I came across a Great Conditioned C3, unfortunately it turned out to be an L48 engine which runs as strong as my 2001 Accord.

I'd like to build it up some and really give myself the Corvette experience I want. Now while I know that some people are into outrageous builds I'm a bit more conservative.

So basically I'm looking in the 300-400 HP/TQ (which is a considerable jump from all my previous vehicles in the under 200hp range).I'm willing to put nearly 5k into the engine build but if I don't have to put that then the left over will be used to overhaul and upgrade many other components. Now my mechanical skills aren't the highest (I come from building computers) but more half of my enjoyment is using what I built.

If I could build the L48 up to that range I'd be pleased, but I'm really looking for Price/Performance and if its unfeasible to build to Par with a crate engine for Cheaper then the obvious answer is Crate.

Any Ideas?


Swift_C3
(Previously Swift_FC3s, I made the change from Japanese agility to American muscle)

 

You can bore it .30 over, put in a cast steel crank, rods, and cast pistons that will be 10:1 compression, put in a retrofit hydraulic roller cam and lifter set, with about .480-.500 lift , .280 - .290 duration and 112-114 LSA.
Add on a set of cast AFR heads with some NAME BRAND STEEL full roller rockers, you dont want aluminum for a daily driver. I suggest some Comp magnums.
Get some hardened pushrods, a dual roller timing set, with a performer intake and whatever carb brand you like the most and you should be at or under 5k after machine work and parts, if you can assemble it yourself and reuse parts like the water pump, pulleys, fuel pump, power steering, and air cleaner. But a water pump is cheap and you could probably get away with that too.
If you can't assemble it yourself, you can get a decent patriot performance 383 crate motor for just under 5k.

 

Its not necessarily a Daily Driver, but I won't be doing any track time with it. Mostly Freeway and an occasional show-off.... the weekend warrior. I've managed to build quite a few mechanical things in my life and I'd love the challenge of building the engine. I basically read and try to soak up all the knowledge I can before attempting something.

Part #s, Names brands anything and everything will be helpful. I've been reading alot about AFR heads and so those will be a definite high point on my list.

Thanks Nova

 

And dont let the build part of it shy you away, a motor really isnt that hard to build. I would see if there were a local corvette club or if you have a buddy to help you with the first build, but after the first one you can hit the ground running. The first engine I ever build was a 355. Second one I build was a 496.
The biggest pain in the neck to me is degreeing a cam. But for your build I wouldn't even worry about degreeing it, just install it straight up.

 

Comp Cams
AFR Heads
Felpro Gaskets
Edelbrock Intake
And you can get a nice balanced Eagle or SCAT rotating assembly for a resonable price.
I would also suggest you use a standard volume oil pump.

 

I did what you’re thinking about and am happy with the results. My block was a ’74 and while I used a different block (got a 4-bolt main block), results would have been fine with the original. With over 100K miles the bore had almost no wear.

I used stock rods. Bought about two-dozen used rods and gave them to the machine shop. They picked the best, magnafluxed, shot peened and bored for a non-pressed pin, ground surface and balanced the rotating assembly. It’s what I wanted to do but it would have been easier to buy aftermarket rods.

I used forged pistons. I’d do that again but many people don’t. There’s been a lot of improvements in rings since I built my engine so I’d read up on the latest and stay away from those designed for racing. Racing engines try to get extra horsepower by reducing ring friction but do so at a cost of longevity.

Your cast crank will be fine. Hopefully you can grind it no more than .010 but .020 will work.

Power is in the heads and cam. Cam depends on dynamic compression which is basically a function of static compression. I used AFR heads and have never been sorry. Probably more than anything I recommend using aluminum heads. Aluminum heads will allow you to go at least .75 higher on compression ratio. I run 10.1 and have never had a problem.

Everyone loves roller cams. They’re better but also more expensive. You can go with a good hydraulic flat lifter cam with a lift of .500 to .520 and be very streetable. AFR heads go to .550 lift out of the box as I recall.

Exhaust is a big deal. Almost everyone on the forum will tell you to get headers but I used the old style rams horn stock manifolds but with the 2.5 inch in place of the stock 2.0 inch. In ’74 I didn’t have a catalytic converter so I went straight dual 2.5 stainless pipes with Restoration Parts mufflers. Works for me – I like it.

Finally, and this may not be necessary but I recommend it: Get a good high capacity radiator. I used a ‘Be Kool’ but there are others. I live in Texas where it’s routinely well above 100 and the engine never gets hot. Before replacing the radiator it did.

