JBA Headers vs. Stone Mountain

[Ripper]

I followed closely most of the threads on headers for the 4.7L

If money was not an issue, would you buy the JBA headers or the Stone Mountain Racing (SS Autochrome) headers, and reasons why? For purposes of this discussion we would be comparing stainless to stainless (no coatings) and also make the assumption that you would be keeping the vehicle they are going on for 3 to 5 years or possibly more.

[v8Toilet]

Originally Posted by Ripper

I followed closely most of the threads on headers for the 4.7L

If money was not an issue, would you buy the JBA headers or the Stone Mountain Racing (SS Autochrome) headers, and reasons why? For purposes of this discussion we would be comparing stainless to stainless (no coatings) and also make the assumption that you would be keeping the vehicle they are going on for 3 to 5 years or possibly more.

JBA because of the fire cone collector and smaller 1-1/2" primaries! I believe these two features give you more low-end torque than the traditional collector and 1-5/8" primaries of the Stone Mountain headers.

[Imdone]

Originally Posted by v8Toilet

JBA because of the fire cone collector and smaller 1-1/2" primaries! I believe these two features give you more low-end torque than the traditional collector and 1-5/8" primaries of the Stone Mountain headers.

Just for fun check out the pics of the S & S headers. Testing will commence in the next week. You can find the pics here.

[Dude Boy]

I'm really impressed by the pictures of the Stone Mountain headers I saw on ebay. The thick flanges and the quality look impressive. They are a lot prettier than uncoated JBA's. I agree with V8Toilet that the JBA's might be a better choice for power gains, but not by a great margin.

[Ripper]

Originally Posted by Imdone

Just for fun check out the pics of the S & S headers. Testing will commence in the next week. You can find the pics here.

They look nice but I want a straight bolt on installation with minimal modifications. I also need to be able to use the stock exhaust for the time being.

[Ripper]

Originally Posted by v8Toilet

JBA because of the fire cone collector and smaller 1-1/2" primaries! I believe these two features give you more low-end torque than the traditional collector and 1-5/8" primaries of the Stone Mountain headers.

I was wondering about this myself. Stone Mountain seems to think it is better to have the larger primaries but I am not convinced.

From the SS Autochrome add:
"Unpublished DYNO Beat JBA and Gibson 18% on HP , and Tq ."

Why don't they publish their dyno results and be done with it?

[Son of Odin]

What exactly does the "Fire cone collector" do?

[v8Toilet]

Originally Posted by Ripper

I was wondering about this myself. Stone Mountain seems to think it is better to have the larger primaries but I am not convinced.

From the SS Autochrome add:
"Unpublished DYNO Beat JBA and Gibson 18% on HP , and Tq ."

Why don't they publish their dyno results and be done with it?

I don't know why they don't post the results. They probably are going by what someone else told them and don't have the dyno sheets. I would take that statement with a grain of salt. Manufacturers always exaggerate their HP claims and are often ambiguous too. I don't have first hand experience with the Stone Mountain headers; my opinion is based on what I have read from TS members who have them and from what I know from my own experience with headers on other vehicles and the JBA I have now. Most of the TS members say that the Stone Mountain headers boost power above 3000 RPM. We are only dealing with a 285 cubic inch V8 too and I feel 1-5/8" short primaries are too big. They would be more fit on a 300 and larger cubic inch street motor.

Originally Posted by Son of Odin

What exactly does the "Fire cone collector" do?

The fire cone collector is just a bung welded into the collector where the four pipes merge. Normally header manufacturers just weld in a flat plat there to take up the space where the four pipes meet in the middle. This cone or bung helps reduce the turbulence that would normally occur when the gases travel from the exit of the primary to the open space of the collector. As they enter a collector with just a flat plate there like the Stone Mountain they tumble at that spot causing turbulence and reducing the efficiency of the header. With a cone there the gases are directed towards the opening of the Y-pipe and they can’t expand since the cone takes up that space so the gases also stay moving and don’t tumble or slow down. This is one of the reasons why the JBA headers make good low-end torque for a shorty header.
Son of Odin

[dyogim]

If money wasn't an issue....

I would go with the JBA's. Main reason: Living in Cali, it would have to CARB legal. If I dind't have to worry about that, I'd go with JBA's.

[Imdone]

Originally Posted by Ripper

They look nice but I want a straight bolt on installation with minimal modifications. I also need to be able to use the stock exhaust for the time being.

They are a straight bolt on there is no modification needed and you are still able to use the stock muffler and pipe.

There are no alterations at all other than the headers, I am using the stock muffler and connection pipe to the y-pipe and tail pipe right now and have posted the #s thus far and the install tips and tricks.

If you are looking for low end power I would highly recommend the S & S headers over all the rest on the market.

[Ripper]

I have decided to go with the JBA headers. Primarily because of the slightly smaller primaries and the lack of complaints about them. I don't want to give up any low end torque and v8toilet's comments on the smaller primaries and collector design make sense to me. Also there have been some complaints about problems with leakage etc. on the Stone Mountains.

Now I just have to decide on an exhaust.

My old '92 Chevy Blazer is sitting on my front lawn witha for sale sign on it. I am hoping to get around $900 for it. That ought to just about cover the headers and exhaust.

[jim65wagon]

Car Craft recently had an excellent article on header pipe sizes.(Dec 03)
It showed how to find peak torque as affected by primary pipe size.
Peak Torque RPM = Primary Pipe area x 88200 / Displacement of one cylinder.

JBA's Torque RPM = 1.767 (pipe area not diameter) x 88200 / 35.625 = 4374

SS Torque RPM = 2.07 x 88200 / 35.625 = 5125
This does not account for wall thickness of the pipes,which could affect the final inside diameter of the pipes making them somewhat smaller than the advertised 1.5 or 1.625 inches. However the SS's are 750 rpm higher at torque peak than the JBA's. I think that even 1.5 inch pipe diameters are too large for the small motor. My 350 chevy in my 65 ran 1.5 inch headers and it cranked to 6000 rpm without any trouble. I'd like to see 1.25 inch headers, these would bring the low end torque a working truck would need. Between the two I'd have to go with the JBA's.

[turnipgreen]

Are you guys having the headers put in or doing it yourself? Getting the headers locally or ordering them online somewhere? If you are doing it yourself and ordering online please pass along any details that might be useful to others.