Looking to do a 350 build with a 4 bolt 350 I have. Looking to either get 400~500+ out of the engine from internals, and later down the road bolt on a supercharger or go turbo, haven't decided... Wondering if theres something I could do to make this current engine push about 4~5##, and later just bolt on.

Current Engine Laying Around

19?? 350 4 Bolt Main
Dist: GM Performance #809-93440806
SB/BB Chevy HEI Distributor
Cam: Comp Cams Xtreme Energy Hydraulic Flat Tappet Lift: .447''/.454''
Duration: 256°/268°
RPM Range: 1000-5200
Intake: Weiand #925-8120
Action +Plus Intake Manifold1955-86 262-400ci4150 Carb FlangeIdle-5500 RPM Range
Carb: Edelbrock 600cfm carb
Heads: Stock L05
Everything else is stock.

 

anyone?

 

i think it will make about 350hp

 

Really just about everything would need to be changed. Getting 4-5 hundred hp out of a 350 requires a fairly radical build. Low 400's could be done if the heads are the vortecs with the small combustion chamber but the cam would need to be swapped to a more agressive cam larger carb different intake like the edelbrock performer RPM. Probably could use a bit more compression still. To get up into the mid high 400s that big time not streetable parts unless you stroked it to like 383 or something then its more doable. Problem is to go supercharged or turbo charged you would build it very differently causeing you to change things around once again. My point is if you want to go FI save your money and do it all at once. Till then just enjoy the build you have as it looks like its a very fun street friendly build.

 

You will need to go further than what you have listed for 450-500hp. For 500hp from a 350 Chev, start thinking about something like this:

* Aftermarket heads - AFR 210s, Dart Iron Eagle 215 or 230s etc
* Aftermarket intake - Edelbrock Performer RPM Air Gap, or Single Plane
* 600cfm carb won't cut it - go 750.
* More camshaft - around 240 duration @ 0.050", .550" lift, 108 LSA.
* Aftermarket rods and pistons with around 11:1 compression.
* ARP Bolts throughout

 

Thank you all. Well I'll just have low 4##'s hp/tq if possible. Would changing heads to vortec be enough to put that out?

 

The lo5 may have vortec heads on it depending on year just incase you didnt know or havnt checked. Vortec heads are pretty amazing im my oppinion especially concidering the cost as even new sets are dirt chep as far as heads go and perform great. I would guess that it would be very possible with a good set of vortecs to get into the low 400s and maintain street ability. You can do a quick Google search on the matter as virtually every magazine that does a budget SBC build features a set of vortec heads and they produce some pretty impressive numbers. Now I still think that cam is too tame to get you into the low 400s though. I mean its probably what around 210 duration at .050? To get into the low 400s were talking more 230s at least on the duration again at .050. The intake as well although im not too familiar with it try it see how it goes but it may need to be swapped. Carb should probably be upped too a bit but you can try it see what happens but i think it will fall a bit short. However a build like this will tend to kill your low end torque which on a street car is what you really want as 99% of the time your in the low end.

 

its a pre 86... vortec came around 96+? hmm.. i'd like to build it so its 4## streetable..

Throw me a streetable build with 4## on a budget?

 

Going to a cam like a 218/222 on a 110LSA or even a 224/228 on a 112LSA would still be fine to drive on the street, have a much better mid range than the one you mentioned, and have nice tough idle without being "cranky".

A 400hp budget build might be something like:

*Eagle "street" rotating assembly - comes with crank, rods, pistons, ARP bolts, rings, bearings etc rated up to 500hp around 9.5:1 comp.
*Dart Iron Eagle 215cc heads
*Edelbrock Performer RPM Air Gap manifold
*Holley/Demon 750 carb
*mid-size cam 224/228, .500 lift, 112LSA, flat tappet

That should make somewhere around the 420-430hp mark and be fine on the street if tuned properly. You could probably save a bit by going with the stock rods and crank and Vortec heads, but the Eagle "Street" kits are pretty cheap and come with everything you need, as with Dart iron heads - cheap and come full assembled.

 

could you explain the cam. i'm not to well informed of understanding the math to the parts...

but over all, i should just re-overhaul the whole engine to get a streetable 400's?

 

224/228, .500", 112LSA

224/228 refers to the duration @ 0.050" lift - 224 being on the intake side, 228 on the exhaust side. Always look at the duration "@ 0.050"" when looking at cam specs, ignore "advertised duration".

