77 Aspen 318

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I just changed to 0w-20 synpower in the 75 vette. Don't have enough experience with it yet to recommend doing it. It's not making any lifter noise or other odd noises. I suspect it will consume oil faster than the synthetic 15w-40 I had in it before, but I don't care about that as long as there is no visible smoke from the exhaust.
 
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I predict that going to a lighter weight oil will improve the gas mileage from unspeakably lousy to unbelievably lousy. In layman's terms that amounts to about .2 of a mpg. You can achieve far more mpg gain by backing off the rear brake shoe adjustment a bit so there is less drag, making sure the tires are at the highest pressure that you can run without inducing poor tire wear, making certain that the engine is tuned as best as possible, installing a vacuum gauge and drive by that, etc., than you'll ever get by running a thinner oil. Does the 318 still have the Lean Burn set up on it ? Back in the day the 318s were known for having pretty good gas mileage, compared to GM and Ford, and still had decent power. I'd bet there are a few mpgs still to be had with the engine tune.
 
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Well, a lot of the tweaks we used to employ to eek out a few more horsepower from the engine will also lead to mpg gains. There is a lot that you can do to increase mpg. They'll be small gains, but it will amount to more than thinner oil will get you.
 
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Try making good power and torque with it. Small 4bbl carb, good intake, decent heads and a 3602bbl cam with small dual exhausts and you should be high teens on better. Run 10w30....it really doesn't matter. In stock form the weight of oil you run is so inconsequential when compared to the rest of the inefficiency in the engine that it doesn't matter.
 
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Originally Posted By: 95busa
Try making good power and torque with it. Small 4bbl carb, good intake, decent heads and a 3602bbl cam with small dual exhausts and you should be high teens on better.
Yeah, that shouldn't cost more than 30 or 40 bucks and a few hours on a Sunday.
 
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Originally Posted By: SlantyNW1990
How about supertech 15w40?
No need to run such a heavy oil in this application, especially if mileage is your main concern. Personally, I would run a PCMO 5W30.
 
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Originally Posted By: bigt61
Originally Posted By: 95busa
Try making good power and torque with it. Small 4bbl carb, good intake, decent heads and a 3602bbl cam with small dual exhausts and you should be high teens on better.
Yeah, that shouldn't cost more than 30 or 40 bucks and a few hours on a Sunday.
The mileage savings would pay for itself. LOL
 
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How many miles? Any chance for a stretched timing chain? I know what was an issue on some V8's. Induction and dual exhaust; wouldn't think headers are necessary. Maybe an O2 sensor, even with a carb, so as to help get the tune in shape. If you can upgrade the altenator then maybe an electric fan.
 
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Originally Posted By: supton
How many miles? Any chance for a stretched timing chain? I know what was an issue on some V8's. Induction and dual exhaust; wouldn't think headers are necessary. Maybe an O2 sensor, even with a carb, so as to help get the tune in shape. If you can upgrade the altenator then maybe an electric fan.
Their were o2 sensors in 77? Didn't know that.
 
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Originally Posted By: lexus114
Originally Posted By: supton
How many miles? Any chance for a stretched timing chain? I know what was an issue on some V8's. Induction and dual exhaust; wouldn't think headers are necessary. Maybe an O2 sensor, even with a carb, so as to help get the tune in shape. If you can upgrade the altenator then maybe an electric fan.
Their were o2 sensors in 77? Didn't know that.
There were, but not on a Chryco 318. The cost of adding aftermarket EFI would never pay for itself. The easiest thing to add injection would be GM TBI. I have done it using used components to 258's with a custom TBI adapter, which worked well, but is labor intensive.
 
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Originally Posted By: turtlevette
A guy asks a simple question on oil and BIOG wants to redesign his engine.
just trying to give him suggestions on how to get the mpg up some.
 
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