What would happen if I just installed a blower on my 76 L48. Its lower compression seems fine. Except I wish it was a 4 bolt main. Just want to pass smog and have a little boosted feeling in the seat. I dont plan on being on the throttle all the time either though. Seems more intelligent than spending a grip on a new cam intake etc...

 

I think you can get a complete "top end" kit for the same price and not all the issues that go along with the blower. plus most of the blowers will not fit under the stock hood, if you stick it up through the hood then you have to be carefull of what the weather is doing. kind of limits when you can drive the car.

on the other hand it would be cool though.

 

What would happen? Women, new friends, trophies, all good!

 

By the time its all said and done youll spend about 5k

If it were me (ca also) id put some afr 180s on it and cam it in the 220-@050 region a good dual plane that has an EO/EGR etc. Youll get a nice kick in the pants for sure. Put some shorties on keep your cats etc. Qjet is just fine.
it will run good. Sniffer cant recognize a stroker bottom end either lol.

 

There would be no problem with putting a small blower on the engine. Your compression ratio is listed as 8.5, but is likely closer to 8.0; so it can handle the blower, if not set very high on the boost.

Of course, the stock pistons, etc. weren't meant to absorb a lot of power, so limit the full-throttle stuff somewhat.

I would agree that the cost of a turbo or blower would be more than a top-end redo on the engine. But, installation of the blower will likely be easier.

P.S. How do you intend to "feed" the blower?

 

what would happen...

the B&M blower was designed for the application - you get 100 hp, and, as long as you're a zealot about avoiding ping, it'll live just fine.

but as was said above.... for 2800 bucks, or so, you can get more hp out of a SBC and not have the hassles of a blower such as: hood clearance, ping, blow-by on tired engines, blowing seals because it pressurizes the insides of the engine. Funny story blow-by on a b&m blower motor in a car I had..... I spent a lot making it handle well and would have oil leak onto the left side header on hard right corners (accelerating corners).... spent a bunch of time trying to figure out why.... eventually, I did after a bunch of tracing. The blower was pressurizing the internal spaces of the engine enough to push oil up the dipstick tube and out onto the header. Of course, the only time the oil was at the bottom of the dipstick tube was on a high-g corner....

build a 383 on the cheap, do a top end kit, or buy someone else's failed 5,000 motor for 2k.... you'll make more hp.

 

Look in the C3 parts for sale section. There was a set up with the webber carbs for sale. Fit under the stock hood.

 

I thought about a blower. Weiand makes a really neat little one that sets on top of the engine. I don't think it was much over $2k for the kit, although you'd have to either cut a hole in your hood or get a new one (cost of hood, paint, etc.).

I found out my engine (a GM 'service replacement' engine for a 1970 LT-1 that was purchased in 1977) was VERY tired. Lots of little things going wrong.

Anyhow, I'm doing a complete rebuild. The only things I kept was the block, the forged crank, the TRW pistons, the valve covers, and the Winter's aluminum dual-plane intake. Other than those 4 items, EVERY part, including nuts and bolts, is brand new.

It is a solid roller with a fairly agressive cam that we're spending a good bit of time putting together.

So for ~$5,500, I have what amounts to a race engine. Of course, that doesn't include the $800 in fueling improvements or the $1k in my MSD ignition system. Damn.

OK...so for ~7,500, I have what amounts to a race engine. It actually surpasses race engines in some aspects. Pretty cool build.

Point is that out of a straight 350 (no bore, no stroke), I'm looking at a conservative 500 HP at the flywheel.

Doesn't sound like a good deal, but GIVEN WHAT I LEARNED FROM MY 1977-VINTAGE ENGINE, I'd hesitate to put a bunch of 'goodies' on a 1976 engine that hasn't been rebuilt. You could do a 'mild' rebuild for $3k and put our $2k supercharger on top of it, or spend that same money for more engine WITHOUT the supercharger by using better components and making different decisions.

If you're STILL really thinking about a supercharger, just rebuild your engine with that in mind. All I'm saying, is that I wouldn't blow my disposible income on a thing that will probably cause more problems with your old engine before taking care of your old engine first.