.500" is the maximum lift of the cam assuming a 1.5 rocker ratio - will be more lift with a 1.55 or 1.6 rocker. I have said .500" lift for both exhaust and intake, but it is not uncommon to have different values for intake and exhaust.

112 LSA is the Lobe Separation Angle - this is usually between 106 and 116 - lower numbers are better for top-end power and less for bottom end torque and drivability - for racing mostly. A higher number is usually a street cam focused on smooth bottom end and idle - 110-112 is somewhere in the middle for a good compromise.

 

224/228 is duration as of seconds?

ok so i understand, say if i have 1.5 rockers with a .5" cam lift, that makes 2" lift?

how do i know whats safe on the heads?

when do i know the intake and carb is to much cfm its not needed?

I know how to build and put together an engine i just don't know the math at all...

 

The duration is measured in degrees of rotation.

The lift is at the valve, not the cam - even a Top Fuel engine doesn't run 2" lift. .500 lift will be fine, you just need a decent single spring, don't need doubles, piston to valve clearance shouldn't be a problem either.

Carb should be between 650 and 750 - either should be ok.

One way to tell if a cam will be streetable is to work out the overlap - take the intake duration (@ .050") figure and subtract the twice the LSA (so 112*2 = 224). If the result is greater than zero, then the cam is getting on the big side (more for performance than street driving), if less than zero then more for streetability than performance. In this case 224 - (112*2) = 0, so it is kind of a hot-street cam without being over the top. Something like a 252/258 cam on a 110 LSA, the overlap is 32 - which is more focused towards performance than streetability.

Obviously what one considers "unstreetable" will vary person to person, as well as stuff like displacement, compression ratio etc, but it makes a good rule of thumb.

Hopefully that makes sense.

 

ok i get it now, but lets consider that I have this and how will I know what a good intake would be for the heads and carb?

 

Generally with carby engines you have 2 types of intake - dual plane and single plane. The main difference between them is the runner design.

A single plane has longer runners which will aid in breathing the top end of the rev range for better top end power, at the expense of low-down torque. A single plane will usually not fit under the hood because they are taller.

A dual plane intake is more for bottom end performance, but runs out of steam early.

A few companies make "hi-rise dual plane" intakes which are somewhere in between for good bottom end and good top end with strong mid range.

The choice is determined by lots of different factors - cam size, application, gearing etc. For a 400hp target a hi rise dual plane like a Edelbrock Performer RPM would be the ticket.

 

is a dual plane need 2 carbs or is it the design as you said?

 

Well when you said you had stock LO5 heads I believe 96 and later LO5s had vortec factory heads so I figured ide just make mention of it as even though i figured you probably ment stock heads that came with the car again just thought ide meantion it. Anyways what i would do to get low 400s on a budget? Vortech heads from summit there dirt cheap flow great and have already been machined for high lift cams. Or if you could allow for like $700 go strait to GM and get their bowtie vortecs theres pretty much the high performance version of an already awesome head. Next edelbrock performer RPM air gap intake topped with a 750 CFM carb, the cam im torn over the XE274H or the XE284H. I hate to use a larger cam that is absolutly neccessary and the 274 might cut just fine it but im very confident in the 284 would do it but you would lose even more streetability.Dont forget the exhaust though. This motor although capable of building over 400 hp would be seriously reduced by the factory exhaust. To me thats about the cheapest way to go about it however thats assuming you end up with 9.5-10 to 1 for compression. So may wanna take a look at those pistons as if there dished thell probably need to be replaced with flat tops.

 

Dual plane intake is just the design. Its immediately noticeable as there is a divider in the intake where the carb bolts down to separate the left and right cylinder runners. Single planes are just wide open.

 

I went to a performance shop and they quoted me about $2500~3000 for them to build me a streetable high 3## on the 350, thats me handing them the 350 block to do all this. I'd rather have it build from pan up now.. :\ and they are the cheapest i could find in CT and reliable. Just rather have it truly overhauled and done..

 

Well it depends what there going to do with it. I mean if they were going to rebuild it, do all the machine work, build it and all that thats not too bad a price depending on what there using for parts. Other wise it doesn't sound too bad. I would deffinetly want some sort of a parts list from them though to see what there going to use.

