i want to do a 302 with about 400 hp and a 7500 redline for the street . I really wanna do something alittle different than the go big engine . Ive always thought it would be cool to have a street v8 that revs to 7500 . Anyone have any ideas or build anything simialr to this .

 

If I were you, I'd do research other than here. All you'll get here is "build a 350, a small engine is a stupid idea to build" "Don't waste your money on a 302 when you can get the same power for less with a bigger engine!" People have not been very helpfull providing the information you and others have looked for.

By the way, a friend of mine is currently building a 283 that'll have 10.5:1 compression and eventually run a 200 shot for that extra bit of fun No idea of the hp levels or what he'll be running his up to but it'll be a fun engine for his car. Also, him and I both have built 350's that zing 7,000+ rpms just fine, his is a little better at the moment

 

There is a reason for the "arguments" against building a 302. Its been hashed over so many times, its boring. BUT, all things equal, it will never make the power of a 350.

There is another downside to having a street engine that revs to 7500 RPMs. They tend to be gutless below 3000. YOu will need lots of stall, lots of gear. IT probably wont be a very nice street driven combo anymore.

 

i dont want a nice street car, i ont mind if its friendy, i have a 4 speed and 4.10 gears and 35 series tires, it wont be below 3500 rpms for much as it will spin right past it or the gears will make up for it .

 

If you are going to build any small block that high, I would strongly reccomend using a solid-roller cam, 3/8" chromemoly pushrods, steel roller rockers, and a stud girdle. You'll want to build the valvetrain to be absolutely bulletproof if you want to spin in that high and have it survive to do it again.

I would also suggest starting with a 4" bore 2-bolt block and have some steel splayed 4-bolt caps installed on it, for the added bottom end strength.

You'll need a 3" stroke crank to build a 302, and a strong one to have it do what you want it to. I know Lunati makes a 3" stroke crank, but I don't know anything about it. I'm sure others make them too. You'll want a forged crank for sure.

Aftermarket steel rods are a must, stock rods/bolts won't like to be spun that high. I've heard good things about Eagle rods. You'll likely want forged pistons as well.

I've actually thought about building a 302 myself for awhile, but never really looked to much into it. What I said above though, comes from what others I know have done with their engines, and those engines make a lot of power (a couple at or above 370 rwhp) and have no issues with turning HUGE revs.

 

thanks adam , thats the kind of info i was lookin for .

 

Here's a secret that few people know. You can build a 302 entirly with common off the shelf factory late model parts.

The LT1 is a standard 4" bore 350. But, it's not the only engine in the Gen II family. There is also a "baby" LT1, known as the L99. It displaced 4.3L. It's got a 3" stroke. The 4" bore of the LT1 with the 3" stroke of the L99 gives you a 302 on the cheap. Conveniently, the 3" L99 crank will fit in any 1 piece RMS block. With the right heads and cam, it could be quite the motor. See below for more info on how one guy built one on the cheap using leftover factory parts. Obviously, for serious RPM, you'll need a bit better than factory stuff, but it's a start.

http://impalassforum.com/noncgi/ulti...=009656#000000

 

I will probly be bashed for saying this, but here is some info if you want to think about it...

I am currently building a 302 based FORD motor. AS bad as it sounds, I would have you go over to a ford forum, look at there 302 combos, IE, head cc sizes, flow numbers, cam durations, intake manifolds- to see what rpm range will get you there with the most power. What i am trying to get at is you can very easily overbuild a 302 engine with 200 cc ports and a vic Sr. intake, a 250@ .050 duration cam and it will probly not have power till 4500 rpm. I would recomend a head of around 160-180 cc, all forged componets, a solid roller of your choice, vic jr. intake if your going carb(even if your going injection, get a elbow and covert it) and have a nice free flowing exhaust.


I can tell you all this because of the motor im build, a 302 based 340 stroker, with 235cc heads, vic jr. intake, small solid roller (around 230 @.050) and a turbo. This small motor is capable of 1100 hp..


But what do I know, Someone tell me im wrong for comparing proven packages from ford to a chevy....

 

4" bore, 3" stroke is a 302, wether Ford or Chevy based. A that 200 CFM intake port is still a 200 CFM intake port. The only difference is where the distributer is.

 

Yeah, but someone will probly have to be a smartass and say the heads have different swirl, differen spark plug location, different port configureations, fireing order, deck heights, intake manifold designs, etc......


Trust me, just wait for it...

 

Theres nothing wrong with being different,and what you propose is very doable.
The guys who get bashed are the ones who want 500hp from their 305,because"I already have it",but want to know how to do it cheap,because it's different.
As long as you know different usually means a bit pricey,your on the right track.

