighter lobe separation. Also is it a roller or flat cam? One more thing, seeing that this is an A body site it would be great to see what effect Schumacher shorty tri-Y headers have on the power compared to the big race headers, especially considering the cost, compromises and flat out pain in the *** issues the big headers cause in an A-body.
Click to expand...

I'd bet the headers will hurt TQ by 25 and HP by 20 or so. They will hurt avg power and power past peak as well. At least with the low deck, the 1 7/8 TTI's are a fair choice for fitment IMO.
I wanted to show the thumpr cam is a performer, not a gimmick. Plus they can make a really wide powerband.
I would use a 275HL cam with a better 1.6 rocker arm, and have it cut on a 108lca.
 
Here's a pic of the RPM intake, and at the bottom is the RPM vs. Victor intake....clearly the cylinder head is holding it back at this point!
 

Attachments

  • March 16th 2012 001.jpg
    99.4 KB · Views: 302
  • March 16th 2012 003.jpg
    96.3 KB · Views: 290
  • March 16th 2012 002.jpg
    115.4 KB · Views: 262
What engine is shown on the dyno graph's? Same engine?
it's quite a jump from the first graph on page one.
 
OH! OK, I missed that, sorry. Been away and busy.

(I like that power curve better, LOL!!!!)
 
I guess I should have posted it in the other post I have...all well. What can I say I'm tired! Working 6 days a week and kids will do that to ya!!
 
You must log in or register to reply here.
-

Back
Top