 

I talked to the guy and i may just wait the 5 years out so i don't have to go through emissions so then i could have a bit more power from the engine. Rather than worry about it being streetable. :P But i did talk to him, IF i was going to go through with it the most i know is he'd get all new parts and a pair of cast iron vortec heads 906, along with a intake for tbi and swap up to a 454 tb, for the cam i don't know specifically but.. thats the most i know..

 

Well technically even swapping in the 350 is illegal and even with a high 300 hp motor i have my doubts you would pass the sniffer anyways. Personally if your concerned about it from an emissions stand point I would deffinetly concider holding off. Nothing worse than having a car you cant register because it wont pass emissions. I mean even just deleating the EGR valve as vortecs dont have the heat risers in them in combination with the high compression alone would make you fail miserably on the NOX. Granted there's virtually always something you can do to make it pass but it can be a real nightmare.

 

Wish my car was older... I just love the trim I got so much for my year though.. -sigh- but

 

No problem and i hear what your sayin about age but its only a few years away. I know I was absolutely ecstatic when my 83 Camaro had no more emissions and soon my 86 T/A will enjoy that same privileged only having to go through just one more time. However having to push it off a few years isnt necessarily such a bad thing as theres lots to do till then. In the mean time there are mods you can do that are even street legal that will be reused on the 350. Also things the should be preped to get ready for a hot 350 like sub frame connectors, a built transmission with a higher stall, and replace the rear axle with something stronger. Stuff like this should really happen first as a 400 hp motor will destroy all of these things its only a matter of time not a question of if. Not to mention you now have years to do the research and shop around for good deals on the parts you want. I mean getting vortec heads through summit, should you decide to go the route, when they offer their 10% off discount alone is a pretty big chunk of change. The glass is always half empty or half full.

 

Yeah, come spring I already decided to buy rear lower control arms, panhard bar & subframe connectors from spohn, just to prep. I already swapped my rear from a open diff 2.73 to a 3.23 limited slip. My transmission was rebuilt along with a torque converter thats aftermarket but honestly, i don't know for what it was built for... either just stock rebuilt or for more performance. i don't know the previous owners expectations toward what they really wanted to do with the car. Since i will be saving my decision will be supercharged 350 or twin turbo 350 now.. looking for either 5~6## hp/tq, idk if im asking for to much now..

 

Well there in lies the problem that everyone faces. To build a monster lots needs to be done more than most people want to do and at an expense greater than what it would cost to buy a vette which would be a significantly better starting point. Its just once you start to ask more from it than it was ever designed to do you basically end up with a whole new car when your done to really make it right less the sheet metal. This is where like you see the reality of the situation kinda hits you in the face. Now again it still could be done and there are ways of doing it more cost effectively but theres an quote i heard on here once a while back that could not be more true "cheap, fast, reliable pick 2 of the 3." However if i might make a suggestion lets talk practicality for a moment when I look into a project rather than start out with numbers its best to define the goal first. What i mean is what do you hope to achieve when this is all said and done? Once a clear goal is defined then figure out how to get there. For example say your goal was to get into the 13s in the 1/4 mile. From there we can calulate roughly how much power that will take and a powerplant can be chosen to best meet that goal and so on. Or if you were looking to build a car that was mostly going to be on the street and probably never see the track as there are no official drag strips in CT we might figure out the range of RPMs your at most on the street and try to build as much power there as possible because as science states acceleration = force/mass so the more force (torque) we can generate at that RPM the greater the acceleration there will be. What im trying to say is outline what you want first and come up with a plan as to how best meet your expectations.

 

I actually like how your explained yourself. thanks! I do plan to go to the track with a buddy once in a while of the year. My 1/4 goal is 10 sec. My car will be mostly on the street, considering it will be in CT like you said. I'm on the highway alot more than the street when traveling.. just want to give some info on my car just so you know what your working with...

