55 Fargo Posted February 24, 2015 Report Posted February 24, 2015 Time again for a tune up, new plugs, new wires, as mine were used points, rotor, etc. I have never been able to get my engine idle as slow and smooth on this Fargo engine, as with the 47 Chryslers engine. I need to do a vacuum test and see whats going on. How smooth and what speed are some of your engines running at? This engine is old and unrebuilt, no doubt some leaking valves, maybe a burnt or whatever. The engine starts well and accelerates fine, just not the greatest idle... Quote
wallytoo Posted February 24, 2015 Report Posted February 24, 2015 my '48 idles exceptionally smoothly at 650 rpm. it will idle all day without a miss. it's my oldest vehicle, and it probably idles the best. Quote
55 Fargo Posted February 25, 2015 Author Report Posted February 25, 2015 my '48 idles exceptionally smoothly at 650 rpm. it will idle all day without a miss. it's my oldest vehicle, and it probably idles the best. Sounds like a good tight engine with fuel and ignition in good form. Mine idles not bad at 650-700 rpm, some roughness, I have heard other flathead 6s running really super smooth at 500 rpm... Quote
NiftyFifty Posted February 25, 2015 Report Posted February 25, 2015 Mine was running like a top at about 700 rpm, but unfortunately my float stuck and my gaskets dried out over this last year of sitting...I started it a week ago and fuel was pouring out everywhere. Quote
wallytoo Posted February 25, 2015 Report Posted February 25, 2015 Sounds like a good tight engine with fuel and ignition in good form. Mine idles not bad at 650-700 rpm, some roughness, I have heard other flathead 6s running really super smooth at 500 rpm... rebuilt, with about 2500 miles on it since. these flatheads are well-balanced at low rpm. mine does not have a vacuum advance (the bigger trucks didn't). i set the timing to "lean best idle", which may not be the spec. it also pulls fine at higher rpm, but i rarely get to 3000. mostly run it in the 2400 to 2800 range. really, from about 15 feet away, it's hard to hear that the engine is idling. Quote
pflaming Posted February 25, 2015 Report Posted February 25, 2015 (edited) I can put a glass of wine on the head and it hardly ripples. Will try that again now after the rebuild. Don't know the RPM's, just know it is very quiet. (Will have to get a fresh bottle!) Edited February 25, 2015 by pflaming 1 Quote
Dodgeb4ya Posted February 25, 2015 Report Posted February 25, 2015 I can put a nickel sideways on both mine while idling. 1 Quote
Jeff Balazs Posted February 25, 2015 Report Posted February 25, 2015 FWIW I think hooking up a vacuum gauge is a great place to start. It can tell you an awful lot.......and paying close attention to the readings is a good way to confirm what adjustments or changes have a actual beneficial effect. I am very happy with the way my truck runs now. And it is by no means a fresh rebuild. One item I came across in my quest to have a real smooth runner was a new idle screw. Most kits don't seem to include this. And my old one didn't look worn at all. But when I decided last fall to go through my carb again.....the kit I got from Roberts had a new idle screw in it. Definitely made a bit of a difference........ With a permanent vacuum gauge connected I swapped this item back and forth just to see if I would be able to read a difference. You can.... and the new idle screw won hands down. Sometimes a combination of few little things like this can make a big difference. Hope this helps, Jeff 1 Quote
pflaming Posted February 25, 2015 Report Posted February 25, 2015 Hey Dodge, is that a wood or a "buffalo" nickel? Lol Quote
ggdad1951 Posted February 25, 2015 Report Posted February 25, 2015 pretty much the same as everyone else. Driving thru the 50's last year people walking in front of me while I was driving in couldn't hear me behind them unless I reved up a little Quote
ruff1148kr Posted February 25, 2015 Report Posted February 25, 2015 maybe you can get a insurance discount for getting louder exhaust LOL Quote
55 Fargo Posted February 25, 2015 Author Report Posted February 25, 2015 FWIW I think hooking up a vacuum gauge is a great place to start. It can tell you an awful lot.......and paying close attention to the readings is a good way to confirm what adjustments or changes have a actual beneficial effect. I am very happy with the way my truck runs now. And it is by no means a fresh rebuild. One item I came across in my quest to have a real smooth runner was a new idle screw. Most kits don't seem to include this. And my old one didn't look worn at all. But when I decided last fall to go through my carb again.....the kit I got from Roberts had a new idle screw in it. Definitely made a bit of a difference........ With a permanent vacuum gauge connected I swapped this item back and forth just to see if I would be able to read a difference. You can.... and the new idle screw won hands down. Sometimes a combination of few little things like this can make a big difference. Hope this helps, Jeff Thanx Jeff, hoping to get the vacuum gauge on and see what I have later today. It is clear sunny and -2f, and cold, shop is 45f right now.....LOL Quote
BobB Posted February 25, 2015 Report Posted February 25, 2015 pretty much the same as everyone else. Driving thru the 50's last year people walking in front of me while I was driving in couldn't hear me behind them unless I reved up a little Guess I'm new to this driving vintage in public. is it customary to gun it when someone steps in front of you?? just making sure I follow proper etiquette. Quote
Young Ed Posted February 25, 2015 Report Posted February 25, 2015 Guess I'm new to this driving vintage in public. is it customary to gun it when someone steps in front of you?? just making sure I follow proper etiquette. At the cruise ins like that if you don't have loud exhaust the people don't hear you and get out of the way. So yes a little rev using the clutch of course to not turn the rev into actual movement gets their attention. I have a 6v siren for my pickup but I haven't found a suitable mounting place without just bolting it onto a fender. Quote
