Guest

Ok, there have been several topics on this, but I am curious on the general consensus on this setup:

The car: 67' coupe, 4 spd., sidepipes, no air/pwr steering or brakes.

The motor going in: 454 block, L89 alum. heads, 435 tripower.

I am leaning towards headers and a sidepipe combo, trying to maximize output exhaust flow. I have had Hedman's on a 454 66' coupe and know they are slightly smaller in diameter than some others out there. But they sounded great with the bb and the orig sidepipes.

Which headers would bolt up nicely to the sidepipes. Also, would you go with a larger diameter sidepipe, other than the oem style, to increase flow, and keep the orig. looking style once the sidepipe cover is installed?

Thanks,
Rob


[Modified by RLH, 11:24 PM 10/28/2002]

Ih2lose

When I purchased mine it had STAUHL big tube headers welded niceley into original style side exhaust pipes, It was real deep and rumbely, definatley felt it in your chest when the car was ideling.I had a high caben temp but it seemed the engine temp was lower.I removed the headers and installed the correct exchaust manifolds and correct side exchaust.I did not see a noticable difference in power.but engine temp went up slightley caben temp went down tremendousley.And the noise level went up and lost the in your chest rumbel feel.Hard to describe but it was a deep bass sound like a boom stereo type of feel from the headers.I like the car better with out the headers on it.

396 RAT

My car is running old Hooker Side pipe Headers.
I dont think there available from Hooker like this any longer?
Not sure?
I didnt want to cut up a new set of chambered exhaust when I bought my car, and it was "funny car" loud, so I had 2 large dia 36" {quality} glass packs installed with the stock tips. The $40.00 one's over the $20.00 models. :lol:
(They fill up the entire space behind the covers, but do fit)
Most feel they are not a performance exhaust, but when you look down them, its just a very large hole the entire length. I think they must flow pretty well?
It was going to be a temp fix. That was 5 yrs ago. It actually sounds really good! I was shocked!, really low, but not too terribly loud,
(Unless you get on it) Any way I now have brand new factory pair of BB
chambered exhaust wrapped up in the rafters, with orig 396 manifolds on the shelf. But am so happy with this set up, they may never get installed!
There is a photo on page 4 of my web page showing this set up.
The headers are really old, but in great shape.
This is just my set up, thought you may want to see what others are running. (Wish I could post a sound bite) There have been many threads on
where to find BB Side pipe headers. I believe there are only a couple Co's left. And are IMO very expensive. Right around a grand as I recall? :eek:



[Modified by 396 RAT, 7:58 AM 10/29/2002]

Guest

Thanks for your replies.

Lose, you bring up a good point with the heat. The 66' bb coupe I had that ran the Hedman's created a lot of cabin heat. So much that on a long drive, the center console around the shifter would heat the crome strips up to the point you almost couldn't touch them. I have original exh. manifolds on it now, and I may just install them with a new sidepipe setup to replace the old ones. I am still on the fence... :rolleyes:

Rat, thanks for the info. I have clicked through your site before and enjoyed looking again just a few minutes ago. Great info. and pics. :cheers: Thanks for your input too. This decision may be harder than I originally thought.

Rob

66427-450

I'm looking for big tube sidepipe header/muffler system that will fit under factory covers as well......

How serious is your 454 going to be?... I mean, compression, heads, cam, rpm range built for??? How are you going to use the car?

There is a HUGE difference in performance (big tube headers/manifolds)..if we're talking about a serious motor at 5000RPM and higher. I have some graphs of Dyno results somewhere........

My own setup is being built to maximize efficiency/HP (and hold together for routine and sustained use) between 5000 and 6500. If you don't plan on making a lot of power up there, and if things like "interior heat" are an issue, then maybe manifolds will work for you.
:seeya

richscorvettes

Rob,

For our 67 I had Sanderson make up a set of headers that worked with the 502 aluminum heads. They were the only ones I found who was willing to make a set that would work with that head. Their quality is great and they fit really well. Then we made a connector pipe from the header to stock 2 1/2" side pipes. Having the headers and side pipes ceramic coated helps keep the heat under control as well as preserving them. I also added foil type insulation in the cabin (over the trans tunnel and floor) as well as a piece which runs between the side pipe and the frame. This has worked well in keeping the heat down.

If I had to do it again I would also consider the stainless setup mentioned in the other thread as I believe someone said they have a header/sidepipe setup that will bolt right on. They might also benefit from a ceramic coating to help keep the temp. in line.

