Fat Hack
09-19-2003, 06:53 PM
I'm kinda surprised at how most gearheads view the 305 Chevy engine! It's been around since 1976, and was essentially the base V8 in many GM models up into the 90s, so there are plenty of them around, and available on the cheap!
The 305 is really just a small bore 350, with the 3.48" stroke common to both of them. This gave GM an engine that would save them a little bit on their Corporate Average Fuel Economy ratings, yet still deliver enough torque to get their vehicles moving! The 305 really strikes an ideal balance between performance and economy.
From a performance standpoint, the 305 rates very well. It's very responsive to common-sense engine modifications and as I stated in another post, and it makes a great street supercharger motor if boost levels are kept within reason! By fate or by design, I've owned, modified and tuned many 305 Chevys, and here are some of the things I observed.
Case 1: The Malibu:
A stock intake works okay, but the 305 really loves the basic Edelbrock Performer. The dual plane design maximizes the engine's efficiency at rpm levels below 5500, and actually INCREASES fuel economy by a considerable margin over a stock cast iron intake and two barrel carb when equipped with a 600cfm Holley. I had the chance to observe and note the effects of manifold swaps on my old "dyno mule" Malibu, and here is what I found.
Baseline: Stock 1977 305 2v................17.30s and 12mpg
Performer intake w/ Holley 600 carb........16.50s and 17mpg
Recurved stock HEI and added Supercoil.....16.30s and 17mpg
Headers w/ turbo mufflers dumped at axle...15.70s and 20mpg
Mufflers removed, 3ft tubes on headers.....15.50s and 21mpg
TRW #274 cam, new chain, flex fan..........15.00s and 23mpg
Full duals from headers Dynomax mufflers...15.10a and 23mpg
K$N stub stack, softer secondary spring....14.90s and 22mpg
Magnum roller tip rockers, 1.52 ratio......14.80s and 24mpg
Magnum 1.6 rockers on exhaust side.........14.80s and 25mpg
<img src=http://www.imagestation.com/picture/sraid80/p008a3d355476d575559a1991bcb4e092/fb0b6c56.jpg>
At that point, I was VERY satisfied with the way the car performed at the track and drove on the street. You really had to DRIVE the car to appreciate it...at 60mph on the freeway, the weight of your shoe was enough throttle to keep the car humming along! The combination was so efficient, it was scary! All this in a hulking four door with stock tranny and rear gears...and 120,000 miles on the clock to boot! My buddy drove the car and was impressed to no end by it's INSTANT throttle response and the way it just "jumped" when you hit the gas!
The logic behind slipping the 1.6 ratio rockers on the exhaust side only was to try and recover what little I had lost by having a full set of duals run on the car. (I drove it on the street for MONTHS with just the three foot extensions on the header collectors!). A friend worked at a speed shop and gave me a set of like-new Magnum roller-tip rockers in 1.6:1 after I bought the 1.52 ones from him.
Case 2: The Pontiac:
The engine was removed from that 1977 Malibu and dropped into a 1970 Pontiac LeMans Sport to replace a screwed up 350 Chevy that was in the car when I bought it. Curiously, the lighter Pontiac was slower than the Malibu, yet it got the same mileage figures! All going to show you just how vital the ENTIRE combination is to gaining maximum results from your vehicle! The Malibu had a 2.73 axle, and the Pontiac had a 3.31 rearend. In theory, the Pontiac shoulda been faster, but never made it!
<img src=http://www.imagestation.com/picture/sraid80/pe7d698bec88ed9f202a0a548ebdcdf93/fb0b6c54.jpg>
Baseline: Malibu engine into Pontiac.....17.80s and 19mpg
Fixed shift cable, fuel line, new plugs..15.30s and 21mpg
Torker 2 intake, carb re-tune............15.20s and 21mpg
750cfm carb, electric fan................15.00s and 18mpg
That's where I stopped messing with that car. The Torker 2 intake moved the powerband up and killed some of the wheelspin off the line. 60 foot times were quicker, but the ET didn't change much. On the street, the Performer intake "felt" better...and had snappier throttle response and tire-burning ability! In hindsight, I shoulda left the Performer on and softened the rear springs and bought better tires...the car had stiff rear shocks and springs with garabage Formula One Super Stocks...the Malibu would squat and go...the Pontiac hazed the one tire off the line! Oh well...lesson learned!
