401 sbc ready for the Dyno

[HQM383]

I don’t think any more power will be squeezed out of this small head 401 sbc. So time for a bit of fun and revisit the guesstimates.

I’m calling it 568hp @ 6500rpm and 532ft/4900rpm from a run with 975cfm carb that wasn’t influenced by multiple runs (the 571hp/538ft/lb run)



Sorry bob, maybe lack of sbc faith clouded your estimate

Or maybe "happy dyno" ............Just kidding. I didn't even know they had a dyno.

Now you need to back it up at the track.

How much the HQ weigh?

Good job all round

Weighs 3350lb on the scales on the ring rd BP.

They guys (Allan and John) told me they they installed the dyno back in about 2007/8 to do their own development work and verify what they build. Back when they done the extensions. They don't advertise as a service or use it to turn a profit.

Happy dyno? Time and track will tell as you say. I didn't have my heart set on a number so it won't be broken if it didn't happen. From the outset the primary goal was to be able to drive to Calder or Heathcote, run 11 flat and drive home with these old antiquated Twisted wedge heads. I like a challenge.

Thanks bob and I'm sure we will catch up one day.

[HQM383]

Had what would be the last dyno session today. Didn't do any runs yesterday as the day before power was down from the day before that and all other days leading up to it (today is Friday, didn't run on Thursday because power was showing a big difference on Wednesday versus Tuesday and days before that). Was found to be the weather station screwing with the correction data. That was fixed and re-installed and todays runs then all but mimicked our other consistent results (Tuesday just gone and days previous to that).

So today was to revisit ignition timing by adding some at idle to see if idle could be improved and then run through the ICE pre-programmed curves one at a time to find best power. Did that and found new best peaks. Full disclosure though. The process was the same as when 571hp was found. Engine warmed up, run to 6500rpm, pop into the cell while engine idling and go up 2 degrees timing, do another 6500rpm run. Done this until according to the ICE chart 36 degrees total all in at 3800rpm. This netted 575hp @ 6250rpm and 538ft/lb @ 5100rpm.

Next we took a closer look at the fuel curve bank to bank (975cfm carb). The afr trend has always started even numbered cyl bank richer than the odd number bank. As it approaches peak tq they even out and after that the banks swap and the odd numbered bank becomes the richer bank. So on the 5/7 cyl corner of the carb we go from a .031" mab to a .033' mab. It done something. Added a couple of ft/lb and hp. So done the same to the 1/3 cyl corner of the carb. This now gave the highest peaks yet of 578hp @ 6250rpm and 542ft/lb @ 5100rpm. Happy to have 530ft/lb+ from 4550rpm to 5450rpm.

Next, took air cleaner off and ran to 6500rpm. Zip, nada. The 11" x 3" with Xtreem lid K&N air filter is a kick ass air filter. Note though that base is a raised base, not flat or drop.

More good news is the Progression Ignition was re-installed to check if it was cooked with the incorrect hook-up and I'm pleased to report it's all good. Fired, app connected and responded to changes. Seems I already have a distributor for the future build of old engine.

[xanadu]

Gremlins in every corner nowadays . That’s awesome! The torque numbers are killer. Not that it’s needed, but I wonder if individual cylinder timing / tuning would net much more?
Well done

[HQM383]

Gremlins in every corner nowadays . That’s awesome! The torque numbers are killer. Not that it’s needed, but I wonder if individual cylinder timing / tuning would net much more?
Well done

Thanks xanadu. I'm certainly happy with it.

Look at the pic below that shows peak hp. Lambda2 was as low as 0.811. Going up the .002" on the odd bank side mab gained a few hp and ft/lb with the few points of lambda it leaned there. I could only imagine having full control over every cylinder would be worth a lot more.

[xanadu]

Absolutely mate, rewards from fuel curve and timing together! Whoa. Wouldn’t it be nice to have a home engine Dyno

[HQM383]

Done the final run yesterday afternoon. All that was done was put the ICE distributor back in and confirm all was good. I wanted to add another 4 degrees to initial timing so did that and took 4 degrees out of box. Results below. Water temp highest for this run than other runs as it was just the one run to check all was good before taking it off.

Would an extra nine to ten degrees water temp inflate results? Only the one run so I'm assuming the oil temp didn't have a big influence.

All done and off the dyno. Won't go in the car until a new converter is purchased and swapped out. Now I have dyno results I'll send them off to the converter builder with all other relevant specs for a more informed converter build.

It would be remiss of me not to mention a few that helped along the way. Without a doubt Steve Cowan has been a great help and sounding board over the last few years guiding me in the right direction with some of the choices I have needed to make. Thanks Steve, your help and advice has been greatly appreciated. James Melmoth (ST handle 'MELWAY') flowed the heads and gave some other great advice like talking me into going a 4.125" Dart SHP block and going bigger with the cam. First iteration with the cam was 8 degrees smaller. Also have to mention all the contributors to Speedtalk present and past. This place is a wealth of knowledge and I often found myself coming back here as a resource if information gathered elsewhere seemed not to jive with the guys in the real world on ST. Thanks everyone.

So for now its sit tight until a well matched converter is installed. Then the engine will be fitted and I will report back on how it all performs in my 3350lb car.

