[mc71454]

I posted a week ago about my buddies 565 BBC with AFR 325 CNC'd heads that was run on the Dyno.

The builder did some testing with a Big $$$ header just for the heck of it.

The first header is his "shop" header an old rusty Stahl with 2" to 2 1/4" stepped setup with a 4" collector with a few small dings in them

The headers are a "work-of-art" says my buddy with stepped tubes 2 1/8 to 2 1/4, extended scavenger collector 4" some kind of venturi tube, etc. they cost the owner $1800 plus. I didn't actually see these headers but you get the idea.

The $1800 headers were made for a similar 555 motor. Let's just say the engines are very close, close enough to make the data valid.

After playing with air fuel ratios, timing, and everything else the $1800 headers lost 35 to 40 lb/ft between 5000 and 6500 RPM and and 30 avg HP from 5000 to 7000.

Next, he will be seeing what happens on the other (header owners) engine when it is complete in the near future.


One other thing, the HVH 1" Aluminum Spacer is good for 7 to 12 HP and 10 ft/lbs on every engine he has built and tested at 500 HP or more. The returns are proportional on lower powered motors.

In fact he doesn't even test the spacers everytime anymore, they just go on the motors.

 

[Bomber '67]

There is a place for super custom headers - but if all the planets are not in alignment then disappointment is sure to follow. For virtually everyone else the more generic headers usually always win. There is a science to exhaust flow - in my opinion too many tricks combined together narrow the peak power band. In some cases it can move the sweet spot of exhaust flow completely out of the desired rpm range.

In the Winter issue of Engine Masters magazine, one of the competitors reveals a bit of what he learned. What he has to say about headers mirrors you buddy's 565 test. He also points out that most people run too large a primary tube - a point that has been made over and over again on Team Chevelle. At shows I still get crap about running generic 2" primary headers on my 496!

Carb Spacers simply have to be tested for each engine. I've often wondered if rather than the increase in plenum volume, that if the extra power comes from having a longer & straighter airflow off the base of the carb.

Thomas

 

[ejrempel]

One other thing, the HVH 1" Aluminum Spacer is good for 7 to 12 HP and 10 ft/lbs on every engine he has built and tested at 500 HP or more. The returns are proportional on lower powered motors.

In fact he doesn't even test the spacers everytime anymore, they just go on the motors.

I used a 1" plastic spacer on my 427 engine and it picked up 10 hp. I used a very nice CVR open alum. 2" spacer and it picked up another 10 hp. I guess that tells me something is too small.

 

[Bob West]

I guess that tells me something is too small.

lol

 

[mc71454]

Thomas,

I feel the same way about about the spacers...

But, I found it interesting that this builder whom builds a significant number of Circle track and High end off-shore boat motors every year would come to the conclusion that the HVH's always work. He didn't say any spacer, just the HVH super suckers.

I picked up 2 HVH super suckers a few weeks ago. Both aluminum 1" for a 4150 carb, going to do some testing with them. But 10 HP is usually hard to see on the track even if get to a track rental next year with the right conditions. Hopefully I can isolate a change in the 60 ft. I will probably test them in 1/8th mile passes to make more passes in a shorter time period for cool down.

 

[mc71454]

lol

Oh MY !!!!

 

[67RS502]

What was the "primary length" on the 2 headers?

 

[mc71454]

What was the "primary length" on the 2 headers?

Don't know, I may be able to find out though.

 

[DragRacer]

Tom,

Very interesting. Thanks for posting. Let us know if you find out any more details.

 

[lemonice]

first what does (hvh) stand for?. when i took my motor to the dyno and we were trying differant things to bring up the hp numbers, the owner put on a 1 inch spacer that had 4 holes in it. it was not alum, it was like a hard cardboard looking thing. my question is this. my intake single plane with one big hole. will this 4 hole spacer hold back any flow? i was thinking about cutting the center out of it and making it the same as my intake.will this help, or should i just leave it with the 4 holes? thanks..