I also tried out a Weiand Team G intake on the Pontiac with an 800cfm double pumper, but never ran it at the track with that set-up. It had a healthier top end charge, and felt about the same as with the Torker 2 off the line. It might have cracked the 14.90 barrier, but we'll never know!
Later on, a Comp Cams 270H Magnum cam was installed and the rear springs were replaced. I added Olds rally wheels and good radials and a cool can for the fuel. This didn't feel any different around town but seat-of-the-pants feel can be deceiving. It never made it to the track in this configuration either.
Case 3: 1977 Caprice Classic:
This one almost mirrored the Malibu Project, with the one odd addition of ANOTHER 200,000 miles! That's right...I got the car with a bona fide 309,000 miles on it from the second owner. The original owner was an old mechanic with family in Seattle who racked up all those miles, yet the engine was never rebuilt! By the time I got it, it smoked a wee bit, but still ran pretty good! I figured why not have some fun with this one, too??!!
Baseline: Stock 305 2v.....................17.50s and 14mpg
Edelbrock Performer RPM intake/600 Holley..16.40s and 17mpg
TRW #274 cam, new chain....................15.50s and 17mpg
Headers, turbo mufflers dumped at axle.....15.10s and 19mpg
HEI re-curve, Supercoil, Stub Stack, fan...15.00s and 19mpg
This car was just a daily driver, and it ate up spark plugs due to oil consumption, but even with all those miles under it's belt, the motor ran flawlessly and the car continued to cruise the neighborhood like a big black crop-duster for a few years after I sold it! My buddy at the parts joint sold me plugs for 50 cents each, so i always had an extra set or two in the glovebox. I'd drive to the track, pop in fresh spark plugs, and run it all night!
Okay, so high 14s and low 15s in 70s era mullet-monsters isn't gonna set the world on fire, but these were heavy stockers with stock torque converters, trannys and rear gears. I seriously dobt that a 350 would have done much, if any better...and I doubt that the 350 would have delivered the fuel economy numbers indicated.
(All MPG figures were observed highway mileage recorded while driving the car to and from Milan Dragway where all testing was done on test-n-tune nights. These cars also went on long trips where the same numbers were observed.)
So...if you were to score a cheap or free 305 from somewhere, and build it as I've outlined here...what do you suppose you'd see in...say, a Model A coupe with an 2500rpm converter, shift kit, 3.90 gears and slicks? We're talking about a vastly lighter vehicle here with better gearing and superior traction. My "test mules" were just warmed over transportation specials in full (heavy!) street trim! Imagine a car that weighed almost half as much with drag-oriented gearing!
All this post is really designed to do is to show you that the ill-respected 305 is a very capable performer that is far too often passed over by rodders. Don't let the smaller bore fool you, they can run with their 350 siblings and do it for less money while returning better fuel mileage!
Who gives a shit about fuel economy in a hot rod? The guy who has to watch his budget, yet still wants to have a fun to drive car that he can build dirt cheap! A 305 powered rod will be mild enough for daily driving, reliable enough to drive to events across a few states, and fast enough to have fun doing it!
By contrast, my first car was a 1969 Chevelle with a 350. Stock engine, trans and gears with a 302 Z28 intake, headers, Holley 780cfm carb and single point distributor with Accel points. It ran 15.20s and got 16mpg. This car was similar in size and weight to the 1970 Poncho, and you see the numbers! They look close enough to conclude that a 305 runs about as good as a 350, but gets better mileage...just what GM was hoping for when they introduced the down-sized mouse motor!
So, find you a 305 that nobody else wants, hit it with the bolt on parts I mentioned, stick a low buck Saginaw four speed behind it, and slip that combo into your hot rod project! You'll get alot of bang for very few bucks! Ain't that what home-brewed hot rodding is all about?
