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Hey guys I'm new here. I have a chevy 305 that is a little "different", an I would like to figure out some things. I've taken it to a mechanic and he timed it and tuned it but is still getting 12.5mpg.
I took a video of the exhaust because I have no idea what cam it is and was hoping someone could guess? Is this why my mpg is terrible?
http://m.youtube.com/watch?v=tJqJ2-nz2-A
Again I bought the car and I have no idea what it has other than the motor or was rebuilt.
First things first, welcome to the forum! I'm afraid your post is going to bring up more questions than answers at first. First, the 305 is not going to be a performer for you in power or efficiency, especially in something as heavy as your El Camino. You're right that the cam is not stock, and that could easily be a part of your problem if the previous owner bought the cam for the idle instead of for improved power & efficiency. The rule is that you select your cam to optimize your engine's power & torque, based on how you plan to use it, and the idle will take care of itself. Unfortunately there's no way to know the specifics of your cam without some pretty major disassembly of your engine. Let's go through some of the basics to see if anything jumps out:
1) Is that 12.5 mpg around town, on the open road, or combination? If it's around town or even combination town & some runs into Overland Park, Lenexa, NKC, etc it's really not that bad, especially if you don't have overdrive. If you still think it's too low, then....
2) What carburetor are you running, to see if the CFM of the carb is in the right range for your engine?
3) Automatic transmission, and do you know what it is by number?
4) How's your compression on each cylinder?
5) What's your ignition system? Distributor type? Any aftermarket "box"?
6) How do your plugs look after a good highway run?
Other guys may come up with other questions, too, but if you answer back with these it will get some dialog started. You might want to start saving your money for a nice 350 crate engine, or even a built out 383 crate from GM Performance Parts with a nice over drive auto.... Again, welcome to CHR.
Where did you buy that car ? If you purchased it in St.Louis I think I know it and if its the car I'm thinking of that ain't no 305.
realy hard to tell what size the cam is by the sound out the exhaust .. when i do is i need to lay my hand on the air cleaner when the engine is running... but more numbers the better like vacuum at idle . a lower dollar cam kit and check valve springs and over all engine shape then recam it. the 305 may not be the best but far from worst yep a 350 or 383 may be better but there were a hell of a lot of the smaller 283 out there pulling big old chevys and boats . 350 or 383 not going to get better fuel MPG if your foot down in it :)Quote:
Originally Posted by Littlechevy
them damn liars over CID i hate them guy.s:rolleyes:i know one really well **)Quote:
Originally Posted by HWORRELL
If you're not sure it's a 305cid engine here's a link to run the numbers - http://www.crankshaftcoalition.com/w...bers_and_codes
Reminds me of Johnny Carson wearing the turban and holding an envelope up to this forehead in an attempt to divine the question......Quote:
Originally Posted by pat mccarthy
.
It is a 305, I ran the block numbers. It's an 82-87 305; Nova/Camaro?? It's an elcamino.
•it has a brand new performer quadrajet on top
•Timed to 8.5* BTDC @ 850rpm
•3-speed TH-350-c
•2.41 rear gears, open carrier.
•12.5 is city driving, it wavers from as low as 10.2-14.4mpg
•its ORIGIONALLY a 305, have no idea the bore or compression?
• it was rebuilt by a previous owner in the late 90's (he passed away and his daughter sold the car, she had no Idea)
•I bought it in Gardner Kansas where rspears is coincidently from.
Here's some pics to evaluate guys
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...ps5d988834.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
Should be enough pictures to get me started.
Thanks guys, anybody have a cam guess? I've been told around a 30-30 cam or more?? Don't know what that is. I just know something ears my gas!
Other post didn't upload. So I will try again if I remember it all.
•Carburetor: performer quadrajet
•engine: 305, not sure of bore/stroke/compression/heads
-I ran the numbers and the BLOCK is a 305, again I don't know how far bored?
-A previous owner built it (I'm the 3rd owner)
-block is from 82-87 Camaro/Nova
•Transmission: TH-350-c 3-speed auto
•Rearend: 2.41 open carrier
•Bought from Gardner KS.
***HWORRELL: enlighten me please, you may answer something. The car according to car fax has been in Arizona, then Kansas, then 5 years ago Missouri, then Kansas again. Origional owner moved from Arizona to Kansas, then to Missouri i think. The previous owner only had it for about 5 years.
