Ok so i am planning on building a 350ci engine with atleast 400hp, but i cant seem to find the best parts for it or even how to go about doing it. my biggest problem is i only have basic knowledge on cars. some of my questions are tpi or carburated i want a supercharger will that change the rest of my engine parts i need, what are some good parts for me to get ect ect.

i only have the block so far, and i dont plan on doing anything until i have the money. which wont be untill the near future.

 

i dont think anyones touched this yet because its a LONG answer

might want to spend some time reading a few of the tech articles off the main tgo web page, the link is right on the sidebar.

when youre planning a motor theres a lot to think of, and EVERYTHING changes if youre going forced induction.

if youre going forced induction you need pistons, cam and heads all designed for your application. When youre compressing air into the motor it raises the compression inside the combusting chambers. where as a N/A(naturally aspirated) motor will have around 10.5:1 compression, a forced induction motor will be considerably lower because when the boost hits itll raise back up. paxton makes a nice bolt in kit for our cars.

That being said 400 rwhp is definitly attainable through a NA 350. First you need to find a set of heads that will support the power you want to make, for what you mentioned AFR (air flow research) 180cc heads are one of the most expensive heads you can buy for your application but will easily meet your goals.

from there you pick a cam that matches what lift your heads flow useable air until, and duration based on where you want your powerband to be, the more duration, the higher your powerband goes.

After that you can run whatever style intake you choose wether youre running carbed or fuel injected.

hope that helped to get you started, youll learn an awful lot from reading the tech articles, doing searches using the search function on the board, and just reading other peoples posts.

 

You remind me of myself, so I'm going to humor you with a novel on this.

What block do you have? 1 or 2 piece rear main seal? If it's a new block, is it a roller block? (meaning, does it have dogbones in it for roller cams?) Is it a 4-bolt or 2-bolt block? Is it a 4 inch bore block? Is it a 305 or 400 block? Is the machine work done already? If not, get that done. If so, are the bores oversized at all? You'll need to know all this.

Supercharging costs a ton of money also, but if you really want the advantages of it, you're going to have to build your motor around it and pay for it. Probably a fully forged bottom end for that actually, which will put your rotating assembly cost from below $500 to closer to $1000.

A carb is going to get worse gas mileage in most cases than fuel injection. Fuel injection systems can also end up costing as much as the rest of your motor combined, plus the cost of the equipment to tune it or to get it tuned. A carb is the price of a manifold, fuel pressure regulator, and the carb itself, plus gas costs. But judging by how much these systems cost, I dont regret goig carb at all. I may pay more at the pump, but I've got at least an extra grand in my pocket. This, along with the fact that fuel injection doesnt actually give you any performance advantage over carbs (just practicality advantages in regards to mileage, emissions) is why so many guys go with carbs I think. Carbs are much more forgiving with crazy cams also.

If you've got hte money, some nice AFR's with 64 cc chambers and 180cc ports (Don't go larger for a street motor) would work great, but if you dont have the money for aftermarket heads, you'll have to pick among stock heads.

Good stock heads to look into (Searches on TGO are a GOLDMINE of information, use it) are 083s, 113's, 062's, and 906's. If you want to go forced induction, some larger chamber AFR's would work great for that probably, but Im no expert on forced induction.

What do you need your car for? Is it a daily driver? Weekend toy? Strip car? You can build a motor with 500hp if you want, but it's probably not going to have good street manners.

When you have your answer to that, figure out the following:

1. What power level are you after? 400 is the high side of reasonable, but doable if you can spend the money on heads. Otherwise, you can get 300-350 pretty easily from Vortec heads (factor heads are much cheaper) but they carry some baggage (intakes, valve lift limitations) to deal with. And remember, you can always try an LS-based motor, but that's much more a modern no-man's land around here. A bunch of guys here have built LS motors, but they're a different animal in a lot of ways.

2. After defining power level, you have to use that to figure out what compression ratio you need? Remember around 9-9.5 on the street, but you can go much higher with race gas, higher compression = more power. If you need more power than you can get at 9.5:1, then that's when you consider forced induction, which would dictate a much lower compression ratio. Go back and forth between this and number 1 until you're satisfied.

3. After defining compression ratio, figure out what heads and pistons you need together. Flat tops and 64cc heads generally are in the mid 9s for compression. Depends on a lot of other things, but I'm ballparking for now. AFRs are great but pricy. factory heads are much cheaper, but have less potential. Do searches and look into 083's, 113's, 062's, and 906's. Those are the "good" heads you'll want. Research heads and constantly refer back to 1 and 2 to make sure they fit what you need, if not, make adjustments somewhere.