 

[black71chevelle]

I have a cheap set of headers on my chevelle that serve their purpose but I was thinking about upgrading to a set of Flowtech After Burner headers, but after reading this maybe I will just keep my old rusty ones. Anybody here of any research good or bad on these things? thanks

 

[Wolfplace]

first what does (hvh) stand for?. when i took my motor to the dyno and we were trying differant things to bring up the hp numbers, the owner put on a 1 inch spacer that had 4 holes in it. it was not alum, it was like a hard cardboard looking thing. my question is this. my intake single plane with one big hole. will this 4 hole spacer hold back any flow? i was thinking about cutting the center out of it and making it the same as my intake.will this help, or should i just leave it with the 4 holes? thanks..

=
High Velocity Heads
They make some pretty cool stuff including spacers that seem to work in most cases.

http://www.highvelocityheads.com/ss.htm

On your spacer, the only way to know if your engine will like an open spacer is to try it on the dyno or at the track.
I can tell you I have not had the best of luck with the four hole spacers on the dyno in most cases & have seen gains from nothing to about 15HP with a 1" open one.
I cannot remember ever having had a loss with an open one.

What works on one combo another may not like.

The books & magazines will tell you that the 4 hole spacers add torque & the open spacer adds HP.

Unfortunately,,,, it appears our engines never learned to read the same books or magazines

 

[66SBCDUECE]

If i am not mistaking the guy who has the patent on these super sucker spacers is Joe Pately{spelling???} who used to port and flow test cylinder heads out of his home from Ludlow ,Mass. and did work for Red Barn SPEED from Springfield area! He did a set of 186 fuelie heads for me in 1980 and was in process of moving south to do work for roundy round boys to get more work. I read somewhere on his spacer patent and realized what a small world it is for sure!! AL

 

[cstraub]

High Velocity Heads
HVH Brodix Manifolds are designed by this company
Joe Petelle is the owner
The Super Sucker was outlawed in the mid 80's by Nascar. It is a proven piece.

 

[Harold Sutton]

I posted a week ago about my buddies 565 BBC with AFR 325 CNC'd heads that was run on the Dyno.

The builder did some testing with a Big $$$ header just for the heck of it.

The first header is his "shop" header an old rusty Stahl with 2" to 2 1/4" stepped setup with a 4" collector with a few small dings in them

The headers are a "work-of-art" says my buddy with stepped tubes 2 1/8 to 2 1/4, extended scavenger collector 4" some kind of venturi tube, etc. they cost the owner $1800 plus. I didn't actually see these headers but you get the idea.

The $1800 headers were made for a similar 555 motor. Let's just say the engines are very close, close enough to make the data valid.

After playing with air fuel ratios, timing, and everything else the $1800 headers lost 35 to 40 lb/ft between 5000 and 6500 RPM and and 30 avg HP from 5000 to 7000.

Next, he will be seeing what happens on the other (header owners) engine when it is complete in the near future.


One other thing, the HVH 1" Aluminum Spacer is good for 7 to 12 HP and 10 ft/lbs on every engine he has built and tested at 500 HP or more. The returns are proportional on lower powered motors.

In fact he doesn't even test the spacers everytime anymore, they just go on the motors.

This Stahl 2" stepped to 2 1/4" must have been done in two steps as the headers are stepped up 1/8" at a time from what i've seen. From what i've observed the 2 1/8" is an ideal size for a 540" Big Block. They always seem to be more responsive than the straight 2 1/4" ones. Also, Stahl builds very well designed products. If a less powerful motor was to be tested or one that operated in a lower RPM band a 2" or 1 7/8" might perform better. Only the collectors have changed much in the past 20 years and some gains can be had there.

 

[Tom Mobley]

Stahl = good, but not many want to pony up the bux. I picked up 25hp over a broad range on a oval track engine with his headers.

 

[Bob West]

I know mine liked a 2" open spacer on top of the Perf RPM intake.

 

[bracketchev1221]

That design definitely works. I don't have a HVH spacer but my Wilson Manifolds 4 hole tapered spacer showed 10 hp over a straight open.

 

[Chris_69_SS]

My junk made 578 hp with no spacer and 605 with a 2" open. That is with a stock 750 d.p. and vic jr.

 

[Bob West]

My junk made 578 hp with no spacer and 605 with a 2" open. That is with a stock 750 d.p. and vic jr.

605hp with your current e.t. in your signature? What gear and transmission,stall and 60ft? I'm just curious, must be about what I'm making right now.