Compression will be your friend,as well as some good alum. heads to fight off the detonation demons,a big solid cam with a matching intake to breath in that RPM range,(Team G or Victor,Vic jr.).
You'll need a way loose convertor,because,as mentioned,this animal will lack in low RPM torque,and willingness to live with the nature of the beast.Combine these things,and be prepared to watch your tach use the second half of the sweep

 

Forgot to mention,if you like a twisty engine,it's also worth looking into the 377 or 348 combo.Has the revving abilities you desire,but with the huge bore/better stroke combo,will produce better low RPM torque than a 302.

 

I'd just rather have people help a person, like some of the others in this thread, instead of the normal bashing of the idea of building a smaller cube engine. Who freakin cares what size it is, just help the person instead of calling them stupid for wanting to do it.

 

if your going thru all the trouble and expense, why not destroke an LS1?? In the process you get better heads, ignition, fuel injection, exhaust, etc. And a factory ecm.

i don't really see myself building another gen 1 motor.

 

i dont wanna use an ls1, i wanna go carbed and use my 4 speed and 4.10 gears . Ive been lookin into a little allready and it looks like this engine will probably cost like 8k with it being buit and dynoed.The crank alone from lunati was like 600 or more . But im just gathering info and getting everything straight now .

 

This is something I'm also looking into. I have a big block 73 camaro and I want my 84 Z28 to have totally different character. I thought it would be interesting to make a third gen with the engine of a 1st gen z28, though with a few modern improvements.

Its sensible to build these engines with as long a connecting rod, and as high compression ratio as practical.

I'm using aluminium LT1 heads since they are cheap, have small chambers and flow enough for high rpm and good power. I already have them modded to work on a gen1 block and the cost was minimal.

A solid cam is a must, but bearing in mind the questionable durabilty of solid roller lifters on the street, I'm going flat tappet.

Attention to cooling is critical.

I'd be tempted to use a small journal early 327 block and prepped 283 crank. Splayed 4 bolt is nice but studded 2 bolt would probably be adequate.

Finally, I'm using a vastly customised (by me) intake manifold with 3 2bbl holleys that ought to provide great top end with a slight boost in low rpm torque.

Remember that back in te late 60's the 302 race engines proved durable with only reworked factory parts, and careful preparation. With modern H beam connecting rods, light forged pistons, a good balance and damper, there's no reason a high reving little engine shouldn't hold together fine.

Much as I don't like to point people away from this forum, the people at the link below know these engines and just what they can do
http://www.camaros.net/forums/index.php?

 

Which is exactly what I was doing in my post in this thread.

Compaing a 302 chevy and ford is a valid comparison, but comparing a 302 chevy to an 1100hp 302 that has been stroked is a little off.

Bottom line is this: if you have the money to build something different, go for it, it makes you happy.

 

I have a 302 in my '69 Z28. It makes 280hp at the wheels using Edelbrock Performer RPM heads, Comp Cams 12-673-4 cam, 1 3/4 Hooker SC's, and a Flowmaster 2.5 inch exhaust. At the track my car runs low 14's at 104 and is about a second faster than stock DZ302's. The slow et is due to the 2.2 1st gear in the M-21 with 3.73 gears. It would scream with a set of 4.56's.

There are guys that swear they run their DZ's to 7,500 all the time. I don't have to guts with my # match motor to go that high, but mine sure loves to run from 3,500 to 6,500. The 302 has a completely different sound and manner than a 350, but you've got to be willing to live with a soft low-end.

I agree with Adam, if you want to spin the motor to 7,500, it needs to be bulletproof - both the valvetrain and bottom-end.

I am also building a 7,500rpm 372 for my 3rd gen. I wanted a bigger motor with the same 'feel' as the 302. Here is the combo:

4.125 bore GM Bow-Tie block
3.480 Callies crank
6" Oliver rods
13.5:1 JE pistons
Custom Cam Motion solid roller (268@.050)
218cc Canfield heads (CNC ported)
Jesel shaft rockers
Victor Jr. intake ported by Wilson Manfields
Crower lifters with HIPPO

This motor should make 550-600 horsepower and it will be driven on the street.

 

I have a 427 sbc in my 89 formula that pulls to 7,800.....
y would you spend so much to get so little ????

 

Because he wants to.I like big inch engines myself,but he wants a 302.Therefore,if your not offering useful information to help him with his goal,your just wasting everones time.

 

Yes sir!

 

kinda like building a 302 ??
unless you have a class rule y waste your time and money ???
i didnt waste anyones time.. Im telling him not to build it...
BTW ive been building cars and motors for 17 yrs

 

Wow, everyone on that site is encouraging different builds. Wish there was more support here. I say go for it.

