I recently picked up a 68 Electra and have probably put about 500 miles on it. I replaced the carb with a rebuilt one from everyday performance AWESOME carb and service from that guy btw. Changed transmission fluid and even added some red bottle lubeguard just because. I set the timing to 10 btdc because it pings a bit at medium-heavy throttle under load It pretty much pings at anything above 4 btdc and I just leave it at 10 because it seems to idle smoother there and the response is a little crisper(I live in CA so best we can do is 91 super unleaded from Chevron) I fixed leaks on both fuel lines. But nothing I do is budging from that 7 mpg. I drive it fairly nice and only get on it for testing purposes. This car does not need to be super fast I ride an aprilia for speed. It runs pretty smoothly from idle right up to whatever rpm it shifts at under full throttle 5k? at that point it makes some noises (im guessing valve float) and the engine stops pulling like it should. I do not have a tach but if I had to guess I would say the rear end is more than likely the standard 2.73's. any suggestions? ---------- Post added at 08:28 PM ---------- Previous post was at 08:22 PM ---------- the engine was rebuilt (allegedly) about 10 years and 25k miles ago. I have not looked at the bottom end of the motor but under the valve covers are immaculate. It does not swallow oil and the engine does not misfire. The plug wires look a lil old and cheap and it has autolite plugs but no arcing or ignition weirdness going on. I was hoping to get 10-15 mpg with this car on rainy or super cold days and if the lame mileage isn't rectified this car is just gonna have to sit grrrrr
I suggest you read my power timing thread here: http://www.v8buick.com/showthread.php?63475-Power-Timing-your-Buick-V8 Your engine doesn't run at the initial timing setting except at idle. As soon as you accelerate, the timing changes, and that is what you must verify. The mechanical advance, and vacuum advance operation should be checked. You need to set the total advance rather than setting the initial and hoping it's right. The 68 Electra came with distributor # 1111285, and was meant to be timed at TDC (0*). Of course 44 years later, the engine could have a different distributor in it, and in that case, the original timing spec goes right out the window. Read my thread and set the total advance.
No matter what you do retard the timing if you ever hear any "pinging"! That will destroy the engine!!!! Are you running a vacuum advance canister? If so I would un plug it till I got the timing set properly and then run a ported source as it will only give extra timing at part throttle. I find the vacuum advance has a huge effect on the highway MPG! Also be sure to set the idle mixture screws to get max vacuum (use a vacuum gauge) and do this with the car in gear and wheels blocked well. This also makes a HUGE difference in MPG if the screws are set too rich. Is this in town MPG or highway only?
You have to figure in the poorer fuel mileage that you get with todays fuel that has ethanol. If you used pure, non ethanol gasoline, your mileage would improve just switching fuels. With that being said, your Electra weighs about 5500 lbs, so its no lightweight either. Thats alot of weight to push around. My 69 Riviera averaged only 14 mpg going to Bowling Green. That was probably with non ethanol fuel at the timel and strictly highway. And I would have to say that my Riviera was tuned to the razors edge.
Get gm top engine cleaner ,seafoam is a different type and clean top of engine should change oil after, you have alot of carbon on pistons and valves heads it may help a bit.But with todays gargage gas its tough.
I only use chevron super unleaded. I also add about five ounces of marine two stroke oil on fil lup has helped with cleanliness on my motorcycle so why not. I do not think its carbon build up. I was under the impression that occasional light pinging is alright and is a sign of optimal tuning but heck maybe honda motorcycles don't know what they are talking about. I know the timing is advancing via mechanical as well as vacuum. I cannot find any vacuum leaks either grrrr
I switched from a points dis to a Mallory unilite and picked up 4 MPG on my 65 Impala when it had the original 283 with a powerglide. Timing,electronic ingnition,and carb tuning would be your best MPG bang for the buck.A good set of wires helps too. And of coarse you'll notice a little better performance doing this. The 65 did high 18s in the quarter mile with the points,and after the dis swap,low 17s,and that car is no light weight. The electronic ignition will burn the mixture more completely,making more power throughout the full RPM range,and running more effient,and not sending uburnt gas out the exaust. After you have all that sorted out, an overdrive trans would be an good investment for MPG also. Without out changing the gear,a 700R4 would be a better choice because of the 1st gear ratio is better to get the car moving. But an adapter would have to be used to mount it,(about $60-$100,depending who you buy it from)the driveshaft will need to be shortened,if you have a ST400 a different trans yoke,and the trans cross member needs to be moved back,and the shifter needs to be adpted. I had to change the trans in the 65 because the stock powerglide couldn't handle trying to get that land barg moving with the 383 I put in it.(at Lapeer dragway I lost first gear and reverse doing a quarter mile test and tune,drove it 45 miles home with only 2nd gear) But even with the 383,and the PG,it got about 18 MPG highway,with the 3.36 dog leg rear gear in the 10 bolt driving it easy @ 65-70. Now with the 3.07 posi 12 bolt with a 700R4 it gets 24 on the highway. Its all about low end torque when your trying to eek out MPG,and running a BBB you should have gobs and gobs of it,you just need to get it to the road. Your car with a good tune on it should get you at least 10 MPG,unless when the engine was rebuilt,a cam too big for everything being stock was installed. Bigger is not always better when it comes to camshafts. A big cam in a low compression engine with stock valve springs,no upgraded torque converter without a higher stall,and a highway gear is a recipe for poor performance,and crappy mileage. A compression test wouldn't hurt to make sure all cylinder are doing what they are susposed to. Tree huggers don't realize that making an older car more effient puts less pollution in the atmosphere,than the pollution building a new car makes. I wish you the best getting that car running the way it should run. And I hope you upgrade it eventually to help save the environment.(much better performance is a very pleasant side effect of upgrading)GL
This is how its idling at the moment. Stupid dwellmeter/tach is fubar after just one use so I cant tell what rpm it is exactly but sounds ok. [video=youtube;k0oPFGKmfbE]http://www.youtube.com/watch?v=k0oPFGKmfbE&feature=plcp[/video]
What ws the factory rated mpg on a 68 Electra anyway? Did they even advertise those figures back then? o No:
At 7MPG he is probably getting less than half of what it should be on the highway. 15/17 hwy and 10/12 city should be in the ballpark. IHMO Bob H.
This is pretty much my goal with my car. I am all about efficiency and am a slight tree hugger myself (having a Navajo father will do that) My dream car happens to be a 67 GTO (or more realistically a 442) with a six speed swap a/c n disc brakes all around. I am going to spend money and take my time with this Buick since I plan on keeping it forever. It's rust free and has been garaged its entire life.
The idle sounds lopey,a closer to stock cam would sound a lot smoother.(sounds cool though) What are the power characteristics of the power band? Is it sluggish off the line before the power kicks in,or does it pull smooth from a dead stop at wide open throttle to get it up to speed? Is your vacuum advance working? I checked my Motor Auto Repair manual,and it says your initial timing should be set at zero degrees,600 rpm in drive for a 400,and 550 in drive for a 430.(the vacuum advance should be disconnected when setting initial timing) And these specs are for a stock cam,if there is a stock cam in it then your idle doesn't sound right,like a cylinder isn't firing,or firing intermittently. It could be as simple as needing a tune up,plugs,wires,cap and rotor,points,set timing right,and get the carb set correct. All of that can potentially double your mpg,if your engine is in good working order.(as in,it has good and even compression on all 8 cylinders,then it is just a matter of tuning) The plugs should be checked for fouling,cap and rotor inspected,as well as the points. If this work is beyond your abilities,a reputable shop should be found to do it for you. Even with a performance cam,your mpg shouldn't be that bad. What engine do you have,is it a 400,or a 430?
It is a 430 for sure. I confirmed the block stamping on the back the other day. As far as the cam is concerned I have no idea what they did with the rebuild. It has true dual exhaust probably factory. I put a shop towel up against exhaust and it does not suck it back in so I do not think it has bad exhaust valves. Both sides of the exhaust run equally lopey so maybe it does have a cam? I have never owned a big block car but did have a 65 Cutlass with a 330 back in the day. It's difficult to tell if the motor makes enough low end because the unfavorable 1st gear ratio the st400 has and Im pretty sure it has the stock 2.73 out back. It can spin the back tire a bit on a hard take off but doesnt pull like I think it should higher in the rev range. I do not think this is a fast car at all but like I said not much of a frame of reference. The vacuum advance works like it should and there are no leaks with it. I did notice last night that the mechanical advance did not advance as smoothly at really high rpms. I do most of the work on my vehicles and have replaced cap n rotor and even the distributor on my Cutlass back in the day but it has been awhile since those days and my father now lives in Los Angeles. I looked up those Mallory distributors last night holy cow they are pricey. When I get home I will take a look at all the plugs. BTW What plugs and wires do you guys recommend? It has autolites on there now which seems kinda odd to me. I was thinking about some taylor wires but would appreciate some ideas.
I'm not convinced that you have the timing set correctly. How do you know the vacuum advance works? Put a vacuum gauge on it. A stock cam should pull about 20" of vacuum, fully warmed up and idling in Park.
I know it works because if apply vacuum it advances the timing and holds it. by apply vacuum I of course mean stick hose in mouth and suck and watch the timing advance LOL thanks for making me admit that .. I did not measure how much it was actually advancing the timing but can tell you that it works as well as the one I remember on my old car. The mechanical advance total NOT including vacuum advance was around 30ish as far as I could tell using my dial back timing light. I did notice that the mechanical advance amount was not a smooth progression at high rpm it jumped a bit up top so to speak. I have the vacuum advance connected to port vacuum directly i bypassed the thermal vacuum switch on the intake manifold.
OK, now your talking. The stock springs inside the distributor will slow the mechanical advance substantially, and you will not be able to see the total advance, because the springs will not let it all in until 4600 RPM. What you need to do is get some lighter springs like those in the Crane adjustable vacuum advance kit. Using the lightest springs will let all the mechanical advance in at around 2000 RPM. That way, you can set the total advance at 32-34*. Afterwards, you can use some heavier springs to bring the advance in around 2500-3000 RPM. In 1968, they used manifold vacuum advance to the vacuum advance. Idling at 0* (TDC) will make the engine run very hot at idle and stop n go traffic. Try full manifold advance, and see how it likes it, after setting the total as above. IF you have the stock (1111285) distributor, it has 30-34* of mechanical advance. At 10* initial timing, your total may be 40-44* when you nail it. You will damage the engine like that. You mentioned the engine idled better at 10* initial. If you use full manifold vacuum advance, it will idle at about 14-18* if the initial is set to TDC. Try it.
I kept it on port vacuum since that was how it was set up before I started messing with anything. Theres a bit of weirdness with this car since I am the third owner and whoever rebuilt the engine used a carb from a 1969 motor. When I get home I will check plugs cap n rotor and re do the timing and connect to manifold vacuum. I have the chassis manual and didn't think to check which type of vacuum I was supposed to be using. I feel like an idiot right now.
You don't have to buy the hole dis.,you can convert your current one to electronic ignition for a lot less,and I have heard they will give you very good results. There are diferent companies to chose from,here are some links on the subject; http://www.v8buick.com/showthread.p...oints-to-HEI&highlight=distributor+conversion http://www.v8buick.com/showthread.p...-way-do-i-go&highlight=distributor+conversion http://www.v8buick.com/showthread.p...Xr-i-Install&highlight=distributor+conversion Just a few links from the search funtion on here. It looks like the most liked conversion kit is the Crane XR-I,with a built-in rev. limiter,and very easy to install. And as far as plugs and wires go,it depends on if you are going to convert to a HEI style ingnition system. You need to start by setting your initial timing to zero (TDC) like the book says. That should get rid of the spark knock also. Spark knock,or "pinging" is not your friend,(I don't know about motor cycles engines,but car engines don't like it!!!)and can cause destructive internal engine damage,like breaking pistons or rods,or putting holes in pistons,bearing damage.....etc....etc.... To much advance will rob power and mpg by the engine working against itself,by firing the mixture to soon will push the piston in the oppisite rotation before it reaches TDC. This is what causes the pinging or rattling noise that is spark knock. Proper timing alone may yeild 3 MPG or more. Save a tree drive an old car.
The correct 68 430 carburetor should be a 7028240. It had .070 jets with .043 primary rods, and BG secondary rods (.0397 tip) The correct 69 430 carburetor should be a 7029240. It had .070 jets with .045 primary rods, and AY secondary rods (.0567 tip) so the 69 carburetor would be somewhat leaner. Probably easier to just replace the primary and secondary rods if you like.
