Thread: Weird thing done to 305, what cam is it?

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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.

Originally Posted by Littlechevy

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 mog 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 moot or was rebuilt.

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

Originally Posted by HWORRELL

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.

them damn liars over CID i hate them guy.si know one really well

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

Originally Posted by pat mccarthy

when i do is i need to lay my hand on the air cleaner when the engine is running...

Reminds me of Johnny Carson wearing the turban and holding an envelope up to this forehead in an attempt to divine the question......

.

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










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


Engine






Carburetor


New exhaust


Trans:


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

Old tires

Engine










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

Old tires

Engine










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

Old tires

Engine










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.

Originally Posted by Littlechevy

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?

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 ?

2.5" exhaust and disc in front yes.

Some pics for you
After new tires

Old tires

Engine










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.