454 to 540 ?
 

Simple question , can a 454ci 4 bolt block go up to a 540ci ?

No.

Simple answer

You can increase the stroke to 4.5" and bore it .100" over to get a 535" engine, or bore it .125" to get a 541".

This is assuming you sonic test it and probably use some block filler. Regardless, the rod angle gets a little dicey for an engine running continuous high rpm.

There are other combinations using 4.25" and 4.375" stroke that reduce the rod angle a little and also reduce piston protrusion at BDC. Reliability is more important than a few cubes. One of the most popular engines we build is a 454 bored and stroked to a 496. We just pulled one off the dyno last week that made 624# of torque and 627Hp. All done by 5800 rpm.

Which one you perfare a 540 or 496 ? I mean if you were buliding a motor for your self , you bulid a 540 or a496 ?

Going for reliability, geometry and easily available aftermarket kits dictate build a 496.

So why alot of people around there always do a 540 if the 496 is better .i am New in this boat stuff and getting confused

People use a 502 block to build a 540, 496 is the normal max for a 454 block.

Guys who already have a 502 can simply bore to 4.5" (from 4.466") because the block is thicker (siamesed), and add 1/4" to the stroke to make a 540".

With a 454, you can still go to the 4.25" stroke and have the same rod ratio (1.5 with a 6.385" rod), but you are limited on bore size.

I think, personally, the 496" is an excellent combination, with .250" longer rods. Sure, the 540 will make 45 more HP by the extra cubic inches, but if using the block you have is what is in the plan, it is what it is.

We probably build more 496" engines for street/strip and marine because of the economic factor. Guys already have the blocks, and usually heads too.

Another factor is your drive. Jumping up to 625# of torque is usually the outer limits of most drives that are on production boats.

I have a 496" build on my Facebook page if you want to check it out. PM for my page info.

Yes. A 540 is a 4.25 stroke on a 4.500 bore (.030 over 502 block). A 496 is a 4.25 stroke, on a 4.310 bore (.060 over 454).

A 540 is a great place to go IF you already have a 502, which alot of boats do. You have a 454 block, so installing a 4.25 stroker kit is a great place to go.

BUT, I dont think every 454 needs to go there. If you can only afford either a new rotating assembly, or a new pair of cylinder heads/cam setup, I'd opt for a good set of cylinder heads, good cam combo, on a 454, over a 496 with $hitty heads, and a flat tappet cam. You can make decent power with todays parts off a 454/468 build. I would keep the bore at a minimum, so you have room to rebore down the road. The gain by going from a 4.250 bore to a 4.310 is minimal. I'd rather have the extra meat in the cylinder walls.

you would need a bowtie tall deck to get anywhere a 540cid engine in a 454 block..not enough safe meat in the cylinder walls on a gm 454 tall deck.....with a set of daty ovals and a special grind i have you can get 600 ponys out of your 454 in a 489 configuration..

I guess I didn't directly answer this. Personally, I would go with a Dart Pro series block and do a 540. I run these blocks as well as aluminum in my drag car at 567" and 580" respectively. I wouldn't bore the thing to 4.6" like a race car though. I like a little meat between the cylinders on marine engines.

In any case, we sonic test every block, in 12 places on each cylinder, before determining a safe over bore size. Don't accept any "generalizations" on wall thickness and which blocks are better than others. Insist on sonic test data, including the calibrated sound velocity value for your particular block.

After splitting a cylinder wall once on a 468, I would absolutely agree with the above ^^^^^^^

A little block filler goes a long way too. Remember, the fill amount and cylinder flex reduction are not a linear equation. If you fill a block 25%, it may reduce flex by 35%...it's exponential to a certain point.

I had a customer with stock 502 blocks at 528" making 800+ each with pro chargers. The blocks were half filled. It is still in service after 10+ years. (With routine freshening, of course)

The top class in offshore racing for many years had a cubic inch limit of .....Two engines no more than 1,000 cubic inches. Almost everyone one of our boats had two 496 motors......just like the one in my avatar here.

