NiftyFifty Posted March 1, 2015 Report Share Posted March 1, 2015 Original factory compression should have still been a minimum 125, and at 85 your in a below 70% of factory spec which is going to cause some running issues, and especially at idle. My original 218 had numbers in your range, it ran quite poor at a low idle, same carb on my fresh 251, ran great until this year long sit. The 218 also exploded before it got 1000 miles on it, it was working so hard to keep up the oil pressure just wasn't enough. Your engine sounds like it has decent oil pressure, but if the wet compression test didn't improve, then sounds like a valve job is the logical place to start rather then hunting down issues that don't seem to be there. I'm not sure I would classify Accell wires better then the Asian junk, I've never had more issues then when I ran those wires on various vehicles I've owned. If the trucks not stalling or hesitating, drive it and enjoy it and work towards a complete rebuild on one of the 251's you have, then when the time comes you have a fresh engine and not a big investment in the other one from piece mealing it to run better. Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 1, 2015 Author Report Share Posted March 1, 2015 (edited) Original factory compression should have still been a minimum 125, and at 85 your in a below 70% of factory spec which is going to cause some running issues, and especially at idle. My original 218 had numbers in your range, it ran quite poor at a low idle, same carb on my fresh 251, ran great until this year long sit. The 218 also exploded before it got 1000 miles on it, it was working so hard to keep up the oil pressure just wasn't enough. Your engine sounds like it has decent oil pressure, but if the wet compression test didn't improve, then sounds like a valve job is the logical place to start rather then hunting down issues that don't seem to be there. I'm not sure I would classify Accell wires better then the Asian junk, I've never had more issues then when I ran those wires on various vehicles I've owned. If the trucks not stalling or hesitating, drive it and enjoy it and work towards a complete rebuild on one of the 251's you have, then when the time comes you have a fresh engine and not a big investment in the other one from piece mealing it to run better. Where did you get the 125 psi compression figure from? What is the compresion ratio for a 250.6 engine for 1955. That seems kind of on the higher side. That would equate to an engine with 8 to 8.5 to 1 psitons and compression ratio. These engines were a 110 hp, most likely around 7 to 1 compression ratio, so new they would have 100-110 psi compression. I sure wish they came with 8.5 to 1 pistons. Valve job smelve job, will still be driving it for a while, it ain't perfect, but am not going to rip into a valve job right away, when I do go in deep, it will be a total rebuild or will have another engine ready to R&R. PS I had a 218 in my 47 Chrysler, came out of a 1950 dodge, had a bit of uneven compression put 6000 miles on her, sold the car, and engine still runs great. It had a bit of idle problem but hardly noticeable. Edited March 1, 2015 by Fargos-Go-Far Quote Link to comment Share on other sites More sharing options...
NiftyFifty Posted March 1, 2015 Report Share Posted March 1, 2015 I got 125 on my fresh 251 after about 50 mile break in, but possibly the newer style dished Pistons improved things a bit, coupled with a decked head, I wouldn't be happy at 85 psi. So if your happy with its way of running, why are you so concerned with your idle....just drive it. I'll go back to worrying about my project and leave you to yours, I'm just shooting for the stars rather then just being happy Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 1, 2015 Author Report Share Posted March 1, 2015 (edited) I got 125 on my fresh 251 after about 50 mile break in, but possibly the newer style dished Pistons improved things a bit, coupled with a decked head, I wouldn't be happy at 85 psi. So if your happy with its way of running, why are you so concerned with your idle....just drive it. I'll go back to worrying about my project and leave you to yours, I'm just shooting for the stars rather then just being happy I would have to say there must be a whole lotta happy campers on here then, no doubt a lot of engines with 100 psi compression. Of course your engine would push out 125 psi with a shaved head, decked block and new pistons. But factory was not that.With the exception of the US built 230 with 2 bbl intake and carb and higher compression head with 132 hp, not sure where some of the 265 bigger truck engines were on HP either. Mopar service manuals state 100 psi compression for an acceptable figure, with no cylinder being out by 10%, so I am offf a little bit. I would think your engine would be in the 125-130 hp range with that fresh rebuild. It would perform a whole lot more with a bit of a cam grind, 2-3 carb intake and split exhaust too. Shootin for the starts, nah gonna keep burnin gas on the ground for now............lighten up, it's stilll winter gotta do something with my time Edited March 1, 2015 by Fargos-Go-Far Quote Link to comment Share on other sites More sharing options...
deathbound Posted March 2, 2015 Report Share Posted March 2, 2015 Here's a link on "how to use & interpret a vacuum gauge" I've posted before & you may have seen it, but others reading this may not have.....hope it helps: http://www.secondchancegarage.com/public/186.cfm 1 Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 2, 2015 Author Report Share Posted March 2, 2015 Okay after working a 12 hour shift today got home at 8:00 PM and decided to have a look at my timing with a timing light. I was specifically wanting to see if the vacuum advance was working on the distributor, and it is. I noticed my timing was about 10-12 degrees btdc, I figured i would retard this. So loosened the adjuster bolt on dizzy, and could only get it back to about 2 btdc, and no more room to turn the dizzy. I then loosened the bottom bolt, and adjusted the dizzy to tdc, with the minor adjuster in the middle of it's travel. With the timing set to 2 degrees btdc, I got out the vacuum tester and reset the idle mixture to a vacuum reading of 19 inches. The engine was warm and I had driven it a bit too, the idle is nice and low at 500 rpm or so, and is much smoother than before. I went for a road test, truck is running great, and idling a lot better. I musta did the 1/4 mile from my place to neighbors to about 60 mph. It is dark and near 0f, but had a good drive, things are running much better, and I did not realize my timing and dizzy were out this much. An old timer on the HAMB said these old 6s don't like too much advance, retard her a bit, guess he was right. Off the line she is nice and quick, had her up to over 3000 rpm before shifting in 3rd and 4th, drove her like i stole her.. I am not saying she is perfect, but is a whole lot better than before... 1 Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted March 2, 2015 Report Share Posted March 2, 2015 I guess I should have asked you about the timing. I just assumed you had checked it and it was within spec. I would typically start off with the timing right in the middle of the range and make small adjustments to the timing until I got the highest vacuum reading within the specified timing range. Once I had checked and verified this I would move on to the idle adjustments. Jeff Quote Link to comment Share on other sites More sharing options...
_shel_ny Posted March 2, 2015 Report Share Posted March 2, 2015 I then loosened the bottom bolt, and adjusted the dizzy to tdc, with the minor adjuster in the middle of it's travel. With the timing set to 2 degrees btdc, I got out the vacuum tester and reset the idle mixture to a vacuum reading of 19 inches. Was the needle now steady????????? Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 2, 2015 Author Report Share Posted March 2, 2015 Was the needle now steady????????? nope not 100%, but the owner of this tester told me it's always like this. I am going to buy my own vacuum tester, and will test again and report my findings. It flickers on about 19 inches Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 3, 2015 Author Report Share Posted March 3, 2015 Here's a link on "how to use & interpret a vacuum gauge" I've posted before & you may have seen it, but others reading this may not have.....hope it helps: http://www.secondchancegarage.com/public/186.cfm Thanx DB, good info Quote Link to comment Share on other sites More sharing options...
whtbaron Posted March 7, 2015 Report Share Posted March 7, 2015 Glad to hear you got it going better. I'm almost 2 hrs SW of Winnipeg on the escarpment. I'd be up for a beer, but I'm not sure when, Things have been pretty hectic lately. Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 7, 2015 Author Report Share Posted March 7, 2015 Glad to hear you got it going better. I'm almost 2 hrs SW of Winnipeg on the escarpment. I'd be up for a beer, but I'm not sure when, Things have been pretty hectic lately. I know the "hectic feeling" thats for sure. Well at least there is some light at the end of the winter tunnel now.....LOL Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 7, 2015 Author Report Share Posted March 7, 2015 (edited) Today discovered that new Bosch copper core ignition wires are making static noise on the radio. I am running NGK B6S sparkplugs. Now should I be running a resistor plug. I did not get any static noise with the old wires. I did notice my video's audio had static after I installed the new wires....WTF Edited March 7, 2015 by Fargos-Go-Far Quote Link to comment Share on other sites More sharing options...
TrampSteer Posted March 8, 2015 Report Share Posted March 8, 2015 I was going to mention the electrical noise. I was wondering if it was a contributor to the issue. Have you checked the engine bay at night with the lights out? I did notice my video's audio had static after I installed the new wires....WTF Quote Link to comment Share on other sites More sharing options...
55 Fargo Posted March 8, 2015 Author Report Share Posted March 8, 2015 I was going to mention the electrical noise. I was wondering if it was a contributor to the issue. Have you checked the engine bay at night with the lights out? yes, it's not arcing or sparking anywhere. This is the result of solid core wires and non-resistor sparkplugs I figure. The old wires were resistor type> I am going to buy resistor type plugs and that should solve that problem.. Quote Link to comment Share on other sites More sharing options...
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