Rich Lagasse

Guest

The setup on the motor now is a 454 4bolt main block bored 30 over, solid lifter/cam combo, pushing 13.5:1 compression :eek: , 435 intake and L89 alum heads.

I am leaning towards tearing it down (the motor was built a little over two years and drove about 10 miles, and pulled out of the car) and switching out the pistons. The exhaust is still TBD.

Rob

Guest

Rich,

Thanks for your reply too. How much of a connector did you need? I'll check on Sanderson too, is there a site for them? I'll go back and check your site on the 67 and look at the coating (like I need a reason to go and check on my favorite 67... :D ). How would you compare the ceramic coating to say the Jet Hot coating?

Thanks again,
Rob

396 RAT

:smash: :eek: :smash: :reddevil :lol:

:cheers:

Guest

Rich, another question. You mentioned possibly taking the stainless setup and having it ceramic coated. Have you seen someone do this? I am wondering if that route, and applying foil underlying to the carpet would dramatically drop the cabin temps.

Thanks,
Rob

66427-450

Re the Sandersons shorties....... you may want to go to the Sanderson web page and look at the dyno results (std headers compaired to shorties).

The difference between a good set of 4 tubes and manifolds with 2.5" pipes is at least 50HP at 6000 revs, and that's with only 427 cubes (old GM test data, that seems to be backed up by testing done since then).

Then see what the shorties would really do for you, over the manifolds....
It all depends on your intend usage, as to what's best for you :seeya

Oh, and I would go with "2.5 inch core" sidepipes (at the minimum), I understand stock pipes only have a 1 3/4" core !!!




[Modified by 66427-450, 5:56 PM 10/29/2002]

richscorvettes

Rob,

The web site address for Sanderson is: http://www.sandersonheaders.com/ I don't know how current their site is but, if I recall correctly, the part number for the big block in a C2 is #BB1.

When I mentioned ceramic coating it was the Jet Hot coating. Sanderson sends the headers to Jet Hot Coatings in Arizona for this and they coat both the inside as well as the outside. The reduction in underhood temp. is significant and it also helps to preserve them. I haven't ceramic coated stainless but I know that Street & Performance has polished stainless headers that they coat on the inside so it's doable.

The connector pipe that we made is straight-forward. We cut off the stock side exhaust pipes about 12" from the 90 degree bend and made a pipe to connect with the header collector. Then I had these coated by AirBorn Coatings in East Hartford. As I mentioned earlier, if someone makes a setup that is already made to work with headers I'd probably go that route.

On the insulation, you can buy a kit to do the passenger compartment trans. tunnel and floor which is thin enough to fit under the carpeting. I added insulation under the seats as well as between the side pipes and frame rail using a quarter inch thick foil type heat insulation available in rolls from Jegs or Summit.

Sanderson also has some technical information on their site regarding header tube size and length that might be of interest. Just look under technical information.

I hope that helps. Just let me know if there is anything else.

Rich

bigblock66vette

Well here is what the hookers look like on my 66'

Mike Smith

Rob -

You should be able to find a good bit of info in the archives on this subject. Although I have no firsthand experience to confirm or deny their statements, a number of posters have shared dyno results indicating substantial gains, particularly over the Hooker sidepipes, using Spiral Turbo Baffles. They are available in sizes to fit under the stock covers. You may want to check the web site at http://www.spiralturbobaffles.com/.

Guest

Rich, excellent info. I really appreciate the replies, everyone. Besides heat, which may not be a problem now, I want sound. Deep, loud... all the better. A couple of people have asked about the intended use of the car, and that is to drive 1-3 times a week, with an occasional 2 day trip here or there. If I am doing the work myself with some knowledgeable friends, then I am hoping for some bolt up solutions. I want to look into the Sanderson headers, and then larger pipes. I just want to keep it as close to stock as possible from the ext, nothing I can do about headers though once I pop the hood.

Rich, want to come down to NC and turn some wrenches? :lol:

Guest

66 and Mike, very nice mid years!!! Thanks for your replies. :cheers:

396 RAT

I see you have a coupe.
Many wear ear plugs in their side pipe coupes.
Something to think about. :cheers:

Colevette

RLH I have a set of BB Sandersons for sale with a new set of SS stock sidepipes or, a ceramic coated 3.5" setup with JCL Spiral Baffles thats fits under the stock covers. If your interested
Cole

Guest

Cole, thanks. Just sent you an email...

richscorvettes

Rob,

Sure, how about next Tuesday? :D

My only other thought would be to really consider how loud you want to go. The headers alone will raise the noise level and anything with a 13.5 compression ratio should be capable of setting off every alarm in your neighborhood! :eek:

Rich