Oh yes. Piston tdc matches timing marks tdc. This is how I checked. Not sure how these motors do with such large deck height, this block is .210 which gave me ~7.8:1. But in a vw motor large deck is bad. I aim for .040 - .080 max
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| Author: | DusterIdiot [ Mon Mar 07, 2016 5:08 pm ] |
| Post subject: | Not really... |
Quote: That's way to much with vacume.
For EI distributors he is not out of the ball park:Pretty much the choices for vacuum cans on these distributors are: 17 degrees for most 1973+ distributors 22 degrees for Feather Duster/Dart Lite (almost 100% of the time except under 6" Hg) or 22 degrees at a gradient on 1978+ Super Six distributors Aftermarket pods are fewer: 17 degrees for most pods (and even for the "super six" pod due to manufacturers cheaping out on production tolerances) 20 degrees for the unmarked Cardone reman pods 22 for Feather Duster/Dart Lite replacements, and older VC-239 pods |
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| Author: | kielbasa [ Mon Mar 07, 2016 5:17 pm ] |
| Post subject: | |
I have a vc185 can. |
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| Author: | SlantSixDan [ Mon Mar 07, 2016 7:40 pm ] |
| Post subject: | |
Quote: I usualy ignore the readings just put the timming just late enough so it won't ping
Yeah, some people think they can time an engine "by ear" and get it optimal that way. They're mistaken; they can't get it any closer than the other side of the border of the state where the ballpark is, but they never seem to let that get in the way of their belief. Quote: all slants are similar compression and cam
Nope.
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| Author: | Mikedodge [ Tue Mar 08, 2016 4:41 am ] |
| Post subject: | |
Unless your u have. Checked the timming mark and know your light isn't out at all your no more accurate. And most engines get a little more power and mpg with more advance as long as you don't let it ping. So unless you have checked the mark and know your light is dead on and care about keeping the factors string who cares |
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| Author: | DusterIdiot [ Tue Mar 08, 2016 6:11 am ] |
| Post subject: | 17... |
Quote: I have a vc185 can.
That should only allow 17 degrees at full vacuum...
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| Author: | SlantSixDan [ Tue Mar 08, 2016 9:55 am ] |
| Post subject: | |
Quote: Unless your u have. Checked the timming mark and know your light isn't out at all your no more accurate. And most engines get a little more power and mpg with more advance as long as you don't let it ping. So unless you have checked the mark and know your light is dead on and care about keeping the factors string who cares
Maybe there's a build-it-yourself coherent thought in there somewhere, but I don't have my waders. :shrug: Probably best if we stick to using English; that's the language most people on this board speak.
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| Author: | kielbasa [ Tue Mar 08, 2016 10:55 am ] |
| Post subject: | Re: 17... |
Quote: Quote: I have a vc185 can.
That should only allow 17 degrees at full vacuum...Also yes, i am sure my timing light is accurate (recently checked against another) and certain the dampener is good, brand new powerbond only as old as the motor. |
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| Author: | ProCycle [ Tue Mar 08, 2016 11:26 am ] |
| Post subject: | Re: 17... |
Quote: ...and certain the dampener is good, brand new powerbond only as old as the motor.
I believe what was alluded to here was whether the marks on the damper and the pointer on the front cover actually agree with TDC at the #1 piston. There are a few ways these things could be mixed and matched and they are not all the same for all motors. If you haven't done so it would be a good idea to determine TDC at the piston and verify that the timing marks line up at zero.