So its a possibility it could have been it St. Louis?
Here are some pics of what it has done to it. I know I can't leave out pics!!
The car: 1984 el camino
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
Carburetor
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
New exhaust
http://i1138.photobucket.com/albums/...0902121411.jpg
Trans:
http://i1138.photobucket.com/albums/...ps28d3aac7.jpg
That's it guys, I've been told it sounds like a 30-30 cam or more but I have no idea and people keep asking me. I thought it was stick until people said it sounded better than a 305
Some pics for you
After new tires
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Old tires
http://i1138.photobucket.com/albums/...ps91056c8e.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
http://i1138.photobucket.com/albums/...0902121411.jpg
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
Some pics for you
After new tires
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Old tires
http://i1138.photobucket.com/albums/...ps91056c8e.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
http://i1138.photobucket.com/albums/...0902121411.jpg
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
Some pics for you
After new tires
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Old tires
http://i1138.photobucket.com/albums/...ps91056c8e.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
http://i1138.photobucket.com/albums/...0902121411.jpg
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
Then it can't be the car I was thinking about because it spent its life in the LOU. But just out of curiosity does your car have disc brakes in the rear ? And 3 inch dual exhaust ?Quote:
Originally Posted by Littlechevy
2.5" exhaust and disc in front yes.
Some pics for you
After new tires
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Old tires
http://i1138.photobucket.com/albums/...ps91056c8e.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
http://i1138.photobucket.com/albums/...0902121411.jpg
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
2.5" exhaust and disc brakes up front
I think it was "The Amazing Carnac" or something like that????Quote:
Originally Posted by techinspector1
With the left hand over the air cleaner and the right over his heart.... Closes his eyes and thinks of the flag... rofl..
Welcome to CHR!
The exhaust sounds like it's fairly open (Flowmaster 40 or similar with headers?) and some work has been done internally which may have included a cam with a bit longer cycle/duration. Do you know the cfm on the carb? 600-650 is fine, anything bigger will definitely consume more fuel and probably not contribute to performance. When you say you ran the numbers - are you talking the casting number of the block or the numbers stamped on the pad on the passenger side of the block?
12.5mpg overall may not be that bad - considering the weight of the vehicle and the rear-end ratio is fairly tall to get things moving. Have you done a freeway drive, say 200-300 miles at 55-70mph? My insides tell me you'll see a dramatic improvement in mpg (say 16-20mpg).
My two cents,
Glenn
I'm trying to uploads pics but they won't upload. It is a performer quadrajet so it's not that great. I think about 600cfm.
It has exhaust manifolds and dual pipes with 16" glasspacks. I will keep trying to upload pics.
Some pics for you
After new tires
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Old tires
http://i1138.photobucket.com/albums/...ps91056c8e.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
http://i1138.photobucket.com/albums/...0902121411.jpg
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
Seems like someone else mentioned that they had to hit a ten post threshold before they could post pictures, something about keeping the spammers out?Quote:
Originally Posted by Littlechevy
Oh I see, well I have the pics waiting. I will upload as soon as it hits 10
yep you bet my turban is out for dry cleaning . but to get this to work the car must be kept under funk&wagnalls front porch over nightQuote:
Originally Posted by techinspector1
If only I knew what Johnny Carson was
The "Tonight Show" host prior to Jay Leno....Quote:
Originally Posted by Littlechevy
Oh okay, thanks haha! One more post and I can show you guys pics
Okay here are the pics
Some pics for you
After new tires
http://i1138.photobucket.com/albums/...psff07c3ed.jpg
Old tires
http://i1138.photobucket.com/albums/...ps91056c8e.jpg
Engine
http://i1138.photobucket.com/albums/...ps37431f11.png
http://i1138.photobucket.com/albums/...ps125b153f.jpg
http://i1138.photobucket.com/albums/...psbbc11b43.jpg
http://i1138.photobucket.com/albums/...ps473f5bd6.jpg
http://i1138.photobucket.com/albums/...0902121411.jpg
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
So that's it. Why I'm asking this question is because people ask what cam it has? I dont know, some people told me it sounded like a 30-30 cam. Don't know what that is? So I thought it was stock but apparently it was changed with the motor rebuild.