Jeff Balazs Posted February 25, 2015 Report Posted February 25, 2015 Thanx Jeff, hoping to get the vacuum gauge on and see what I have later today. It is clear sunny and -2f, and cold, shop is 45f right now.....LOL Brrrrr...Tee shirt & shorts weather here......might warm up to 80 later. There could easily be a few things affecting your idle. Small vacuum leaks...settings.....worn ignition components.....dirt in the carb.....etc. I like to tinker so I tried a lot of different things. Different plugs for example do have an effect. I am very happy with the results I have got........once it has warmed up. Even here where it is pretty warm it is a cold blooded son of a gun. Jeff Quote
55 Fargo Posted February 25, 2015 Author Report Posted February 25, 2015 (edited) The results, vacuum reading is 18 with slight oscillation. That is the best I could get. I set Carb then advanced timing to get the highest reading.It was about 15-16 without adjusting timing. I did notice a lot more take off power, after I changed timing. 18 is the highest reading, slight movement down 1, goes from 3 to 25 when you hit throttle, then returns to 18, seems normal. The minor movement, may be old plug wires or the cap rotor or sparkplugs themselves. I will replace all this week I have a good leak at the exhaust pipe to manifold gasket, not helping ,matters I suppose... Edited February 25, 2015 by Fargos-Go-Far Quote
Jeff Balazs Posted February 25, 2015 Report Posted February 25, 2015 (edited) You probably don't have a PCV set up so it sounds like a warm compression test may be in order to pinpoint what is causing that slight oscillation. Could just be a sticky valve? One of the things I did with my old engine even after dropping and cleaning the oil pan etc....was to do several oil changes to get all the crud flushed out. Each time it ran a bit smoother and quieter. I dropped the pan again in December and there was a fair amount of tar like sludge build up that I am certain was flushed and deposited in the pan because of the detergent oil I am running now. I even pulled the valve inspection covers to have a good look. Everything looks nice and clean now and over the course of time vacuum readings and compression have risen slightly. At idle and warmed up I get a vacuum steady reading of 20.5 so I know my methods have worked. Oh and Btw I checked cold clearances on the valves early on and never made any adjustments to any of them. They just got quieter and quieter as time has gone on. Hope this is of some help. Jeff Edited February 25, 2015 by Jeff Balazs Quote
55 Fargo Posted February 25, 2015 Author Report Posted February 25, 2015 Here is the video for this test, Quote
Jeff Balazs Posted February 25, 2015 Report Posted February 25, 2015 My screen resolution here is crap......but that looks to me like you probably have at least one valve that is either not seating or is hanging up. The only other thing that looks about the same is a bad PCV valve. If you do a compression check you should be able to narrow it done to a specific cylinder. You might also get a clue just by looking at the plugs. When I started on my engine #5 cylinder was a bit low.....and the corresponding valve or valves were a little noisy. It has since cleared up and compression on all 6 cylinders is within about 5# of each other. When all is well there should not be any noticeable fluctuation in the vacuum reading. In other words the needle should remain extremely steady. Jeff Quote
55 Fargo Posted February 25, 2015 Author Report Posted February 25, 2015 Thanx Jeff, I am also leaning toward a valve hanging up or not seating tightly. I have a compression tester as well as a cylinder leak down test kit... Quote
Jeff Balazs Posted February 25, 2015 Report Posted February 25, 2015 I think that is a reasonable assumption for one of these engines......but it would be useful to have the results of the other tests. If it is just a valve hanging up then it may wear in and correct itself like mine did. I know this is a touchy subject but I do believe that some motor oils work better than others. I think there is enough of a difference in certain formulations that selection does make a difference. I like Castrol GTX for this application. And I don't think it hurts to add a bottle of high mileage STP.. Has worked well for me so I will stick with this. Jeff Quote
55 Fargo Posted February 26, 2015 Author Report Posted February 26, 2015 (edited) just warmed up engine and went for a ride, throttle response is very good, lot more pickup, since I advanced timing some. it accelerates well, decelerates well, just a bit of a mis at idle. I was flooring this truck to speeds up to 60 mph on my frozen gravel road, and it's 0f outside.....LOL what a red neck Everything but idle seems decent, and I haven't changed plugs or wires yet... Sidenote, I have 3.23 gears, and it is not bad off the line, still need to start out in 2nd, as 1st is still too low, shifting into 3rd powerband is fine, but need to be above 35-40 mph to really have power into 4th. It seems sluggish under 1500 RPM for powering up. I do think perhaps 3.55 would have been a better choice of gears, I do not think I ever need overdrive, and if I hop this engine up, or build my other, having an extra 30-50 hp would be great... Edited February 26, 2015 by Fargos-Go-Far Quote
55 Fargo Posted February 27, 2015 Author Report Posted February 27, 2015 Here is the 2nd video, installed new wires and plugs. 2 spark plug wires had a lot of resistance. I also installed new exhaust pipe to manifold and gasket. This is as good as I can get it, not sure what else to do, most likely a sign of old age. My compression tester end is too long for this engine, so can't test compression till I get another fitting or tester.. Quote
Jeff Balazs Posted February 27, 2015 Report Posted February 27, 2015 Just out of curiosity is the engine well warmed up when you took these readings?. Do you get slightly lower readings when it is still cold? I would expect it to be 1/2 to 1 or so inches lower when cold than when fully warmed up. Just gauging from your weather it might take a half hour or so to truly warm up. It certainly isn't a horrible reading for an original engine. Jeff Quote
55 Fargo Posted February 27, 2015 Author Report Posted February 27, 2015 Hi Jeff, it was somewhat warmed up but not fully like a good run in summer. It runs much better in warmer weather, it is real cold, and it even seems like it more noisy in this type of weather too. She is running okay, but would like to have it better, but may not be possible without a complete rebuild. Quote
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