up until a few days ago, I always wanted an lt4. I just bought my 1st vette about 2 months ago, and a 6 sp was mandatory, but the price seemed too good to pass up, so i settled on an lt1

I paid 11000, for a green on tan 6 sp with 75k miles. Its not mint, but its great, there is only a couple minor things with it that make it not mint. It has a clean title as well, so I think I did okay.

Anyways, there has always been this talk that the lt4 was as quick as the Zr-1, or so ive read, w/o the headaches that zr-1 engines sometimes give you, again, so Ive read.

I do know the 330bhp is a low number, i have seen dyno graphs that suggest 350-360 range, but so much more money to buy the car to begin with. I just saw a 96 CE lt4 go on ebay for 16250, which is way more than i paid.

Now after reading on this forum, with a good set of headers and exhaust, as well as a lt-4 hot cam kit, you can have easily the same power of the lt-4. I think i read a sig that had those mods and he put down ~350rwhp or something crazy like that.

the reason I post this is about 2 weeks ago there was a poll on which was the best engine, lt1,lt4,lt5,l98 etc and i voted lt4, but now id vote lt1....

its just a thought i had im my head :lol:


[Modified by 94 M-6, 10:55 AM 12/19/2003]

 

They are basically the same engine. The main difference lies with the .100 raised intake runners in the LT4 heads and the matching intake manifold. There are other subtle differences as well such as the filleted crank journals, dual mass balancer, a slightly smaller combustion chamber for higher compresssion ratio. And the LT4 comes with roller rockers and lightweight sodium filled exhaust valves as well.

However most all of these differences can be had for a nominal price of around $2500 from your local GM Performance parts dealer or from Summit Racing. All of this can be had in a form of a LT4 Hotcam conversion kit. It comes with a set of LT4 heads, intake, HOT Cam, roller rockers and other miscellaneous parts. Claimed Hp for this kit is around 425Hp or something like that. It is a good deal when purchased as a kit. The heads alone when purchased alone are over $1200 from a dealer.

 

Without heads? :skep:

LT4 has bigger valves, different heads, higher compression, and higher redline also.
-=-=-===--===-==
New camshaft design
Larger valves
Roller rocker arms
Revised Head design
Head Gaskets
Revised Piston Design
Positive-twist top piston rings
Fuel System
Intake Manifold
Roller timing chain
Specially machined crankshaft
Dual-mass front torsional damper
Nodular iron main bearing caps
Teflon rear crank seal

http://grandsportregistry.com/lt1vslt4.htm





[Modified by tailgunner, 4:37 PM 12/19/2003]

 

The general opinion is that the stock LT4 is making about 350 crank HP. Many believe that GM underated the LT4 because they didn't want to make the LS1 (rated at 345hp) look bad.

The LT1 responds well to basic mods, and as pointed put can be upgraded to LT4 like specs.

 

Here is a side-by-side comparison chart: http://corvetteactioncenter.com/specs/1996/lt1lt4.html

 

As mentioned above there are several differences.

Bottom line to me though really is if you want to keep it stock or lightly mod with boltons the LT4 is worth it. If you are going to heavily modify , heads/cam or more , get a 94-5 LT1 . Its cheaper initially and can be modded with almost the potential of the LT4.

As you can see (I bought an LT4) , I thought I would be keeping it near stock......yeah , right :D

 

Most people that has the LT1 will option for aftermarket LT4 heads made by AFR. Then using a ported LT4 intake to mate to the heads. The bad boys will normally stroke the engine anyway and use a quality forged crank thats much better than the stock LT4 cast crank anyway. So either way it can be done with a LT1 or an LT4. I had a LT4 crate engine that I parted out years ago. The only part I used was the block, intake, fuel rails brackets, valve, timing covers and oil pan. I sold the heads and everything inside the engine. It was all new parts literally so they went fast. Thats what I used to build my 396 out of. I recouped several hundred $$$ from the parts sales. $1000 alone for the heads, which at the time was in high demand.

 

It just seems to me that it is just not true you can convert an LT1 to an LT4 by a top end kit. For example the piston rings on the LT4 is different than LT1 because as a recall the quote from GM is "blow-by went off the scale on an LT1" above 5800 rpm. GM also beefed crank... point is GM felt an LT1 bottom end wasn't reliable above 5800.

LT1 is a great engine as is and even better when moded, but just matching hp by top-end work doesn't make the two engines totally equal. LT4 would still be a tad better as I have stated above...

 

You are correct, if a LT1 bottom end is retained then of course its not quite a LT4. But for all intents and purposes performance wise with the LT4 kit with the HOT cam it will exceed that of a stock LT4. I haven't heard anything about the LT1 engines having excessive blowby on a LT1 based engine.

There are lots of F body boys other there as well as many Y body guys out there running into the 6300 RPM range on a regular basis with out any problems. Several are on this forum as well. Once the GM cranks are replaced with aftermarket forged units, the durability issues cease regardless of if its a LT4 part or not, aftermarket manufactured 4340 crank quality and high RPM durability far exceed that of OEM parts. Especially that of the PM rods that GM has been using all these years. I wouldn't trust those rods in anything but a mildly modified engine, and I wouldn't even consider them for a blown application.

But you are correct as for just bolt on LT4 kits to a LT1, the true LT4 maybe just a tad better on the durability issue. But the LT1 with the HOT cam and the LT4 heads and intake would out run the stock LT4 in a drag race, but not by a whole lot :)

 

quote

Its cheaper initially and can be modded with almost the potential of the LT4.

