LT1 / LT4 Tech question..
Thread Starter
Pro
Joined: Jun 2002
Posts: 636
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From: Finksburg MD
LT1 / LT4 Tech question..
Does it make a difference on the Headers on either LT1 or LT4.. As long as they are D port.. Or is the LT4 larger? I am looking at buying headers if you didn't guess..
Burning Brakes
Joined: Nov 2001
Posts: 1,241
Likes: 9
From: Houston TX
Re: LT1 / LT4 Tech question.. (dsg049c)
i'm not sure if this is specific to the LT4, or all LT-series, but the exhaust ports on my LT4 are raised relative to L98 ports. the hooker longtubes are so overly large that the tops lined up perfectly with the top of the exhaust port, but the gaskets intruded. the blue felpro (i forget the number) exhaust gasket opening was a little taller, and only just barely intruded. i ground on it a tiny bit so it didn't.
-michael
-michael
Race Director
Joined: Oct 2000
Posts: 14,064
Likes: 1,166
From: N. Alabama
Re: LT1 / LT4 Tech question.. (dsg049c)
I believe they are one and the same. I used TPIS coated headers. The headers and random flow cats gave me 24 more HP over hot cam and corsas alone. However, I had to grind most of a day on the TPIS to remove the obstructing weld bead in the entrance of each tube, had to grind out clearance for bolts since the sleeves were not in alignment, and had to bend the air tube to clear valve cover. Personally, mine weren't far removed from crap when I got them. :smash:
Team Owner
Joined: Apr 2001
Posts: 22,267
Likes: 3
From: Dallas TX
Re: LT1 / LT4 Tech question.. (MSR)
YES! THere is some difference but I can't figure it out yet. LT4 and LT1 are not the same.
I bought a set of used 2061 hooker headers and broke tha passenger side one because it didn't fit right. Called up Jet-Hot and every set for an LT4 they have sent out the passengerside have broken. There is a different distance between the ports and the pipe coming down to the cat. If you go with long tubes, that all gets changed though.. but with shorties you have to watch out! :yesnod:
[Modified by GlockLT4, 8:31 PM 2/13/2004]
I bought a set of used 2061 hooker headers and broke tha passenger side one because it didn't fit right. Called up Jet-Hot and every set for an LT4 they have sent out the passengerside have broken. There is a different distance between the ports and the pipe coming down to the cat. If you go with long tubes, that all gets changed though.. but with shorties you have to watch out! :yesnod:
[Modified by GlockLT4, 8:31 PM 2/13/2004]
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: LT1 / LT4 Tech question.. (dsg049c)
The intake side had the runners raised by .10" supposedly... that's the reason for the LT4 style intake.
The exhaust runners were massaged but the actual exit port demensions shouldn't change. Reference this pic ... (you'll have to scroll down a bit ) http://www.grandsportregistry.com/lt1vslt4.htm
Looks like the throat was hogged out a bit and the water passage was expanded to fit. But the actual exit point looks about the same. Makes sense. Most flow gains are seen closer to the valve "throat" and surround the valve itself ( "valve unshrouding, short turn radius mods, valve seat cuts, etc.)
The exhaust runners were massaged but the actual exit port demensions shouldn't change. Reference this pic ... (you'll have to scroll down a bit ) http://www.grandsportregistry.com/lt1vslt4.htm
Looks like the throat was hogged out a bit and the water passage was expanded to fit. But the actual exit point looks about the same. Makes sense. Most flow gains are seen closer to the valve "throat" and surround the valve itself ( "valve unshrouding, short turn radius mods, valve seat cuts, etc.)
