Header/q16 BBC dyno test

[CGT]

I have a concern in that first test that at 5200 rpm the TQ and hp are 30 numbers different, it should much closer like in the second test!

Its hp in both columns..?

[randy331]

I have a concern in that first test that at 5200 rpm the TQ and hp are 30 numbers different, it should much closer like in the second test!

Its hp in both columns..?

So the HP should always be the same at 5200 rpm even on dyno tests with 2 different size headers ?? or a test with and without Q16?

LOL

Randy

[randy331]

2 1/4 headers are still to big in my opinion. 2 1/8 max or 2 by 3.5

I would bet a 2" x 8" stepped to 2 1/8" x 10" stepped to 2 1/4" x 12" to a 3" coned merge collector that grows to a 3 1/2" x 10" would work good for this cu.in/hp/rpm. But that's just me.

Good test Randy.

Something like the header you suggest would be my guess too, but it is what it is at this point.
The primary tubes on the chassis headers are 33"-34" with just the collector that came on the headers. 8" or so.
The dyno headers were a little shorter primary with same length collector.

Randy

[randy331]

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[mag2555]

Sorry, my eyes where still half closed when I posted at 630 am est!

[F-BIRD'88]

Good job...Good report.

[Bob M]

Another 700 hp 781 head build! Nice results. If my junk doesn't make 700 hp with my 308 Iron Eagles, I'm scrapping it!

[maxracesoftware]

2 1/4 headers are still to big in my opinion. 2 1/8 max or 2 by 3.5

I would bet a 2" x 8" stepped to 2 1/8" x 10" stepped to 2 1/4" x 12" to a 3" coned merge collector that grows to a 3 1/2" x 10" would work good for this cu.in/hp/rpm. But that's just me.

Good test Randy.

Something like the header you suggest would be my guess too, but it is what it is at this point.
The primary tubes on the chassis headers are 33"-34" with just the collector that came on the headers. 8" or so.
The dyno headers were a little shorter primary with same length collector.

Randy

input 98.70% VE input in PipeMax v3.98
and it gets = 711.5 Peak HP at 7000 RPM
needs a 1143 CFM Carb ... and you have 1150 CFM Carb .. great !

Header Specs are :
--- Single Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
Diameter= 2.058 to 2.183 Total Length= 32.3 to 35.5 inches long
a 2 1/8th Primary Pipe would be worth testing

--- Conventional Straight Tube Collector Specs ---
( TQ ) Diameter= 3.503 to 3.753 Best Length= 17.4 and also 34.8 inches
( HP ) Diameter= 3.753 to 4.253 Best Length= 17.4 and also 8.7 inches

[randy331]

It would be interesting to see if it responded to some more aggresive lobes, but I know rpm and revability is the goal.

I'd be surprised if it didn't respond to some faster lobes based on what we've seen in the past.

He's talking about a more serious build for this same class. Better bottom end parts. Some lighter valves would be nice too.
More compression, more rpm, etc.

Rules are very open on the heads, other than it has to be a GM head.

We'll see how it goes.

Randy

[Walter R. Malik]

It would be interesting to see if it responded to some more aggresive lobes, but I know rpm and revability is the goal.

I'd be surprised if it didn't respond to some faster lobes based on what we've seen in the past.

He's talking about a more serious build for this same class. Better bottom end parts. Some lighter valves would be nice too.
More compression, more rpm, etc.

Rules are very open on the heads, other than it has to be a GM head.

We'll see how it goes.

Randy

Aluminum ...?
Bow Tie or O.E.M. Production ...?

[randy331]

Aluminum ...?
Bow Tie or O.E.M. Production ...?

Sorry I should have clarified better, iron GM heads only on big block.
So any iron head from GM, welding etc is legal.

Randy

[Walter R. Malik]

Aluminum ...?
Bow Tie or O.E.M. Production ...?

Sorry I should have clarified better, iron GM heads only on big block.
So any iron head from GM, welding etc is legal.

Randy

In that case I would probably run the #6272990 heads; LS-6 & LS-7.

[randy331]

Aluminum ...?
Bow Tie or O.E.M. Production ...?

Sorry I should have clarified better, iron GM heads only on big block.
So any iron head from GM, welding etc is legal.

Randy

In that case I would probably run the #6272990 heads; LS-6 & LS-7.

Yea, I agree. Like it to be a bigger bore shorter stroke of same cubes of much better parts.
4 inch strokes produce a lot of piston speed.
Titanium valves too.

He said he may just go ahead and start making payments on his future engine. LOL

Randy

[randy331]

Well, the engine in this thread is going to get some up grades over the winter.

It's getting an aftermarket block for reliability and for future use as a more serious build.
Don't look like his budget is gonna allow titanium valves so the current cam will stay, but we may test positions on the dyno this time. Didn't last time.
Probably step up the vacuum some since it liked that.

A different intake is one up grade. It has a 4150 hvh now. What intake would the ST crew suggest ?
May do some more work on the heads too.
I'll give it some more comp.
May test collectors.

Other budget friendly ideas ?

Randy

[D.B.O.]

So the dyno headers test and the test with Q16 are exactly the same, hp/hp, rpm/rpm? What fuel was used in the header testing?