A 30-30 cam is what Chevrolet used in 375hp Corvettes in 1964 and so named since the valve lash is 30 for the intake valve and 30 for the exhaust valve. It's also a solid lifter cam which will be somewhat noisy and have a definite lope.
Nice Elky!!!! Sure do like to see a clean and shiny classic!!!
Thanks!
So what does it sound like? It doesn't sound like a comp cam to me.
Sound doesn't mean much, really. If I had to guess I would say the favorite "poser" cam on the market, the Comp Thumper!!!! Comp Cams also has a free download called "Cam Quest". If you input accurate information about your car and your engine it will give you some good choices in cams and other valve train components for a car....
now who.s has the turban on:) a cam is numbers that they grind on a iron or steel core the numbers are base circle size.lowest part of the lobe the heel and then ramps of lobe s opening closing ramps numbers . then lobe centers all numbers there is no not really a sound thats trade marked in cams any cam grinder can copy the numbers of another cam company other then the parking lot cams that compcam sell as thumpers that may be trade marked. the cam is numbers that if the company has the masters and tooling then any one can copy a cam i had cams copied so to say thats a Isky or Lunati .Howards .Comp Cam . Erson Cam .Crower .many others .it would be very hard to say as many of the smaller grinds cams. some companys buy and put in there nice box with nice stickersQuote:
Originally Posted by Littlechevy
Nice clean Elky, good score. Definitely NOT a "30-30" cam, one of them is just barely streetable, and has a serious "lope", not to mention the solid lifter's "rattle" - they just sound different. Yours sounds like the Erson Perfomance RV cam I had in my '59 - rrumbly, but not lopey.
Okay that was with the electric choke on idling I think around 1,250rpm. Here is it idled down. Here is lope.
http://m.youtube.com/watch?v=Mna8VulLRCU
This is what it was like when someone told me it sounded like a 30-30. This was a could start after a couple days.
I got 18 mpg from the 305 in my 78 firebird.
It's been a while, but I think it was a .490 lift with a 290 duration. If those numbers are whack,then Tech will call me on it.
BUT, it was .060 over, and factory 2 bbl, long headders, and massive flowmasters, 2.56 rear ratio, and th350.
I miss that car. No, not a BB monster, but it had spirit, and put to shame many a rice burning young-un.
You are asking an impossible question, any answer is simply a quess. No One can listen to a motor run and decipher which cam is in there!Quote:
Originally Posted by Littlechevy
If you really want or need to know, a couple of dial indicators and a degree wheel can unravel the mystery... or get to the cam to read the numbers.
Look back through the posts and you'll see a consistent pattern, with Mike'scutting to the chase and giving you the only option, if you really have to know.Quote:
Originally Posted by 34_40
I know your Elky and how you take care of it, and I'd say that you're likely looking at your "messing around" mileage - daily driving around town, lots of stop light/sign stops & starts, occasional runs at highway speeds, etc and your 12.5mpg is really good for that. Am I right in this assessment? If you want to know your "true" mileage fill your tank, jump on I-35 and head north (no tolls that way :)) about a hundred miles at the speed limit, driving like you have a raw egg under the gas pedal, hit an exit and head back home light on the throttle all the way. As you pull off the highway go straight to a gas station, refill the tank and note the miles driven and gallons used.
I think you'll find that the biggest reason for your "normal" mileage is that 2.41 rear gear! Those are super high highway gears, bought with highway efficiency in mind since they didn't get an overdrive transmission. I expect that you're getting into the throttle a little heavy on your starts, compensating for those tall gears, and probably staying into it pretty deep. If you're looking for better around town performance the biggest "kick in the pants for the bucks" would be if you dropped in a set of lower rear gears, like something around 3.23 to 3.55, but know that your highway mileage is going to suffer. The only way to get both worlds is to swap to an overdrive transmission or GearVendors OD into it, along with the lower gears.
Bottom line, don't start just buying parts and changing things without a plan. You've done right asking about your cam instead of tearing into it and buying something just for the sound. My advice? Enjoy what you have, think about where you want it to be in five years, write down a detailed plan and start saving your $$ until you can take steps toward your end goal. Sorry for the long winded post...;)
You guys are all wrong----------Its gotta be a cam out of a Rotary engine---------
If you are looking for milage---your plan should be to either look at converting the truck to an LT1 package or a later LS take out package along with accompanying electronic overdrive and associated wiring harness/ ecm---------