Ok so this is going to be my first engine build. My dad and instructors have built numerous motors so when i need help putting everything together and such i can go to them but trying to start figuring stuff out without them just telling me what to buy. I have a 91 Camaro rs. Currently has the 305 TBI hooked to a 5 speed but looking for a 6 speed from a ss. im going to put a limited slip in and have motive gear 3.90 gears at the house. i have some parts chosen put need help with what to take out and replace and add. i want to be in the 400 range to be hopefully at the wheels. i may spray it but not till later on down the road.
The block i just bought it a 69-79 350 370hp, that was taken to shop and bored .030" decked and washed. not sure if its a roller or flat tappet the cast number is 3970010. id like to go roller based off what ive read about them being better and lasting longer.
id also like to go carb because im just more comfortable with them and have no experience with the FI. i have a 4 in cowl already on car for clearence but may go over to a 5 but cant find a metal one yet.
the parts i have so far are:
-Scat Crank 3.480 stroke (Sca-910442)
-Scat 4340 Rods length 5.700 (Sca-25700)
-AFR 195cc Heads (AFR-1040)
-Edelbrock Preformer RPM Air Gap Intake (7562)
-Holley 750cfm double pumper carb

I need to find a cam and the right pistons. then all the little goodies. all help would be greatly appreciated thanks

 

Regular flat top pistons and a ported dual plane plus a custom 280 xfi on a 108 lsa will make your numbers or close to them. Or lunati voodoo 282 cam i believe, its around 231/239

280xfi on 195 afr's is a bad **** combo in any 350-383 motor. Just change lsa for the intake you use. Actually i like 108-110 lsa in most builds. But even the 113 can make serious power on those heads. Stock dual plane intake will hold it back. Good port job could be 20-25 hp

 

To spin the motor high enough I would use a solid cam. I don't like hydraulic cams at high RPM. Solid don't have lifter pump up. I would use Lunati#638-72400-16 roller lifters. I had a set of crane lifters like them once. You can change cams with out taking the intake manifold off. You just loosen the rockers spin your cam and they stay up so you can change the cam with them still in the block. Match it with cam Lunati#638-40120730 it will work great with the parts you have, has a broad torque curve and good lift. This should get you pretty close to 450 HP with the parts you already have.

 

If spraying is an option, go for good forged pistons. I like (and use) Wisco pro tru pistons.

Flat tops, 5 to 6 cc
This would be real good http://www.summitracing.com/parts/wi...make/chevrolet

You said block was decked, but didn't say how much so I'm gonna assume 0 deck.

Those pistons and heads will put you at 10.25:1 compression with a 4.100"x.038" head gasket.

Your block is NOT a roller block so you will have to use a retro fit roller cam. This cam looks pretty good for your combo http://www.summitracing.com/parts/hr...make/chevrolet

Preformer RPM Air Gap Intake will work great, I do not recommend a single plane like the vic jr that was mentioned in your other thread.

4" cowl will fit this setup fine.

1-5/8" long tube headers will work, but if you need to buy, then 1-3/4 or 1-7/8" long tubes will be much better.

 

Hyd roller with the right lifters and springs will turn 7500 rpm in those heads. If you cant get the power by then you need more cubes

You'd be alot better off tho if you had a factory roller block to start with tho. Cost of retrolifters are almost as much as solid rollers

 

im not going to spray starting on my first motor maybe in a few years and a couple nights where i just cant sleep ill change everything to spray.

 

summits saying this isnt for my block tho. i dont have a roller block

 

how do you feel about night riders cam and piston choice even tho im not going to be spraying. i was hoping to keep 10.0:1 compression so i wouldnt have to run a higher octane but i guess ican backdown the timing a little since hes saying its going to be a 10.25:1

 

There is more than a single book worth of info to be said about compression and octane needs.

You will not have any probs with 92/93 octane fuel on this engine.

I will not get into great detail here about it right now but here's a few things.

1) Cam size.... The cam has a major role in what octane will run w/o detonation. The bigger cams will "bleed off" some of the cylinder pressure. This is also why you can't run a big cam in a stock low compression engine.

2) Head material...
Iron holds heat in longer/better, this can cause hot spots or the fuel to burn before time. This means compression has to be lower.
Alum. transfers heat better, cools down faster.. You can and in fact must run more compression with alum heads.

3) Head chamber design...
The faster the burn is, the less timing is needed to make peak power. Less timing, lower risk of detonation.
The older bowl shaped chambers needed 36-40* of timing to make peak power.
Where heads with kideny or heart shaped chambers only needs 32-34* of timing to make peak power.

4) Quench design/height. By running a tighter .038" to .042" quench height you can run more compression with less risk of detonation.

10.5 to 10.75:1 compression on 93 octane is very 'do-able' with today's modern cams and alum fast burn heads.

 

ok so i run the cam and lifter kit with those pistons i have to measure for rod length but i can still use the scat crank right. and im going to learn how to port heads in a few weeks but what are you talking about 5 to 6 cc with the pistons. are you saying thats what should be ported or the pistons having a 5 to 6 cc chamber?

 

The CC volume of the piston top. Even a flat top piston has "space" to fill.

The valve relief notches can be bigger/smaller and this will change the CC volume of the piston.

If you look at the piston I linked to in the other reply, you see it has 2 deep valve relief notches
http://static.summitracing.com/globa...-pt001a3_s.jpg
The total volume of those 2 notches totals 5.4cc on that piston

Here is a 4 valve relief piston. It has 4 notches that are not as deep, the total CC volume of this one is 6cc http://static.summitracing.com/globa...350-30_w_s.jpg

The CC volume figures into the formula for adding up compression.

Larger CC dish or flat tops kills off compression, just like larger chamber heads does. Smaller CC pistons bumps compression up, just like smaller CC heads do.

With pistons you also need a valve notch that's deep enough for your cam so the valves don't hit the pistons.

 

Hey boss,
I'm in the middle of a similar first build, so while I'm not an expert, I may be able to help you a little.
To start, those are gorgeous heads, and getting that kind of power out of them shouldn't be hard at all.
As mentioned before, compression is your friend here, higher compression means more usable torque throughout the whole power band. That said, You should probably shoot for 10.5:1 compression, It's where most engine builders feel comfortable with on pump gas.
With those heads, you'd be in the mid-9's if you used flat tops. You could buy a set of quality domes to fix that, or you could use flat tops and have the heads shaved down like .025. Dont trust the calculators, they tend to overshoot. Flat tops are lighter, which will make balancing the crank cheaper, and will add a little power. It also works out to a nicer quench, which is important for a nice compression. It's the way I would go, but it's not all important.
As for what specific kind to get, hypereutectics are probably your best option. They're light, and you can run less piston to wall clearance, so it won't rattle so much. While they're not as strong as forged, your crank will fail long before the pistons.
The crank is the weakest part of your build, but scat makes good stuff, so I wouldn't sweat it too much. I wouldnt trust it with a big pull of nos though. If you know the target bobweight, you can pick pistons that will balance nicely.
Stick to a dual plane if you can, you'll get way more torque for street driving. That rpm air gap is a great choice. Rpm is what will kill that crank.
While rollers are awesome, they aren't the be all and end all they're worked out to be without a good cam choice. They get pricy quick without a roller block. Hydraulic roller lifters will give you the most lift of any lifter, and dont require setting valve lash. A decent set of new ones wont pump up unless you have springs that are too heavy or dont know your shift points. Solid lifters are great for high rpm, but you'll throw a bearing on that crank before you get to the point where it matters. If you can find an l31 engine, you can get a nice 880 roller block, and those vortec heads can be resold for a pretty penny.
That cowl is huge, you will have space unless you go for a tunnel ram. Throw a cold air kit on that puppy. It doesn't look cool, but it is cheap power.
Hope that helped, pm me if you have more specific questions.

 

Wrong. TRUST THE CALCULATOR. It will be as accurate as the numbers you feed it. GIGO = Garbage In, Garbage Out. If you guess wrong with the numbers you put into the calculator, than the result is just a guess. If you MEASURE ACCURATELY, the number out of the calculator will be perfect.

3.48" stroke / 2 = 1.74"
5.7" rod
1.560" piston compression height (MAKE SURE this is what you are buying)
= 9.000" rotating assembly.

Was your block "0" decked, which is, exactly 9.000" crank centerline to deck?
How far into the hole, or above, is your crank, rod, piston? Measure.

4.030" bore
3.480" stroke
65cc chamber (typical for AFR195... guessing)
+5cc dished piston (what are YOU getting?)
9.000" deck - 9.000" crank/rod/piston = 0.000" deck clearance
0.036" compressed gasket... guessing. This can be used to set quench.
SCR = 10.37:1

How many guesses? You should measure, and/or fill in YOUR numbers to get YOUR engine's CR.
Pistons in the hole 0.005" / deck height of 9.005" opens quench a little, and lowers compression to 10.24:1.

 

Cam is abit big imo. Much better for a hotter 383. In a 10.5 355, its not gonna move well under 4500-5000 rpm. It will turn 7000 with the right intake and 195-210 head and make killer top end. It will make the big hp tho just alot higher in rpm range.
Guys have made 400 whp with alittle less cam than that

 

Ah, used the wrong set of AFRs for my calculation. I apologize. If nothing else, this demonstrates what you get for being careless. He's right, measure, and then measure again.

 

I have to disagree with you on that.

I run a bigger cam on my 355. 249/252@.050" with 200cc heads and it's a beast from 2500-7000 rpm. I run a 3500 stall and 3.89 gears. No lack of low RPM torque. Was a daily driver for a couple of years with this combo as well.
My 0-60 mph is 2.9 seconds, no track time on it yet but guessing 60 foot times will be traction limited to high 1.4's, low 1.5's on my nitto drag radials

 

Sorry, but a lot of your info is wrong.

Crown style is not what makes up piston weight. It's the alloy used to make pistons. There are domes that is lighter than the common flat tops.

Not all pistons are created equal
70's and 80's cast stock 350 dish pistons are in the 750 gram range
Vortec stock pistons are in the 650 gram range
Speed pro hyper flat tops are in the 590 gram range
Speed pro forged flat tops are in the 610 gram range
Wisco forged flat tops are in the 457 gram range

Good forged pistons of today, do not run loose clearances like the old TRW slugs of 30 years ago. It's all about the alloy they use. A lot of the forged pistons runs .0025" to .0035" piston to wall clearances. IIRC my wisco pro tru pistons ran at .003". That's just a hair over what you would run a hyper piston at.

The scat 9000 crank is very strong. In fact it's almost as strong as a stock forged crank, and lighter than a stock cast crank. I'm going on 10 years on my scat cast 9000 crank, in a 11 second daily driver.

My old combo I shifted at 6400 rpm... New combo I shift at 7200/7300 rpm. Again 10 years with this crank.

My speed pro hyper pistons are the only part on my engine that failed. #2 cyl piston cracked from top ring land up and across middle of crown. That was after about 4 years of use.

I noticed the crack before it let loose.. (Had heads of doing a head and cam swap when I noticed a line across piston)

Rebuilt with Wisco pistons, new bearings, same scat crank.. That was 6 years ago


For 5-6 years the car was daily driver (only car in fact) and also seen 1/4 mile track time almost every weekend. For the last 4-5 years, it has became my weekend toy

 

Hydraulic roller? If so thats as big as the cam in my 400" sbc. Way to big imo. I'd be impressed if you can get a 1.6 60' with only 3500 stall on that setup. But i'm sure it flys up top

 

No, it's a solid flat tappet cam.

With my old combo (less cam, less heads, less stall, less gear) I ran 11.40's @ 118 with 60' times in the low to mid 1.6's

 

Oh ok. A hyd roller of those specs would act different. It would act abit bigger because no lash adjustment

 

Yep, a solid cam does act about 4-8 degrees smaller than the same duration hyd. due to the lash as you mentioned.

Also a roller cam has a more aggressive lobe profile than a flat tappet cam, but some of the modern mech. flat tappets are getting pretty aggressive and as close to a roller cam ramp speeds as possible

 

Pretty much you can take the lash setting and divide it by 2 and subtract that form your duration, so a lash of .020 would be 10* smaller than advertised as a basic rule of thumb.

 

I heard that old rule of thumb before. It gets you pretty close but the more aggressive the lobe the less accurate that is due to the ramp speed being faster, but it's still close.

Mine is a tight lash Howards cam. .015" listed lash.