I have an MSD but don’t use it. Still run points. Guess I’m old school but it runs well into the mid-6000’s and doesn’t miss. (I keep the plugs fresh.) With this engine a Holly carb of about 700 cubic feet per minute will meet your needs. I run a dual plane manifold.

The best part is planning the engine, then seeing how well it met your expectations. Have fun. (You will need tools – and they’re expensive. Consider this. If you don’t want to invest in tools – including micrometers, you may be better of with a crate engine.)

 

I just went through all this with my '76. I have the luxury of knowing its history- my sister bought the car from the original owners, an elderly couple that drove it 23,000 miles from 1976-1993. I bought it from her in 1997 with about 35,000 miles, and it had been driven in the rain exactly twice since new and my sis only opened it up once. I put another 18,000 very easy miles on it before deciding I wanted more power.

The reason I described all that was to give you a head-up that you will probably face the same things I'm about to describe, so consider it when you evaluate your budget.

First off, given when yours (and mine) was made, the rear differential will probably need attention. I've just been through mine, expect to spend at least $1800 to have a top notch rear differential done right by either Gary or Mike on this forum if you find what I found- worn side yokes (expect this due to the poor steel used in these during the mid-70's) and a worn spider gear cross shaft bores in the posi case (posi case had to be replaced). I opted to splurge on changing the gear ratio. After having gone through "doing it right" myself, believe me when I say that Gary and Mike earn every penny because it was as involved as meticulously building (as opposed to just assembling) a good engine.

Next, the suspension and steering is probably in need of attention. The shocks, U-joints, bushings, front end, springs, ball joints, and steering pump and valve may need a little love. I opted to replace the front and rear springs, shocks, all ball joints, front end bushings, hoses, and had already replaced the P/S control valve (they're awful about developing leaks). All this will cost roughly $900 if you do the work yourself.

Finally, make sure the brakes are in good shape!

You might be able to leave the transmission alone, but I opted to put a shift kit, vacuum modulator, new seals on the front pump, output yoke and shift selector shaft, put in a new filter, reprogrammed the governor, added a drain plug to the pan, new speedometer gear, and a new rear (rubber) mount while I was at it. Cost: about $150.

Just food for thought, these are 35 years old now and even well preserved ones have decomposed parts and had a few marginal design issues (like the rear differential). The engine work is fun, but if it causes everything else to break- or worse, become unsafe- it's a lot less fun.

 

I've been hearin a small clunk when I usually take a right turn from a stop (I think it might be the rear brakes and I know i have to do some of the brakes anyhow). I usually build from the brakes -> suspension and then start the engine work. I'm gonna work a bit differently this time as I want to add just a bit more power first.

 

You don't need aftermarket heads, nor forged-anything nor a different distributor nor roller-anything in order to meet your stated goals.

• small dome pistons sealed power p/n H618CP
• cam & lifter kit summit p/n sum-K1103
• service & clean your heads include new "z28" springs (ie sealed power p/n VS739R)
• thin steel shim head gaskets felpro p/n 1094
• bore & clean your block
• polish/grind your crank
• check/resize your rods include fresh rod bolts
• bearings, timing set, gaskets etc.

Above merely outlines a std overhaul but includes cam & piston upgrade. Easy 310-325hp on pump premium at no more than 9.8:1 compression; probably under $1500 if you adhere to plan-budget & purchase wisely & you assemble. Use "leftover" to fix "clunks", fresh tires/brakes etc.

-add- Swift ... suggest you add an approximate geographic location to your profile.

 

Thanks for the advice Jackson! I'll be looking at the P\N's that you posted, that definitely helps!

Also I updated the profile a tad, I'm in California near Santa Barbara, in a small town, not too many vette's around here. I love the weather of this place a little dew this morning and I know it won't be above 80 today.

 

Some 8 years back I did a month-long job near Oxnard ... weekends I drove North; visiting Santa Barbara, Santa Paula Airport (vintage & warbirds) and Solvang. Oxnard & Ventura OK ... but North was real nice ... even brought back a few cool pieces from beachfront artists along SB. Parts of SB are great for walking. Of course the pastries in Solvang are great but hi-lite probably beautiful old RC mission. Heck walking around Santa Paula airport nice too; friendly folks happy to talk about planes ... hangar flying same as bench racing. In all fairness, must also credit Oxnard with a small but nice aircraft museum w/ friendly folks. Was there around Thanksgiving & weather was quite nice. All in all, the task kinda sucked but weekends were great. You're blessed to live in such a nice area.