c3corvettes

Hello fellow corvette enthusiasts,

The old 305 finally died. I recently removed the left cylinder head, and found a piece of the outer edge of piston #1 (no compression at this cylinder when tested 4 months ago) broken off! I'm pretty sure now why I was having issues.

I've decided that I want to pull the engine out and replace with a crate, but not with another 305, oh no no no no no. I would like some guidance as to what my options are out there. I live in California, and I'm subjected to smog tests (visual and sniffer) every two years. The vette has the computer just like the 81's out there. What can I get for more umph and still pass smog? I'm very excited about taking on this project as I'm pretty much starting from scratch for engine options.

Thanks in advance!

randyredleg

I have a 383 that smogs comfortably. This was originally a federal car, so I am not sure if the limits are the same as those for your California car.Do you have an old smog report that shows the limits? I can check to see if my results are within those guidelines.

fauxrs2

Running a 350 in lieu of the 305 is a no-brainer - you gotta do it, its a moral imperative The question remains just how much can you get away with.

I know many folks have passed smog with a ZZ4 motor, though the heads I dont think have a heat crossover,im not sure...you will need the crossover for EGR functionality so no crates with vortech heads (which is a crying shame).

You can run full length or shorty headers so long as they have the AIR tubes. Dont worry too much about an EO number for these, in 10 years in CA. I've yet to get called out on my full length headers and they dont have an EO.

You could also run the "Universal 350" its weak (240hp) but is a good starting point. However I think you would be better served running somehting with a roller cam like the zz4 - for peace of mind (dont have to worry about flat tappet cams) and for the increased lift.

A 383 is possible but I think maybe getting a bit dodgy there, it can be done but I suspect everything would have to align just right to allow you to pass comfortably over a period of years.

as far as smog requirements go - see this sheet

c3corvettes

If I go with the "universal 350" I guess I can always change out the cam and heads for more power right? I would be interested in changing those parts before dropping it in though. I would definitely go with air injected long tube headers if there's no problem there. I have read somewhere before that no matter what engine I choose, I need to install my carb, cam and distributor into the replacement motor. Is this true? I need more info as I'm very eager in starting this frame on resto and want to invest my money wisely. I would be so upset to invest in the engine time and money only to find out that I didn't pass the tests. That would really SU**.

Thanks for the insight and tips please keep it coming.

c3corvettes

Would it be wiser to build my own 383 motor? I'm in for the long run with this project so I'm not in a hurry to have a running motor dropped in, which is why I would also consider not going with crate. Besides I know I would learn a lot from building my own and it would be a lot a fun.

fauxrs2

I prefer building them to buying them myself, but only because I enjoy the building part, and of course you dont have to have all the money up front. Building an engine isnt difficult and there are plenty of experts in So Cal you can run to for help.

All that said, theres alot of parts you will have to get obviously, including the block for one. this could add up quickly especially if you also add in the cost of machining. Its a toss up in my opinion, you could go either way.

Goody

If you are up to the extra work you should really take a good look at dropping in an LQx/LSx series engine. Comparable power, better fuel economy, improved driveability and passing smog is much easier without a troublesome carb. You only have to run the emissions that came installed on that year engine.

This eliminates the smog pump, air tubes, and the single cat. Would require going to a referee station to pass smog and then a new VIN is assigned to correspond to the new engine.

Requires a bit of research here in Cali but a very doable alternative.

fauxrs2

I agree a LQx or LSx combination offers many advantages over the earlier gen small blocks, however I think it might be alot for ones first engine build/install. Certainly not insurmountable, but it will require more effort, more money and more expertise than simply an engine he can bolt back into the car.

Mewn

I think you should install one of these engines and register your car in Ohio or Florida, somewhere that does not require inspections.
http://www.ultrastreet.net/engines/434_ultrastreet.asp

c3corvettes

WOW! That's an impressive looking motor. Looks mean.

Vette80regon

I have a 80 which is also a California car. Oregon has relatively stiff smog too. But... I have a regular ol crate HO 350 which easily passes smog. It has headers, 3" true dual exhaust, dual catalytic converters.
I don't even have the AIR pump assy or any of that stuff.
As long as a SBC is properly tuned, it is plenty efficient.

OregonVette80

BTW... here's a pic of my 1980 California car crate engine bay.
It was built on the LT-1 specs btw...

350cu in. SBC no AIR or smog stuff, easily passes DEQ requirements



more:
nore the 2" drop down air cleaner assy. The wingnut of the filter lid just scrapes the hood. Tight, but fits perfectly!


more:




it's nice and "somewhat" cleaned up the engine bay without all of those whacky oem hoses and shields etc... engine runs very clean, efficient & provides relatively good gas milage.

c3corvettes

OregonVette,

Did you reuse the original distributor, carburetor, camshaft and computer from the California 305?

Thanks

BTW your engine bay does look clean. Good job!

OregonVette80

It is a universal HO 350 crate engine btw...

1. Did you reuse the original distributor? YES! oem HEI is a great platform

2. carburetor? NO! I used the Performer Edelbrock 600cfm. it too is a great, stable, platform which was dyno tuned to be as efficient all the way through (from 0-5800 RPM)

3. camshaft? NO the camshaft isn't too racey. It has a very slight "blump-blump" sound to it. VERY streetable, pretty mild & user friendly. I don't know/remember lift duration etc etc...

4. computer? Hell no!!! Your 80 doesn't need it either. Just put in a regular ol 350 SBC crate engine and you are going to be plenty happy over your anemic 305.


Here's a very safe & sound starting place:
http://www.gmperformanceparts.com/Pa...l.jsp?engine=0

I can't give 100% endorsement that your car will pass your area smog requirements but, a carburated 350 SBC is a very efficient platform. I just had to make sure it was dyno tested to pass & have dual catalytics. They don't check for AIR system/pump in Oregon. I would contact a Vette shop or classic car shop in your area aand see how they handle DEQ/smog.

Good luck!

OregonVette80

it's actually on sale for $3400

http://www.crateenginedepot.com/stor...1329-P5C2.aspx

mods... I don't know if they are supporting vendor or not. don't ban me for helping a brother out

randyredleg

In California, regardless of how clean the engine might run, you still have to pass the visual to confirm all smog equipment is there.Just had mine done and he traced all the vaccuum lines, including those on the stock air cleaner. Even made me hook up the plastic spark delay on the distributor.I don't think true dual exhausts are allowed, even if you have two cats.

OregonVette80

time to move

PRATASEIS

Ramjet 502