I'm looking to pick up a 4 speed C3. Mostly it'll be a cruiser but I want to have some fun at track days and autocross events. I'm thinking a 5 speed upgrade and 3.73 gears along with brake suspension and traction upgrades are my primary goals. EVENTUALLY (At least 2 years, probably more) I'd like to drop in a beast of a motor.

However 190 HP just isn't going to do it for me... My Camaro pushes something close to 300HP and is enough to make me happy. That's enough go to make track days, autocross and the local 1/8th mile exciting too.

So I'm trying to figure out, what's the cheapest way to top 300 HP and torque on what will probably be an L48? Something to keep that grin while I work on all the other bits.

I kinda suck at this stuff, but trying to research and look around, I'm thinking the following stuff would work. What do you think? Did I miss something? Any better ideas?

http://www.jegs.com/i/Chevrolet-Perf...oductId=749896
http://www.jegs.com/i/Comp-Cams/249/CL12-238-2/10002/-1
http://www.jegs.com/i/Chevrolet-Perf...rentProductId=
Plus a side pipe exhaust set up

 

Buy a C4. You can get what you want and spend less money doing it.

 

But those are significantly more ugly...C3s are simply WAY too good lookign to give up.

 

Replace your rocker selection with Competition Cams roller tip 1.52, think you have room to not exceed the heads max lift of .475.

 

Would .006" of lift make that much of a difference though? The Comp Cam rockers are 100 bucks more.

 

I have to be honest...I'm a fan of dealing with human beings.

Jegs and Summit is fine and all, but they'll sell you whatever you'll buy. There is a LOT more that goes into improving an existing engine than picking parts. Those parts need to WORK TOGETHER to produce power. One thing may kill another thing.

I love stopping in and shooting the breeze with my "speed guy". He has forgotten more about SBC engines than I'll likely ever learn. We discuss things and end up going in the right direction every time.

One thing that hits me is you're thinking about a flat tappet hydraulic cam and flat-tip rockers. 300 HP would be MUCH more attainable if you consider a full roller setup. And I know it is more of a pain in the butt, but the single change of ditching the hydraulic lifters for solid lifters would also get you an easy 10%+ bump in horsepower. I wouldn't use them on a daily driver (you'll be adjusting the valves every oil change), but on a "Sunday" car that sees under 1,000 miles a year, solid lifters is easy power. Roller tips is a no-brainer. I have a "cheap-o" set on mine that I bought for $75. They're only good to about 450 HP (low/stock spring rates and heights), but that's OK. I'll get better tips when I get a better cam!!!

Sure...new heads, new intake, headers, ignition, carb, cam...each new part will get you something. But don't give up the little 'in between' things that add up to huge power gains.

I'll bet a roller-solid-roller (roller followers, solid lifters, roller tip rockers) cam engine, equally built, would make an EASY 50 horsepower over a flat-hydraulic-flat cam engine.

Even the carb...bench tests have shown that annular boosters make nearly 100 ft-lbs more torque at 1,800 RPM over dogleg boosters on a 400 HP engine. The PEAK horsepower is only 3 HP more for annular, but you get LOADS more torque under the curve with annular. And nice little HP boosts at lower RPM. This is due to the improved atomization.

Point is: Choose each part carefully. There are little nuances here and there that, for $30 on the cam or $20 on the carb, could leave 15 HP on the table here and 30 HP there. Before you know it, you've saved a whopping $300 but have left 100 horsepower and 100 ft-lbs of torque ON THE TABLE because of part choice.

A speed guy and engine builder will guide you through this stuff. Jegs won't.

 

I love the C3...but with all of those changes even a C5 FRC or Z06 would likely be cheaper in the end...and offer better performance.

The Vortec top is personally one of my favorite "cheap power" additions, and your list is a combo I've done often.

 

Most articles I've seen claim the stock Chevy rocker is not a true or consistant 1.5 ratio. Plus the roller tip reduces some friction loss.

 

Roller rockers would be a 'fine-tuning' modification. Not big HP gains with that one. Regarding issues of 'accessibility' and 'affordability', my suggestions are:

1. Recurve your distributor and set timing for best performance;

2. Verify that your carb throttle linkage is operating smoothly and without restriction, and that the secondary throttle plates in the carb open completely when the accelerator pedal is fully depressed;
[Note: This may seem trivial. But, you would be surprised by how many engines are underpowered simply because the carb does not fully open at WOT.]

3. Install a free-flowing exhaust with adequately sized tubing;

4. Install a good set of shock absorbers. Improving handling can be as important as having more power;

5. Now you are into engine "internals"...cam, heads/valves/lifters, pistons (C.R.), intake manifold, headers--more expensive stuff.

Changing carburetors is unlikely to make any significant difference, if the carb is built and functioning properly. Save your money--or rebuild what you have if you think it needs done.

 

I wasn't planning to change carbs, everything I've read says the Q-jet is more than enough for my application. I included the rockers since the heads don't come with them and I don't think I'd want to reuse the old ones. I understand the advantages of a roller cam, but I think I can hit my target for this motor without the big extra cost of converting. Folks have convinced me on roller rockers though. Would there be any problems with flat - Hydraulic - Roller? I don't think I want to switch to solid lifters, the car will driven enough I'd prefer not to have to do adjustments.

1: Timing adjustment and tune by someone smarter than me was also planned. I don't even know what "recurve the distributor" even means, any good links to info about that?

2: Never would have thought about that, good to know!

3: Totally planned! Was thinking probably the hooker header and sidepipe kit.

4: Also totally planned, part of the suspension mods I was talking about.

