I still say someone should buy an LT4 and trade me heads & intake. I wouldn't have a real LT4, but I'd settle for a hybrid. (not talking gas/electric)
LT4 vs. LT1
Racer
Joined: Mar 2005
Posts: 399
Likes: 2
From: Newtown PA
Back on topic, I definitely prefer an LT4 over the LT1. Its was the state of the art in GM LTx design. Why not buy the best of the breed.
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
basically you do not have an lt4.. you have a lt1 with a cam from gmpp. if you had an lt4 you would have lt4 heads, cam, intake, pistons and crank.. so yeah.. you basically have a lt1 with an aftermarket cam.
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
I know I said this before & plan on having an LT-4 intake when engine is upgraded.As far as heads I'll have the cylinder head shop guy that does work for our shop do the headwork(port & polish,upgraded valves,springs,& cam suggestions).When that time comes will also ask questions on this forum.You guys are awesome.BTW a porsche boxter S owner came in to our shop & asked me questions about his cars.He was a nice fellow who was down to earth & asked if I wanted to take his car for a ride.I did,thought it was nice but liked my vette better.I asked if he was a member on a porsche forum.He said yes but most members were more interested in keeping car shiny & not much technicial questions.THAT WOULD SUCK being a member & talking about car soaps & waxes all the time.Even if your a member here on corvette forum & don't fix your own car I'm sure your a car freak like the rest of us,& thats all that matters.
I live,eat,breath,&...... cars in general.Even after work I still read about cars,internet,etc.This is a sickness,but I love it.
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
Those red intakes look cool.I know I said this before & plan on having an LT-4 intake when engine is upgraded.As far as heads I'll have the cylinder head shop guy that does work for our shop do the headwork(port & polish,upgraded valves,springs,& cam suggestions).When that time comes will also ask questions on this forum.You guys are awesome.BTW a porsche boxter S owner came in to our shop & asked me questions about his cars.He was a nice fellow who was down to earth & asked if I wanted to take his car for a ride.I did,thought it was nice but liked my vette better.I asked if he was a member on a porsche forum.He said yes but most members were more interested in keeping car shiny & not much technicial questions.THAT WOULD SUCK being a member & talking about car soaps & waxes all the time.Even if your a member here on corvette forum & don't fix your own car I'm sure your a car freak like the rest of us,& thats all that matters.I live,eat,breath,&...... cars in general.Even after work I still read about cars,internet,etc.This is a sickness,but I love it.
I know I said this before & plan on having an LT-4 intake when engine is upgraded.As far as heads I'll have the cylinder head shop guy that does work for our shop do the headwork(port & polish,upgraded valves,springs,& cam suggestions).When that time comes will also ask questions on this forum.You guys are awesome.BTW a porsche boxter S owner came in to our shop & asked me questions about his cars.He was a nice fellow who was down to earth & asked if I wanted to take his car for a ride.I did,thought it was nice but liked my vette better.I asked if he was a member on a porsche forum.He said yes but most members were more interested in keeping car shiny & not much technicial questions.THAT WOULD SUCK being a member & talking about car soaps & waxes all the time.Even if your a member here on corvette forum & don't fix your own car I'm sure your a car freak like the rest of us,& thats all that matters.I live,eat,breath,&...... cars in general.Even after work I still read about cars,internet,etc.This is a sickness,but I love it.Last edited by pr0zac; Oct 30, 2009 at 01:13 AM.
Melting Slicks
Joined: Mar 2004
Posts: 2,141
Likes: 2
From: Pittsburgh Pa
I stand corrected about the rods. They have the same part numbers. I've read about quite a few instances of spun rod bearings in LT1s that have been reved beyond 6100 rpm. I believe that the main reason for this is the tight rod bearing clearances and perhaps the rod bolts. Why is this not a problem with the LT4s or is it?? I have a cam, beehive springs, roller rockers, etc. in my LT1 and I do not rev it past 6100 rpm. The engine feels like it still has more power past this point but I am reluctant to rev it higher. I am I being to conservative with the rpm?