I know a guy who had an EASY $25k in bolt-ons on his 2007 Shelby GT500 Mustang. Holy-crap fast car. Really fun. All the way until the evening he got it reposessed. Spent all his money on the PARTS and didn't pay the PAYMENT FIRST. Funny way to do things. It'd be a shame to put go-fast bits on an engine if you're not working with good fundamentals, is my only point.

 

The stock hood won't close.

 

Contact member 76vet. He has or had a b&m set up with webbers on the side that will fit under a stock hood

 

on both counts.
I had a '82 Trans Am with a 305 and put a B&M blower on it and it became instant fun. The drivability was great but hood clearence was the biggest issue. I wound up cutting up a 2nd hood and worked out a T/A type scoop.
That being said build a 383 torque motor. It will be just as much fun and no ugly details to work out.

 

I would rather get bigger cam and aluminum heads for the price you might spend for getting a blower. It will give you lot more power with no hood modification.

 

Careful. Put a blower on a 36 year old engine and you just might shove the crank right through the oil pan and onto the ground. I think you might need to beef up the bottom end a bit before you can be confident of any kind of reliability.

 

Actually, the mid-70's C3 engine has a LOT more potential than the HP GM gave it. That same engine (block/crank/...) was capable of a bunch more HP in the late 60's/early 70's and they had absolutely no problem with reliability (within reasonable use by the owner).

An extra 100 hp over the anemic power of the mid-70's isn't going to damage much....again, if you keep the boost reasonable and don't overdo it.

 

736 hp is how much extra they can stand (only upgrading to ARP bolts).... don't ask me how I know

 

L48 is really pretty good match.

Low compression, big chambers, wide cam lobe separation (i think). Just the stock cast pistons are the weak link.

For a blower u want the following combination:

large chambers in the heads

wide lobe separation angle for the cam

forged pistons

Just a rule of thumb for blowers adding 8-10 psi to stock engines: up to 50% power increase.

cardo0

 

I'm in the middle of a resto-mod and have a Weiand 142 mini blower. Due to so much $$ going towards everything else, I plan on putting the blower on a basic stock replacement 8.0-8.5:1 cast piston 2 bolt main I have lying around. I'll use it in the car temporarily while I work out bugs in the chassis build and while my "real" motor is being built.

I have been investigating and looking into them for a long time. They are not anything like bolting on a 6-71 blower and are actually pretty safe for your L-48. Keeping the supplied pullies, you'll only be at about 5 psi. As stated previously, as long as you keep the timing conservative to stay out of ping, there's really nothing more to it for a basic set-up. It is what they are designed for.

You could do heads and a cam to make similar power for similar money, but typically the RPM range ends up higher. With the blower the off throttle response and torque is unmatched.

And a 5 in. Glasstek cowl or similar is required.

(My "real" plan is to use a late model gen 1 roller block I picked up and build a 383 for the mini blower)

 

Mmmmm. Tasty.

My goal is to make 1st gear absolutely worthless. Can't floor it without shreading the tires. And I'd like the car to "squirm" in second.

Basically, I want more power than I could reasonably do anything with.

If my current engine build doesn't accomplish that (solid 500 HP), the Weiand 142 won't be far behind. I'll just need to keep it at very low boost...3 PSI or something. Or, I could pull my engine back apart and replace my TRW mini-domes with a lower compression piston. Went full-floating on the rebuild, so it would actually be pretty easy.

If I'm not careful, I'll convince myself that this would be a good project in a few years. While I'm swapping frames, perhaps. Hmmmm....

 

Great info guys . Appreciate all opinions.
oringinal q-jet. I was told 750 cfm is a good match Y/N?
26000 miles. (original)
L-88 hood (=4 inches i believe)
383=Smog scares me. Can it work?

 

750 double pumper, but you need to modify the carb for boost reference (very easy to do, will post pictures if anyone wants to see how-to)


Just a bit more on blowers, they develop up to 8 psi boost. What that means is driving around town and at idle they barely stay at zero vacuum, and as rpm increases so does boost.

It's when you get to about 3200 rpm that the magic starts happening.... and while I do agree that the cast pistons can be an issue; my own experience says that it's the rod bolts which are first weak link in the chain.

both of these issues don't have to be fatal be religious about curing ping, run good gas (even a bit of E85 or Avgas), and avoid redlining the engine.

but start doing long, smoky burnouts and you'll find the stock rod bolts will bite you.