540 or supercharge ths 454?
 

Ive got a 454mag w 350hrs and want a lot more out of it. Money is definately an issue. Reliability and fuel economy are important too. That all said, what is the best route for me?

There's no replacement for displacement, but building a 540 the right way will probably cost more than putting a SC on a 454. That being said, your 454 Mag will not have inconel exhaust valves, and that is pretty much a requirement for a reliable SC engine. At 350 hours, you are probably looking at a refresh to run the SC. A 540 might be the best way to go.

put some fresh valvesprings in it, bolt on a blower, and enjoy! To get similar power and torque from a 540 N/A, you'll need good heads, decent cam, new intake/carb, etc. Money wise, best bet in my opinion, do the blower. You'll be pleasantly surprised.

I had a buddy install a pair of whipples on 454 mags years ago. Engines had about 300 hours on them at the time. Ran great after the blower install for a long time.

If you go the blower route, which will work good, you definitely need to change the head gaskets to felpro or cometic. You will either by choice or at an inoportune time need to change them, and that's if it doesn't create other issues when it blows the stock head gaskets.

Reliability and fuel economy?

Seriously?

A 540 NA will likely give you a little better fuel economy since it isn't spinning the parasitic drag of a blower.
A 540 NA will likely give you better reliability if you run a mild cam and light valvesprings.

So the question is, what power are you seeking? If you want reliability and big power, you may be looking at a supercharger on a 540.

All of the combinations mentioned will give you the ability to produce a lot of power. Reliability, though, assumes milder cam profiles and easier work for the valvetrain. Most bigblock problems come from exhaust reversion, valvespring failure, lifter failure, detonation, and lean fuel mixture. Compression and boost lean towards detonation. Cam profiles and valvespring rates lean towards valvetrain problems.

You want to make big power on a budget, bolt on a blower and fool your motor into thinking it's bigger.

You want reliability? The devil is in the details...

MC

Also you might think about the pistons in the 454 I believe they are cast not forged and will need to be changed for the boost. They may not last long. Corrrect me if im wrong. Just my thought.

Since its a 454 "MAG" it will already have forged pistons

I have SC 502's, and I can tell you. About every 10 hours, you need to change the oil. The blower pushes gas past the rings and you get gas in your oil. Go with the 540. They make bigger blocks than a 540. You can get a 800hp engine that is not supercharged now days, but it will be bigger than a 540.

how much bost are you running on that motor? i have been kicking around the idea of a super charger for awhile now also. i have a 454 block that i was going to turn into a 496 and now i have been thinking i should go 540 instead but ta 496 with a low boost supercharger seems appealing.

540>454sc
There is no contest that the N/A motor is going to give you more reliability and the mpg is going to be similar. I think a supercharged 454 APPEARS cheaper because you aren't thinking of the little things. Cometic head gaskets, she'll need rings if not pistons, head rebuilds with at least better springs and really should have valves as well. Fuel pump, gauges, and a few other odds and ends. Now tally up selling your 454 and bolting in a 540, I bet the final cost is pretty similar

That is what I was thinking. What should I look to get out of a 454 mag with 400 hrs (or maybe more hrs by time I pull it)

Also...sell it as is or freshen it up then sell?

Not sure I can agree with ya on that. There really isnt a need to replace rings, pistons, valves, on a 454 mag with relatively low hours, just because your bolting a supercharger on. Heck, most engines that have superchargers sitting on top, were bolt ons.

To build a 540CI running engine from scratch, youll probably need somewhere around 15k by the time its fully dressed, and ready to bolt in and run. Esp if you sell your 454 mag and need accessories.

You've got a good point. I was saying replace valves, springs, and pistons from a reliability standpoint. I missed that it was a 454Mag

I would do a 454, you could bolt that blower on and rebuild the engine 2-3 times over just in the cost of buying one 540.

Buy a used blower kit that is like new off E-bay for around 1800-2500$ (I see them all the time) and next year when you want even more speed you can turn up the boost/hp more by simply changing top pulley, Smitty

i am pondering the same ideas mentioned here, either big cubes or supercharger. if a supercharger is kept at say 5 pounds on a relativiely well built motor such as a 454 mag, how long is it going to last? i have a 454 that i was going to do a 496 stroker kit on, forged crank, forged pistons, H beam rods, full roller and then possibly add a supercharger later on as my budget allows. i was thinking about scraping the 496 and going to the 540 but the cost goes up to the point that the supercharger would be more cost effective. not trying to thread jack sorry if i am

Take it from me. I have almost twice as much into 2 sets of heads, intakes and carbs on my 454's than I do in my 2 B&M 250 blower setups that I just bought. Granted I have custom ported heads and intakes, the best in valves, and springs. This setup on my 454's are 600HP on a 540 it dyno'd @ 783HP with a dual carb tunnel ram setup. If I had to spend my money again I would first buy the blowers and then do the heads and then cubic inches/or bigger blower.

Get the blower! It will be 1/4 the cost.

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