My current car is:
1989 Camaro RS, 305 TBI, tuned chip, msd dist cap, msd coil, open air element 14 x 3, tbi spacer .5", gapped plat spark plugs, stock 15" rs wheels, 3.23 limited slip drum rear, stock exhaust w/ headers but end with flow master exhaust, 3.5" steel cowl hood w/ OAE trim, x2 10 subwoofer w/ box, ac delete pulley & blower motor housing, wonderbar

 

Ok well now lets talk some numbers. Your car being thats its a later modle camaro and being an RS on top of it lets assume its around 3500 lbs with the driver which i think is a little generous but well go with that. This means to propel something of that weight to 10 seconds even would require just under 700 hp! To hit a flat 11 second time this would require about 520 hp. So figure to get into the 10s you would need between 520-700 hp. This means we either have to abandon the idea of using a N/A 350 (unless we could work in a shot of NOS into the equation lol) or do some serious work on that weight. Keep in mind too that weight is just factory weight not including sub frames roll bars or anything like that. Futher more because this is going to be a street driven car it has to be atleast some what well mannered with decent low end torque. Probably dont want to have a car that hesitated constantly in the low RPMs idles at 2k rpms dosnt run on pump gas stuff like that. This leads me to believe youll need a hot 350 with a fairly decent shot of NOS, forced induction 350. You could also do things like go 383 or swap in a big block because here bigger is better because the bigger the motor the more tame it can be while hitting the same HP output and thoes numbers are pretty imposing. Next up is the trans although you could build the 700r4 up to be reliable at those kinda numbers it will be immensely expensive. A better choice would be to go with a turbo 400. Its much much cheaper and i believe the "weak point" in thoes trans breaks at like 500 tq stock. Another problem with building motors up too radical is you start to need a larger stall converter but for the street you want something on the low side. Depending which way you go we can get into that further but i wouldnt like to use more the 3k at the very max for a street car. Now the rear end. Really theres not much of an option here just replacement. For something like this ide use the ford 9 inch but others will recomend the chevy 12 bolt either will work but i like the 9 in better and its stronger. Gearing for a radical motor is again going to have to be on the steep side more so the more radical the motor. This is kinda in contention with the th400 idea because it has no overdrive so the steeper the rear gears the worse its going to be on the highway which being that u said your going to spend a lot of time here a steep rear end with no overdrive might be pretty rough. This is really just the beggining as we still havnt talk about stucteral issues, suspention work, traction issues lol, and there has been made no mention of legality or what it would be like to drive a car like this on the street. It really goes to show why there arnt many 10 sec cars on the road lol.

 

Would aiming for 11~12 second be more reasonable with a 350 with engine work and a bolt on?

 

A 10sec NA street car is a pretty serious piece of kit. My old LS1 made 417rwhp and ran 11.89 @ 118mph on street legal tyres (Mickey Thompson ET Streets) with a T56 and 3.9 gears in a car which weighs roughly 3800lbs.

That car was pretty wild on the street, it would light up the tyres at 80km/h without a problem, and in the wet it was down-right dangerous.

A 12 sec car would probably be a better option - around 400hp should get you there in a Camaro which is not a big deal for a 350 Chev. Around 500hp will get you deep into the 11s, or even high 10s with the right setup. Once you get into the 11s though, that is where you will need to consider more about the setup of your car than just power. All the power in the world is no good if you can't get it to the ground. Suspension, tyres, and the strength of your driveline all needs to be considered.

It is probably best to consider first what you use the car for - daily driver, weekend cruiser, street/strip terror or pro-street drag car, and do your homework as to what is best to suit.

Personally, a 400hp 350 would be a great compromise for all of the above. You have enough power to do something stupid, with daily driver reliability, so you can use the car every day, drive it to the track to run some mid-low 12s, burnouts or whatever you want to do.

Many people get caught up in power figures. Setup and power delivery is the key to a great performing car. Many people don't realise what a 500hp car do or what kind of pressures that 500hp or 500ft-lbs puts on engine and driveline components.

 

The car only comes out in the spring, summer, fall. i don't bring it out in the winter. It will be the daily driver i guess if that's the selection. Theres moments i'm going to act stupid, i'll admit that. So in the area of 400~525 are the numbers i should be looking for though? I do plan to swap in 3.73 gears to the diff and then upgrade to strange. Would the 89+ alu driveshaft handle the tq or would i have to go carbon fiber? Anything i should look towards to beef the body? The car is a ttop car as well, forgot to mention that.

 

Yea 11s-12 would be a bit more do able as described earlier it woult take about 520 hp to hit 11 flat but to hit a 12 flat it would take about 400 which is within reach of a hot 350. Personally I still think you would be best off with a shot of NOS because you could build a real tame street able motor that could perform like a hot 350 on demand. I dont really think we could go much farther than 450 on a N/A 350 while maintaining any semblance of a streetable motor. If you had it stroked out to 383 during the rebuild as its probably going to be punched out anyways there wouldn't be so horrible price wise and would be much more street able for a given hp. As far as the drive shaft the stock steel or aluminum ones have held up to 400 hp but beyond that you may want to consider going to an aftermarket aluminum. I dont really know what the exact hp limit is on them but thats my take on it.