 

i just thought it would be fun to have an engine that would rev that high. The guy who will build my engine kinda shyed me away from an engine that revs that high too , hes like i can build it but ...I know its an uncoomon thing to make a smaller engine but i thought it would be cool to have a nice screamer engine . With 4.10 gears and a muncie m-20 and stock size tires ill be able to keep a 302 right in its power range.

 

Why not build a large displacement engine that will rev that high then?

 

Same answer to why we have been at war as long as we have... Because we can and i guess can offord it.


Everyone knows with the rite parts, you can take even a 454 BBC up to 8000 all day long. But he wants a 302, and that is what he needs info on.

 

If you want to build a 302 to be unique in a way that few people will even realize let alone appreciate, then have at it. If you're building it because it will "rev high", then maybe you should re-evaluate your objectives. If you're not being honest with yourself about what you're trying to accomplish then you're just setting yourself up for disappointment.

 

Exactly.

 

Its what he wants to build. I agree with the idea that it is not the best engine to build on, but it is what he wants. How would you feel when a car completly stomps your 350/383 and you go up to the guy and what he got and it is a 302. Maby that is the purpose in building this engine.

 

I've been doing more research, and with studded 2 bolt mains the factory L99(baby LT1) 3" crank will handle 7000 RPM and 400-450 HP, but factory rods won't take it. Just some more info, take it as you will.

 

I'd be a whole lot more impressed if it was done with a 305. Or maybe a 283 or a 265.

 

Exactly what another friend of mine is doing. His big block will be turning 9,000 rpm, with a blower on top

 

I would say that the rods are good to 500, but I would be more afraid of the stock crank to 7K, though I do it myself

As far as stomping someone with a small engine, there is a transverse to this also. One day when you get your *** kicked by someone with a 350 with a lot less money in it, you will realize that the cost efficiency just wasnt there.

 

If you want some good rods you can alwayse look into the Pink rods. They were factory rods in the 50s and 60s. My dads friend had them in his 383 and spun it to 7500 almost every day.


What i would realy like to build is an old 265. They used to destroke them to 232 i think it is and spin them 12000, and that was back in the 60s with nitromethane.

 

What i would realy like to build is an old 265. They used to destroke them to 232 i think it is and spin them 12000, and that was back in the 60s with nitromethane. [/B][/QUOTE]

i think that is quite optimistic. you need more than a short stroke to make rpm. The valve train is the week link.

 

there are also plenty of affordable aftermarket rods that are superior to pink rods and brand new.

 

I don't want to sound like i'm against the idea, i'm not. I also know it is not the most cost effective or practical. What kind of a 4 speed are you using? That right there is a major short coming in your combo. Typically they have tall first gears and or a broader gear spacing. You should look into a t56 with the tightest gear spread and a really deep rear gear (4.88+) or a richmond 5/6 speed where you can spec the ratios you want. Either choice will make your car much faster and more livable.

 

I dident say the motors lasted i just said they did it. This was in the 60s, they filled the block with cement just so the block itself would not come apart

 

sorry, not buying it. 12000 on a pushrod motor is BS. Modern nitro cars even nascar are limited to roughly 9000 rpm. its not the stroke that limits them its the valve gear. the new yamaha 600 spins to 17000 but it is an overhead cam design.

 

Build a 302 with 8:1 compression and run a big turbo.

 

Its been 2+yrs since i read the artical so my details are alittle fuzzy. It was an artical in the 1965 Hotrod Magazine. They were running 8s in the 1/4 spinning most of the way down the track with a powerglide. It might not have been 12000 but it was up there.

 

you CAN carb an LS1.. go to Edelbrock and get their LS1 CARB kit. RPMS are supposed to be in the 6500 markwith thier kit.. why not do that?

and LS1 short block will cost you about 800$ or at max a 1000$.. the carb kit is 700$.. walla... a 346ci that spins to 6500.. and a 330hp engine without ANY big upgrades like a cam or anything..

i would think that is the best route..

 

I have a 3.25" stroked 400 SBC in my 1985 IROC. It is really a pleasure to drive. Docile and mellow until you romp on her and then she screams. The first thing LS1 owners ask me is if I did an LS1 swap because it's characteristics are similiar. I started with an .030" 400 block and used a steel large journal 327 (3.25" stroke) crank. Off the shelf SRP's originally intended for a 400 with 6" rods where chosen along with a set of 6.25" long Dyno-flo Ultralight 4340 rods. I originally had it going with AFR 195cc heads with 58cc chambers but I wanted to do side by side testing with a standard built 350 and due to some major ignorance by the builders, the AFR's are back at AFR for some rework. A story that is too painful to share.

