How do I get 375hp out of SBC 350. [Archive] - Team Camaro Tech

: How do I get 375hp out of SBC 350.


4U 2 NV
Dec 3rd, 01, 06:54 AM
I have a chance to get a 350 from a guy I know. I was reading some Chevy High Performance magazines and that say I need Vortec heads, Cam, Edelbrock Intake, 650cfm Carb, and headers with dual exhaust just to get 350hp. I use to know a guy that had 375hp on his 350 and didn't have vortec heads. So what can I so with stock heads to get that kind on hp.

75CamaroSS396
Dec 3rd, 01, 07:13 AM
4U2NV, what heads do you have know and what kind of money are you looking at spending, and what kind of drivability.

I have a 73 Chevelle and is putting out 466hp at the flywheel and 482ft lb tq. with old 64cc fuelie heads.

JE 10.5:1 350+.030=355
Lunati crank(3.48 stroke)
Lunati rods (5.7)
292H Comp cam .501" lift 292 adv dur 244@.050
with 1.6 Harland sharp roller rockers
64cc 291 heads with massive port and polish
2.02/1.60 valves.
Weiand X-celerator single plane intake
Holley 750 vac sec. 72fr/76rear 4.5PV
MSD Dist./6AL with 7000 rev limit/MSD Wires
36*timing all in by 2600.
4.10 with TH400 3500 stall 27" Dunlops
Car is 3800lbs with me and runs 12.6 @ 117 which shows the car has more potential but I can't leave the line at more than 1300 rpm or traction becomes non existent. My car gets 10-12mpg and never overheats can be driven wherever if you don't mind the high rpms and stays reliable enough to be my daily driver.

HOTRODSRJ
Dec 3rd, 01, 07:39 AM
Horsepower is dependent on several factors regardless of parts etal. This is what it boils down to

1. Cubes.....the more the more potential when used appropriately.

2. Volumetric Efficiency...the more air you can pump through the engine the more power you will make.....like a supercharging affect. This involves head design, intake design, cam grind and exhaust system.

3. compression ratio...the higher the more power.

4. the peak power rpms that you can turn appropriately with your engine design.

5. the btu content of the fuel you burn.

Hp = 14.7 (atmos pressure figure at sea level) X VE X CR X Cubes X peak RPMS /792,000 ( a constant for gasoline fuels)

If you think of hp like this....the result will be all the accrutiments that you choose for your engine will fall in line with your thoughts.

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STEVE JACK
ConceptOne Pulleys and Brackets

http://streetrodstuff.com/Products/pics/thumb_198_1.jpg

4U 2 NV
Dec 3rd, 01, 10:37 AM
I want this car to be my daily driving car that I take to work. 75CamaroSS396 has a monster engine in his car. That is too much for my car. I'm going to go look at the engine on tuesday to check numbers and compression. I'll post what it is later. I allready have a Holley 750 Vacuum sec. and Edelbrock performer intake. Now what heads, what valve size, and what cam can I put in it to get 375hp no more no less that is all I want. The guy who had 375hp in his car was all engine and no NOS. That is what I want. All engine.

Deimos
Dec 3rd, 01, 12:10 PM
Heck I will sell you a 355 short block made that still fresh on the stand for 1,100 (1,400 invested). It has 9:1 compression forged pistons with a 72 cc head and 10:1 with a 64 cc head. It will make in upwards of 400+ horsepower. It was made by an engine shop in town and now is for sale because my friend lost his job. It is TRW pistons, 4 bolt main, 350 bored and honed .030 over. Hey if your interested. Comes with oil pan, flexplate and balancer. It coms with a crane cam 286H and crane lifters. Put an old pos heads on and you could drop the horsepower down to 375. Will with 2.02 vlaves can get you 430 hp. Good luck.


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It is better to burn out than fade away

[This message has been edited by Deimos (edited 12-03-2001).]

PDQUICK
Dec 3rd, 01, 12:11 PM
Well, you can start by throwing that manifold and carb away!!

If you think that's a monster 350, you should seriously consider more inches!

