easy horsepower?

[shortchevy84]

hey all. i checked the specs on the chevy v8's from www.chuckschevytruckpages.com/..... and i am quite disappointed with the specs. 305 v8 non california makes 160hp, and same with the 350!!?? doesn't make a lot of sense. is this true? there was a 35lbft gain in torque but thats not that much for the extra CI. anyway, since the figures are so dissapointed for the gas mileage, how would i go about getting it around the 300hp mark. not too worried about torque. i thought it should be really easy to get that power out of the 350, but thats alot of hp to gain from a measly 160-170. i read all the forums of getting power through a comp cam 260 energy, and new intake and headers...but that doesn't seem to be nearly enough. unless the cam works miracles..??any input on that is would be nice. i've got 350 with flat tops, edelbrock performer air gap intake, mild cam(not sure what type) stock rochester Q-jet, K&N air filter. i'm not very happy with the power output. i mean its better than my old escort...RIP..hehe... but i'm just not seeing the all the potential i'm reading about. all i want is a daily driver that can knock the socks off any lil ricer that pulls up next to me. i wouldn't mind having a nice lopey idle from a big cam, but i still need it to run well in winter.ie -35 degrees celsius..gotta love canada. and i would love to be able to run on 87 octane gas, or whatever the regular quality is. i really don't wanna do a complete rebuild, but i would defenitely consider upgrading the cam. i've considered superchargers, but that is a little pricey, and from what i read, sounds like it could be risky and harmful to the engine. headers come this summer so thats a few more hp, but with all the stuff i got, i'm betting maybe 200hp is being put out of my 350, and thats rather upsetting for the amount of gas i'm burning. are there better stock parts i can get from a wrecking yard like smaller heads, better cam or anything else?? i did read that a 3970010 block could have come stock out of the factory with 300hp! thats a rather large jump from the 160-170 that other stock one's put out. anyway. i'm rambling on now. sorry about that. thanks for any responses or ideas on how to go about achieving anywhere inbetween 300-350hp in a daily driver.thanks

[PaulCline]

Get a comp cams 262H cam, a set of motown sportsman II heads, use the recomended springs and lifters for the cam, and you'll be pulling around the numbers you want, and still have a streetable engine. You can get everything you need from Summit or Jegs.  

[Sano]

You'd see a good difference in power and response if your heads/cam/intake rpm ranges all matched. If it were me then I'd get the heads (if they are 2.02 heads) ported/polished and flow checked, and a cam kit that matches the rpm range of the air gap. if its an rpm then its I think 3000-7000+ and the performer rpm is 2500-6000 or 6500...I'd just get a hydraulic flat tappet cam and not a roller for the sake of money. But Roller rockers and lifters would be a good for a slight power increase but overall for a some relief on the valvetrain. Thats should give you a good increase. Although I do find it wierd that you don't have that much power. MY friend  has a 79 camaro that hadd stock 170hp, and he just added a 270 cam kit and a an edelbrock performer rpm intake along with a new 650 carb and 2 1/2 inch exhaust/hooker headers. With his 3.8 posi rear end he ran a 14.7 in the quarter which is a lot better than it was stock being 16.9.

[roundedline]

All components of a engine need to be compatible to get the most gains.  Truck engines were not built to run alot of power, they were build to haul loads.  You can't put a cam in the otherwise stock motor and expect 150hp increase.  The stock springs will only handle about .450 of lift, before you get a cam bigger than that, you need to change the springs, if you have to change the springs, you might as well save up and get some decent flowing heads.  You also need an intake to match the power range of the heads/cam.

BTW, just because the BLOCK description says it was for a 300hp motor does NOT mean by purchasing such block will instantly give you 300hp.  It is the components installed in the block that makes the power.  ANY SBC block can be made to make power, so don't get hung up on descriptions.  All SBC were exactly the same from 1955 to 1992.  There were high nickle, 4bolt / 2bolt, 1-piece seals etc, but they are the same block.  2 bolts can be made into 4 bolts, but unless you are building a race motor, 2 bolts are just fine.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

Edited by: roundedline at: 12/30/04 2:06 pm

[shortchevy84]

thanks for the input everyone. i've looked at the comp cams website. the cam for me seems to be a 268H cam:
hydraulic flat tappet cam and lifter kit. LIFT 0.454, intake duration advertised:268 degrees.exhaust 218 degrees. rpms: 1500-5500. Lobe sep. angle 110 degrees. is this sounding like the kind of camshaft i'm looking for?? if so, what else am i gonna need to buy to have this cam installed. i was thinking new timing chain. i think i need new springs too, and like you said i might as well look into new heads. the sportsman II headers do seem to be a good choice boasting 30-70hp out of the box. what am i going to want,straight or angled plugs?? what, if any, are the advantages of each? or is it just personal preferance? what size heads will keep me with a small enough compression ratio that i can stay on low-mid grade pump gas. i have flat top pistons. also, will my performer air gap intake be sufficient with rpms of idle-5500, where as the performer rpm is designed for 1500-6500? anyway, thats enough questions for now. so much for me to learn before i spend all this money. thanks in advance!