I'm currently running Protopline Vortecs with Comp Beehive springs and titanium retainers. The reason I mentioned that is you need to keep your valvetrain as light as possible to rev. and consider an AFR Rev Kit. Jesel Sportsman Shaft rockers would be great but certainly not necessary for your target horsepower. Match your rear gear for the revs. I'm using 4:10's and the lack of low end has never been an issue with this combination. Even with full Spohn heim joint suspension, street tires are totally overmatched.

 

If you decide that 302 cubes and 400 hp is your goal, shoot for it......its your decision. here are some things to think about though.

realistically, the only reason most of the smaller cubic inch motors 'seemed' to be screamers was that they had some odds in their favors:

small stroke, less steel to throw around, really minor
small journal, in some cases, less friction due to bearing speed.
small stroke, less CFM per rev, so older, smaller port cylinder heads flowed to better match cubes.
lazy cams with tons of duration, not alot of lift. gave the motors a higher rpm range due to duration, had to spin em up to make any power, plus with low lift, valve events were not as dramatic.
solid lifters, kept valve train lighter, and springs in check.
compression! needed for the lazy long duration cams.

so nowadays, with great cylinder heads, and light valvetrain and a solid cam, you can mimic the feel of the high RPM 'old time screamers', and make a ton of power. thats the bottom line.

if you are starting from scratch to build something up, you are certainly going to want to spend money where it counts. that means great cylinder heads, and great valvetrain. everything else is a wash price-wise, so get the biggest stuff that fits with minimal work.

now sure, if you have the stuff sitting around or can get it cheap, by all means, build what ya got, but you fundamentally will make less power with less cubes.

bottom line, get great cylinder heads and light valvetrain, you can spin any amount of cubes to 7500 all day long. the bigger motor wins though.

obviously you have to make sure the bottom end can handle it. find out the goal HP, and size accordingly. cast cranks balanced well can handle more power than you think, but make sure you get good rods, more importantly, rod bolts. Chevy's are at an advantage with rods, since they always made decent forged rods.

anyway, thats my take on the subject, not that anyone asked.

good luck and have fun with it!

 

My point exactly. Dont get caught up in the "short stroke/high rev" thing. The limiting factor to the SBC isnt the stroke, its the valvetrain. Yes you will need a sturdy rotating assembly, but the valvetrain will limit your RPMs long before the stroke will. Ask anyone that has a 400+ ci small block that spins to 7500. Those extra cubes sure make it more fun (and more powerful).

 

jwscab makes some excellent points. What interests me about the 302 idea is I would like to see one with the improvements in technology that we have. Anything you thought you knew about the 302 could and probably does change when you throw out the old technology (heads, cam, carb/manifold, etc.) and replace it with what's available now. Even if you go budget, Vortec heads far outclass anything the 302 came with from the factory in the early 60's. Toss in a good roller cam with assymetrical lobe configurations and a good aftermarket fuel injection intake, such as a Scoggin-Dickey base (assuming Vortec heads), SLP runners, and a ported stock plenum, and suddenly the "soft" low end doesn't become an issue.

The reason I bring this up is ultimately bigger cubes should always mean more overall power, all things being equal. Problem is, for the daily driver, it's not always practicle to drive a big motor. Gas prices being what they are, many of us see the smaller cube motors as a way to get decent mileage and still have a motor that gives thrills. Some of us, for what ever reasons, don't see parking the 3rd gen in favor of an import then roll out the 3rd gen when it's time for fun as an option. Overdrives behind big motors really help on the freeway but in daily stoplight traffic, they don't help much.

 

The problem with putting the TPI on it, is that you just eliminated all of that "high Revving" fun everyone is babbling about. Its gone, forget it.

As far as gas mileage, you wont see any better mileage out of a 7500 rpm 302 than you would a 350 or 400 for that matter. Gas mileage and performance dont go hand in hand. Pick one.

 

If you want to build a good fuel economy 5 liter SBC, build a 305.

If you want to build a good power 5 liter SBC, build a 302.

If you want to build the best streetable power SBC, build a 350/383/400.

I find this kind of thread distressing (kind of like "what kind of oil should I use" threads). Not because they have no technical merit, but because people try to suspend reality in favor of pipedreams. My first instinct is to lock these kind of threads because of the flame wars that are sure to commence. I'll give this one a little more time, but I'm growing weary of it.

 

I completely agree, if were talking stock TPI. But a Holley Stealth Ram, for instance, powered by a Commander 950, FAST, or Electromotive engine management system with two different programs? This isn't budget tech but you get the picture. I bet you might even be able to pull it off if you knew your way around a multi-adjustable carb like a Mighty Demon. I would definetly concede that if your going to buzz any motor at 7000, good gas mileage is nonexistant but I'm not totally convinced you can't have it both ways.

 

Make yourself a 5 liter LSx then. Closest thing you'll find to even come close to the premise (7500 RPM and streetable).