[steve cowan]

1.35 ft/ lbs and 1.46hp/ cube.
Potentially at your weight
10.1s @ 130 mph ,something to work towards for sure.
I have had water and oil around 150 - 155 f on dyno as it takes some time to get heat .
Normally for me at the track it's an hour between runs or longer so getting oil temp up is difficult as it is load related more than coolant temps.
I have enjoyed this thread,I think you have done well.
8" converter and 4.1 rear gears will get you better than 10.5s if you can hook.
Nice work well done .

[408 Nova]

That's a fantastic running engine right there. It's gonna haul the mail quite nicely!

[skinny z]

Progression Ignition...

Did you manage any A to B testing with the Progressive compared your best results ignition-wise?
This came back to me while watching this 406 dyno test on the Unity MotorSports Garage channel. If you do/have seen it, what are your thoughts on the results?

[Tom68]

Did you manage any A to B testing with the Progressive compared your best results ignition-wise?
This came back to me while watching this 406 dyno test on the Unity MotorSports Garage channel. If you do/have seen it, what are your thoughts on the results?

That's the big distributor, may have additional ignition amplification ?

Progressive used to do a non programmable high output module for these.

[HQM383]

Progression Ignition...

Did you manage any A to B testing with the Progressive compared your best results ignition-wise?
This came back to me while watching this 406 dyno test on the Unity MotorSports Garage channel. If you do/have seen it, what are your thoughts on the results?

No, I didn’t take the Progression any further second time around other than checking it was working. Didn’t see the point if it was missing over 6000rpm. I would like to try it in the car and do real time adjustment for street duties.

The video? He says early it’s a controlled test with all componentry held the same other than modules between the distributors so that’s what’s getting tested. In reality it’s timing curve that’s tested between distributors. If he wants to be “scientific” about a controlled test he has to copy the DUI dizzy curve to the Progression. The dyno output graphs have to be accompanied with timing curve for each run to draw meaningful conclusions between what they are testing. Maybe he has another video coming but he has missed an opportunity to show how timing can be dialed in with the Progression distributor on the dyno, which at the same time can be instructive to his audience on effect on ignition timing at various rpm and loads.

To deviate a little from the topic at hand I’ve followed along this Sleeper series by Unity. The engine has some good heads on it, far better than I have on mine. On one of the videos it flashed up on the screen “WRONG CAM!” several times. Here is a phenomenal opportunity to use his mentors cam selection methods and put the “RIGHT CAM” in it and share results, if anything to silence their critics and reinforce the validity of the method. Along with the “right” manifold one would think nudging 600hp isn’t out of the question. They have only just tipped over 500hp so far haven’t they?

[skinny z]

Did you manage any A to B testing with the Progressive compared your best results ignition-wise?
This came back to me while watching this 406 dyno test on the Unity MotorSports Garage channel. If you do/have seen it, what are your thoughts on the results?

That's the big distributor, may have additional ignition amplification ?

Progressive used to do a non programmable high output module for these.

I saw that it was an HEI and though to myself it kind of tosses the validity of the test somewhat out the window.
I think though that it more the ease of tuning that was the real takeaway.

[skinny z]

Progression Ignition...

Did you manage any A to B testing with the Progressive compared your best results ignition-wise?
This came back to me while watching this 406 dyno test on the Unity MotorSports Garage channel. If you do/have seen it, what are your thoughts on the results?

No, I didn’t take the Progression any further second time around other than checking it was working. Didn’t see the point if it was missing over 6000rpm. I would like to try it in the car and do real time adjustment for street duties.

The video? He says early it’s a controlled test with all componentry held the same other than modules between the distributors so that’s what’s getting tested. In reality it’s timing curve that’s tested between distributors. If he wants to be “scientific” about a controlled test he has to copy the DUI dizzy curve to the Progression. The dyno output graphs have to be accompanied with timing curve for each run to draw meaningful conclusions between what they are testing. Maybe he has another video coming but he has missed an opportunity to show how timing can be dialed in with the Progression distributor on the dyno, which at the same time can be instructive to his audience on effect on ignition timing at various rpm and loads.

To deviate a little from the topic at hand I’ve followed along this Sleeper series by Unity. The engine has some good heads on it, far better than I have on mine. On one of the videos it flashed up on the screen “WRONG CAM!” several times. Here is a phenomenal opportunity to use his mentors cam selection methods and put the “RIGHT CAM” in it and share results, if anything to silence their critics and reinforce the validity of the method. Along with the “right” manifold one would think nudging 600hp isn’t out of the question. They have only just tipped over 500hp so far haven’t they?

In my reply to Tom above, I thought the test had lost some of it's merit with HEI to traditional small cap.
That said, if both were locked at 34°, then what? That would have revealed the differences in hardware and electronics as opposed to differences in timing at various RPM.
I agree 100% on copying the curve from the DUI to the PI. But more to the point is the ease with which that can be done. That's the selling point. I believe that was what Andy was alluding to at the end of the vid. But yours breaking up at 6000 RPM takes some of that away though. What gives?

Now his mentor and cam selection, I'd like to see that too.

[Tom68]

Weighs 3350lb on the scales on the ring rd BP.

If you go to Calder you'll have to drop in and put it on the individual wheel scales.

Scaled this beast recently.

20240331_082121.jpg

[HQM383]

Weighs 3350lb on the scales on the ring rd BP.

If you go to Calder you'll have to drop in and put it on the individual wheel scales.

Scaled this beast recently.

20240331_082121.jpg

Does it need to go on a diet?