5: That's what I'm trying to figure out.

If I can keep power additives under about $1500 bucks, that leaves room in my budget for the drive line and suspension upgrades I want to do. While I have some leeway since this is all still in planning, the more I spend on engine the less I can spend on other stuff. I'm not concerned with being the fastest guy around, I just want a bit more umph when I put the pedal down without going to some crazy gearing.

This build is very similar to one done by Chevy High Performance (that's the Cam they recommend) that breaks 400HP. Granted I'll have dished pistons and likely some engine wear, plus I won't have 2 weeks on a dyno to get everything Juuuussst right, but then I'm not shooting for 400+ either Yet...

Anyone have an opinion on the Jegs Intake? I've read some nasty things about them. Any recommendations on a decent intake that fits under the stock hood and fits with the Vortecs?

Thanks guys, I appreciate all of your advice

 

Take everything from CHP with a grain of salt...or the whole box. They shoot for big dyno numbers that have no relationship to what the engine will make in the chassis.

Expect around 1 HP/CID at the flywheel with that combo and you won't be disappointed - maybe a bit more with the headers/sidepipes...does Hooker make those for Vortecs in the C3?

The Edelbrock Performer Vortec EPS is a great choice

 

maybe look at a elderbrock rpm intake,a comp cams 268 extreme cam with matching springs ,and some good headers .you can find a newer hi out put HEI distributor for $125.check competition products for prices.

 

Well I would recomend the C4 as well, I bought one a couple of years ago and my son in law is Auto Crossing and Road Racing the heck out of it. I have more money into my long block than the entire C4. OK so you can't be talked out of the C3, thats OK I can't either.
So you need to decide on a Early, Middle or Late C3, exspect to pay more for a Chrome Bumper Car. If You want a 5 Speed then I would start out with a Clutch Car. You should be able to find one with a 3:36 or 3:55 Rear End wich will work fine with the 5 speed. Most of all check the car out for Rust, there are Cars out there that have very little You may have to travel to find them but its worth wile. The west Coast has good ones and they sell for less than they do in the Rust Belt.

 

I've considered this combo as a cheap upgrade.

http://www.summitracing.com/parts/SM...ComboContents/

 

I’m confused. You want a C3 and you want 300 HP?

1969 base engine was a 350/300HP and the next motor up was a 350/350.
Plus IMHO, the 1969 was one beautiful C3…love the gill slits!

 

SAE Gross not Net. Realistically those motors would be more like 200-250 bhp.

Any of the early chrome bumper cars are also significantly more expensive than the later years, sadly putting them generally out of my price range. Even a raggedy early C3 seems to start over 10k while Mid years in decent condition can be found for 6-8k, fastbacks for another grand or two less.

Believe me though, If I can find a steal on a 69, I will jump on it like fleas on a dog.

Course I say that and boom, there's a beautiful 68 right on the top of craigslist for 4k... Damn you world for trying to make me a lier!

 

I can't help but throw in my .02 cents here.

I wrestled with the exact same dilemma on my 81. I ended up selling the whole motor, carb, smog stuff, exhaust, manifold etc on this forum and Craigs list.

It all sold surprisigly fast. I got just shy of enough to buy a Blue Print short block 383.

If you can pull this off, then all you have to do is use your 1500 or so to pick up some Dart #31 cast iron vortec heads for 450.00.

I got a Howards cam that is right at the limit before having to do valve work. I got the inexpensive roller rockers.

This is a flat tappet motor and cam. Flat tappet motors and cams have been around for an awfully long time. They have passed all my longevity and strength tests.

Can't go wrong with the Edelbrock performer. I am using a Performer RPM air gap.

Found some Hooker long tube side headers on ebay. Added the mufflers from Summit.

I sold the Q jet cheap. Just wanted to get rid of it. I personally do not like them at all. Too complicated, too messy, too many hoses, vacuum lines, gizmos and thingies that I can never get right.

Holley for me. All Holley all the time.

There are many folks that will tell you that you must have a 750 cfm carb. This is just not true.

Your motor will pull as much air as it needs. This depends on CI, rpm and the efficiency of your breathing system. The normal motor is about 83% efficient. If you have a nice intake, heads and exhaust, remove smog stuff, you may increase efficiency to 85 or 90.

This is the number you want to raise when you start modifying the breathing system.

Add porting and polishing etc etc you may bring it close to 100.

Add super or turbo charging and you may even top 100%

The average 350 with 85 to 90 efficiency, at 6500 rpm will draw about 609 cfm. A 600 cfm carb will work just fine.

So you have to ask yourself, how often will I be realistically putting this beast at 6500 rpm or higher? The average joe on the street almost never tops 5500.

The occasional weekend warrier may hit as high as 7500 from time to time.

For the vast majority of us, even with modified motors, a nice Holley 650 cfm is all the carb your motor will ever use.

 

What is your budget for 1) a vette, 2) upgrades?

 

About 15K over the next 2 years.

Hoping to nab a decent condition car for 6-7K. I can do most repair work myself, so I'm figuring (hoping) for ~1k immediate repairs needed.

With any luck (and some ramen noodles...) I can hopefully knock out engine upgrades, tires and brakes come next tax season.

 

Flogging a dead horse, but 15K nets a pretty darn nice C5 FRC...

I would sure run the math on the C3...what I don't see factored in is body work and paint, or interior/cosmetics....which can easily tear up that budget on it's own.

If you want a C3, get one and enjoy - but if you want a fun DD and something that can carve up the autox course, a C5 is pretty hard to beat for the $$$.