4. Figure out whether you want to go fuel injected or carb. Compare prices. Carbs are easier to find used that fuel injection setups unless you go with factory fuel injection which has shortcomings. Refer back to 1 and 2 and 3 to make sure it fits your needs, if not, make adjustments.

5. After figuring out what cylinder heads and pistons you need, and what fuel injection you want, you figure out what cam you want. There's a GREAT tech article about this, read it, learn it, love it. Cams are much less confusing than they seem. They throw flurries of numbers at you and you get blinded but it's really very simple when you figure out what they are. In order of importance, you get duration at .050, valve lift, duration as a whole and LSA. Duration at .050 is the most important but different manufacturers measure this differently. Do a LOT of research on cams to find out what results different people have gotten with different ones. A roller cam is going to be different than a flat tappet cam, your block will dictate which you will use. I'll ballpark a number out for you for the sake of comparison. Try not to go above 230/230 duration at .050 for a street car, depending on a lot of different things. Make sure your cam matches every previous point I bring up. It's going affect your compression ratio indirectly, and it has to work well with your heads. If you go with fuel injection, that will also limit you to what cams you can use. At worst, make a post about this later on when you're picking out parts and people here will be glad to give you feedback on different options. Referback to 1, 2, 3, and 4 to make sure it still fits your needs, if not, make adjustments. Seeing a pattern?

6. Figure out after all this what kind of power level you're going to be at after all the above steps are done, build your bottom end appropriately. Do searches on what people have used. Cast cranks arent as strong as forged crankshafts, but most people dont need forged. Forged rods are stupid not to get, pistons can be cast, cast hypereutectic, or forged. Induction, power level, and budget dictates all of this. Do some searches on it. Im building a 300 rwhp motor, I have a cast crank, forged rods, and hyper pistons. This is a fairly common setup. Look into rotating assembly kits from Scat or Eagle on summitracing.com or jegs.com . If you buy one, make sure it's already balanced. You can get it balanced locally but it's just less of a hassle to have them take care of it already. Refer back to all previous points to see if everything is still working out, if not, make adjustments.

7. From here you've got to do the research and figure out ALL the rest of your parts. You'll know what you need because the parts you already have will dictate them. IF you dont know, do a search, then ask.

Do NOT underestimate the search here. There is damn near 10 years of knowledge, frustration, feedback, and results on here, you can find almost anything if you know what to search for. The farther you dig into the rabbit hole, the more you'll learn, the more questions you have, the more searches you're going to do, the more you learn. You can figure it out if you want to. It's not nearly as complicated as it seems, but it's about trying to put together a combination that fits, and that's where all the research comes in. Parts that will bolt together, while definitely an important part of having a good motor, wont make it a good motor all by itself.

 

Thanks to both of you for you input.


unh im not sure i got the block for free from some guy on craigslist so im trying not to look a gifthorse in the mouth. but i will put pictures up of it. and yes it still needs machine work, ive been told not to bore it for it causes future problems, its going into a weekend car one i will drive on the street, i want to drop it into like a 72 stingray or chevelle but im not sure yet.

 

boring the block will in NO way cause future problems... unless it has already been bored to its max and then it is about useless... i would say if it has already been .040 over to not even bother... personally i wouldnt even touch it if it was .030 over


the block is going to be the BIGGEST determining factor at this point we need pics or casting numbers... located on the driverside bellhousing flange

 

LOL vortex you werent kidding about writing a novel

two different things in regards to boring it.

Firstly theres the old saying theres no replacement for displacement. You can bore out a block to gain 5-10 cubic inches over all which will indeed give you a little bit of extra horsepower.

Realistically tho you dont bore a block unless you have to. The only reason to bore a block is if theres big gouges in the cylinder walls that are still repairable, but you need to take all of that metal out to repair them.

otherwise what a machine shop will do is hone the block, which is just taking a very thin layer off the inside of the cylinders to make sure you have a nice flat surface for your piston rings to seal againts. you need to know exactly what your block has been honed to so you know what sized pistons you need.

Now if you have a 350 block and want more cubes, what people do is put a 400 crank in a 350 block. I think in some cases there is some minor clearancing that needs to be done, however if youre spending the money to buy an all new rotating assembly (crank, rods pistons) for about 100-250 dollars more you can get a stroker rotating assembly.
this will take a 350 (bored .30 over) and turn it into a 383. this is your best option for making lots of power.

You can run a 200 cc head no problem with a 383 which makes it easy to hit 400 wheel horsepower.

 

the casting #s where a bitch to read since they where all messed up but its

3970010

should have pics uploaded by the end of today hopefully

 

Thats a 2-piece rear seal, non roller block. Could be 2 or 4 bolt main. Very common block, used 1969-1980. I'm acutally building one for my brother's 'Vette right now.