Let the goldchainers pay alot more for a 350 crate engine and a Muncie trans...they won't go much (if any) faster, and they can brag about how much more money they spent than you did!!
http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif
Hey...it's YOUR money, I'm just trying to help you save some of it!
http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif
The 305 is really just a small bore 350, with the 3.48" stroke common to both of them. This gave GM an engine that would save them a little bit on their Corporate Average Fuel Economy ratings, yet still deliver enough torque to get their vehicles moving! The 305 really strikes an ideal balance between performance and economy.
From a performance standpoint, the 305 rates very well. It's very responsive to common-sense engine modifications and as I stated in another post, and it makes a great street supercharger motor if boost levels are kept within reason! By fate or by design, I've owned, modified and tuned many 305 Chevys, and here are some of the things I observed.
Case 1: The Malibu:
A stock intake works okay, but the 305 really loves the basic Edelbrock Performer. The dual plane design maximizes the engine's efficiency at rpm levels below 5500, and actually INCREASES fuel economy by a considerable margin over a stock cast iron intake and two barrel carb when equipped with a 600cfm Holley. I had the chance to observe and note the effects of manifold swaps on my old "dyno mule" Malibu, and here is what I found.
Baseline: Stock 1977 305 2v................17.30s and 12mpg
Performer intake w/ Holley 600 carb........16.50s and 17mpg
Recurved stock HEI and added Supercoil.....16.30s and 17mpg
Headers w/ turbo mufflers dumped at axle...15.70s and 20mpg
Mufflers removed, 3ft tubes on headers.....15.50s and 21mpg
TRW #274 cam, new chain, flex fan..........15.00s and 23mpg
Full duals from headers Dynomax mufflers...15.10a and 23mpg
K$N stub stack, softer secondary spring....14.90s and 22mpg
Magnum roller tip rockers, 1.52 ratio......14.80s and 24mpg
Magnum 1.6 rockers on exhaust side.........14.80s and 25mpg
<img src=http://www.imagestation.com/picture/sraid80/p008a3d355476d575559a1991bcb4e092/fb0b6c56.jpg>
At that point, I was VERY satisfied with the way the car performed at the track and drove on the street. You really had to DRIVE the car to appreciate it...at 60mph on the freeway, the weight of your shoe was enough throttle to keep the car humming along! The combination was so efficient, it was scary! All this in a hulking four door with stock tranny and rear gears...and 120,000 miles on the clock to boot! My buddy drove the car and was impressed to no end by it's INSTANT throttle response and the way it just "jumped" when you hit the gas!
The logic behind slipping the 1.6 ratio rockers on the exhaust side only was to try and recover what little I had lost by having a full set of duals run on the car. (I drove it on the street for MONTHS with just the three foot extensions on the header collectors!). A friend worked at a speed shop and gave me a set of like-new Magnum roller-tip rockers in 1.6:1 after I bought the 1.52 ones from him.
Case 2: The Pontiac:
The engine was removed from that 1977 Malibu and dropped into a 1970 Pontiac LeMans Sport to replace a screwed up 350 Chevy that was in the car when I bought it. Curiously, the lighter Pontiac was slower than the Malibu, yet it got the same mileage figures! All going to show you just how vital the ENTIRE combination is to gaining maximum results from your vehicle! The Malibu had a 2.73 axle, and the Pontiac had a 3.31 rearend. In theory, the Pontiac shoulda been faster, but never made it!
<img src=http://www.imagestation.com/picture/sraid80/pe7d698bec88ed9f202a0a548ebdcdf93/fb0b6c54.jpg>
Baseline: Malibu engine into Pontiac.....17.80s and 19mpg
Fixed shift cable, fuel line, new plugs..15.30s and 21mpg
Torker 2 intake, carb re-tune............15.20s and 21mpg
750cfm carb, electric fan................15.00s and 18mpg
That's where I stopped messing with that car. The Torker 2 intake moved the powerband up and killed some of the wheelspin off the line. 60 foot times were quicker, but the ET didn't change much. On the street, the Performer intake "felt" better...and had snappier throttle response and tire-burning ability! In hindsight, I shoulda left the Performer on and softened the rear springs and bought better tires...the car had stiff rear shocks and springs with garabage Formula One Super Stocks...the Malibu would squat and go...the Pontiac hazed the one tire off the line! Oh well...lesson learned!
