[NeighborsComplaint]

Whoa. That motor cranked out those numbers with a holley square bore mounted to a spreadbore intake with an adaptor? Holy moly, another theory (mismatch costs power) becomes urban legend!

I wait in watchfull anticipation for a "correctly matched" carb and intake combo though I don't know how it could get much better than the initial results!!!

[gtofreek]

No, No, No. It was with a q-jet on a stock manifold.

[Half-Inch Stud]

James, Appears to be very nice Street/ Strip combo capable of sustained highway driving.

[Skip Fix]

Paul I have some D port 4 tube cheapo Hookers new I'll never use I'll make you a deal on!

"Whoa. That motor cranked out those numbers with a holley square bore mounted to a spreadbore intake with an adaptor? Holy moly, another theory (mismatch costs power) becomes urban legend!" Not this one but my track test was and picked up with the square bore on an HO intake.

Here is a picture of the Edelbrock adapter I think it blends the primaries better than the other generics. It comes as a 4 hole but I opened it to a 2 hole.

[hurryinhoosier62]

I want to see what it does with a SD modified factory manifold and some 4 tube headers. I'm betting 475-480hp is possible.

[pontibeast]

Originally Posted by Skip Fix

Paul I have some D port 4 tube cheapo Hookers new I'll never use I'll make you a deal on!

"Whoa. That motor cranked out those numbers with a holley square bore mounted to a spreadbore intake with an adaptor? Holy moly, another theory (mismatch costs power) becomes urban legend!" Not this one but my track test was and picked up with the square bore on an HO intake.

Here is a picture of the Edelbrock adapter I think it blends the primaries better than the other generics. It comes as a 4 hole but I opened it to a 2 hole.

I will do you one better. I am swapping out my dead 350 for a 455 and I got a really good deal on a set of Hooker Super Comps that are going on the new engine. There is a set of old Summit headers on the 350 I would be happy to send you for the low, low price of shipping only. They are far from pretty but are sound structurally. They should be done in three weeks, just let me know.

[gtofreek]

Thanks for the offers guys. It sure would be nice to have some 4 tubers around for dyno testing. Unfortunately, it won't do any good for this engine test. Nor will it really matter as he has RA manifolds to put on. I think these 3 tubers are pretty comparable to the RA manifolds.

[NeighborsComplaint]

Originally Posted by gtofreek

No, No, No. It was with a q-jet on a stock manifold.

Whew! Had me worried for a minute there.

Were those Cyclone 3 tube headers the old aluminized (sprayed with melted aluminum) with the individual flanges for each tube?

[gtofreek]

Well, round #1 of dyno testing is complete. I bolted on a CNC ported factory iron intake. Dummy me forgot to disconnect the vacuum advance unit when I set the timing the other day. Rechecked it today[yes, yes, without the vacuum advance hooked up], and it only had 18° of total timing. The dyno operator kept telling me that can't be right. There's no way it made that kind of power with only 18°. But that's what it was. So I left it there, and made a pull with the 91 pump gas to get a good comparison, and it made 470 HP. Only 5 more peak HP than the stock intake. It lost a little bit of torque too, so the average HP from 3200-5500 was only 2 HP better. But it did carry the peak HP out over several hundred RPM, to 5900, and up there, the ported intake made 30+ HP more than the stock intake. Set the timing at 36°, figuring now it's really going to make some power. It went from 470 HP with 18° timing to 473 HP. Tried 38° it lost power[made 465 HP]. Tried 34° it made 474 HP. Tried 32° and it made 479 HP over a 300-400 RPM range. I will get a printout tomorrow. It was getting late, and I forgot to get one. Tomorrow we will try the Victor intake, and Holley carb Jeff built. That carb is a 750 HP, that flows 999 CFM. I think I will try light lashing the rockers too to see if the lifters quit pumping up at 5900-6000.

[gtofreek]

Originally Posted by NeighborsComplaint

Whew! Had me worried for a minute there.

Were those Cyclone 3 tube headers the old aluminized (sprayed with melted aluminum) with the individual flanges for each tube?

They are Cyclone headers, just not aluminized with individual flanges.

[Cliff R]

With few exceptions most of our Pontiac engine builds make best peak power right at 30 degrees total timing. They don't change much adding more timing, and with these things it's best to be conservative as the dyno is a static test. The engine isn't heat soaked like it will be in the vehicle, and it's will also live under the hood in a much hotter environment.

I still remember when I first installed my current 455 into my Ventura. Can't remember how or why, other than being in a hurry to make the race, but when we got to Norwalk with the car and checked the timing the distributor was off just far enough that it hit the intake manifold and I could barely get 26 degrees timing out of it.

Rather than pulling the distributor at the track we just raced it like that all weekend. I figured it would run close to the roll bar rule anyhow, so slowing it down some would have been a good thing.

The first three runs were right around 11.30/120mph, a solid .2 under the roll bar rule with only 26 degrees total timing!

We ended up adding weight to the car, dropping another 2 degrees timing out of it, and shifting at 5000rpm's instead of 5800 to get it slower than 11.49.......Cliff

[Blued and Painted]

Originally Posted by gtofreek

I think these 3 tubers are pretty comparable to the RA manifolds.

Really?

[vidguy]

Great info Paul. Thanks for the work and the test and tune!. The advantage of the ported intake really comes into play at the higher RPMS. Good absolute data for people doing this.

"5900, and up there, the ported intake made 30+ HP more than the stock intake"
That seems like a big difference at the top end.
In my case, the ported intake would not be a good value for my particular combo and intended use.

I'd like to hear theories as to the ported intake's affect and the combo's use of it?

