Headers or No Headers, That Is The Question?
Thread Starter
Instructor
Joined: Jun 2002
Posts: 176
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From: New Albany IN
Headers or No Headers, That Is The Question?
I'm rebuilding my '70 L46. Block .030 over, Crank .010 under, Pistons 11:1, Heads L46 ported and polished, Intake aluminum but still fits under small block hood, 650 Holley 6210, cam hydraulic nice for street. I have and had on the engine before the rebuild all the original factory chrome including the chrome spark plug heat sheilds, which by the way make it a bitch to get to the spark plugs and wires, also have power steering. Just want to get some input about adding a set of headers and any other thoughts on this project or changes or suggestions. Please put your 2 Cents worth in and how many times do you get asked to do that.
Just another Corvette guy
Joined: Feb 1999
Posts: 8,518
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From: Palm Springs, CA.
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
Hey Don,
It sounds like you have some decent stuff in there. I say splurge and put a nice set of Hookers in there too, you won't be sorry.
Greg
It sounds like you have some decent stuff in there. I say splurge and put a nice set of Hookers in there too, you won't be sorry.
Greg
Instructor
Joined: Jul 2003
Posts: 153
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From: shores of lake erie pa
Re: Headers or No Headers, That Is The Question? (Greg)
hay
i have a 68 that i am in the process of croming the engine,and next fall the first thing to do is add some crome headers. go for it.
chuck
i have a 68 that i am in the process of croming the engine,and next fall the first thing to do is add some crome headers. go for it.
chuck
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 2
From: New Zealand
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
The only downside is that I've heard that headers can fry the leads......otherwise it depends on how stock you want to keep your car and how much you need the money for other things.....I believe the original rams horns flow pretty good and there are coatings available to dress them up....
BTW......very nice vert :thumbs:
BTW......very nice vert :thumbs:
Race Director
Joined: Feb 1999
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From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Re: Headers or No Headers, That Is The Question? (standup)
I put shorty headers on mine and wouldn't go back. Alot of people on here have done the header thing.
Race Director
Joined: Mar 2001
Posts: 11,322
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From: Living in the Hartland
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
Really depends on your cam specs. Rams Horns do flow well for a cast iron manifold so if you have a mild cam you might not pick much up with headers. Headers aren't that hard to add so why not run it with the rams horns and if you feel you need more add the headers. Dynomax coated headers are a good buy at about $220 and really help keep the heat down under the hood. Post your cams specs and the eng/cam gurus with advise.
Drifting
Joined: Sep 2001
Posts: 1,427
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From: Boxford Mass
Re: Headers or No Headers, That Is The Question? (Fevre)
I have a set Hookers that are Jet-Hot coated outside & inside. I didn't notice a heat change anyway after installation. I'd go with the smaller 1 5/8 inch header. You'll also have some exhaust work to tackle.
Thread Starter
Instructor
Joined: Jun 2002
Posts: 176
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From: New Albany IN
Re: Headers or No Headers, That Is The Question? (Jack71)
Thanks Guys. I'm leaning toward the headers. I'll get those specs. on the cam and post them and more info on the intake. Keep givin' the input.
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Racer
Joined: Jan 2003
Posts: 296
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From: Sarasota FL
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
Dynomax ceramic coated. Reasonable, good look and sound and flow, easy to install. A worthwhile upgrade but I scoff at the stock 80 thanks to the feds that year! Have fun.
Marc
Marc
Melting Slicks
Joined: Apr 2000
Posts: 3,286
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From: San Jose California
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
The L46 is a great engine and you've done a few nice things to it. You have just entered the realm of obtaining a noticeable benefit from headers, however, I really disliked the ground clearance lost when I put them on L46 with an under car exhaust system. The rams horn manifolds really aren't too bad, Corvettes raced with them until about the mid 60's. But you would probably get as much benefit from shorty headers without the ground clearance problems as you would with tube headers as long as you are running through anything but an open exhaust system. For open exhaust, the tube headers will have a bit of an advantage, but probably less than 15-20 hp.
Chuck
[Modified by Chuck Harmon, 1:58 PM 7/27/2003]
Chuck
[Modified by Chuck Harmon, 1:58 PM 7/27/2003]
Melting Slicks
Joined: Apr 2000
Posts: 3,286
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From: San Jose California
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
The L46 is a great engine and you've done a few nice things to it. You have just entered the realm of obtaining a noticeable benefit from headers, however, I really disliked the ground clearance lost when I put them on my L46 with an under car exhaust system.
The rams horn manifolds really aren't too bad, Corvettes raced with them until about the mid 60's. But you would probably get as much benefit from shorty headers without the ground clearance problems as you would with tube headers as long as you are running through anything but an open exhaust system. For open exhaust, the tube headers will have a bit of an advantage, but probably less than 15-20 hp.
Chuck
The rams horn manifolds really aren't too bad, Corvettes raced with them until about the mid 60's. But you would probably get as much benefit from shorty headers without the ground clearance problems as you would with tube headers as long as you are running through anything but an open exhaust system. For open exhaust, the tube headers will have a bit of an advantage, but probably less than 15-20 hp.
Chuck
Racer
Joined: Jun 2001
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From: Sanford Florida
Re: Headers or No Headers, That Is The Question? (Raydon 3000)
Yes on the headers, and I am skeptical of that much compression. 11 to 1 is quite a bit for what I am assuming is a dual plane manifold, and a nice street hydraulic cam and 650 carb. You may want to rethink that to match your other components a little better. What are the actual specs on the cam? :cheers:
Melting Slicks
Joined: Apr 2000
Posts: 3,286
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From: San Jose California
Re: Headers or No Headers, That Is The Question? (boredsoIstrokedit)
Actually, I think the 11:1 compression is great! If they are factory pistons the true compression for those TRW supplied pistons is 10.5:1. But the 11:1 is what I think made the L46 such a great motor. The L82 was basically the same engine with low compression. While a good engine, the L82 I owned didn't have the "bite" that my L46 had. I think you will be ok if you run the highest premium gas you can find, at least 92 octane. Remember that the low compression engines were supposed to be able to run on regular whcih was about 87 octane at the time. The no lead gas of today does not build up deposits which caused much of the preignition and knocking problems of before. If you intend to race the car at a track, use 100 octane just to be safe and perhaps to be able to advance the dist a few extra degrees for a bit more performance.
Chuck
Chuck
Melting Slicks
Joined: Sep 2002
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From: Engineers do it better.
Re: Headers or No Headers, That Is The Question? (Jack71)
I have a set Hookers that are Jet-Hot coated outside & inside. I didn't notice a heat change anyway after installation. I'd go with the smaller 1 5/8 inch header. You'll also have some exhaust work to tackle.
:iagree: My first upgrade was the headers. Biggest bang for the buck. Do it. :yesnod:
Team Owner
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From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
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St. Jude Donor '06-'10, '13
Re: Headers or No Headers, That Is The Question? (Alwyn678)
I have the Hedman thermal coated headers. They fit nice and helped the engine a lot.
Thread Starter
Instructor
Joined: Jun 2002
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From: New Albany IN
Re: Headers or No Headers, That Is The Question? (BSeery)
Stopped by the shop today, having a problem finding an intake that will work with the Holley Spread Bore, fit under the hood and still add noticeably to the performance. The cam, hydraulic, intake and exhaust, .480 with a 1.75 rocker arm ratio. Now dose anyone have any suggestions on intakes?
[Modified by Raydon 3000, 10:17 PM 8/11/2003]
[Modified by Raydon 3000, 10:17 PM 8/11/2003]