Whats the Differance?
Team Owner
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From: Fort Knox, KY
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There's an SAE paper that compares and contrasts the two engines.
It discusses history, cooling, lubrication, breathing, ignition, etc.
The name of the paper is "New Generation Small Block V8 Engine," SAE paper 920673, by Anil Kulkarni of GM. It can be obtained from the SAE by calling 412-776-4841.
It discusses history, cooling, lubrication, breathing, ignition, etc.
The name of the paper is "New Generation Small Block V8 Engine," SAE paper 920673, by Anil Kulkarni of GM. It can be obtained from the SAE by calling 412-776-4841.
Instructor
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From: philadelphia,pa pa
I have a set of L-98 headers on my lt-4 the main differences I saw was the ports on the l98 headers were not "D" shaped also the emmision air tubes were all together different. I have the hookers and the fit is great I constantly get told how nice they look and how well they tuck up under the car.If I was to do it again I would probably buy the hookers again but without the emmisions tubes.
Team Owner
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From: Athens AL
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Originally Posted by ian1992red
Thats the thing. I want the longtubes, and Im doing away with all the emissions. Am I losing anything by going with an L98 Header vs. an LT1 Header?
Its only that the L98 header might need to be modified at an exhaust shop to work with the rest of the exhaust.
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Pro
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From: Fort Worth TX
I already have all new cat back from flowmaster, never installed. Doing away with the cats and all. I know they are going to have to do a little fab work to make it all fit. But im prepared for that. just wanted to make sure I wasnt losing anything performance wise....
Race Director
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From: The Top of Utah
Originally Posted by richN
I have a set of L-98 headers on my lt-4 the main differences I saw was the ports on the l98 headers were not "D" shaped.
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Pro
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From: charlotte nc
Originally Posted by CFI-EFI
Not the ports on the headers, but all the Corvette L98s with the 113 heads, 1988-up (?), have the same or similar "D" shaped exhaust ports in the heads. You really don't want your headers to have a matching "D" shape.
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Pro
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From: Fort Worth TX
Originally Posted by dwestsr
That's right. The "D" shaped exhaust port is designed as an anti reversion feature and is supposed to be used with a round exhaust pipe. Otherwise the anti reversion effect would be lost. The purpose of the ant-reversion feature is to partially block the rebound from the exhaust pulse. The flat pat of the "D" is supposed to act like a one way dam to restrict the back pulse so as to help exhaust scavanging and reduce polution of the intake charge when the both valves are open during the overlap phase of the cam cylcle.
OK...
I may need a little help to understand here.
The D shaped port on the head is supposed to be used with a round exhaust tube...
So something like this would be the used with the LT1 appilication?
SEE ATTACHED....
Then why are the seperate headeers made for the LT1 and L98 applications?
Racer
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From: Tucson, AZ. L98-85 AUTO COUPE: 120k MILES: daily driver. SOUND OFF IF YOU'VE BEEN THERE. Ex-Jumpin' Junky-82nd Airborne-2/505 PIR: 1st ID-1/16th Inf: Recon Marine Retread. GOD BLESS GRUNTS.
i believe the d shaped port is meant to be matched with a non-d header. the d shape is used as an anti-reversion device, (prevents backflow), and this will only work with a header that has a round type shape. the higher lip stops backflow.
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From: Construction Sucks! MI
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mainly how it's going to connect to the rest of the exhaust system. i'm putting lt1 headers (EM) on my l98. i've ran into a few clearance issues (slave cylinder and the huge 84-87 starter), but nothing that couldn't be fixed. The collectors line up pretty straight to the rest of the system and i'm just using band clamps to connect the two since there is no flange.
Team Owner
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From: Athens AL
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Originally Posted by ian1992red
So agian I ask, why is there different headers for the l98 and the lt1.
What is the differance?
What is the differance?
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With whatever headers you choose, what you don't want to is to block the top of the D port. This will restrict flow and negate the advantage of the D port design. There are three kinds of header flange/port designs for these cars. Round port which are only suitable for pre-'88 heads, oval port, which will work well with both styles of heads and D port specific.