okay, I have been giving this some thought, and wanted to bounce some ideas off you all.... my 93 has over 213k miles on it... still runs fine, not burning oil, compression good etc.... my mechanic says I could go another 100k easy.... however I am thinking about dropping in a new engine next year... two simple goals, 400 rwhp with 390+ torque, and a daily driver....

So do I have to stick with an LT1 configuration or can I go with something completely different? Money-wise we are talking about 5 to 7 thousand dollars... and no I am not interested in moving up to a C5.....

Thoughts?

 

few hints...dont build...buy a 383/396 short block with 4 bolt mains...go with AFR 205 cnc heads with a mild cam and your at 400 rwhp all day with a nice idle 25 mpg and another 100k of trouble free driving...

 

Golen makes a lot of nices LT1 longblocks already sorted out. A little more money then doing it yourself but worth it in my opinion.

http://www.golenengineservice.com/html/lt1_lt4.html

 

I thought the LT1's were short block.... I like their prices, especially since I will not be doing the work myself.....

 

LT1's are "smallblocks" a "shortblock" is basically the bottom end of an engine, assembled. Basically crank, rods, pistons, rings, bearings, block, and some other parts sometimes. A "longblock" is a shortblock with heads on it, and sometimes cam, timing chain and cover, oil pump, oil pan or any variation of parts. But a longblock always includes the heads.

400RWHP on an LT1 isn't that difficult I don't think, but in a daily driver you will need to go to 383 or bigger. I think a 350 would be lopey/jerkey at low rpm to make that kind of power. You could get 350 rwhp from the 350 pretty easily and cheaply and be plenty streetable. With your budget, tho, I'd go to the 383 and 400RWHP. Man, I need a bigger budget!!!!

 

Have you thought of a supercharger? You can rebuild your existing motor with a supercharger in mind. Better pistons, good quality forged crank and rods and maybe a mild cam. Larger injectors, and a good tune should easily get you to 400HP or more. Balance the reciprocating assembly and blueprint everything.

My otherwise stock 6-speed 02 coupe has a Vortech S-2 supercharger running 7lbs of boost at full throttle, a water-cooled intercooler with a SuperChips tune. It does have a Corsa Indy cat-back exhaust and factory exhaust manifolds. It dynoed at 440HP/403 ft-lbs of torque at the rear wheels. It idles at the stock idle RPM, drives just like a stock LS1 and delivers 30+MPG at 70 with the cruise control.

But when you stomp on the loud pedal, it's pretty hard to keep it in a straight line I can shift down to 2nd gear at 60 MPH and spin the tires.

 

I have thought about supercharging however I am not sure how problematic that would be for a daily driver.... I average about 100 miles per day usually so reliability is a primary concern...

 

With 500 rwhp, reliability is already a questionable. I make much less than that, and have torn up alot of parts over the years.

 

Like any HP motor, how ofter you use all of the available power is a factor in longevity. Beat on it daily and you can expect some sort of wear and possible part or component failures. Drive like grandma and parts last longer.

The thing that makes turbo or supercharger application work is that "normal" street operation does not (or should not) put that much of a strain on the motor. For example in my setup, the 7psi boost is in only at WOT. Just driving in traffic on city streets my boost gauge doesn't show much boost at all. Freeway cruising actually shows vacuum.

How you set up a forced air induction system has a lot to do with longevity (as does the weight placed on the gas pedal ) of the intenal engine components. On my Vortech system, the size of the drive pulley determines in part how much boost is generated. I could go to say 8-9psi boost with a pulley change and that would place an additional load on the pistons, rods and crank, not to mention the drivetrain.

 

 

thanks for the crash course in supercharging... the question I have though is this, if I built (bought in my case) an engine that has the horsepower and torque your engine is putting out, wouldn't that be a better option? A better option from the standpoint of not having to deal with another belt and/or the special needs of a supercharger?

 

Driveability plays a large part in deciding which way to go. I love hearing the sounds of engines with "lumpy" cams but when you add high compression, big cams, lots of head work, etc., I believe that driveability especially at low speeds can suffer if not be uncomfortable.

Gas mileage is also a factor with highly modded motors. Proper matching of prerformance equipment and having everything tuned right is very important but there will be some reduction in fuel economy with internal mods. If the car will be a daily driver, that is an important thing to consider, given the current cost of 91 or 92 octane gas.

As far as HP output, my motor should be somewhere around 510-530HP at the flywheel considering a roughly 15% loss due to the drivetrain. I would listen to motors that put out that kind of power using internal mods (cam, heads, headers, etc) and see if that's what you want to live with on a daily basis. My motor is quiet (outside of the Corsa exhaust) idles very smoothly at the stock RPM and drives like any stock C5. Until I hit the throttle.

Guess it's all in which way you want to go. Either internal mods, forced induction, or even Nitrous will give you the power you want. How it's done is personal preference. Cost is also a factor in reaching a particular performance level. Price out both ways and see which works best.

 

thanks for the info, great stuff.... as I have not made a final decision I am considering all the options.... when you say driveability at low speeds may suffer, in what sense? Or uncomfortable in what sense? I had a 68 firebird, 455 big block with a nice cam, car sounded like it was panting..... felt like it to... I didn't mind it at all... is that what you are talking about?

 

Yeah that's what I had meant, I have had some cars with really big cams and they were a PITA at slow speeds. 25MPH speed limits on city streets pretty much forced me to stay in 2nd gear to keep revs up enough so the engine wouldn't bog or at least not load up. But that was back in the days of carbs and no tuning other than timing and carb jetting.

 

ok.... just making sure we are on the same page.... I am wondering though if the computer and me having an automatic would compensate for some of that? I don't know, which is why I am bouncing ideas around before I commit to a course of action....

 

Here's my thought. If you want 400 RWHP you can rebuild your current engine and then supercharge it. (Your gaskets seals etc. won't stand a supercharger without rebuilding). Or, you can buy or rebuild yours as a stroker.

Option 2 is much less expensive with less down time. I vote for a 383 stroker with your heads ported and a strong but streetable cam. If you have an auto you will need a heavier stall. You should also do LT headers at the same time. A well built short block by a reputable builder would be a great starting point.

 

Stroker power vs Blower power......the eternal question.

IMHO, a good engine builder is fairly easy to find. And building a good engine (even a stroker) is very easy for the good builder. So, the reliability factor, even in a performance build, can be very high. And when something does go wrong, a good mechanic can sort things out fairly easily.

On the other hand, I've seen blower engines fail quite early in life.....say after 30 to 40K miles, due to problems with the blower and how it's used/tuned/etc. Even blowers from 'reputable' companies have had problems. And once installed, who can you turn to, to sort things out.....a local mechanic (maybe?), a local tuner (perhaps?), the dealer or manufacturer (yeah.....right!)?

With any application, reliability is built into the product. A stroker is almost always more reliable than a blower......whether the blower is on a stock(ish) engine......or a built engine.

This is, IMHO and in my experience.

BTW.....my 415 RWHP/450 RWTQ 396ci LT1 (Impala SS) just rolled over 105K miles last month......and for six of the 10 years I had the engine, it was a daily driver !

FWIW......

KW

 

thanks KW for weighing in.... my concern with a supercharger is exactly that, who will work on it and how long will it last....