Back on topic, I definitely prefer an LT4 over the LT1. Its was the state of the art in GM LTx design. Why not buy the best of the breed.
Back on topic, I definitely prefer an LT4 over the LT1. Its was the state of the art in GM LTx design. Why not buy the best of the breed.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
As we all know it doesnt take long before stock performance sucks. If modifying to drag race the number behind the LT means little. The things I like about the LT4 are the stronger dana 44, more porting potential in the heads, and the higher rpm tach.
LT1's can come with the auto which is better for drag racing when built right. Aftermarket heads and stronger rear can be added. The LT1's are slightly less expensive to purchase and easier to come by. I've also heard OBDI(pre-1996) is better for passing emissions in some states.
Both cars are great Corvette's to own. IMO
LT1's can come with the auto which is better for drag racing when built right. Aftermarket heads and stronger rear can be added. The LT1's are slightly less expensive to purchase and easier to come by. I've also heard OBDI(pre-1996) is better for passing emissions in some states.
Both cars are great Corvette's to own. IMO
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
My shift points are currently set to 6400 rpms.
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
I thought the intake port was higher on LT4 heads? You're saying the LT1 and LT4 intake manifolds have the ports in the same place? Or just that they're the same shape & volume, but different location?
Safety Car
Joined: May 2002
Posts: 4,659
Likes: 82
From: Toronto ontario
The LT4 ports are the same as the lt1. the casting is raised to be in a higher location to match up with the raised ports on the cylinder heads. There is nothing special about the manifold.
about this special lt4 dana 44
about this special lt4 dana 44
Burning Brakes
Joined: Oct 2009
Posts: 773
Likes: 2
From: Minneapolis MN
Really?Well I'll just port/polish the extra intake I have & paint it red.
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
My shift points are set at 6000. Last time at the track, I experimented a little with holding it in gear longer and trying to make it shift right before it hit the 6400 RPM limiter and got slightly better corrected ETs. I want to get some time on the dyno and some datalogs first, but I'm probably going to raise the shift point to around 6300, and the limiter to 6500.
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
I don't think there's anything special about the D44 in the LT4 cars, I think he was just highlighting the fact that since LT4 was only in stick shift cars, they all had D44 as opposed to the auto cars with D36.
Prozac, correct me if I'm wrong on this one.
About the ports being the same on the manifolds... Wow. So then on the LT4, is there a "step" between the intake port on the manifold and the intake port on the head? Or are the intake ports the same on the heads too? I always thought the LT4 heads flowed better because the top of the intake port was higher, increasing intake port volume and flow, and a raised exhaust port allowing increased exhaust flow. I guess I just ASSumed that meant the intake manifold would match.
Guess Weird Al was right, everything I know is wrong...
Prozac, correct me if I'm wrong on this one.
About the ports being the same on the manifolds... Wow. So then on the LT4, is there a "step" between the intake port on the manifold and the intake port on the head? Or are the intake ports the same on the heads too? I always thought the LT4 heads flowed better because the top of the intake port was higher, increasing intake port volume and flow, and a raised exhaust port allowing increased exhaust flow. I guess I just ASSumed that meant the intake manifold would match.
Guess Weird Al was right, everything I know is wrong...
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
Thanks. I think I understand now. So if a guy put an unported LT4 manifold on a new set of AFR 195 LT4 style heads, it would be the same as an unported LT1 manifold. But the LT4 manifold COULD be ported to match while the LT1 manifold wouldn't have enough metal to port match without compromising the port "roof."
Race Director
Joined: Jan 2002
Posts: 12,261
Likes: 85
From: O'Fallon Missouri
I'm pretty sure the new AFR 195 Comp heads will work with either the LT1 or unported LT4 intakes. Jim Mason "96GS#007" sold his ported LT4 intake and bought a new LT4 intake for his 383 build with the Comp 195's.