-Heads and their chamber size?
-Cam?
-Data points of folks that have dyno tested the intake on other motors.

This thread could be used for reference in the future .
I'd like to learn something here.

If it's true that you want to run the timing as low as possible while making the most power and good vacuum, so far 18 degrees it is. At least on the 91 Octane.

So we are up to 474 hp/503 lb-ft so far out of this engine.

We ended up adding weight to the car, dropping another 2 degrees timing out of it, and shifting at 5000rpm's instead of 5800 to get it slower than 11.49.......Cliff

So the later pulls, while the engine is warmer may result in better performance..

[gtofreek]

Originally Posted by Blued and Painted

Really?

Yes, I do, since these open headers on a 500+ HP 407 only made 16 more HP than a set of 2.5" RA manifolds with complete exhaust system, including mufflers bolted to it.

[gtofreek]

Originally Posted by Cliff R

With few exceptions most of our Pontiac engine builds make best peak power right at 30 degrees total timing. They don't change much adding more timing, and with these things it's best to be conservative as the dyno is a static test. The engine isn't heat soaked like it will be in the vehicle, and it's will also live under the hood in a much hotter environment.

I still remember when I first installed my current 455 into my Ventura. Can't remember how or why, other than being in a hurry to make the race, but when we got to Norwalk with the car and checked the timing the distributor was off just far enough that it hit the intake manifold and I could barely get 26 degrees timing out of it.

Rather than pulling the distributor at the track we just raced it like that all weekend. I figured it would run close to the roll bar rule anyhow, so slowing it down some would have been a good thing.

The first three runs were right around 11.30/120mph, a solid .2 under the roll bar rule with only 26 degrees total timing!

We ended up adding weight to the car, dropping another 2 degrees timing out of it, and shifting at 5000rpm's instead of 5800 to get it slower than 11.49.......Cliff

But that's not a fair comparison since your engine has KRE heads with a much more efficient combustion chamber than a 670 closed chamber head. Dave did work the chamber some, but you still can't duplicate a modern chamber 100%.

[gtofreek]

Also, with the 32° timing it still made right around 500 ft. lbs., but I saw more of them than before. With 36° timing it only made 480's on torque.

It made 11.5" of vacuum at 900 RPM.

[tom s]

Paul,that timing is very unusual with low CR and 91 gas with our iron pontiac heads IMO.I have dynoed LOTs of iron heads from 61 to 69 from pass car,SD and RA V heads and with our 91 gas they have always made more HP with 36-38 degrees total.The fact that Dave has done some work shows it helped some.Nice numbers.Tom

[Cliff R]

"But that's not a fair comparison since your engine has KRE heads with a much more efficient combustion chamber than a 670 closed chamber head. Dave did work the chamber some, but you still can't duplicate a modern chamber 100%."

No, ALL of our Pontiac engines builds come in at or very close to 30 degrees total timing for best power.

That includes the ones we've done with 670 heads, ported 48's from KRE, ported 62's from Dave at SD, Super Duty 455 heads, and my old 455 with 6X heads. With the tight squish we use in those engines all of them have made best power right at 30 degrees total timing.

I'd add here that we also run pretty high compression ratios (compared to what most folks do) for our pump gas engines. None of them aside from the 455 HO and SD builds we've done have been under 10 to 1.

As for 30 degrees being the magic number for total timing, the only engines that have deviated from that were when we used the old style "bathtub" chamber E-heads. Those engines required 37-41 degrees to do the same thing......Cliff

[HWYSTR455]

I know this isn't a very good comparison, but I will say that, the majority of my 400, iron head builds, in the 9.7 - 10.3 SCR range, 32 was my magic number for total. I added max of 10 degrees vacuum, usually 6 or 8, and had it drop out kinda quick. Pretty sure you can search here for old posts of mine that state that. In the one build, due to cam selection, I used 30, but think that was to allow for a better driving experience with vacuum advance and prevent det. (low rpm load)

I always ran a bit of gear too, the build here will probably need adjustment once it's in the car.

You can monkey with initial timing and manifold vacuum some if you want/need more vacuum.

I've spoke to a few people and commented on this build and thread, even have provided the URL. They are still talking about it, and are not easily impressed people. Kudos to you again Paul!

.

[hurryinhoosier62]

Originally Posted by gtofreek

Well, round #1 of dyno testing is complete. I bolted on a CNC ported factory iron intake. Dummy me forgot to disconnect the vacuum advance unit when I set the timing the other day. Rechecked it today[yes, yes, without the vacuum advance hooked up], and it only had 18° of total timing. The dyno operator kept telling me that can't be right. There's no way it made that kind of power with only 18°. But that's what it was. So I left it there, and made a pull with the 91 pump gas to get a good comparison, and it made 470 HP. Only 5 more peak HP than the stock intake. It lost a little bit of torque too, so the average HP from 3200-5500 was only 2 HP better. But it did carry the peak HP out over several hundred RPM, to 5900, and up there, the ported intake made 30+ HP more than the stock intake. Set the timing at 36°, figuring now it's really going to make some power. It went from 470 HP with 18° timing to 473 HP. Tried 38° it lost power[made 465 HP]. Tried 34° it made 474 HP. Tried 32° and it made 479 HP over a 300-400 RPM range. I will get a printout tomorrow. It was getting late, and I forgot to get one. Tomorrow we will try the Victor intake, and Holley carb Jeff built. That carb is a 750 HP, that flows 999 CFM. I think I will try light lashing the rockers too to see if the lifters quit pumping up at 5900-6000.

I was correct: 475-480 hp. Geez, this is one impressive 400.