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angelf0926 03-25-2013 12:43 AM

chevy 454 hp??
 
Hey guys so as I stated a while ago I bought a 454 from a friend for $400..ran awesome before we pulled it out of his truck..he sold it since he doesn't have his truck anymore..everything was stock...3999289 block with 781 heads..I know this engine has great potential...I want to get 400hp out of it MAX...I have heddman headers, eddy 750 cfm carb, eddy torker intake..now since I'm sure this engine is stock...what would b my HP numbers if I were to add these accessories and without tearing the engine apart?? What about the compression ratio?? Car is only for weekends/street?? What do u think? Suggestions are also welcomed :)

bigdog7373 03-25-2013 01:35 PM

can't tell you anything unless you get the cam specs and compression ratio.

angelf0926 03-25-2013 06:12 PM

Not sure about cam...I'm sure all specs are stock from factory...including pistons and cam..I would just like to know if these accessories will still enable the engine to make good power..I might even consider just rebuilding it stock to raise compression to 9:1 and perhaps the biggest cam tht will fit..

bigdog7373 03-25-2013 06:21 PM

Quote:

Originally Posted by angelf0926 (Post 1660353)
Not sure about cam...I'm sure all specs are stock from factory...including pistons and cam..I would just like to know if these accessories will still enable the engine to make good power..I might even consider just rebuilding it stock to raise compression to 9:1 and perhaps the biggest cam tht will fit..

Is that block casting number from the back of the block where the trans bolts up or from the front?
I'm trying to look it up but I'm not really getting much info.

angelf0926 03-25-2013 10:44 PM

Yes its from the back of the block where the tranny bolts up..believe its a 73-78 block...not 100% sure...

bigdog7373 03-25-2013 10:49 PM

All i can find is that it's a replacement smogger engine. Most likely mid to late 70's. Low hp, low compression, cam so small it might as well be round. You'll have a hard time making 400 horse with it as is. A simple cam swap with a good intake and exhaust will get you there or very close. Maybe a little head work too.
Not saying it's a bad motor at all, it's a good starting point for a build actually.

angelf0926 03-26-2013 01:30 AM

So what are your suggestions?? Rebuild short block stock..get compression up with domed pistons, some work on the heads..bigger cam, throw in my carb, intake and headers and I should b good to go

bigdog7373 03-26-2013 08:54 AM

What do you want to do with the car? Its not hard to get 400hp from a 454. You shouldn't even have to touch the short block, unless you want to throw some new bearings in there. Just get the heads milled with a port and polish. You want compression around 9:1. Then just a good cam intake and carb and you're set

angelf0926 03-26-2013 12:28 PM

Just want the car to cruise...have fun here and there..don't want the engine to sound like a beast and have no power u get me.. In order to install a new cam..the block would have to be turn down right?? Sorry for the dumb question I'm a newbie still..

bigdog7373 03-26-2013 02:49 PM

Nope just pull the old one out and put the new one in.

techinspector1 03-26-2013 05:15 PM

Street motor 454
 
Assuming these heads have the stock valve sizes, 2.06"/1.72", they won't be a candidate for high hp. You don't want high hp anyway, not in a tractable street motor. You want high torque, so let's build a torque motor that will put a grin on your face.

Check main bearing bore for roundness and parallelism of all holes. Align-hone or align-bore the main bearing bore to correct mis-alignment or out-of-round.
Indexing off main bearing bore, cut block decks to 9.790" block deck height. Bore cylinders to 4.310" for these pistons....
KB Pistons for Automotive Applications
Assuming that your heads are ~119cc (you'll never know for sure until you cc them, but we'll assume 119 for this exercise). Using a head gasket of ~0.040" will put the squish at ~0.050", right where I'd want to be with a BB. Static compression ratio will be 9.10:1 and dynamic compression ratio will be 8.46:1, just right for crappy pump gas.

You MUST match the cam to the static compression ratio, so I would use any of these in this build. Choose one.
CompCams 11-203-3
Crane 103052
Engle 2212H
Iskenderian 396256
Lunati 10110101 or 10110212

Rochester Quadrajet (750/800) mounted on a Edelbrock Performer RPM #7164. Equal-length, long-tube headers with H-pipe installed before the mufflers. 3.55 or 3.73 rear gears with an Auburn posi. Might be even more fun with a slightly looser converter than stock. (tire wear WILL be a problem until you learn to control this combo).

I used the Crane cam on this DynoSim and retarded it 4 degrees from straight up to get the best numbers. Here's the cam timing @0.050".....
IVO -1, IVC 37, EVO 39, EVC -3

Here's the head flow I used, from Stan Weiss' website.....
0.100" 69 57
0.200" 142 103
0.300" 190 127
0.400" 217 158
0.500" 238 179
0.600" 270 197

RPM HP TORQUE
1000 76 400
1500 133 466
2000 200 525
2500 257 540
3000 300 526
3500 340 510
4000 370 485
4500 360 419
5000 312 328

Peak volumetric efficiency 79.8% @3500 rpm's
Peak BMEP 174.6 lbs @2500 rpm's

angelf0926 03-26-2013 05:38 PM

Quote:

Originally Posted by techinspector1 (Post 1660673)
Assuming these heads have the stock valve sizes, 2.06"/1.72", they won't be a candidate for high hp. You don't want high hp anyway, not in a tractable street motor. You want high torque, so let's build a torque motor that will put a grin on your face.

Check main bearing bore for roundness and parallelism of all holes. Align-hone or align-bore the main bearing bore to correct mis-alignment or out-of-round.
Indexing off main bearing bore, cut block decks to 9.790" block deck height. Bore cylinders to 4.310" for these pistons....
KB Pistons for Automotive Applications
Assuming that your heads are ~119cc (you'll never know for sure until you cc them, but we'll assume 119 for this exercise). Using a head gasket of ~0.040" will put the squish at ~0.050, right where I'd want to be with a BB. Static compression ratio will be 9.1:1, just right for crappy pump gas.

You MUST match the cam to the static compression ratio, so I would use any of these in this build. Choose one.
CompCams 11-203-3
Crane 103052
Engle 2212H
Iskenderian 396256
Lunati 10110101 or 10110212

Rochester Quadrajet (750/800) mounted on a Edelbrock Performer RPM #7164. Equal-length, long-tube headers with H-pipe installed before the mufflers. 3.55 or 3.73 rear gears with an Auburn posi. Might be even more fun with a slightly looser converter than stock. (tire wear WILL be a problem until you learn to control this combo).

I used the Crane cam on this DynoSim and retarded it 4 degrees from straight up to get the best numbers. Here's the cam timing.....
IVO -1, IVC 37, EVO 39, EVC -3

Here's the head flow I used.....
0.100" 69 57
0.200" 142 103
0.300" 190 127
0.400" 217 158
0.500" 238 179
0.600" 270 197

RPM HP TORQUE
1000 76 400
1500 133 466
2000 200 525
2500 257 540
3000 300 526
3500 340 510
4000 370 485
4500 360 419
5000 312 328

Peak volumetric efficiency 79.8% @3500 rpm's
Peak BMEP 174.6 lbs @2500 rpm's

Thanks a lot I appreciate your time. You're right a torquey engine is better for me since I won't b seeing the track at all..by the way..can you give me an estimate of these costs?? Im 21 years of age so my budget is limited..

bigdog7373 03-26-2013 06:37 PM

Quote:

Originally Posted by angelf0926 (Post 1660680)
Thanks a lot I appreciate your time. You're right a torquey engine is better for me since I won't b seeing the track at all..by the way..can you give me an estimate of these costs?? Im 21 years of age so my budget is limited..

Head work should be around $300. Bearings and gaskets $100ish. Cam can vary a lot, from $89 to $350+.

cdminter59 03-30-2013 09:44 PM

chevy 454 hp??
 
The first thing I would do is pull a head off to check what kind of pistons I have flattop or domed. If it has flattop pistons the compression ratio will be around 8.2 with the 781 heads. It would probably be better to find a set of closed chamber heads to use with flattop pistons. Casting numbers 3964290. This would boost the compression up to about 9.1. A good hyd. flat tappet cam to use would be Howards, Hydraulic Flat Tappet Cam & Lifter Kit, Chev BB - Competition Products. Don't forget to get valve springs to match camshaft. An Edelbrock Performer RPM dual plane intake and a Holley or Quick Fuel 850 carburetor will add the finishing touch. If I were you I would sell that Torker intake and Edelbrock 750 carburetor. That torker is worthless as a stock intake.

vinniekq2 03-31-2013 08:27 AM

If you used the 264 mega cam(one up from techs sugguestion) it would have more rumble in the exhaust.I would use that cam @ 1-2 early.If you also machined the heads for 2.19/1.88 oem valves and resurfaced the heads,that would give more power,but would cost more money.
The trouble with techs combo is it would probably give you decent mileage for a BB and be a great DD.


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