NA 454 or turbocharged 355

[terror396]

hello all

which is better for driving in sand and dune climbing ( no mud / no rocks )

I have a LT1 shortblock with standard bore and I can buy the intake manifold + all other stuff really cheap
I will add forged rods + low compression pistons + a t70 turbo + it will be controlled by megasquirt + ported stock heads + 2.02/1.6 valves + ported intake
it should make 550 - 650 rwhp
and it should start boosting at about 2500 rpm


the other choice is to buy a 454 but all 454 here are truck engines with small oval ( peanut ) heads << I don't have money for bbc aftermarket heads
I will also use EFI on the 454 because I want to get better milage


I want to use as much stock parts as possible

thanks

 

[DavidB]

LT1 = RPM required for sand...454 = grunt for crawling, etc. Sounds like you can do the LT1 cheaper/easier too. The foh-fiddy-foh would make more power in a built-to-the hilt comparo, but that's prolly not what yer lookin' at right?

PS what are you puttin' it in? If it's a heavy vehicle you might should to the 454.

 

[LongIslander26]

Lt1

Fer Sure, RPM's are what you need for the sand, so the turbo'd motor would be the way to go.

 

[no1uknow]

I agree about the RPM's.............

 

[sled_dog]

well the only stock stuff you would have left on the LT1 would be the crank and block. And I can't say I'd be keen on running 600 turbocharged HP through a stock cast crank... You are probably gonna spend twice as much on the LT1 getting it good to go as you would with the big block, but you won't make the RPMs with the big block. Why turbo? I mean, you could make 450HP out of an NA small block much cheaper and more reliably. Would require far less tuning too. Also, LT1s with OptiSpark and any form of dusty dirty conditions, don't mix. So you would need to conver to an aftermarket crank trigger setup or new intake and put a distributor on it.

 

[terror396]

PS what are you puttin' it in? If it's a heavy vehicle you might should to the 454.

a blazer

 

[terror396]

well the only stock stuff you would have left on the LT1 would be the crank and block

the stock parts that I will use are
the block + heads + intake + fuel rails + throttle body + crank

And I can't say I'd be keen on running 600 turbocharged HP through a stock cast crank...

some guys are making 500-700 hp on nitrous and still using the stock crank
and the turbo is easier on the crank than Nitrous or superchargers

Why turbo? I mean, you could make 450HP out of an NA small block much cheaper and more reliably. Would require far less tuning too. .

I am thinking also in doing a 383 LT1
it'll be more reliable than the turbo but has less in the fun factor

Also, LT1s with OptiSpark and any form of dusty dirty conditions, don't mix. So you would need to conver to an aftermarket crank trigger setup or new intake and put a distributor on it.

I can drill the intake for rear distributor ( same as sbc ) or I can do furd EDIS setup

 

[DavidB]

Kinda figgered that...i'm no engine guru...you should prolly get some more info from some guys who are. my brother has a pretty mean k10 with a 305 that's stock except for the intake i ...he pretty much goes wherever he wants. my jeep had an inline 6, 100 hp 230 lb/ft. we both had lockers f/r. mine would go anywhere but big dunes. like i said the 454 might actually be better for your heavier blazer. i've heard it said that there's no replacement for displacement. i figger that's true unless you're running something light at high speed...then it's HP. most blazers aren't exactly light my brother's truck is pretty light. no bumpers, rollcage, just 1 ton axles.

 

[dirtwarrior17]

Sand is all about hp and floatation..... meaning lighter weight, big tires, and lots of hp. I don't see a reason to go bb unless were talkin drag racing or stump pulling. If you want to hit the sand dunes then the sb would be the better choice. But supercharge it and buy a better crank. I had a stock 350 that had a crank snap in half. my tranny was shifting hard at the time but otherwise there was no reason i should have broke a crank. why not spend 400 bucks now instead of 1000 later?

I say supercharge it because you don't have to wait for spool up and deal with sending oil to the turbo. superchargers make power as soon as you turn the motor on and will continue to kick a turboes ass all the way through the power band. It'll be snappier and have more low rpm grunt if you supercharge it. Or you could build a serious N/A mouse motor like sled dog said for the price of the turbo or supercharger.

Forced induction is a badass way to make power but its alot less reliable and more prone to wear than a n/a motor.

 

[blazinzuk]

Depending on what type of dunes you run and how you run them If you are a balls to the wall kind of guy go with the turbo on the small block you will be above 3000 rpm most of the time anyway but if you start and stop alot the big block would be a better choice. Out here our dunes are way steep so you have to keep going or you will have a hard time getting out.