What is this motor going in?? A 468 with some good heads is a great Low Budget motor for single engine applications with a Bravo drive. we raced a 26' Corsa with a 468 and a Bravo drive and ran mid 80's mph. I wouldn't spin it much past 5500 rpm for too long unless you spend the cash for a good rotating assy. If you cant get the Cubes you want then Heads are the Key. There is a difference of about 200 hp from the crappy heads to the semi expensive good ones... Lots of good info in this thread....

Matching the head to the cubic inch and rpm is paramount. We have build combinations that made over 700hp with a GM 781/049 oval port head. You have to be careful not to fall into the "bigger is better" trap, just because the price is the same.
A properly prepped 270cc intake runner head will outperform a 310cc Brodix on a 468 on HP and TQ. In addition, the BSFC will be lower, netting better economy. It's all about air speed, atomization and cylinder filling.

Camshaft is also very important. There are a few key considerations.
1. Intake events and valve lift, in relation to piston speed ATDC. At 70°-75° Of crankshaft rotation, this is when the piston is moving the fastest. You need to match this to events at the valve when the port is able to flow very strong. Remember, engines do not make vacuum, per-say, on the intake stroke, they just try to equalize the pressure differential between the cylinder and the atmosphere outside the engine.

2. Intake valve closing events. This is dependent on airspeed and will dictate cylinder filling ABDC. Close the valve too soon and you lose intake charge. Close it too late and you will back charge up the intake tract. Late closing is also responsible for low cylinder pressure.

3, Exhaust opening events. If you open the exhaust too soon BBDC, you will blow off some of the pressure meant to push the crank down on the power stroke. This in turn leads to pumping losses on the exhaust stroke.

4. Obviously, lift comes into play with the cylinder head data as well. Lobe centerlines and duration almost fall into place when calculating the timing events that are required for each engine.

Engine design is very fun to do. I've been fortunate enough to do this as a living for close to 30 years now, and over 25 with my own business. Each engine is a challenge as well as a job. I would not do it if I didn't enjoy it.

I suggest anyone getting an engine built to learn as much as they can and be involved as much as possible with the build. It's very rewarding.

Yeah, Yeah, And then you gotta try to Not Suck water back up the pipes?
Like I said before, some good info in this thread....

With only 6 posts......where the heck have you been hiding for 3 years? Nice posts!

+1

LOL - Took the words I was thinking while reading that.

"Who in the F is this dude and where the F did HE come from?!" Rev Ronnie will get along great around here. Way to kick it off on OSO bro! Nice!

You sound like a man that understands the science behind the horsepower , nice post .

Thanks guys, I appreciate it. I've been on here for a while, just mostly reading and such. I'm actually an outboard guy myself and I spend some time on S&F.
Unfortunately, that place has gone a little haywire lately with a guy getting a sex change and some real poor work by supporting vendors that they won't let go of.

I do a lot of work for marine shops up here and a few individuals as well. I'm thinking of getting into a larger boat again for river duty so I like the action over here. There is a lot of real world knowledge.

Where can i contact you rev.ronnie so we talk , i need an engine

This is a 498" oval port engine we dynoed a few weeks ago.
Hyd. Roller, pump gas.
The broad torque curve really makes for strong mid range and good fuel economy.

[ATTACH=CONFIG]522169[/ATTACH]

Just for fun, here is one we dynoed last weekend. It's a pump gas, 605" street Hemi. Again, big torque and exllent BSFC numbers. This is going in a car, of course, but a real driver...AC, overdrive, real pro touring.

You will notice the distinct difference in the BSFC numbers (Brake specific fuel consumption). The first engine was run on pump premium, which contains nearly 20% ethanol around here in the winter. The fuel curve reflects that. It's not only rather rich, but it likes a higher fuel mixture at peak torque than at peak horsepower. Straight alcohol engines are like this to a higher lever. They vary .around 2 on the BSFC from peak TQ to peak hp.
Now look at the second engine. Straight non-Oxy fuel, 92 octane. Nice straight fuel curve.

This is why dyno tuning is so important. Getting a good timing sweep, fuel curve and keeping EGTs in check are the goal.

Ok, sorry to totally hihjack the OP's thread!!

Thanks for the hihjack !!!!! :coolcowboy: