In an attempt to settle and arguement, what would you think a L98 with the follow setup would run and would make in hp/tq and 1/4mi. times. Would it outrun a similar setup 4th gen subbing the with an LT1 obviosly with same cam and exhaust and drivetrain. -Vortec heads fitted with higher lift springs for cam -a CC305 cam 220/230 .510/.510 114 LSA w/1.6 RR -Vortec HSR. -Hedman LT's and Hooker CB -2500 Stall

The LT1 will make more power and should be faster. It appears that the stealth ram becomes a limitation once you reach the 400hp mark. In stock form the vortec heads and Lt1 heads flow about the same. However, when ported the LT1's will flow more than a set of ported vortecs. The LT1 is also running more compression which is another power advantage over the vortec. Both motors will be monsters but the Lt1 should have the edge. If it goes in a heavier car than the playing field becomes more equal.

Yeah it will be close, but I'll have to call LT1, unless it's a 93-95 with ****ty 2.77s and no ram-air package.

Guess there's only one way to find out!

4th gens never came with a 2.77 They could get a 2.73 which was worse

Actually the Vortec heads flow 15-20 cfm more then stock LT1 heads. Would that not give you enough difference to outpower the LT1 comp: advantage little alone the LT1 weight disadvantage. I was kinda thinking the Vortecs would edge out the LT1 hands down.

They may flow a bit more unported but the LT1's have more going for them. I would sacrifice 15cfm or so to have 50lbs less weight and a 10.5:1 compression ratio. The compression ratio difference alone will have the LT1's making more power. If the two are ported the LT1's can flow near 300cfm.

That would be a very close race, assuming both cars are tuned for the cam. Since you're addressing every advantage the LT1 has over the L98, the playing field should be leveled. True, the LT1 may have little more compression, but the Vortecs not only flow more but they have a better combustion chamber (even though they are designed after the LT1).

What about the rest of the package? Gears, tires, suspension mods, driver ability. That's what this will depend on...

And lets NOT assume that LT1 heads regularly hit 300cfm even when extensively ported. That's usually not the case. Most are lucky to see 275cfm fully done.

hehe

And I've seen several LT1 port jobs done by a local speed shop that flowed 270-300 CFM. The wide difference because of the skill of the porters. But 300 isn't all that uncommon if you are good and have a few sets of heads under your belt.

Any of the lloyd elliot packages hit near 300 CFM, if I remember correctly. And those Heads/Cam packages are good for up to 420 RWHP.

No. Lloyd Elliot, one of the LT1 premier porters, with much experience, has his top of line, no holds barred, stage 3 LT1 heads at 275cfm. That's a far cry from 300cfm. And about those speed shop monkeys getting 300cfm: either they need their benches calibrated, they're not testing at 28", or they're flat out lying.

True im not losing any weight off the car but im not gaining any either and most thirdgens are lighter then there portly 4thgen siblings. My fully loaded GTA is just over 3400lbs on the scales with a good 80-100lbs subbox in the rear well.

loyd is a local guy down here. i had him do a set of lt1 heads for a freind, and told him to do a minor port job and leave the stock valves in. this was a 6 speed car with a hot cam and a set of mac headers and mostly stock other than that, and it dynoed 369whp.


i appologize to you all for my missguided and irrelevent negitive comments towards loyd, and i admit i was wrong to have said them in this topic.

Ah, well my memory served me wrong. I went and looked it up, it does indeed say 275 on his site.

On the speed shop around here, I'll have to call them, but I'm sure I saw those numbers.

He's highly respected and recommended by the LT1 crowd where I live. And it seems that is the case with most of the LT1 oriented message boards. They can't all be clueless street racers!

Even still, I don't think I've ever heard of a stock LT1 casting producing over 280cfm. And that claimed 280cfm I saw was at .650" lift and with a measured 212cc runner. A LOT of material was removed.

Stock castings have indeed hit 300cfm, AI is getting a little over 300cfm.

Who?

And running this by a record holding speed shop that's quite experienced with LT1's, he agrees with you. 300cfm is possible. However, it requires angle milling a TON to achieve a 21* valve angle, and relocating the intake ports over quite a bit. All of this requires a custom intake, offset rockers and lifters. And not only do I not think the LT1 in question in this post has any of this, I think the heads are stock. Total cost involved "a ton, likely several thousand at least!"

Lets drop the "potential" issue.

http://www.advancedinduction.com
I agree, I sincerely doubt his heads are extremely worked if anything. Getting 300cfm doesn;'t require going 21* and relocating, its still rare to get them that high, a good porter should be able to get 280 cfm no problem.

Holy moly. Its a LT1 war. I have no doubt LT1 heads can flow.My buddy just bought a set of Stg 2 heads that flow 265 cfm with 1.94 valves @ .600lift. and he's running a GM 847 with it. However. Im talking about stock LT1 heads which flow something like 210cfm stock if im not mistaken. All im trying to do is prove for cheap i can level the playing field and come out on top with a cammed LT1.

Vej.

Give me call if you get a chance. I would like to speak with you and find out what you are talking about and who said these things about me.

Maybe we can meet up tomorrow sometime.

Lloyd Elliott
972-617-5671

I think the L98 would win. It dosent take much to outrun an LT1 car. LS1 on the other hand....thats a different story.

Either one of them done up can tickle that 300cfm barrier at that point it wont matter if it conventional or LT1 smallblock.

This whole scenario is kind of dumb lol

My vote would go to vortecs for the simple fact that I dont like the associated plumbing and modifications you have to do to run LT1 heads on a reg small block.

In a perfect world given those constraints, it would be a close race, either way it should be a fun combo, and not really worth arguing over, its more like splitting hairs at that point if everything is the "same" between the cars.

I dont see the Stealthram limiting a motor at the 400 hp range either.

later
Jeremy

Yes it sucks but apparently it is true. There was just a big discussion on this between RB and another gentleman who have run this induction on healthy motors. Both exibited serious power drop offs after the 400hp mark was reached. I will see if i can find the link.

how would a ported L98 rack up against the tec's and LT1's?

I have an 89 GTA with L98 stock short block, unported vortec heads with upgraded springs and screw-in studs, SDPC base, stock upper TPI and shorty headers. Still stock cam and I run 13.5-13.9@100-102 mph.

LT1s in my area with stock cam and minor boltons only manage high 13s@100 mph, so considering that I have a restrictive upper TPI and heavy 3rd gen I vote for the Vortecs in a "true" comparison.

Sorry i dug up the grave of this old post. But im am getting the feeling the Vortec's have the "gusto" to hold on par with the LT1 to an extent. Also does anyone know if Lloyd Elliot would port Vortecs seeing as the are a very similar casting to the LT1 in the first place.

If you are going to spend the money to have some iron vortecs professionally ported, you may as well just buy some good flowing aluminum heads.