 

[sled_dog]

Well, I don'[t want to start a Supercharger vs Turbo debate but here it goes. Maybe you build boost a little quicker, but once a turbo builds boost it will kick the crap out of a supercharger all day long. Also, many centrifugal supercharges need oiling plumbed too them as well. Thats the only kind of blower I would consider in this case. The number one enemy of force induction is, heat. I wouldn't run a Roots style blower on anything other then a hotrod or drag car. You get a lot of heat in the desert, and if all you are doing is continually heating up your blower(and air charge) you are losing power by the minute. GM High Performance recently put a blower on a new GTO. every dyno run they made and every pass down the track, it got slower and less powerful. Because the supercharger was getting hotter and hotter. The only way they even came close to fixing it was a 50 shot of nitrous just to act as a second intercooler(cause the first one did little to help it all). A good front mount intercooler will be a must for either situation here.

 

[CyberSniper]

Well, I don'[t want to start a Supercharger vs Turbo debate but here it goes. Maybe you build boost a little quicker, but once a turbo builds boost it will kick the crap out of a supercharger all day long. Also, many centrifugal supercharges need oiling plumbed too them as well. Thats the only kind of blower I would consider in this case. The number one enemy of force induction is, heat. I wouldn't run a Roots style blower on anything other then a hotrod or drag car. You get a lot of heat in the desert, and if all you are doing is continually heating up your blower(and air charge) you are losing power by the minute. GM High Performance recently put a blower on a new GTO. every dyno run they made and every pass down the track, it got slower and less powerful. Because the supercharger was getting hotter and hotter. The only way they even came close to fixing it was a 50 shot of nitrous just to act as a second intercooler(cause the first one did little to help it all). A good front mount intercooler will be a must for either situation here.

Actually, a Lysholm blower (twin screw, Whipple, et cetera) is as efficient as a turbocharger but starts building boost when you want it.

That being said, a bigblock has no business in the sand unless you're pushing 100hp/liter and is built for 7500-8000rpm abuse.

The LT1 will nickle and dime you do death in a high horsepower high rpm application. You're better off starting with a neused LS1... plus the LS1 is 125lbs lighter.

 

[dirtwarrior17]

used ls1 will be cheaper? pretty much every piece made on that motor will cost you 2x's more than the lt1....not to mention the turbo or supercharger kits(cheapest one i've seen is 5 grand).

You are probably gonna spend twice as much on the LT1 getting it good to go as you would with the big block, but you won't make the RPMs with the big block.

On what? Hes putting a megasquirt system on it.

 

[sled_dog]

used ls1 will be cheaper? not to mention the turbo or supercharger kits(cheapest one i've seen is 5 grand).

How you figure? STS turbo kits for Gen III engines don't go ABOVE $3800. http://www.ststurbo.com/products

Here is a used LS1 blower setup, cheap Magnacharger

I just don't see what the point of using a Gen II motor is AT ALL. The heads maybe? You can adapt those to older engines. I mean, you will remove the timing system(which for its flaws is still more accurate then the distributor VRS setup)? You will remove its fuel injection(only to replace it with some aftermarket setup you likely can't buy parts for at the parts store)? And you will spend more money building it? Why? I don't particularly see any reason. If it were me, I'd build and Gen III or a Gen I motor. Either is a better option IMO. LS1s are lightweight, high tech, and powerful, and Gen Is have SO many options.

 

[CyberSniper]

used ls1 will be cheaper? pretty much every piece made on that motor will cost you 2x's more than the lt1....not to mention the turbo or supercharger kits(cheapest one i've seen is 5 grand).



On what? Hes putting a megasquirt system on it.

A neused LS1 goes for about 3k with computer. By the time you get the megasquirt 3 built, splayed caps bought and block milled, intake machined, forged non-twist crank, et cetera you can have a block that makes 400hp with a cam swap that weighs 125lbs less on a heavy day.

Not even an ATI ProCharger (best centrifigul) or a Whipple (best lysholm/twin-screw) costs $5k. I'd rather have either of those in the sand than a turbo anyway... you can wrap a supercharged engine's exhaust and keep a lot of the heat out of the engine compartment and focus on oil/water cooling.

 

[dirtwarrior17]

But your getting a used motor......... build it up from the crank and the cost changes... you don't know if they wrecked it, ran it out of oil, didn't change the oil, etc. IMHO the ls1 will cost him more... it may not be soon but it will in the end. A used motor is a sketchy way to go whether its dune runnin or dd.

with tax and shipping its over 5k or damn close.... there is about a 1200 dollar difference between the ls1 supercharger kits and the lt1 kits.

If he goes with forced induction the ls1 will cost more...

For 3k he could have zz4 shortblock(forged crank, 4bolt main) with dart heads. Another 1300 and he has Fuel injection. your talkin about 400+ hp 450 ft lb tq with fuel injection for 4300 bucks and its all brand new. Last time i checked gm wanted 6k for a new ls1 and it comes with 320 hp and 345 ft lbs. you save 125 pounds but you pay 1700 bucks for it and your down 80+ hp and 100+ ft lbs.

It's a toss up with a used motor.... it could last or it could blow up 1 mile after you drop it in. I would sell the lt1 and build a first gen if it were me.