 

That is probably the single most common SBC casting. It was used in 350s all through the 70s (most of which were pitiful performers, which don't let people fool you, DOES NOT MATTER at this point); and a few 302s and 327s as well.

It's SO common, that you can go to some junkyards, and literally trip over piles of them waiting to go the foundry to be melted down. You can often pick them up for free if you happen to be buying something else at the same time.

It's as good as any other 350 casting for building a motor from; except that it doesn't have the roller provisions (duh). Things to look out for are all of the typical 70s quality control problems, which that block casting is KNOWN TO BE afflicted with; casting core shift, porosity, cylinders that aren't vertical (tilted front to rear), lifter bores that don't point straight at the cam, starter bolt holes that are drilled too far from the crank, BH flange not perpendicular to the crank centerline, BH dowel pins not centered on the crank centerline, head dowel pins in theh wrong place such that the heads aren't held in the right place, and so forth. An "inferior" casting with NONE of those QC issues, is a FAR BETTER foundation for a motor, than the "best" casting that DOES have them. GET THE BLOCK CHECKED BEFORE spending money on it, it truly sucks to either waste money on machining an inherently defective block and having to scrap it, or going through the entire build process only to end up with a motor that won't start or eats cams or eats trans pump bushings or whatever. YES, it happens; YES, IT CAN HAPPEN TO YOU.

To make power, don't get all wrapped around the axle about expensive, romantic-sounding, "only the best for me" type of bottom end parts. At such a low power level, that stuff just isn't necessary. Spend as little as possible on those parts. Stock parts will work fine, except that if you use stock rods, you MUST replace the rod bolts, or you MUST BE willing to risk your motor turning into unexpected catastrophic shrapnel. I'd suggest a stock or stock-replacement crank (Scat, Eagle, or Lunati for example); stock or stock-replacement rods; and either forged or hypereutectic flat-top pistons. On the pistons, THE MOST IMPORTANT THING to watch out for, is the "compression height"; most "replacement" pistons, such as SpeedPro, will locate the tops of the pistons .020" farther "down in the hole" at TDC than stock, which is already about .025" or so. Failing to take this into account will lead to RADICALLY over-estimating the compression ratio, and usually to a lack of low-end torque due to over-camming for the ACTUAL compression. The end result is a motor with no leave whatsoever, and a totally "soggy" bottom end; one of those wonders you see from time to time that are only capable of running "from a roll". You'll end up building one of those that you see on here from time to time, about "I just spent $4000 building this mountain motor, and it won't even spin the tires from a stop like my old LG4 would". Very bad feeling.

As you can tell from the above description, the right COMBINATION of parts, and the appropriate MACHINE WORK, are FAR more important than the brand name (or even the price) of the pistons themselves. Do not skimp on machine work, and DO NOT buy it from the low bidder, just because it's the low bidder. Machine work takes time. Time is money (they charge basically by the hour). Good machine work, which is to say, attention to detail and not skipping steps, takes EXTRA time. It also takes a good, qualified, experienced operator ($$$/hr) using good quality, well-maintained equipment (more $$$/hr). Lots of hrs x lots of $$$/hr = lots of $$$. If there's ANY ONE PLACE to spend money in a short block, it's in the machine work. A well-built motor made of mediocre parts will run better and last longer than a sloppy-built motor made of high-$$$ parts.

Next, pick a set of heads. Something in the 180-200cc range is about right. Afr 195s, TF195s, Dart 180s or 200s, and the like, are about right. Stock Vortec heads are OK too, but impose other kinds of limitations that by the time you overcome them, you will be dangerously close to aftermarket money. If you decide to use the Vortecs, concentrate on how to work WITHIN their limitations as much as possible, rather than how to overcome them; the latter is economic suicide.

Next, pick a cam. You CANNOT do that until you know the properties of your heads and your short block (compression). Cams are CHEEEEEEP. Even the very best are still only a TINY fraction of the total cost of the project. The difference between the cheeeeepest cam you can buy and the best cam you can buy, will DISAPPEAR within a handful of tanks of gas. Spend whatever it takes to get THE RIGHT cam for the rest of the combo. There is no point in ruining an otherwise good combo by trying to cheeeep out on the cam. Although, it's a good idea to have some sort of an estimate of what the cam you need will eventually look like, because that will affect the machine work and parts choices (valve springs, valves, valve lengths, etc.) for the heads. For a 400 HP motor, figure you're going to need a cam in the high 220s to low 230s of intake duration, with somewhere between .500" and .550" of peak lift, with the most aggressive possible lobes (Comp XE, Lunati Voodoo, etc.). If the heads are set up for such a cam, you'll be in good shape.