 

Well i don't mind going to a supercharged build for a 350. I'd rather not waste money on a nos setup, imo.

 

Well if you didnt mind going forced induction that would be best. I mean you could get a low 400 hp 350 but you could do the same with FI and have it be more streetable and with better gas mileage. I think it was super chevy got a 302 with 500 hp and like 20 MPGs. Granted this will be kinda pricy as not only do you have to get a supercharger or a turbo set up but theres a lot of custom work to be done to make it work and the motors internals will need to be changed around a bit as you know already. Idk at that rate though a 383 looks more tempting as you dont really need an FI system to get into the 11-12 bracket but a 383 would be more capable than the 350. The 383 would just be cheaper and easier while still accomplishing the same thing. A 350 could do it just the 383 could do it better.

 

If you go with supercharged, then it is a different kettle of fish - lower compression (should be in the high 8s rather than high 9s), different cam profile, forged pistons rather than cast or hypereutetic, H-beam rods rather than I beam, and a forged crank would definitely be a good idea for extra insurance.

With the right setup, you can easily make 500+hp at the rears, with a decent twin turbo setup 1000rwhp is certainly possible. Don't forget what this will do to your drivetrain though - make sure that the box, diff and tailshaft are built to cope with the power level you are going for - probably best to talk to a reputable driveline specialist (preferably someone who has experience with high hp drag racing).

 

I know this might sound out of line but i really do love the 350, i don't know why but i've always admired them more than a 383... Well I feel that I've made up my mind and would rather go supercharged 350.. but for my goal what would my gas mileage be and my quote on price? I see this to be a project 5 years down the road so i don't have to worry about emissions so it doesn't have to be "streetable"? I don't know if streetable means emissions worthy or not...

 

Well... how long is a piece of string? Your gas milage will depend on the amount of power you use, how well it is tuned and how you drive it.

I would probably go far a fuel injected setup - it will be easier to tune, potentially make more power, and get better fuel economy.

As for the cost, that will also depend on how much power you want, and what you intend to do with it, and how much of the work you can do yourself. For a full forged bottom end, with 6/71 blower, fuel injected, mechanical roller cam making 600rwhp, with the gearbox and diff strengthed to suit (street use) - don't expect alot of change from $20000.

Speed is not cheap - how fast do you want to go?

 

Well when people say is it "streetable" they really mean can this thing actually really be driven on the street not so much from a legality standpoint just physically can it be driven on the street reasonably lol. For example if the compression ended up being so ho that you needed race gas thats not too street friendly. Or because the heads and carb if you went that route were so big that everytime you took off from a stop light it hesitats badly and never has good throttle response untill +3k RPMs. Or if the cam is so large that your low end torque is so bad it has a tendency to stall if not kinda "launched." Or it has to idle at 2K rpms because the cam is so lopey that it simply will not idle any lower reliably. Or a lot of times race carb will tend to load up if just kept are part throttle cruise sort of flooding out. Real race carbs dont have chokes which means absolutely nightmarish starting when cold. Real radical motors require high stall speeds and if the torque converter has a +3-4k stall speed the trans will tend to over heat particularly on the highway because cruising at 2k RPMs the converter is just slipping in the lower RPMs generating tons of heat. Also many of the really really bullet proof parts built for racing dont really have a long life expectancy. Im sure youve seen in catalogs not for street use and a good portion of the time its for this reason. For example i was talking with another gentleman that had a really bullet proof aftermarket transmission (dont recall the brand as it was something i hadn't heard of) but he has to change the fluid at some ridiculously short fluid change interval i cant remeber now but it was either a few hundred miles or so (not exactly sure it was a long time ago but i do remember it was more frequent than oil changes) and even at that rate it doesn't have a real long life expectancy before needing a rebuild. Or even gas mileage and i mean i know builds of this nature dont really concern themselves with gas mileage too much but like for example a gentleman i did work for had a 65 ford mustang with a supercharged 427 ford motor that got literally 1 MPG roughly. I could go on and on all day about all the issues you run into trying to drive a race car every day but i think you get what im saying in terms of what i mean by is this something that is streetable. Legality is part of it i guess but mostly what people mean by it is can it actually physically be driven reasonably.