Almost the potential? haha...that's funny. Lets' not forget that the LT4 engines didn't produce much higher performance times because of the extra wieght it has. I like the LT4's better than the LT1's if i would of known about them I would of bought an LT4, but i wouldn't sell my LT1 for an LT4 unless it was a spectacular deal. Car and driver posted poor reviews about the performance of the LT4's. There a few that posted some good 1/4 numbers but the ones i've seen go down the track haven't did better than mid 13's.

Want LT4 performance install a gear, good intake, 1.6rrs, crank pulley, It'll trap 110mph and low 13's even 12.9 i saw it with my own eyes..forum member Diel.

This may be interesting to some. All old articles of ZR1s LT1 LT4
CUT and PASTe the whole Link..
http://images.google.ca/imgres?imgur...UTF-8%26sa%3DN



[Modified by blk95, 2:38 AM 12/20/2003]

 

Beyond the physical differences between an LT-1 and LT-4, there are some other factors that drive up price. For one, it was only offered one year, which makes it somewhat collectable and desirable. The CE you mentioned is a limited edition car as well and not all were LT-4s. Couple that with the GS and the fact that '96 was the end of the C4s. All of this, plus the additional HP contribute to the higher prices for the LT-4s.

Less than 17K for an LT-4 Collector Edition seems pretty cheap all things considered.

Sure you can mod an LT-1 to run with an LT-4, but then I can mod an LT-4 to run with a Z06.

 

Sure you can mod an LT-1 to run with an LT-4, but then I can mod an LT-4 to run with a Z06. [/QUOTE]

:iagree: But you'd have to spend alot more money to match the ZO6.

 

Driving ability has a ton to do with the ETs people turn, especially in 6-speed cars. In my LT-4, I am nearly always between 12.95 and 13.20 depending on air and track conditions. I have seen Z06s run slower than me by several tenths at the track on the same day, but I would not say that my car is faster than Z06s.

Ahh, I love these convrsations, it's what makes having these cars fun. No one is right an no one is wrong! :thumbs:

 

Ya, these conversations are fun.....
I've see ZO6's do crapy, but then again one guy with a blue stock Z06 did a ridiculous run of 11.9@117 so some things just seem hard to believe but somehow they happen. I don't think i've seen LT4s get that :confused: :D

Here's some education i've learned and saw on some HP#s produced

Best dyno on LT1 287 worst 248
LT4 309 worst 280
ZR1 380?one guy on the forum posted hard to believe,
worst 333rwhp
ZO6 360-345
Dyno's spill out the guts about the engines, and the drivers that drive them are another story all together. That's what it all comes down too.


[Modified by blk95, 2:56 AM 12/20/2003]

 

The dyno numbers you show seem right on. My LT-4 made 305 with the simple bolt-ons in my sig.

 

Hmm we have guys here in Portland that routinely spanks them ZO6 boys. Car and Driver Magazine with their so called pro drivers was never able to do any better then 12.7 while GM tests say that it will do a 12.4 seconds while burning off a 0-60 in less than 4 second, none of which Car and Driver was able to substaintiate with their test mule. I am sure that a ZO6 can be modded to do well into the low 11's as with any car.

There are lots of 10 sec normally aspirated 396 LT1 F bodys as well. Corvette0096 here on the forum used to routinely hit 12.3 consistantly and spanked many ZO6's here locally, and he is doing it with a 85 C4 with a Super Ram inducted ZZ4 crate motor which has since transformed into a 383. He is looking for high 11's now. Time for a Cage there Rich!

Point is, you can buy yourself a used LT1 car say a 94/95 version for well under 20k, do some mods to it and blow the ZO6 boys away and still save a bundle versus the cost of a new ZO6.


[Modified by tjwong, 7:20 PM 12/19/2003]

 

Just don't forget that the Z06 shines in more than just the straight line. If all you want is 1/4 times then the C4 isn't the best car for it.

But then, I'm biased. I'm selling my C4 for a Z06. :D

 

For 1500$ in mods my 94 lt1 spanks Z06's on a regular basis. Add my 75 shot and me and my buddies procharged Z06 are dead even.

 

I've beaten many a LT4 with my stock LT1 six speed. Comes down to the driver everytime.

 

I'm the one who posted the 350rwhp last week. I had the same choice and could not find an LT4 car in my price range.

My 350rwhp was achieved thusly:

Hand ported heads, mild pocket port with 3 angle valve job, unshrouding the valves and smoothing the intake entry portion.
LT4 Hot cam kit installed by the same speed shop at the same time.
Price out the door $4500 including the cost of the hot cam kit.

To finish off the package TPIS headers and full 3" custom exhaust with no pinch down anywhere. Includes x-pipe, Random tech bullet cats, and Dynomax bullets. No where in the exhaust is it less than 3" from the header collectors back through the tip. This is important.
Price out the door including parts $1750.

Still running the 48mm stock throttle body

It passed emissions with flying colors with all smog equipment connected including EGR pipe.

The setup demonstrably works together with a big boost in the mid range from 3000 to 5000. SOTP confirms the torque boost.

I have bought a set of wheels to fit DRs and this year I will seriously chase a good ET.

Price for the car 3 years ago $20000. The cost of the mods $6250. The extra cost of an LT4 at the time I bought $10000.

Surprising C5 owners and blowing their doors off, priceless.


[Modified by 94lt1torchred, 10:18 AM 12/20/2003]