I was eyeing a gen 3 or gen 4 camaro as a possible CAM/HPDE car as I have been enjoying watching Sam Strano build out new parts for his Gen 4.
I definitely like that the newer ones come with LS power stock but when browsing craigslist I see a ton of Gen 3's where people have swapped in built 327/350/383s with carbs from the 60's my question is why? Why are they removing a more modern v8 and fuel injection to put in an older one?
Besides the motor differences are the Gen 4 worth the price premium over the Gen 3 cars? In some ways I prefer the Gen 3 styling but the interiors are pretty lol GM in the 80's
Because tpi is not as easy to work with as a carb. Nor is tbi.
They can also be doing it for converting from v6 to v8.
I disagree with them getting rid of efi, but thats the crammit section of the market.
I know someone who runs a small block in a tube frame TT car. I asked him about moving to an LS. He said something about head flow and how it was easier, and much cheaper, to make decent NA power on a small block through a carb than an FI LS. He might be blowing smoke, but it's given me things to think about.
This is on a race car where things like cold start and creeping in traffic aren't really a concern, so it may not be valid.
NickD
SuperDork
5/23/17 7:23 a.m.
mazdeuce wrote:
I know someone who runs a small block in a tube frame TT car. I asked him about moving to an LS. He said something about head flow and how it was easier, and much cheaper, to make decent NA power on a small block through a carb than an FI LS. He might be blowing smoke, but it's given me things to think about.
This is on a race car where things like cold start and creeping in traffic aren't really a concern, so it may not be valid.
Cheaper, perhaps. Easier? I doubt it. The LS engine heads flow way better than a lot of aftermarket SBC heads.
Brian
MegaDork
5/23/17 7:33 a.m.
I would say look at when those carbed third gens had been built. "Easy" EFI is a more recent advent. Also, I imagine that GM TPI is a less ubiquitous system than the iconic 5.0. It was easier and cheaper to just use 4 barrel setup.
Well, SBCs are dirt cheap to buy and modify, for one. I think a lot of it also has to do with familiarity, guys who grew up on carbed SBCs and know how to tune them, but have never messed with FI.
We have a machinist at work who is a perfect example, he's an old muscle car dude with a constantly rotating stock of fix and flip barn finds. I had the oil pan off my LS a few months back installing an Improved Racing baffle and cracked a corner off of it while reinstalling because I didn't realize a piece of the old gasket was stuck in place. Had the pan welded and gave it to this guy to skim the flange flat and when I was talking to him he made some comment about the LS engines being too "new fangled and complicated" for him.
As for 3rd gen vs 4th gen, the 4th gen have a arm suspension up front vs struts on the third gens. I think they also swallow a bunch more tire, like 315s at all four corners are no problem with the right offset wheels. Brakes are better too, at least on the LS1 cars.
Because EFI doesn't work within 25' of a mobile home, where most of these swaps take place
NickD wrote:
mazdeuce wrote:
I know someone who runs a small block in a tube frame TT car. I asked him about moving to an LS. He said something about head flow and how it was easier, and much cheaper, to make decent NA power on a small block through a carb than an FI LS. He might be blowing smoke, but it's given me things to think about.
This is on a race car where things like cold start and creeping in traffic aren't really a concern, so it may not be valid.
Cheaper, perhaps. Easier? I doubt it. The LS engine heads flow way better than a lot of aftermarket SBC heads.
Cheaper/easier to a point, maybe. 400+ hp in an LS is stupid easy, just a cam swap away. I'd imagine somewhere right around that hp range is where the LS becomes the cheaper/easier option.
pres589
PowerDork
5/23/17 7:46 a.m.
Something not directly asked about, but, the 3rd gen has a steering box [like a truck], the 4th gen is rack and pinion [like a car].
Simplicity. Im not even old and have removed fuel injection from several engines and replaced it with a decent intake and 4 barrel.
The stock TPI chokes a 350(though it makes good torque in the process). A carb+intake+mild cam will provide similar torque as a stock TPI setup and bump HP to about the same numbers.
If looking at the 4th gens (tire+steering+suspension seems like good reasons for HPDE) is it worth the premium for LS years vs the older ones
As is often the case, there are several reasons. The TBI systems on the third gen cars was pretty crude and while they ran OK they were really only an incremental step up from a carb. The TPI systems were more sophisticated but the manifolds were optimized for low RPM torque and really limit the ability to make a lot of power up high. In addition, there's no flash memory in the ECUs. Custom tunes need to be burned into an EPROM and there are few shops setup to do that so tuning involves shipping EPROMs or an aftermarket ECU.
Simplicity and low cost. I built a 3rd gen IROC for a gentleman a couple years ago. Stroker 383 carbed with a turbo 400. He wanted the computer, FI, and all the electronics and emissions etc. removed. While everyone raves about the performance and fuel economy of the LS and other modern engine/trans drive lines there's a lot to be said for old school simplicity. If you don't have the myriad of sensors and other stuff they require then those items don't cause problems.
WilD
Dork
5/23/17 9:31 a.m.
It seems like the question is being over analyzed. If the question is "why put an old tech carbureted SBC in a 3rd gen rather than an LS"?, I don't have a good answer other than it was likely cheaper. If the question is, "why put an old tech carburated SBC in place of the original 3rd gen engine?", then the answer is cheap (relative) performance upgrade (potentially massive). Have you driven a TBI 305? The torque is OK but they are relatively unexciting. Don't even get me started on the V6 equipped cars.
Probably because Gen 3s were in the horrific pit of smog years. There were a couple years in the 80s where the most power you could get in a camaro was 160hp. You can always build on the SBC, but with the smog years it wasn't just a simple thing; cam, heads, intake, carb, exhaust, dished pistons... everything was matched and set up well for that 160hp. Its so much easier to drop in an older assembly that already has potential.
SEADave
HalfDork
5/23/17 11:29 a.m.
I know that on this site folks claim they can LS swap a car for three nickels with a ball of twine, but in the real world most completed street driveable LS swaps end up costing a lot more than the average 3rd gen is worth. Fuel, cooling, gauges, etc. all add up quick.
As to the 3rd gen vs. 4th gen question, the 4th gen (especially the LS cars) are better performance wise in every measure. But they are worse in two important ways; initial buy in and ease of maintenance. A good, clean manual trans LS car still brings pretty solid money, $7500 and up around here, while 3rd gens are easy to find under $2000. 4th gens have the engine tucked way up under the cowl and are a bear to work on, while the third gen has the engine under the hood. If all you want to do is get it right and leave it stock this isn't a huge deal because the 4th gen is pretty reliable, but if you want to do a lot mods and tinkering it is definitely something to consider.
Jaynen
Dork
5/23/17 11:54 a.m.
I can completely understand swapping out the 80's smog pit of hell GM motor, what surprised me is that these 350s were very old often like 1960s vs some sort of newer sourced crate motor. It just surprised me they would be so old unless there was some loop hole regarding age of engine etc.
For HPDE/Autocross CAM class I am not sure how much the EFI vs Carbed setup would matter or how finicky the carbs are. It seems like for that purpose however the Gen 4 has a lot more going for it with the big wheels/tires stock and better suspension design
Jaynen
Dork
5/23/17 11:56 a.m.
gearheadmb wrote:
As to the 3rd gen vs. 4th gen question, the 4th gen (especially the LS cars) are better performance wise in every measure. But they are worse in two important ways; initial buy in and ease of maintenance. A good, clean manual trans LS car still brings pretty solid money, $7500 and up around here, while 3rd gens are easy to find under $2000. 4th gens have the engine tucked way up under the cowl and are a bear to work on, while the third gen has the engine under the hood. If all you want to do is get it right and leave it stock this isn't a huge deal because the 4th gen is pretty reliable, but if you want to do a lot mods and tinkering it is definitely something to consider.
Cost is an issue, I would not want to leave it stock either way. But I do tend to like to mostly drive my vehicles not wrench on them once I get them setup. Something actually fairly easy to work on yourself be it suspension/motor etc is nice.
I see fairly ratty some even swapped Gen 3s for less than 3k for sure 5-7k sometimes more for decent gen 4 with manual trans.
I'd take a modern carburetor over 30 year old EFI any day of the week, especially the TPI.
Jaynen wrote:
I can completely understand swapping out the 80's smog pit of hell GM motor, what surprised me is that these 350s were very old often like 1960s vs some sort of newer sourced crate motor.
For me and SBCs, I usually have enough parts sitting around to probably make 3 SBCs for cheap or free, so a $4000 crate motor has zero appeal for me. I understand why some people go that route, but buying a crate SBC (to me) is like buying bottled water. Why would I get 10% more for $2 when its free from the well?
To make a long story short if you want to build a performance Gen 1 SBC for cheap you will have a carburetor or be hacking fuel rails and injectors onto a carburetor manifold, and the F body has always been a cheap performance car.
None of these cars came with a "more modern V8", all the the third gens used a 305 or 350 gen 1 small block, mostly the 305 (a small bore gas mileage design from the 70s), most were carbureted from the factory up until the late 80s, then mostly throttle body injection from there which has the same performance issues as a carb. The factory port injection setup is somewhat rare and doesn't flow very well. The best SBCs were mostly built in the 60s, with the exception of Corvette stuff and the last of the gen 1 truck engines with "vortec" heads, so if you're putting one together on a budget it's likely going to be made from a lot of old parts on a block cast whenever the one you picked up was cast. The blocks can take something like a 0.060" overbore before they're scrap (ideally that's 6 rebuilds) so there are a lot of old blocks still running around out there.
pres589
PowerDork
5/23/17 1:02 p.m.
I kind of think a 305 built with Vortec heads and a TPI/Megasquirt setup should be a good performer on the street and a cheap place to start. 305 cars came with manual transmissions where as no 3rd gen 350 car got a manual.