Then, last of all, pick all of the peripherals; intake manifold, exhaust, carb, ignition, etc.

What kind of budget do you have for this?

 

no matter what you decide to do spend the money on a forged bottem end brlieve me it'll pay for itself 3 fold. if you are wanting to go forced inducted try and keep your compression between 8.5 & 9.5:1

 

Wow, there are some GREAT write ups in here, very knowledgeable people.

 

 

"Then, last of all, pick all of the peripherals; intake manifold, exhaust, carb, ignition, etc."

What sofakingdom said at the last will make or break your goal. You will need a 1st class exhaust system and intake to reach your goals. These are called "supporting mods". They will make or break your project.

Also any of the heads he posted will do the trick. They should be mildly ported by a professional to make your goal easier. If you don't have good heads you might as well forget about making the power you want.

By the way I'm running 10.73" compression on 91 octane with no problems. That is with .035" quench.

 

 

I wouldnt worry too much about the bottom end either, build whats there and if anything ditch the factory rod bolts and thats about it. Even if you supercharge it. I'd be a lot more concerned about the head gaskets and rings than any of that other stuff. And the trans... surefire way to kill a 700r4 is put some power in front of it.

Do you need to run a TPI? Reason I ask is it becomes a hurdle at that power level and with a carb you dont have that issue of addressing it in whatever manner you feel will work best.

 

what the hell are you talking about. Theres no point in running forged crank or rods if youre making less the 400 wheel horsepower.

might be worth throwing some forged or hyper pistons in if you want to run a shot of nitrous or something, not to mention they will survive just that much more detonation or wany other hardships better then stock stuff.

just get the stock stuff balanced with new pistons, put in good bearings and good bolts, good head gasket, and good rings.

 

scottygowild


step 1 BUY AND READ THRU THESE 4 books,
BEFORE you buy a single part,
it will save you thousands of dollars and weeks of work, if you don,t have an excellent grasp of all the basic concepts youll make expensive mistakes

http://www.themotorbookstore.com/resmchstvi.html

JOHN LINGENFELTER on modifying small-block chevy engines
http://www.amazon.com/John-Lingenfel...pd_sim_b_img_1

HOW TO BUILD MAX PERFORMANCE CHEVY SMALL BLOCKS ON A BUDGET by DAVID VIZARD

http://www.amazon.com/Build-Performa...6449811&sr=1-1

SMOKEY YUNICK,S POWER SECRETS

http://www.amazon.com/Smokey-Yunicks...6449683&sr=1-1

 

Not trying to steel your post, but pretty much doing the same thing that your doing. These are the parts i have so far:

- Pistons-Speed-Pro cast aluminum10.2:1 compression ratio with 64cc combustion chamber. Ring grooves are 5/64'', 5/64'', 3/16''. 1/pkg.
-Crank-14088526...305,350...cast....medium journal...3.48" stroke
-Block-10243880...350...95-00...2 or 4...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal.

I bought the block(2 bolt mains) with these parts, I am also trying to make about 400hp @ flywheel. I have a $1300 budget. Is that reasonable? If so, what cam and head combo would you guys recommend? mainly street with occassional strip.

 

for $1300 you'll have to buy a lot of cheap, used parts. It can be done but it wont be easy and dont forget to include an exhaust system (headers etc) in your budget. You'll ahve to buy bolts and gaskets too probably. Easily into the $150 range for both of those (I think I spend around that on just the bolts... $70 for bolt kit, and $60 for head bolts).

Is the machine work done on the block? That will cost you a HUGE chunk of money if you need to get machinework done, and if it hasnt been done already, you need to get it done. It's not really optional if you want your investment to last, and $1300 is enough money taht you dont want to waste it.

Some L98 083 heads, squarebore intake and Holley carb will cost you around $500 all together if you're really lucky and buy used. The bottom end will cost you about $500 all together if you buy decent budget parts. That still leaves pretty much the entire valvetrain to pay for, plus all those other nickel and dime parts that will just kill your budget.

You're going to have to do some research about how hard it will be to get 400hp at the flywheel with L98 heads. I couldn't tell you. It would seem to me that i would be pretty easy, but it would require a medium or bigger sized cam probably.

Im no expert on motors, but I just went through the same learning process over the past year getting mine together...



A 350 on a budget is a 350 that you have to take some calculated risks with as far as longevity and reliability go... I generally chose to wait a little longer, spend a little more money ,and get some nicer parts, and hopefully it will pay off with a solid motor... but these things are pretty unpredictiable, so it'll be interesting to see if it stays together.