I also tried out a Weiand Team G intake on the Pontiac with an 800cfm double pumper, but never ran it at the track with that set-up. It had a healthier top end charge, and felt about the same as with the Torker 2 off the line. It might have cracked the 14.90 barrier, but we'll never know!
Later on, a Comp Cams 270H Magnum cam was installed and the rear springs were replaced. I added Olds rally wheels and good radials and a cool can for the fuel. This didn't feel any different around town but seat-of-the-pants feel can be deceiving. It never made it to the track in this configuration either.
Case 3: 1977 Caprice Classic:
This one almost mirrored the Malibu Project, with the one odd addition of ANOTHER 200,000 miles! That's right...I got the car with a bona fide 309,000 miles on it from the second owner. The original owner was an old mechanic with family in Seattle who racked up all those miles, yet the engine was never rebuilt! By the time I got it, it smoked a wee bit, but still ran pretty good! I figured why not have some fun with this one, too??!!
Baseline: Stock 305 2v.....................17.50s and 14mpg
Edelbrock Performer RPM intake/600 Holley..16.40s and 17mpg
TRW #274 cam, new chain....................15.50s and 17mpg
Headers, turbo mufflers dumped at axle.....15.10s and 19mpg
HEI re-curve, Supercoil, Stub Stack, fan...15.00s and 19mpg
This car was just a daily driver, and it ate up spark plugs due to oil consumption, but even with all those miles under it's belt, the motor ran flawlessly and the car continued to cruise the neighborhood like a big black crop-duster for a few years after I sold it! My buddy at the parts joint sold me plugs for 50 cents each, so i always had an extra set or two in the glovebox. I'd drive to the track, pop in fresh spark plugs, and run it all night!
Okay, so high 14s and low 15s in 70s era mullet-monsters isn't gonna set the world on fire, but these were heavy stockers with stock torque converters, trannys and rear gears. I seriously dobt that a 350 would have done much, if any better...and I doubt that the 350 would have delivered the fuel economy numbers indicated.
(All MPG figures were observed highway mileage recorded while driving the car to and from Milan Dragway where all testing was done on test-n-tune nights. These cars also went on long trips where the same numbers were observed.)
So...if you were to score a cheap or free 305 from somewhere, and build it as I've outlined here...what do you suppose you'd see in...say, a Model A coupe with an 2500rpm converter, shift kit, 3.90 gears and slicks? We're talking about a vastly lighter vehicle here with better gearing and superior traction. My "test mules" were just warmed over transportation specials in full (heavy!) street trim! Imagine a car that weighed almost half as much with drag-oriented gearing!
All this post is really designed to do is to show you that the ill-respected 305 is a very capable performer that is far too often passed over by rodders. Don't let the smaller bore fool you, they can run with their 350 siblings and do it for less money while returning better fuel mileage!
Who gives a shit about fuel economy in a hot rod? The guy who has to watch his budget, yet still wants to have a fun to drive car that he can build dirt cheap! A 305 powered rod will be mild enough for daily driving, reliable enough to drive to events across a few states, and fast enough to have fun doing it!
By contrast, my first car was a 1969 Chevelle with a 350. Stock engine, trans and gears with a 302 Z28 intake, headers, Holley 780cfm carb and single point distributor with Accel points. It ran 15.20s and got 16mpg. This car was similar in size and weight to the 1970 Poncho, and you see the numbers! They look close enough to conclude that a 305 runs about as good as a 350, but gets better mileage...just what GM was hoping for when they introduced the down-sized mouse motor!
So, find you a 305 that nobody else wants, hit it with the bolt on parts I mentioned, stick a low buck Saginaw four speed behind it, and slip that combo into your hot rod project! You'll get alot of bang for very few bucks! Ain't that what home-brewed hot rodding is all about?
Let the goldchainers pay alot more for a 350 crate engine and a Muncie trans...they won't go much (if any) faster, and they can brag about how much more money they spent than you did!!
http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif
Hey...it's YOUR money, I'm just trying to help you save some of it!
http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif