70chev Posted March 30, 2011 Share Posted March 30, 2011 So I have tried new plugs, cap, wires, changed the carb and it still has a miss.....I am going to pull the engine and see what is going on. It’s got to be something internal. It has needed a rebuild for sometime might as well do it while I have the money. My question to all you out there is what suggestions to you have to get the car to be the most fuel efficient? I am not concerned with power I would rather have the best fuel economy possible. It is a 350. Quote Link to comment Share on other sites More sharing options...
monte70car Posted March 30, 2011 Share Posted March 30, 2011 I would say fuel injection setup a overdrive trans and a rear gear. What is the current mpg you are getting? A set of vortec heads or maybe even a set of chevy fast burn heads would make a difference compared to the stock 70 heads, plus the power gain. Quote Link to comment Share on other sites More sharing options...
70chev Posted March 30, 2011 Author Share Posted March 30, 2011 Let me rephrase the question. I would love fuel injection, but that is way out of my price range. I am thinking more along the line of boring it over, cam, carb, change to a small stall converter, headers, intake and so on. Thanks, Wayne Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted March 30, 2011 Share Posted March 30, 2011 I'm curious to see if your cam went flat, like it does with so many hot rodders running flat tappet cams these days. If the budget allows, I'd go with a short duration roller cam and Vortec-style heads. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted March 30, 2011 Share Posted March 30, 2011 How about doing a compression test before pulling the motor. If you need head work going with a set of Vortec heads is a cost effective option. What kind of gear do you have in the car and do you plan on changing it? Quote Link to comment Share on other sites More sharing options...
70chev Posted March 31, 2011 Author Share Posted March 31, 2011 I did a compression test it was: #1 cylinder 160 PSI #2 170 PSI #3 160 PSI #4 175 PSI #5 160 PSI #6 150 PSI #7 160 PSI #8 160 PSI My dad also said that the cam went flat hmmmmmmm.....good he be right?? Have no clue on the gears it's all original I would change them if it means better gas mileage. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted March 31, 2011 Share Posted March 31, 2011 Wayne - they have been pulling the zinc out of the oils big time over the last few years. The zinc is not good for modern catalytic converters and most modern cars have roller cams, so no big deal. But the zinc is crucial for a flat tappet cam! I didn't know it, and always ran regular Castrol GTX 10/30, and my cam lost a lobe, and another lobe was on its way out. You can tell by a loose rocker. But once the lobe is gone, you can't just tighten the rocker - you gotta replace the cam and run an oil with high zinc. Why not pull the valve covers and see. Quote Link to comment Share on other sites More sharing options...
70chev Posted March 31, 2011 Author Share Posted March 31, 2011 that what happend last spring. two of the rocker arms came lose, and I changed the nuts and it was ok until now..... My friends use that Harvest King oil from the L & M fleet store because it is full of zinc. What oil do you use??? Quote Link to comment Share on other sites More sharing options...
JOHNA01374 Posted March 31, 2011 Share Posted March 31, 2011 You can turn the motor over by hand with the cover off and watch the rockers. If the cam is bad you'll notice some of the rockers don't move as much as the others. As for Oil. I'm running 15-40 Rotella with the Comp-Cams Cam break in additive. I got a whole case of the stuff a couple of years ago cheap from a shop that was going out of business. I had a cam go flat about 10 yrs ago and I've been using this combo ever since and have not had a failure. Quote Link to comment Share on other sites More sharing options...
72 LS5 Posted March 31, 2011 Share Posted March 31, 2011 I still haven't gotten my new engine fired up, but I went roller this time so its supposedly not an issue. Regardless, I'm probably going to use an Amsoil that is specific to older vehicles. Quote Link to comment Share on other sites More sharing options...
70chev Posted March 31, 2011 Author Share Posted March 31, 2011 Yes, I had the passenger side valve cover off and the 4 in the back dont move as much as the 4 in the front. Quote Link to comment Share on other sites More sharing options...
Andy's Auto Posted March 31, 2011 Share Posted March 31, 2011 Wayne, the coolest thing about a little block Chevy is you can build the whole thing for around $1000 and make it your own. My biggest pride in my cars is that I built them. From the engine, transmissions, brakes, suspension, and interiors. Nothing feels better than the first time that basby fires up. Nothing wrong with anyone with pockets deep enough to hand thier cars off to someone else to get work done. Hell, without it I am out of buisness. But picture this. My Malibu just went 10.28@132 because I built it that way. It was a long hard road to get there. and mileage? Build it right, keep it in tune, stay out of the pedal on the right. You would be amazed what these 4 wheeled boats can do. But we are scewed. You now have to run a ZDP additive in your oil, and ethanol Stabil in our fuel. But we make other people jealous who are Monteless. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted March 31, 2011 Share Posted March 31, 2011 If it were mine I would go with a mild hydraulic roller, a set of Vortec heads, a performer intake. Get the Q jet rebuilt, and a set of small long tube headers, and get some good spark. That is if you are not concerned with power and would rather have the best fuel economy possible, as you stated. That will still get you a pretty stout engine. I would be real careful with piston selection. Mild cams create more dynamic compression because they have less overlap between exhaust and intake. I would shoot for a 9 to 1 piston with a D cup to get quench on both sides of the combustion chamber. Try to keep the piston to head clearance to .040 to .045 that will help with efficient combustion. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted March 31, 2011 Share Posted March 31, 2011 Quote Link to comment Share on other sites More sharing options...
70chev Posted March 31, 2011 Author Share Posted March 31, 2011 Thanks Mike, Thats what I wanted to know. By the way, we have the same car (red with black top) looks good Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted March 31, 2011 Share Posted March 31, 2011 Mine gets poor fuel mileage Quote Link to comment Share on other sites More sharing options...
70chev Posted March 31, 2011 Author Share Posted March 31, 2011 Yeah, but at least yours runs....... Quote Link to comment Share on other sites More sharing options...
DRDIRT11 Posted March 31, 2011 Share Posted March 31, 2011 to say the least. looks like it will pull the wheels off the ground. Quote Link to comment Share on other sites More sharing options...
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