Take a look at the GM fast burn 383! It's not as cheap as the "gimme" from your buddy but with the reasonably mild "GM Hot Cam" they say it will make 425HP and then you won't have to worry about whether or not your combination will "work" after it's done.

If you want big power with nice drivability, always remember:

THERE'S NO REPLACEMENT FOR DISPLACEMENT!! http://www.camaros.net/forum/smile.gif

Deimos
Dec 3rd, 01, 01:34 PM
Well any gearhead can tell the 383 does not produce any horsepower over the 355. What makes it quick is the torque it produces. That is why a real gearhead does not look at hp becuase it just a ratio number it is torque that gets you down the track. I can garuantee that the 355 is better built than any 383 fastburn. It has been honed, bored, and decked. Scoggin dicky isn't the know all end all. It also probably is as experienced as a machine shop. Considering the are concerned with quanity not quality. Now if we took my 383 and pitted it against a fastburn I would wipe the floor with that thing considering 430-450 is not that much hp. If you want we can tell him to do a 377 which would be less torque but capable of doing higher RPM's, but me just won't go there.

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It is better to burn out than fade away

Tracy Focht
Dec 3rd, 01, 01:44 PM
<BLOCKQUOTE>quote:</font><HR>Originally posted by Deimos:
Well any gearhead can tell the 383 does not produce any horsepower over the 355. What makes it quick is the torque it produces. That is why a real gearhead does not look at hp becuase it just a ratio number it is torque that gets you down the track. I can garuantee that the 355 is better built than any 383 fastburn. It has been honed, bored, and decked. Scoggin dicky isn't the know all end all. It also probably is as experienced as a machine shop. Considering the are concerned with quanity not quality. Now if we took my 383 and pitted it against a fastburn I would wipe the floor with that thing considering 430-450 is not that much hp. If you want we can tell him to do a 377 which would be less torque but capable of doing higher RPM's, but me just won't go there.

<HR></BLOCKQUOTE>I think he brought up the GM 383, because more cubes, more torque. And a good reputable warranty to boot.Not to mention they in his back door.Texas.

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383 Speed-O-Motive stroker kit with Holley 750DP, RPM intake,MSD6a box,World Products Sportsman II heads, ported and polished with 2.02/1.60 valves,64cc,TRW forged pistons with 10.7:1 compression, Comp Xtreme 284 cam,Crane pushrods, Comp Cam 1.6 full roller rockers,ATI damper, 40 series Flowmasters, 4.11 gears with TH350 and Hughes 3000 stall.

[This message has been edited by Tracy Focht (edited 12-03-2001).]

pdq67
Dec 3rd, 01, 04:52 PM
My 2 cents, please. Heck, headers on a stock 350hp/350 should get you 375hp, easy. But you will have a problem with fuel unless you go with aluminum heads.

As for heads, a good set of big valve double humps will work, but usually it is cheaper to get new heads than to modernize them.

Yes, a 9.5 to 1 CR. engine, the Performer with a tuned 3310-2 750 cfm Vacuum secondary Holley, Or Stock Q-Jet. A set of good long four tube headers, the above mentioned heads, al or ci. And finally a good cam of say 218 to 224 degrees intake duration. And you should by about right.

But you gotta admit, that is one thumping SB!!! IMHO. pdq67

75CamaroSS396
Dec 3rd, 01, 07:07 PM
Why is 375hp a concern, when you could have more and not sacrifice in drivabilty. Take the AFR combo 350 9:1, headers, AFR RPM intake, 218/223@.050 .460/.470, pull 16" vac, 600 Holley, and 800 rpm idle. This is a very fun and drivable combo making 420hp/435lb ft tq. plus it has over 350lb ft tq at 2500 which is good because that is where a street car needs it. I have a few friends who copied this motor (3 to be exact)and one has it in a 69 corvette(mostly drag car) pulled 11.25 at 120+, then changed to a roller cam and bumped compression to 10.25, changed converter and everyting accordingly and car now runs 10.80 (but still working on traction problems), true this is a lightweight car and not driven on the street much but it is very drivable. I want you to build what you want and like, but at the same time I hate to see people waste their money on something when probably for the same amount they could have more. But like I said build it they way you want it not hte way others want it, I simply give suggestions.