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| Author: | kielbasa [ Tue Mar 08, 2016 2:20 pm ] |
| Post subject: | |
Oh yes. Piston tdc matches timing marks tdc. This is how I checked. Not sure how these motors do with such large deck height, this block is .210 which gave me ~7.8:1. But in a vw motor large deck is bad. I aim for .040 - .080 max
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| Author: | Reed [ Tue Mar 08, 2016 2:40 pm ] |
| Post subject: | |
The basic point be discussed here is that over the years the slant six was put in various vehicle with various camshafts and emmissions pacvkages, resulting inbase timing specifications that vary from 16 BTDC (lean burn 80s motors) to 5 ATDC (mid 70s motors). In order to retain acceptable driveability, the internals of the distributor were adapted. Advance governers allowed different amounts of mechanical advance, advance spring allowed different rates of advance, vacuum advance pods provided different amounts of vacuum advance at different levels of vacuum. When using the original distributor with the original unmodified engine, it is best to star with the factory specified base timing. You can usually advance the timing a bit to gain some performance and economy, but advancing too much may cause pinging. When you have customized the engine to increase compresion ratio (either through a cma change or machining the block or head) timing may need to be adjusted. When you are usoing a distributor from a different engine, the best course of action is to either start with the base timing for the engine the distributor was originally installed on, or disassemble the distributor, note the amount of degrees advance provided by the governor and the amount provided by the vacuum advance, and use those numbers to figure out base timing through subtracting from an ideal total mechanical advance of 32 degrees all in by 2800 RPM, unless the vacuum advance brings in more than 20 degrees advance, in which case that amount should also be suybtracted form base timing. The vacuum advance is just grvay after the base initial advance. The old advice about "advance it until it pings and back it off a bit" isn't very accurate and will not provide optimal results. Further, it simply isn't true to say that the timing requirements of all slants is basically the same. For example. I recently purchased a 76 D100. Factory base timing is TDC. I thought I was being clever and advanced the base timing to 10 TDC. THe motor pinged at light load son the highway and going uphill. I retarded it to 5 BTDC and it seems to run even better and have better throttle response. Little adjustments make a difference, and large initial advance numbers are not necessarily best for your application. |
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| Author: | kielbasa [ Tue Mar 08, 2016 2:54 pm ] |
| Post subject: | |
"I welded and filed the governer to .380. Used green and blue spring. (Adjustable posts are set to stretch spring as far as possible I believe) Set timing to 12 degrees. Adjusted valves to cam card spec. New 185 vacuum can set 2 turns out" This is how it's currently setup. Sorry I forgot to mention apparently when I started this thread it was set to 14 degrees initial for some reason. But I turned it down the otherday back to 12. Also noticed timing mark jumps around about 4 degrees while at idle. I had this problem before, changed the mopar ignition box, fixed it, now it's back again. I turned my idle up a bit which helps with the roughness a little. Then noticed with vacuum gauge it wanted another half turn out of mixture. Took it for a drive up the small hill by my house and didn't ping, but I usually Check at a steep hill I drive maybe once a week. I was thinking of going hei maybe will help with irratic timing issue. I do have a bit off a flat spot off of idle, maybe adjusting the pod would help? How exactly do I do that, another turn or 2 out? I'll keep updated when I hit that big hill see if it pings. |
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| Author: | Nicademas [ Tue Mar 08, 2016 10:48 pm ] |
| Post subject: | |
Just a thought here. When you say Quote: Adjusted valves to cam card spec. did you adjust the valves after the motor was at operating temp? If not your valves my be to tight and not closing all the way. I had a similer issue and thought it was my timing but no matter what I did It would not idle right. Also when you said Quote: Also noticed timing mark jumps around about 4 degrees while at idle. I had this same symptom. Hook up a vacuum gauge and see if your Hg is close to 10 but fluttering around one degree like your timing. If you want you can watch my videos when I had this issue to better understand what my motor was doing. 1st video is motor at idle with the issue. https://www.youtube.com/watch?v=MpRM6Wuz_Ao 2ed Video is my vacuum with the issue https://www.youtube.com/watch?v=F8qGxnim3H4 3rd Video is of the timeing with the issue https://www.youtube.com/watch?v=sYPDEtVAHL0 4th Video is vacuum after the valves were adjusted with the choke on. https://www.youtube.com/watch?v=Rkj4c5UQJsM In case you were wondering my motor is a '79 225 and I run it at 12TDC. I dont know what the vacuum advance is as I haven't re curved it yet. |
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| Author: | kielbasa [ Wed Mar 09, 2016 12:07 am ] |
| Post subject: | |
Valves set while hot and running. Oregon cam #125 I believe it's .012-.014 During idle my vacuum slightly bounces inside of the 20 and 19 mark. |
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| Author: | SlantSixDan [ Wed Mar 09, 2016 9:25 am ] |
| Post subject: | |
Quote: Valves set while hot and running. Oregon cam #125 I believe it's .012-.014 During idle my vacuum slightly bounces inside of the 20 and 19 mark.
That sounds healthy and proper (and too-tight valves will not cause pinging; if anything they'll alleviate it while causing other problems).I think you'd probably like HEI better, though I don't know that it'd solve your ping issue. |
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| Author: | Reed [ Wed Mar 09, 2016 10:30 am ] |
| Post subject: | |
Bouncing/fluttering timing at idle can be cause by a work timing chain or by an improperly controlled mechanical timing advance mechanism in the distributor. Springs with loops too long, springs with not enough tension, even sloppy pickup plate mounting can cause timing to bounce at idle. I would worry about that before making the very worthwhile upgrade to HEI. |
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