matt_82transam

im rebuilding another sbc 350 and I was wondering if anyone can tell me the possible power this engine should put out, ok here it goes
The block is a 1970 4 bolt 350 with original crank
-It is bored .030 over and has all new bearings, and pistons(compression rating is 8.6:1), rings.ect
-it also has 76cc chamber rebuilt(ported) 400 heads from 1971 and 1973 that are flow matched with intake manifold.
-comp cams extreme energy xe256H cam that is rated for
1000-5200rpm, has .447/.454 lift , 110* lsa , and the duration at .050 is 212/218
-1.5 roller tipped rockers
-edelbrock performer air gap manifold
-edelbrock performer series 750 cfm electric choke carb (1411)
- high flow oil pump
-all new valve train
- true roller timing chain
- holley 7 psi electric fuel pump w/regulator
-shorty 1 5/8 coated headers
- open element f kit

Half of the items above arent purchased yet becuase I wanted to double check with the experts out there if all the parts above are a good match to work together and produce strong lower to midrange power.

For possible et guesses I currently have a rebuilt th350 transmission, 2.93 7.5" posi rear end, and full 3" single exhaust is already done with dynomax super turbo muffler.

Thank in advance

82camaro

Well, it's your engine, but....If you are wanting good midrage/low end torque. Toss those heads and get a set of vortec heads--they are cheap for new heads. Then a better cam (at least the 268H). Without overdrive you can get away with a bigger cam without hurting mileage/drive-ability down the highway(because of the rpms you will be running). Shoot for 9.5 to one compression --pump gas will have no problem with that. Speed demon or road demon or road demon jr. carb. Stealth intake. Should produce a ton of torque and be a sweet street engine...
But hey, it's your car

SweetS10v8

ahh double post

SweetS10v8

My $.02....

Too much carb and too little compression!!!!! Dont be afraid of domed pistons!! Especially with 76cc heads...And 650 wil be plenty of fuel, and will give you better throttle responce!

I ran a simular motor, a 350 with 8.5:1 compression and a 750 DP. I thought it was fun, but when I switched heads to 64cc chambers bumping the compression(both heads flowed almost the same) And put on a 650 DP the difference was night and day!!!!

Seriously, youll shoot yourself if you dont get at least 10:1! More compression means more power, better throttle responce and better gas milage at part throttle!

With those 2 changes youll have a great street motor! Your already ahead of the game by not trying to over cam the motor..

Here is a quick Desktop Dyno of your motor the way you have it setup...

SweetS10v8

pic was too big, RESIZE...

matt_82transam

hey s10v8, can you please give me another deskot dyno prediction.
ok here it goes,
keep everything I initially said which includes 750 performer carb, but change the performer air gap for rpm air gap.
Go to higher compression pistons and redo heads to acheive 9.2:1 compression. Get a bigger cam like the comp cams 262 cam which is rated from 1300 - 5600 rpm and has 218/224 duration and .462/.469 lift.
I hope this setup helps get the hp or tq numbers in the 300's but at lower rpms. THanks for help

if it still sucks then try the 268h cam. It sais it works good with headers here http://www.compcams.com/catalog/016.html

SweetS10v8

Here ya go...

Squeeks83

i have a 350, .30 over
78cc chamber smogger heads
stock pistons, crank and rods.
cam is 224/224 at .5
edelbrock performer intake
edelbrock 600cfm carb

and about 8.2:1 compresssion or so with stock 4valve relive pistons

but im puttin 213 RWHP and 307 RWTQ
i might put some 64cc chamger vortecs and see what numbers i can put down after that, im bettin ALOT more.

put your cash into the heads, thats where you make the more power from.

Squeeks83

here is a screen capture of a DDY2K of my 355

SweetS10v8

Hes right, to make power ALWAYS spend as much as possible on heads

matt_82transam

thanks alot for the reply s10v8.
THat dyno result was for the 262 cam right?
I know that newer heads would be better but im going to port and polish the 76cc ones and they are going to have 2.02/1.60 valves and thats still with the rpm air gap. However I have a new plan for the carb. I went on the holley website and I used that carb size formula and found that if my 350 had max rpm around 6000 and 6500, and with the decent lift for street on the 262 cam, a performer series edelbrock 650 cfm carb should be plenty.
what would the dyno show this time?thats with 9.2:1 comp.
THanks so much for feedback

kfoley

I would step up at least to the XE268 cam, and definitely some dome pistons to get the CR about 9.5:1.

matt_82transam

ok I finally made up my mind.
but first is the PERFORMER air gap the exact same thing as the performer but with the only difference of keeping a bit cooler at higher engine temp???im really thinking so
-Therefore I am going with the Performer EPS(1000-5500) which has peak power around 3500 rpm.
-650 Edelbrock AVS m/choke (using formulas, this carb should be perfect)
and I can set the secondaries to kick in whenever
-really port/polish heads,portmatch to mani,2.02/1.60 v,r tipped rs
-comp cams extrme energy 262 cam with 218/224 duration, .462/.469 lift , good for 9.0:1 to 9.2:1(exactly what Im aming at)
*looking at the comp cams website http://www.compcams.com/Technical/Dy...62H-10_001.asp
this cam should produce the peak torque really close to the rest of the setup*
^by the way, on the link to the dyno sheet, they are using a performer manifold, so the eps should really fly^
MY POWER ESTIMATE = 410 lbtq@3600rpm/ 350HP@5400rpm

SweetS10v8

on the program i use its generic, single plane or dual plane..all of em have been using a dual plane.

matt_82transam

hey can you send me that program, it seems neat

and by the way thanks a lot for all the dyno stuff help
sweetS10,

SweetS10v8

Its desktop dyno 2000....Im sending you a PM