Difference betwin 454?
 

hello guys, as some know, I have a 72 chevelle with a 454 from a 73 chevelle that develops about 250 HP ...
What I want to know is what is the difference between a 450-hp LS6 454 and mine?
And also how to increase a little the power of my 454? thank you Waving

I dont have any first hand comparisions between 454's. But I can tell you that differences in hp and tq numbers for the same displacement motors are do to different combos.
Cylinder head flow and combustion chamber designs. Piston design (flat top, dome, etc) Compression ratio and camshaft profiles all have a part in the total output of a engine.
I would guess that if your motor had the proper compression, good flowing heads and intake. And a cam that matched cylinder head flow. You could make just as much power as a LS6. JMHO

I have an Edelbrock performer pipe 2.0 and a holley 850 cfm carb, what could I put a tree like cams?

No comprenday

what cams can i use for this? sorry i'm french

You need to get a total package. Talk to a head porter and get there recomendations

Another thing to keep in mind is horse power ratings. In 1972 they rated gross horse power. That is, they measured the horsepower at the flywheel. Since you lose horsepower through the drive train, the numbers were misleading. In 1973, they switched to a net rating. They actually measured horsepower off the back wheels. This gave a much more realistic rating, albeit a depressing one. A 350 horse power car in 1972 was only rated at at say 290 in 1973 with no changes to the combination.

Primarily what changed was compression ratio dropped and cam profiles changed. GM opened up the combustion chambers and dropped lift and duration on the cam. Since a 454 bore and stroke remain constant, a new set of pistons, heads and cam will start pumping horse power like a big dog. None of this is easy, but it's definitely doable.

HELLO EVERYBODY,
could you help me to choose performance parts that can be put on my block?
What is the best solution for more power by keeping a reliable engine?
cylinder head rectangular port or oval, camshaft, and I confess that I would like to put a blower but I do not know if my original engine can handle ...
thank you

Hi, I think you need to not duplicate an LS6 but rather build the engine you already have for more power. I think an LS5 would be easier to duplicate with what you have if you are trying to clone an engine. The LS6 came with a 3963512 casting block with 4 bolt mains, Forged Nitrided steel crankshaft, 7/16 HD connecting rods 11.25:1 compression TRW forged pistons, and there were a few different casting numbers for cylinder heads but the 3964291's were the most popular if I remember correctly. I think they were Rectangular port closed chamber heads and the engine used a solid lifter camshaft combo.

Your 1973 454 is most likely a 2 bolt main 361959 block with cast crank, 3/8 rods, flat top or dished pistons, and smaller oval port heads. There is no reason you can't build up what you have into something fun that makes plenty of power on pump gas. There are many magazine articles in archives online if you did a google search on a good pump-gas 454 build. The engine will make good torque with your original heads if you did a valve job and changed out the pistons for a little more compression. There are hydraulic camshafts that are far better than anything that was made in the 6o's and early 70's. You can find something with a good amount of lift and duration, maybe even a dual pattern camshaft. You can get coated pistons and low friction rings, keep the 3/8 rods and have them machined with quality bolts and stud the main caps. A properly balanced rotating assembly will give years of reliable service.
The best place to start is pull your valve covers and see what the casting numbers are on the heads. If they are decent heads, rebuild them and run them. If they aren't so desirable you could step up to a set of aftermarket heads. The secret to big block and any internal combustion engine really is to be able to move air and fuel in and out as efficiently as possible. For a street engine larger oval port heads will provide good low end torque which most people don't realize is more important than horsepower. Sorry if this was a little long but I wanted to help you understand what you have and what you could build with what you already have without spending way too much money. I hope this helps you out

Thank you for the explanation, now I know I need to watch and I hope you will soon present to guide me if I have other problems because you look good to know my engine I'm a little frenchie who does not know too the operation of the big block .... (at home more often you drive with 1.4 liter or 1.8litres engine of 90 to 150 horsepower ... lol

Doesn't matter where you are "frenchie". These guys know there stuff and it sounds like you are on your way to the motor and hp that you are looking for.

Don't rule out the possibility of getting a "crate "engine. There is many choices of different power applications and price ranges also that can save time and headache of building an engine, especially if one is somewhat novice in mechanical ability ....I get a personal satisfaction from building my own, but there are times you wish it was as easy as hitting the "enter " key to purchase one! !

I think the change was to measure HP with standard accessories attached, still at the flywheel. Standard accessories being alternator, exhaust manifolds, etc. Prior to that HP was measured off a basically bare engine. I may be wrong though, that's just what I recall.

GDwrench does have a good point. You could drop in a 454 HO or the ZZ454 and it is basically a modern version of what they would have come with. The best part is with HEI ignition and a hydraulic roller camshaft you won't have to do much in the line of maintenance also. It may be worth it.
http://paceperformance.com/i-6255291...te-engine.html
http://paceperformance.com/i-6255351...te-engine.html

Right or wrong that's the direction I went when I replaced the 396 in our Chevelle. I opted for the 454 HO, there is a Chevy dealer, Rinke Chevrolet, that is one of the biggest sellers of Chevy crate engines anywhere. They have them stacked up in rows. Anyway they offered the best price so I picked one up. A 502 would have been nice but I wanted to stay with a mechanical fuel pump. I also needed the threaded boss for the 4 spd clutch Z-bar. Is it the best engine for the price? I don't know but it's a roller cam so no worries about wiping a cam because of low ZDDP levels. Had some oil burning issues, replaced the intake manifold gasket twice and pretty much cleaned that up.

Comes with essentially an Edlebrock RPM intake. Has the Chevy bowtie cast in it but looks identical to the RPM performer I had on the 396. Comes with flexplate, I had to replace that with a flywheel. Does not come with ignition, carb or other accessories but valve covers and all the other accessories from the 396 bolted right on. It does come with valve covers but I wanted to use the old chrome ones off the 396. I can't say it's the best engine available for the money but it runs on pump gas, has torque (500 ft lbs) that won't quit and runs good and strong. What's really nice is the torque starts right out of the gate and just continues through the RPM range.

There are other engines available for the same or less so you need to weigh all the factors. Just saying that it is an option and not necessarily a bad one.

Hello everyone and thanks for your response, i have a question, what did you think of my engine soud? I think it isn't normal (air noise at the valve cover breather cap) pchiiiitt
http://www.youtube.com/watch?v=jUV1D...eature=related
http://www.youtube.com/watch?v=rhB-U...eature=related

Hey guys, I have good news I think ... I just disassemble my rocker cover and I find probe industries 1.7 rockers :drunk: and the number on my cylinder head is 353045. Do you think this is a good thing?

Could that be 353049? That would be the original heads for that engine. If there are machine shops around you that work on those engines you could have larger valves installed, 2.19" intake, 1.88" exhaust versus the original 2.06" intake and 1.72" exhaust and have the combustion champers cleaned up. Those oval port heads will work well if the rest of the combination matches. You don't need rectangular port heads. Install a performance cam, moderate, nothing to radical. You can have the heads milled down or the block decked to increase compression but that isn't necessarily required. You can get over 400hp out of 8.5 to 9.0 compression if the rest of the parts match up. You also need to think about what octane rating gas is available there in France. I don't know but I suspect it's pretty low so you might not want a high compression engine. Put on an set of headers if you don't already have them. That's the best improvement for the price that you can make for that engine.

Have the ignition timing checked and see if you can get it up to around 16 to 18 degrees initial advance, that's after the other things are done. Big block Chevy engines like a lot of advance in the timing. You may also want to consider a little smaller carb. A 750 or 770 CFM carb with vacuum secondaries would work well on that engine. The 850 will work but it's more than your engine needs. Unless you have a ready supply of cheap gas, I doubt it, a smaller carb will work fine. Bigger isn't always better.

Not sure how easy it is to get all those things done in France. Here it's no problem at all. If you can't find an engine shop that knows something about Chevy big block engines, the crate engine as mentioned may be a better option since all the work will already be done. I know shipping and import taxes may be a lot. You have to weigh the 2 options, build your engine or buy a crate engine, and decide which is the best based on where you're located.

thank you for your answers fast and accurate, but my heads are numbered 353045 cons I'm afraid my bridge bolt 10 does not take the shock ... What can I put as a bridge (adaptable)


in terms of gas here is 1.55 euros per liter approximately 2.10 dollars ...:butt1:

Sorry, can't find the 353045 casting number. 353049 are common and a decent head to work with. Can you ask the question again, I don't understand.

$2.10 per liter, around $8 a U.S. gallon, that's pretty expensive. Do they have different grades of gasoline there, different octane ratings. Do you know what the octane rating is?

Hello, I want to know if the 10 bolt rear end is strong enough, I'm afraid he breaks ....

We have gasoline with 95 octane and 98 octane ...

Hello, a friend want to give a 94 camaro Z28 rear end, can i put this on my chevelle or is it to big?

But remember the octane ratings in Europe are different then they are stateside. I BELIEVE Euro 95 is equilavelent to US 93. It's been a few months since I've seen a pump so just guessing here. I'll email on of my buddies back in Germany and ask him to write it down next time he goes for a fill up.