LS2 Carburated Or 350 Small Block Carburated

[Duffman77]

I dont think that its overkill but 400 hp is going to drive like 400 HP whether it is a gen I smallblock or a Gen III smallblock. There is no doubt that the LS2 is a better engine but do you want to spend $2K more as you said to end up with the same 400 hp or whatever you decide in the end?

My dad had about $5000 canadian in it at the time (our dollar was at 65 cents at the time and is at par now). He had the block already so he was in to it for a basic overhaul kit: bearings, pistons, rings....... the new heads (see above link)plus machining work. We assembled it ourselves. His is probably only around 350 HP though as he still has crapy stock manifolds and could have had more cam and went with a bigger carb and the RPM manifold. His has a nice lopey idle and its about as much as the stock converter wants to take. We copied a magazine build that was in a HOT Rod magazine that featured the heads (it was the first magazine to point out the potential of those heads at the time).

 

[c3po]

Duffmann, is your Dad going to get headers soon, I am just wondering if the 400 horsepower LS2 would be more streetable than the 400 horsepower small block, I would like a smooth idle, do you know what cam he has in his, is it the GM Hot Cam that is rated at 218I and 228E, headers would really wake up his engine, does he have dual exhaust, dual exhaust woke up the El Camino and the headers helped out upstairs in the rpm's quite a bit.

 

[Duffman77]

He has got a Comp Cams but I dont know the exact specs. I believe 2+teens and I know the valve lift is under .450" because he didnt get the high valve lift heads. He does have duals, but he has no plans to do headers on the truck anytime soon. I have convinced him for the next project though.

You can get some "Rhoads Lifters" that bleed some duration off at low RPM to improve idle quality. Higher LDA on the cam grind tends to smooth it out too. I'm just guessing off the top of my head but his might be 110 degrees. Ultimately your cam selection is going to be the deciding factor on final idle quality, HP and RPM IF you have a decent cylinder head that has adequate flow feeding the engine.

 

[XS650]

Quote:
dont think that its overkill but 400 hp is going to drive like 400 HP whether it is a gen I smallblock or a Gen III smallblock.


Difference is, you can drive a 400 hp LS2 like an old lady's grocery getter all day long and it still pulls nicely right off it's smooth 700 rpm. Not as good if he uses a carb though.

The LS2 is about 100 lbs lighter too, a nice improvement on a nose heavy car.

Either engine is a good choice if done right.

 

[Black Bart]

Hey patman you got your new ZR-1 ordered yet.

 

[Patman]

Originally Posted By: Black Bart
Hey patman you got your new ZR-1 ordered yet.


I only wish! I can't even afford one of the wheels! I know someone who has a deposit down on a new ZR-1, but he just purchased John Carravagio's personal C6 Z06, which is 640hp, so he might end up selling his spot in line for that ZR-1 now. I just need to win the lottery....

 

[c3po]

So we are saying the carburetor is not as smooth, so a carburated LS2 is going too run like a carburated small block 350.

 

[XS650]

Originally Posted By: c3po
So we are saying the carburetor is not as smooth, so a carburated LS2 is going too run like a carburated small block 350.


I wouldn't expect it to be much different.

I got the impression that you want

1. A considerable amount of power, like 400 hp
2. And engine that will rev high.
3. Something you can putter around in with lots of low speed oomph.

If you go small block and back off a bit on item #2, you could get a 383 SBC or so that met your desires. If you spend 98% of your time below 6000 rpm, maybe winding way out won't matter much to you. An engine that shoves you back in the seat at any normal driving speed instead of saying "who, me?" like a big cammer is nice to drive.

LS2 seems like almost a waste unless you are going to use FI and take full advantage of it's characterists.

I'm trying to apply logic here, but that only goes so far on performance cars, in the end, you are best off doing whatever lights your candle.

 

[Black Bart]

Originally Posted By: Patman
Originally Posted By: Black Bart
Hey patman you got your new ZR-1 ordered yet.


I only wish! I can't even afford one of the wheels! I know someone who has a deposit down on a new ZR-1, but he just purchased John Carravagio's personal C6 Z06, which is 640hp, so he might end up selling his spot in line for that ZR-1 now. I just need to win the lottery....
I was thinking you could make the payments from what you get as moderator

 

[Steve S]

What is the intention for the cars use? Hotrod ,dailey driver? The high torque at useable rpms usually is the best.There is no substitute for cubic inches

 

[c3po]

The intended usage is going to be daily driver, 383 is going too waste too much gas in my opinion, like I said before the cam is real mild on that LS2 compared too what I would need out of a 350, it would have to be a cam of 210I and 221E, I have read of guys doing ZZ-4's and the power was not enough, Edelbrock has a nice crate engine rated at 363 HP and 405 TQ, but it uses a targetmaster block with the 2 piece rear main seal and cast pistons, sorry but everything I have read tells me cast pistons do not like high rpm, the LS2 has a flat torque curve that peaks at 5000 rpm, wheras something like that Edelbrock crate engine peaks at 4000 rpm and then falls off, I have had the 305 up too 4500 rpm, I just want to be sure I dont put something in there that will lose power upstairs, I figure with the LS2 it will be more than enough and then some more, with hte Hot Cam rated at 218I and 228E that LS2 has 500 horsepower and 450 on the torque if I stepped up the cam later, whereas the 350 with that Hot Cam would have a little over 410 horsepower, it just seems there is so much more potential with these LS motors, and yes the car could eventually be a hot rod in that I do not have any heat or A/C.

 

[BuickGN]

From the factory, the LSx motors' main advantage over the traditional smallblock is the killer heads. Many other "little" things too, but the heads are what stand out.

If it were me, I would go with the LSx motor, especially coming from a 305. You're going to have more power down low and a lot more mid and top end power. The weight savings are nice too. With simple bolt-ons and a small cam you can have 400+hp and be very streetable without a lope. If you're looking to run 8s, I would go with a traditional smallblock.

 

[c3po]

It seems with the LS2 you would have a nice idle and that is what I am looking for, no I am not looking too run 8s, or go too the track, for me too have a small block built up too match the power of the LS2 I would be giving up driveability with a more aggressive cam and be losing gas mileage, also the LS2 has a lighter valvetrain which is nice because the motor can rev more, and since everything is aluminum, meaning the heads and block that is an advantage.

 

[Buffman]

I'd stick with the LS2 mainly for the reason of not being impressed with Golen Engines.

 

[c3po]

I will tell you this, Chad over there at Golen Engines is a great guy but it seems he is into performance engines, when I asked him what weight oil should I use with the 350 he wanted to build he said 20W-50, I said weight one minute I may be driving this car in the winter, he said we can build the tolerances in the engine a little tighter for a 10W-40, this all sounds like the car would be eating gas, the other thing he was talking about was a FAST Fuel Injection System, but I have read there are some problems with any aftermarket fuel injection systems, I could see myself having a problem and going to a GM dealer or some garage and they would look at the FAST System and say we can't fix it, also with hte LS2 I could always put fuel injection on it down the road, what if I got the engine from Golen and did not like the idle quality, I have not heard from 1 person on this board who has bought a Golen Engine or knows anyone that has and I think there are 20,000 members on this board, you might be asking why I even considered Golen, that was because they balance and blue print the engines whereas the other crate motors skimp on parts somewhere, 1 last thought on Golen, they wanted too throw a $65.00 Harmonic Balancer on the engine, I said I have a TCI Rattler that I paid about $270.00 and is on the 305 and it is fantastic, so he said well you can use yours, if he skimped on that part where else on the engine might he skimp, he agreed that the TCI Balancer was a fantastic product.

 

[Buffman]

I have quite a few friends with Golen Motors. Most of them have issues with severe oil consumption. My good friend goes through a quart of oil every 1000 miles on his 383 from Chad. Quite out of hand if you ask me. Other people have had the same luck. Of course his is still under warranty, but there should be no need to ship an $8000 motor back to someone when it should have been done right the first time. If you go to http://www.ls1tech.com and go to the LT1 section there's at least one thread about Golen in there.

 

[BuickGN]

Originally Posted By: c3po
I will tell you this, Chad over there at Golen Engines is a great guy but it seems he is into performance engines, when I asked him what weight oil should I use with the 350 he wanted to build he said 20W-50, I said weight one minute I may be driving this car in the winter, he said we can build the tolerances in the engine a little tighter for a 10W-40, this all sounds like the car would be eating gas, the other thing he was talking about was a FAST Fuel Injection System, but I have read there are some problems with any aftermarket fuel injection systems, I could see myself having a problem and going to a GM dealer or some garage and they would look at the FAST System and say we can't fix it, also with hte LS2 I could always put fuel injection on it down the road, what if I got the engine from Golen and did not like the idle quality, I have not heard from 1 person on this board who has bought a Golen Engine or knows anyone that has and I think there are 20,000 members on this board, you might be asking why I even considered Golen, that was because they balance and blue print the engines whereas the other crate motors skimp on parts somewhere, 1 last thought on Golen, they wanted too throw a $65.00 Harmonic Balancer on the engine, I said I have a TCI Rattler that I paid about $270.00 and is on the 305 and it is fantastic, so he said well you can use yours, if he skimped on that part where else on the engine might he skimp, he agreed that the TCI Balancer was a fantastic product.


The FAST system is nice for making maximum power. We have one in use on my dad's GN (the fast GN). It's "safer" for the motor on a very fast car and is great if you outgrow the factory ECM. There's a reason I didn't use it on my GN. It used to be my daily driver and I didn't want to pull the laptop out and make adjustments everytime the weather changed. It's not for the beginner, they even recommend taking one of their classes in order to tune it.

I hear they've come out with new software that's supposed to be improved in every area but I have no experience with it. Still, in your case, if you decide to go to fuel injection which I highly recommend, use a factory mass air ECM especially if 400hp is your goal.

 

[c3po]

Buffman, I totally agree with you, if I am going to spend that kind of money it better not leak, 1 thing I forgot too mention Chad was trying to recommend forged pistons on the motor, I thought it was overkill, it seems he is into building drag race engines or something but to be honest I have learned a lot from this thread and I will look on LS1.com under the LT1 section.

 

[c3po]

I went over to LS1.com and read about Golen Engines in the LT1 section and gathered a lot of good information, I also read more about the camshafts for these Ls motors and it seems the 1 that is in the carburated LS2 is speced for good mileage and emissions, amazing that a cam with a 204I and 208E is rated on that engine for 440 horsepower and 400 pound feet of torque, I also found out that by bolting a set of AFR LS1 cylinder heads I could have even more power and not give up driveability, but my plans are too start out with the cam that comes with the LS2 crate engine and see how it goes, those AirFlowResearch heads would add about 30 more horsepower and torque, I have a Turbo 350 transmission right now but I will probably have to go to a Turbo 400 transmission to handle that kind of power, maybe normal driving would be o.k. for the Turbo 350 but if I put my foot into it I do not know how long it would last, both of these transmissions will bolt up to the LS2 according to Pace Parts.

 

[HM12460]

c3, have you thought about a ramjet 350? with a turbo 700-R4? or maybe a 4L-60E?