355 sbc build
 

im putting together a 355sbc w/13.5CR,220cc heads,270@50/700 lift roller and tunnel ram.how much h.p. you think this combo will make?its going in my 70 chevelle w/ a 4-speed and 4:56 gear w/a 29.5 tall tire.car weighs 3500lbs.any suggestions are welcome on engine combo.[/b]

Re: 355 sbc build
 

:D Need a little more info here....what manufacturer on the heads, the cam lift and duration...you are running a tunnel ram need to know what you are planning to use for induction like carbs, their size, or if you are using fuel injection is it gas or alcohol...then maybe we can help

355
 

comp cam roller w/274@50 dur. and 700 lift.750's carbs and e85 fuel if i can run that kind of compression on it if not race gas.brodix heads

Here's my take: 355cid, fairly big heads, long duration cam, tunnel ram, 4-speed, heavy car = a real pig out of the hole. Your gonna need a LOT more gear to get it moving and keep in an rpm range where it's happy. 7500rpm plus would be my guess. Personally I'd ditch the tunnel ram and go with a good single carb race manifold, one 750 or 800 cfm should be plenty, race gas, 5.13 or more gear. I'll bet you could run e85, but getting it right will be a pain, especially with 2 carbs......jmo
Johnny

355
 

well i've got a holley strip dominator i can put on it.i can do a 5.13 gear also.i thought a 4.56 would put me through the back door at 7200 and now that i think about it that aint near enough.wanted to run e85 because i live in houston,tx. and its hot down here and its gonna see some street time.

cam
 

how big a cam can i get in a factory block?

You can put well over .700 lift in a stock blk. useing 1.6 rockers, but you are going in the wrong direction. A car that heavy and with a 355" engine will not perform in the qtr. or on the street. Anything bigger than .630 lift and 106 lobe ctrs. will only slow the car down unless you can keep it in the 4000 rpm plus range. Case in point my Malibu@3200lbs. 377" with a .668 lift is dead, just not enough torque. Engine performed very well in a dragster, but i would be better off with my .625 lift cam or even the original .597 flat tappet that i used to run. The only reason i haven't changed the cam is that i'm putting in a 434" motor. The car does run 6.50's and 10.59@125 with the 377 but it ran 6.45 with the flat tappet cam all on alcohol.

JMO

Zip.

Very good advice....I agree top to bottom.

355
 

so if i run a solid cam around 600 lift I'll be better off?What about the duration,was I even close at 270@50?What should the car run with that set up?I almost forgot,i guess 106-110LCA?

sbc vs bbc
 

maybe i should just put a bbc in it and go fast.whats your thoughts on that?think i can build one for same money sorta???????????

So, what parts do already have? If you have the 220 heads already, maybe consider a 383-388 stroker. Will make more torque and if you stay with a smallish flat tappet cam, in the range of 250-260 duration @ .050 and .550-.575 lift, will perform well in a heavy car like yours. I built one a few years back and he runs 11.40's in Denver and I think he's run 10.60's in Topeka in a 3200 lb Camaro with 4.88's and a 29.5 tire......just a thought. Just don't get caught up in the "big heads, big cam, big carb" thing, because you won't be happy with it.


Johnny

355
 

thats encouraging johnracer!!!how much compression you think i need?I think i'll toss the tunnel ram and put on my strip dominator with a 750 carb.you think i need a roller cam or solid cam?I got three of ya'll telling me basically the same thing so thanks to all.

355
 

oh i forgot i've got the heads and block,and the 4-speed.

Ok then, if you don't have a rotating asm yet, I'd build a 383 -388 deal. 383 is .030 over and 388 is .040 over. 13-14:1 compression is good. This is a race only engine correct? As far as cam goes, either is fine, just keep the duration fairly short. You probably won't see much performace difference between a .575 lift, 260 duration @ .050 flat tappet and a .630 lift, 260 duration @ .050 roller. Proper break-in with a flat tappet is crucial though. Make sure you get matching springs for whichever you choose.

Of course a bigblock is always good. Just remember you'll ad another 170lbs to the car with a bbc.......and it's way cool to run good with a small block!

355
 

thanks johnracer,i'll run the flat tappet(it's dam sure cheaper)and get the complete cam kit.and i do no about proper break in.do i need to run 116 race gas or 110,105???????I no to much octane is bad also.

now a 383
 

do i run 1.6 roller rockers or 1.5,s or split them or what.do i need to degree the cam or stright up?DAM I ASK LOTS OF QUESTIONS!!!!do i need to put block cement in the motor?what size header?i was thinking 1and7/8 or bigger.

110 should be fine, and yes, degree the cam in at the cam card specs and be sure to check piston to valve clearance, rod to cam clearance and rod to block clearance. Rocker ratio may depend on the cam choice. I ran a Comp 12-609-5 in a 13.5:1 406 for years and it made great torque. I had 1.6's on the intake and 1.5's on the exhaust. The 383 I told you about has a Comp 12-612-5 in it with 1.6's on both but he's lighter than you by several hundred pounds. I'd go with the smaller cam or something similar if it was mine. No, you don't need to rock the block. 1 3/4 tube is best, but no bigger than 1 7/8. Bigger tubes kill torque.

383
 

thanks for all your advice

Here is the flat tappet cam i ran, i still have it and getting ready to put into a 406" 10.5 motor in my prostreet 1998 Sonoma stepside truck.
It actually ran 6.26/6.36 on a good nite in my malibu with a 377" @ 3253lbs, but i don't have those tickets, the one i could find is 6.45. I had a 6.20 gear and i run a PG with a 5500 stall converter. I donot know how you can keep the RPM range with a 4 sp car. I have Bodix T 1 heads which is not a crap for flow rates. I think this cam would be too big @ .050 for a 4 sp car, but that JMO, but i really like the cam with the PG and a 5500 stall converter. My Protreet truck will have a 5.67 gear and PG with brake and a 4000 stall converter. I expect it too run mid 10's on Hoosier 1850 street slicks on pump gas. I think it will weigh about 2700/2800lbs.

These are just my opinions, and don't spend your money on my opinions.
The other thing is i recently built a 468" b/blk for less than $1000.00 short blk. it's in a 3700lb Biscyne on pump gas it runs 10.50's @ 126mph on hoosier street slicks

Zip.

http://img.photobucket.com/albums/v5...tcambullit.jpg

110 would be my first choice.

Cp

355
 

as far as the 4-speed you would be amazed how i can speed shift it,no really,really!!!220cc heads i think will be fine with full race port work.you think a 4.56 is enough gear or do i need 4.88s?th e car will see the street more than the track but i must have a fast ass street car!!!!!!!!!!!!

355
 

hell im even all for buildin a 8000 r.p.m. motor if it'll get me to run 10.00

It'll be happier on the street with 4.56's but will really 4.88's or more. IMO if you want to run 10.00, especially in a heavy street car, a bigblock might be a better choice, or a sbc with a Procharger.....