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I'm thinking about going ahead and building 1 of my 454's my goal is to get at least 500hp out of it.Question is, does anyone out there have any combonations or recipes to achieve this.I want this motor to be street friendly.I'm putting this motor in my 72 chevelle.
500 is alot to ask for on pump gas r u on a fixed budget?
Aye, 500 hp may be a lot to ask for from a 350 on pump gas, but a 454 should handle it no problem. We're only talking 1.1 hp per cu in. It would require 1.43 hp per cu in to make 500 hp from a 350. You could always get a 496 crank out of one of the late model 8.1 engines, toss it in your block, and then you would need only 1 hp per cu in and that is a very reasonable power output on pump gas. With 496 cu ins, your engine is very close to GM's 502 and I would just copy the 502. You may be able to throw in a bigger cam and increase the compression ratio over the GM setup to make around 550hp on pump gas.
look into a edelbrock performer rpm kit, even with a stock crank, 30 over flat top pistons, and a 750 holley with that kit will get you at 500 or better, plus it would be very streetable, that would be at the crank, not tires...
Do a google search on: 500 HP 454 and you'll find a bunch of info.
It's not hard to get 500 crank HP from a 454 on pump gas. If you're willing to use 92/93 octane, it's even easier.
BlownGoat on here was helping me decide on what to use when I build my 454 and he was telling me to use Eagle crank and rods and JE pistons with around 11:1 compresson. I plan to run my engine on pump gas and then raise the octane level when at the strip a bit for better performance because my 48 will be on the street at local hot rod meets, local cruises, etc not JUST the strip. Oh and when me and BlownGoat were talking about the power on the 454 we were talking around 600-650 so 500 will be good with Eagle crank and rods and JE pistons. Not sure about the original crank if it checks out right since I have little experience with high performance engines and still learning, I am just telling you what I have learned so far from members on the boards.
500 HP is easy with a 454 on pump gas...shoot for about 9.5/1 C/R, good oval port heads, stock valve size is OK, dual plane intake, 750 carb (3310 holley is fine) hyd.cam with about 230 degrees dur. at .050 and mid .500 lift and you're there....cast crank is fine, no need to go with forged, and 2 bolt block is all you need. I personally would stay away from Eagle products....they're imported, which in itself isnt necessarily bad, but their quality control is poor...lot of variations in their measurements. Scat is a much better product, still from China, but quality control and machining is done here in US. And FMXhellraiser, no offense, but there is no way you're going to run 11/1 with pump gas!
Alright, well like I said that is what I was talking to BlownGoat about. Maybe he said 10:1 without pump gas, but pretty sure we were on the same page at the time of the convo. I am not saying I am going with 10:1 or nothing. I just ordered about 4 big block chevy books and they are supposed to help tons. I haven't gotten to reading them yet since I am finishing reading some other books on chassis and metal forming.
Ok I meant to say 10. not 11 I just saw that. Sorry.
OK, that's better!! 10/1 is doable, just be careful with ignition timing and check for detonation. You pretty much have to run the best gas you can get at the pump with 10/1, 92 at least and 93 if you can get it.
There is a place a few miles from here that sells 93. It has something a bit higher (can't remember) also that I used to use when I would race dirt bikes. Like I said, I don't know what I will put in it for sure. I still need to read the books, save the money and get more info from others on it. So the more I am wrong and you guys correct me then that will save me the trouble down the road.
10.5:1 compression is possible in a 468 with iron heads on 89 octane, I've driven a car that did it. That's California 89, too. Fuel injection and a computer that can control timing to do it.
Yes, you can retard timing to prevent detonation, but then you're losing much of the power that you could have if the timing was run at higher level...you can run a bigger duration cam too, to bleed off some C/R, but same results...either way, you end up with an engine that's a slug compared with the way it should be running.
invest in a good set of heads with port work
It was no slug, it made 310 whp and over 600ft lbs of torque just off idle to 4800 rpm.
O.K fellows I appreciate all the info and hope you keep it coming. I built a few 454's but I don't think any of them ever reached near the 500 mark,I had 1 perticular one in a 71 sb chevy truck with 350th drove on the street every day.the track we have here is an 1/8 mi. and the best time I ever turned with this truck was 8.40, I don't know that is in 1/4mi times,but this truck was no slug. This 72 chevelle I have now has the same gears as the truck and is probably about 1500ibs lighter I would like to turn at least low to mid 7's in the 1/8 with this car if that helps any. thanks, WJR
11:1 is possible to run pump gas with.
It is? I don't know anymore, some people say yeah, others say no.
It is all in the cam you can run a cam with a lot of duration that is ground on the correct lobe center and it will bleed off compression!
But then wouldn't it be pointless in a way to have that much compression? Say you wan't 11:1 and then you get a cam that will let some of that compression out, then that is pointless I am thinking. I am not saying I am right here, I am just basically asking I guess you can call it.
One of the primary reasons for bumping up compression ratios is for that very reason, big cams bleed off cylinder pressure. High compression ratios are more for compensation than they are for power in high rpm engines. The other reason is for better efficiency. Torque is directly related to cylinder pressure and hp is a relation between torque and rpm. If we take a torque cam, they actually develop a higher mean effective pressure than a cam that makes a lot of hp, but they torque cam cannot flow enough air into the cylinders at high rpms to make enough pressure to make any power in those rpms. That's where the big cams with tight seperation angles come in. They can flow more than the torque cams at high rpms, but their mean effective pressures are still lower therefore torque is lower. They do make more hp, though, because the engine is spinning faster.
FMXhellraiser, you've got it right....no way are you going to run true 11/1 CR on pump gas. And you right about what you're thinking, if you bleed off compression with a big duration cam, or retart timing to avoid pinging, then you've lost all that you're trying to build. Shorter duration cams, as well as a closer LSA, close the intake valve earlier, keeping more cylinder pressure in the engine....more power! But at the same time, more chance of detonation. It's a trade off, you cant have both...either you want a race engine, and it wont be very responsive at street RPMs, or you build a street engine that's a killer from idle to maybe 5K RPMs. You have to look at dynamic compression ratio, not static C/R....get a good book on big block chevy's and read up on it. I have a dynamic CR calculator if you're interested. You need rod length, cam specs, piston volume, all the details. But dynamic CR is what the engine sees, and that's what's gonna work with your combo, or destroy it.
Johnny, thanks for that info. By the way, I have about 3 or 4 of the Chevy Big Block books and haven't read them yet since I ordered about 10 books right now and reading 5 books for school so no time right now. As soon as spring break hits here I am going to be reading them up like hell. I hear they help a lot and will help me save money when building them too. I am going to try and find a block at the Food Lion Auto Fair at Lowes Motor Speedway here. Is there anything I should look for before I buy besides cracks in the block? I need to find a club around here to join so that way I can get help that way but most of the clubs here are just old guys that hang out on Wednesday nights for an hour or two and then leave and nothing else. I am sure there has to be something here in this city since it's the biggest on in NC.
Well said! I didn't say it wasteh best way to go just that it could be done! 76GMC is correct!Quote:
Originally posted by 76GMC1500
One of the primary reasons for bumping up compression ratios is for that very reason, big cams bleed off cylinder pressure. High compression ratios are more for compensation than they are for power in high rpm engines. The other reason is for better efficiency. Torque is directly related to cylinder pressure and hp is a relation between torque and rpm. If we take a torque cam, they actually develop a higher mean effective pressure than a cam that makes a lot of hp, but they torque cam cannot flow enough air into the cylinders at high rpms to make enough pressure to make any power in those rpms. That's where the big cams with tight seperation angles come in. They can flow more than the torque cams at high rpms, but their mean effective pressures are still lower therefore torque is lower. They do make more hp, though, because the engine is spinning faster.