steve cowan wrote: ↑Sun Apr 09, 2023 4:52 pm
I just watched Eric video on the the AFR intakes as cast,cloverleaf only removed,and ported .
As expected the ported intake fattened the curve a few.
With a ported set of heads to suit the cubes,rpm etc I think that ported AFR intake would work well.
Unless I missed something. The engine was around 20hp from repeating itself from the last dyno session....in the same form as it was in. Which would kill any thoughts of what changes to the manifolds did from the previous session,,, But maybe i tuned out too early, because as soon as i gathered that....I realized there was no actual data there.
Thats a lot of variance, so that only leaves room for assumptions, especially when testing things like that. I have never had that same issue when dynoing the same engine on the same dyno at a different time of the year with very different weather.
Thats a lot of work to go through, in the name of learning, to be doing it on a dyno that is that far off from being able to repeat itself from day to day.
Did I miss something? Wasnt the engine way off in power from last session?
You did.
It was off 18hp off one intake but I’m about certain it was a leaking intake gasket. Once switched to another manifold that was used in previous session it was off 4hp although torque was within 2.
Knowing this I tried to compare everything from just one session.
I hope that helps.
Eric Weingartner
Weingartner Racing LLC
918-520-3480
www.wengines.com
steve cowan wrote: ↑Sun Apr 09, 2023 4:52 pm
I just watched Eric video on the the AFR intakes as cast,cloverleaf only removed,and ported .
As expected the ported intake fattened the curve a few.
With a ported set of heads to suit the cubes,rpm etc I think that ported AFR intake would work well.
Unless I missed something. The engine was around 20hp from repeating itself from the last dyno session....in the same form as it was in. Which would kill any thoughts of what changes to the manifolds did from the previous session,,, But maybe i tuned out too early, because as soon as i gathered that....I realized there was no actual data there.
Thats a lot of variance, so that only leaves room for assumptions, especially when testing things like that. I have never had that same issue when dynoing the same engine on the same dyno at a different time of the year with very different weather.
Thats a lot of work to go through, in the name of learning, to be doing it on a dyno that is that far off from being able to repeat itself from day to day.
Did I miss something? Wasnt the engine way off in power from last session?
You did.
It was off 18hp off one intake but I’m about certain it was a leaking intake gasket. Once switched to another manifold that was used in previous session it was off 4hp although torque was within 2.
Knowing this I tried to compare everything from just one session.
I hope that helps.
Does it have a bunch of vacuum under the carb at wot? I suppose if the intake gasket was real real bad, or if an engine had a bunch of vacuum at wot it could be. But I have done manifold swaps on the dyno and literally had them squealing(from vacuum leak at gasket) at idle, but not affect wot fueling or power.
Regardless, Im glad you got it sorted. Thats certainly a big effort on your part.
Unless I missed something. The engine was around 20hp from repeating itself from the last dyno session....in the same form as it was in. Which would kill any thoughts of what changes to the manifolds did from the previous session,,, But maybe i tuned out too early, because as soon as i gathered that....I realized there was no actual data there.
Thats a lot of variance, so that only leaves room for assumptions, especially when testing things like that. I have never had that same issue when dynoing the same engine on the same dyno at a different time of the year with very different weather.
Thats a lot of work to go through, in the name of learning, to be doing it on a dyno that is that far off from being able to repeat itself from day to day.
Did I miss something? Wasnt the engine way off in power from last session?
You did.
It was off 18hp off one intake but I’m about certain it was a leaking intake gasket. Once switched to another manifold that was used in previous session it was off 4hp although torque was within 2.
Knowing this I tried to compare everything from just one session.
I hope that helps.
Does it have a bunch of vacuum under the carb at wot? I suppose if the intake gasket was real real bad, or if an engine had a bunch of vacuum at wot it could be. But I have done manifold swaps on the dyno and literally had them squealing(from vacuum leak at gasket) at idle, but not affect wot fueling or power.
Regardless, Im glad you got it sorted. Thats certainly a big effort on your part.
That manifold was the one that I bought from auction that someone did a horrible job of port matching. When they were grinding the grinder went across the intake surface so it had gouges in it. They sealed when we first put it on but picking up the engine from the manifold without the silicone even setting up and after taking all the manifolds on and off I don’t think the gasket was sealing anymore. The clue came with the air fuel ratio becoming leaner by about half a point from the last test. It did have a lot of vacuum with the two barrel.
Eric Weingartner
Weingartner Racing LLC
918-520-3480
www.wengines.com
This will be interesting, I always bang on about Edelbrocks Windsor F4B having 4 ridiculously short runners.
Well this isn't as bad but as pointed out in the video 3, 5 ,4 and 6 have shorter than usual runners.
Some but not all C3BXs were like this and every C4B that I've seen.
Brodix DP short runner.jpg
c4b3bcompare.JPG
c3bx.JPG
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Ignorance leads to confidence more often than knowledge does.
Nah, I'm not leaving myself out of the ignorant brigade....at times.
My Air Gap Rpm with the divider cut all the way down worked as good as my 300-25 Strip Dominator on my 358 and the Air Gap had better 60ft. 1/8, 1/4 mile ET.
My Air Gap Rpm with the divider cut all the way down worked as good as my 300-25 Strip Dominator on my 358 and the Air Gap had better 60ft. 1/8, 1/4 mile ET.
With or without a spacer?
There's been so much manifold-speak lately that I've completely lost track.
My Air Gap Rpm with the divider cut all the way down worked as good as my 300-25 Strip Dominator on my 358 and the Air Gap had better 60ft. 1/8, 1/4 mile ET.
With or without a spacer?
There's been so much manifold-speak lately that I've completely lost track.
1980RS wrote: ↑Mon Apr 17, 2023 9:59 am
My Air Gap Rpm with the divider cut all the way down worked as good as my 300-25 Strip Dominator on my 358 and the Air Gap had better 60ft. 1/8, 1/4 mile ET.
1980RS wrote: ↑Mon Apr 17, 2023 9:59 am
My Air Gap Rpm with the divider cut all the way down worked as good as my 300-25 Strip Dominator on my 358 and the Air Gap had better 60ft. 1/8, 1/4 mile ET.
1980RS wrote: ↑Mon Apr 17, 2023 9:59 am
My Air Gap Rpm with the divider cut all the way down worked as good as my 300-25 Strip Dominator on my 358 and the Air Gap had better 60ft. 1/8, 1/4 mile ET.
What was the max rpm?
6800 rpm.
I know it's been laid out somewhere here before but for the sake of searching I'd like to ask the engine ingredients.
One thing I know for sure is that there's an RPM Air Gap with a completely removed divider (as opposed to out of the box) and a 1" spacer.
And that's is 358 CID. For the record I calculate my 357 from the 4.04 x 3.48" bore and stroke.
I don't recall any details on the heads or the cam. Although I believe the latter is a flat tappet?
How all of that plays together within the subject of manifold testing is noteworthy.
I know it's been laid out somewhere here before but for the sake of searching I'd like to ask the engine ingredients.
One thing I know for sure is that there's an RPM Air Gap with a completely removed divider (as opposed to out of the box) and a 1" spacer.
And that's is 358 CID. For the record I calculate my 357 from the 4.04 x 3.48" bore and stroke.
I don't recall any details on the heads or the cam. Although I believe the latter is a flat tappet?
How all of that plays together within the subject of manifold testing is noteworthy.
Won't be anymore testing on my 358 as I sold it yesterday. Guy had a hard time believing it ran in the 11's let alone 11.30 until I showed him the video of the car running that. I'll have some more stuff to test soon.
Just dug out my old Sept. 2008 Chevy Hi performance Mag with their 16 manifold test.
The Brodix HV1016 of the 6 modern dual planes tested had low lowest avg. hp and torque. Not by much only 2-3 ft-lb of torque and 2-3 hp less than most others the RPM air gap was 7ft-lb and 6 hp better average. Interestingly the brodix had the second highest hp peak but the lowest torque peak. the engine tested was a 383 10.5 cr Brodix IK 200 head with a Comp .525/.525 224*/224* 110* LSA solid roller cam.
I know it's been laid out somewhere here before but for the sake of searching I'd like to ask the engine ingredients.
One thing I know for sure is that there's an RPM Air Gap with a completely removed divider (as opposed to out of the box) and a 1" spacer.
And that's is 358 CID. For the record I calculate my 357 from the 4.04 x 3.48" bore and stroke.
I don't recall any details on the heads or the cam. Although I believe the latter is a flat tappet?
How all of that plays together within the subject of manifold testing is noteworthy.
Won't be anymore testing on my 358 as I sold it yesterday. Guy had a hard time believing it ran in the 11's let alone 11.30 until I showed him the video of the car running that. I'll have some more stuff to test soon.
