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Old 01-28-2019, 05:21 PM   #1
eighteenninetytwo
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OK - it's time for some schooling.

My 75 Blazer is just about finished in terms of bodywork, interior etc etc.
its been ticking over nicely for a couple of years now and I haven't needed to get myself involved at ALL with the mechanical side of things - head gasket went and a mechanic fixed that. There is an oil leak, and that needs to be fixed but its not real bad, and I suspect that the exhaust manifold isn't sealed properly where it joins the engine from the sound. None of this has been an issue as its a mall crawler, never leaves our town and it most strenuous use is taking kids for ice cream or to soccer games half a mile away.

However, it's now at the point where I think I need to investigate and see what I actually have, and what can be improved - especially as I'm getting 7 miles to the gallon.

So - low hanging fruit first - I need to figure all relevant engine and carb specs? It's a 350 V8 small block but that's as much as I know right now.

This will be a learning process for me - its time for school.
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Old 01-28-2019, 11:41 PM   #2
Dads79GMC
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Re: OK - it's time for some schooling.

Best of luck and enjoy! Mike
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Old 01-29-2019, 02:58 AM   #3
rideair
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Re: OK - it's time for some schooling.

When was the last time is had a good tune-up and valve adjustment?

The key problem to me would be the ticking, is it just a valve adjustment, lifter, burnt valve, etc.. (repair price goes, up-n-up) From there, your oil leak, just a oil pan leak, head gasket or a rear main-seal (same here)? Does it burn oil? If so, when does it smoke? Ever done a compression test? What's the numbers?

Not saying this is the best way, but first look at the overall mileage on the engine, how it's been maintained, etc... and do an overall assessment of the engine. Depending on your answers and the problems you find, you maybe money ahead just to replace it with a new crate 350, depending on the overall condition, current mileage and how all the problems add-up. Bite the bullet now and enjoy for a long time.

Anymore after a certain point, you can buy a new engine with a 3 year/100,000 warranty for about $1,800.00 that can be changed out in a day/two.

Also the question becomes, which do you have the most of, Time, Money or Effort? Think about this for a second, how much time will you spend researching all the information you need to know to fix all the problems? Next, how much time will you spend fixing all the problems you find and the cost of running to the parts store, etc...

I think back all the weekends spent fixing crap where if I'd just spent a few extra dollars I could have been driving the crap instead ;-)

Good Luck,
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Old 01-29-2019, 02:03 PM   #4
eighteenninetytwo
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Re: OK - it's time for some schooling.

Hmmm the time / money equation is one thing I hadn't thought about actually. Neither is exactly abundant right now but probably of the two I can at least get hold of some dollars and pay them back. Time is gone once its used up.

Answers to a couple of the questions : Not been tuned since I've owned it as most time has been spent getting the bodywork and interior done. Never done a compression test but no it doesn't burn oil, and no it doesn't smoke.

I DO have time and money to get a gauge and then run compression tests though, so that suspect is where I shall start and shall then report back.
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Old 01-29-2019, 03:52 PM   #5
rideair
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Re: OK - it's time for some schooling.

1892,

If it were mine, since it's not smoking or burning oil, I'd give it a fresh tune-up and valve adjustment (not a bunch of money) and see how it does. During the valve adjustment you'll get to see how clean/dirty the heads are, possibly adjust the ticking sound out, see how the spark-plugs are burning (clean/dirty) etc... adjust the carb, etc... You may find this will take care of your problems, increase gas mileage, etc..

Now, if you find the plugs are dirty with oil, you can't adjust out the tick, etc.. you might want to do a compression test and see what you've got and go from there.
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Old 01-29-2019, 04:43 PM   #6
eighteenninetytwo
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Re: OK - it's time for some schooling.

errrrr..... I'm not seeing where there is a ticking sound?? Oh I gett it - sorry my fault. "Ticking over nicely" is a British phrase for "running well".

The engine sounds great, but its feels weak and the mileage sucks bad. Is a valve adjustment something I can learn to do, or it is mechanic and $$$$ time?
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Old 01-29-2019, 07:18 PM   #7
rideair
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Re: OK - it's time for some schooling.

1892,

Ok, lets start over!

Do a basic tune-up, points, plugs, condenser, plug wires, dist. cap, fuel filter, air filter, oil, oil filter. Check timing, Check the carb. for correct air/fuel mixture.

Do the above and see how it runs. Doing this you will also learn where your oil leak is coming from.

You can find youtube videos on all the above, not real hard to do. At one time it was called being a "Shade Tree Mechanic". You will need a few basic hand tools along with a set of feeler gauges and a timing light.

Start at 1:00pm on a nice afternoon with a six-pack of your favorite beer. Drink one beer per-hour until finished.
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Old 01-29-2019, 07:24 PM   #8
eighteenninetytwo
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Re: OK - it's time for some schooling.

Perfect. Thank you. Sounds like the starting point I was after.
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Old 02-05-2019, 12:34 PM   #9
eighteenninetytwo
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Re: OK - it's time for some schooling.

Started this project on the weekend. After watching numerous videos on you tube I got the (manual) choke working properly, adjusted the idle speed and gas/air mix on the carburetor (Edelbrock 1405). This is just part of the learning process for me so I'll have to do it all over if I change stuff of course. Still smells of gas when running a bit though - a friend suggest i might want to figure out the springs and jet sizes in the carb.

Eventually I set the idle speed to about 800 when not in gear and it drops to about 600 when in gear and stopped. Any objections or commentary on those numbers? I intend to change the plugs this coming weekend also, I have standard AC Delco plugs but I'm open to suggestions if there are any highly recommended for a 350.

Last edited by eighteenninetytwo; 02-05-2019 at 01:58 PM.
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