[This message has been edited by 75CamaroSS396 (edited 12-03-2001).]

nitrous383
Dec 3rd, 01, 11:10 PM
low 11s with 420 horsepower? in a an old vette? Im a firm believer in chevy power,and the AFR heads make unbelievable power,but that doesnt sound right. I have an 81 camaro,and Im throwing in a fairly serious 383 stroker with about 475 hp,I will be lucky to get 11s with that much from what people are telling me,so how can 420hp get low 11s? Im not calling anyone a lier,I would just like to know because that sounds cool,pump gas 350 doing 10s! cant beat that!

blown67ss
Dec 4th, 01, 12:13 AM
How much do you want to spend. 375 HP is really easy to get out of a 350. Stay around 9.5 cr or you will never get full timing out of it. A cam with about 228-230 dur at 050 and 486 to 500 lift with a set of headers and true dual exhaust,650-750 carb mechanical secondarys for a manual vacumn for a automatic,and a single plane intake should get you 375 to 400 hp Good luck, but I feel that you can't beat a stroked 383 for the street

PDQUICK
Dec 4th, 01, 04:05 AM
Deimos,

Didn't mean to bash your 355! Hell, I'm running a 450HP 327 in my "daily driver/road racer". Of course, it only makes about 340lb-ft of torque at 7000 RPM. Simple physics: HP=(torque)(RPM)/5250!! I have a pretty good handle on the small inch, well built, hi-reving engine thing!!

Tracy,

Thanks! That's just what I was trying to say. Why screw around with a bunch of mis-matched parts in a non-optimized combination that you aren't that familiar with when you can go buy what you want all assembled with a warranty???

4U 2 NV - Why is 375HP the magic number? What are you trying to do? If you want 375HP out of a 350, build a spec. LT-1!! Of course their compression was a bit high for todays unleaded pump gas!

4U 2 NV
Dec 4th, 01, 05:02 AM
I thought that 375hp would cost a lot of money and a regular 2-bolt block would not handle it. But 75CamaroSS396 says I can have more hp & tq for the same money (420hp/435lb ft tq). Deimos wrote "What makes it quick is the torque it produces" then this answers my question on the corvette engine my friend wants to buy. We looked up the specs in the Chilton Books and found it only has 245hp but it has 350 lbs/tq with 308 gears. Yet it runs good. Thanks guys like I say you always learn something new on this board everyday.


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1979 - 305ci
Holley 750cfm Vacuum Sec.
Edelbrock Performer Intake

75CamaroSS396
Dec 4th, 01, 04:46 PM
Nitrous 383, the motor was put together following the exact specs of AFR's engine (we called and got all the details of it), the vette sees about 90% strip action, it doesn't have all the luxury items (heat, A/C, etc.). I believe it weighs about 2700lbs, (can't rememeber exactly). When the as spec AFR motor went in it it pulled 11.28 at 121mph, he left the line at 1800rpm because he is a real good chassis tuner and knows his stuff, car has 4.88's and th350 with a MSD limited to 7000, and he hit the limiter about the last 40' of the track. We pulled the motor changed to lightweight crank, aluminum rods, and Ross racing pistons(10.25CR), custom solid roller, and AFR single plane manifold, kept the AFR 180 heads, changed to a 7700 limiter, car pulled 10.80 at 129 (but had serious traction problems). Now after working on traction issues it's best time is 10.50's with highest mph of 136. Vettes are light and if you remove unnecessary parts and unwanted parts they get even lighter. Plans are to build another motor with 220 AFR heads and 12:1~CR, roller cam, etc., and add a two stage fogger NOS, tub out the back, and a few other mods, but keep it street legal. He's hoping for 9's or better but we'll have to wait and see.

4U2NV, I bet if you bought parts through ebay (to make it a 383), and shopped around for some used AFR heads went with 9.5CR, torqy cam, you could have a 12 sec motor easily and all for less than $2500. The question is will your car handle a 12 sec motor. But if you want 375hp then by all means, build it the way you want it.