[PaulCline]

When you change the cam, you have to change the springs. To keep your warranty, you need to use the springs recomended by Comp Cams. The 72 CC chamber heads would be your best bet if you want to use cheap gas. I would choose straight over angled plugs, mostly just because I know they'll clear headers designed for the truck. The air gap manifold will work fine, but it isn't one I'd use personally.

[shortchevy84]

thanks for the help. depending on what the shops around here carry, i'll probably get edelbrock heads with about 70c chambers...but should i get performer, or performer rpm? i'm thinking rpm cuz they should make more hp. From what i can tell from the edelbrock website, performer does idle - 5500, rpm does 1500-6500, so rpm should be what i'm looking for cuz thats the rpm range for the cam. it says i need hardened pushrods too. any idea on the price of those? so if everything works out, i should be getting a 268H Comp cam, with edelbrock performer rpm heads (70cc) with the correct springs for the cam, hardened push rods, and whatever timing chain that i'll need to make it all run smoothly. can anyone forsee me running into anything else that i'll need to make a reliable daily driver with lots of play power? the only thing i can think of is the torque converter..? would i need a new one, or beefier transmission/driveshaft/diff? i have a rebuilt th700 R4, stock driveshaft and no idea what differential. thanks again!

[roundedline]

If you are going to get all of these, I recommend getting Edelbrocks Performer RPM Package.
Look here:
www.edelbrock.com/automot...vy_2a.html

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[shortchevy84]

i already looked into the power packages, but there is alot of stuff there that i don't think i need, or want. i've read that if tuned right, which apparently is really hard, a rochester Q-jet can perform as good or better than an aftermarket carb. i already tried to get a new carb, i bought a performer 650 or something, but i looked at it, and how hard it was gonna be to install, i was gonna need a lot of new parts just to switch carbs, so i then took that one back to get the edelbrock q jet, but that was almost 400 bucks more than what i had already paid for the performer carb. and thats just crazy talk! so i'm happy with my q-jet, i'll get the guys at prostock(the place i'm gonna get all my work done at) to adjust the carb. they should know what they're doing since all they do is build race engines. next i just bought a new intake(performer air gap) so i don't really want a new one, even though its not perfect for the rpm range i want now. but i'm hoping it will still work. i called prostock a few months ago, and they told me, to get that horsepower, i shouldn't go with an edelbrock package, cuz they could do it for a lot cheaper with mix and match parts that have already been tested. so thats what i was kind of trying to do. get input on different cams and heads that would make my desired horsepower. i'm hoping i won't have to get that package, although the dyno chart showing 420 or whatever does make me drool. but that could be alot of extra coin when i might just be happy with the 310 hp. thanks for helping roundedline, and any more comments/input would be much appreciated. i'm not buying the parts for probably another 3 months or so. i'm doing the research now so i don't waste my time and money. Thanks!!

[shortchevy84]

i've just been browsing through the edelbrock and comp websites, and i've noticed that the heads don't seem to include any rockers? is this true? if so, is it worth it to upgrade to roller rockers? they advertised 15-30hp over stock, and extra strength/less wear on valves/guides. sounds like a win win situation to me. i'm assuming its just a direct swap? website is www.powerandperformancene...ode=mgRCKR
thanks  

[pdq67]

Imho, the power you want is no farther away from you then making sure by using the needed chamber cc sized medium valve to big valve heads so that you have an adequate CR., your Q-Jet, a good old CC 268HE or Crane 272/272 Energizer cam, a set of 1.625", four tube, long headers and a good free flowing exhaust system....

Try to match stock head cc size, deck height and headgasket thickness so that your motor is right at 9.75 to almost 10 to 1 CR. so that you can still run GOOD pump gas!!

I use the ROSS Racing Pistons sit's compression ratio calculator..

I figure the Cali. motors are right around 8 to 8.5 to 1 CR., so probably are running both dished pistons, .039" or so thick composite headgaskets AND 75/76 cc chambered heads???

Try to use a stock, 64 cc head, and Fel-pro's #1094, .015" thick, shim headgaskets and you should be up right at 9.5!!

(I use a stock, "down in the hole" piston measurement of .025").. As well as try to shhot for a quench number from .035" to .045", (deck and headgasket)...

I bet you won't believe the difference in performance!!

The only down side to this is that the older stock, 64 cc heads don't have hardened valve seats so you may be better off installing a Vortec head system along with the needed dedicated Vortec intake...  They are EXCELLENT heads for your use.

I personnally wouldn't worry about hard seats and just pour about half a quart of good old "Snake-Oil" named, Marvel Mystery Oil in my gas tank at fill-up and the rest in my oil at oil change!!  Good old MMO is an EXCELLENT old-time, "top-Oil" product that lubes valve stems, guides and seals, rings as well as cleans the motor from both the oil side AND the gas side when used in both...

I figure you should be looking at least at 325hp to 340 hp uncorked!!!  A great pump-gas street motor hp, imho...

pdq67

[1976Scottsdale]

My 78 has a rebuilt 350 with all standard size stuff except the cam, which is a crane energizer 284 cam.  One word, Lumpy.  It lopes very noticably, but it can be made to idle well enough to run an auto trans, but it will make power, lots of power.