Slant Six Forum :: Tuning help after rebuild

I have found its hard to get the bub out with the points. Get an electronic set up and she will smooth out plus better top end. Have you set your dwell on your points, I think its like 35 for a slant. It will make the most difference. After you set your point/air gap (same thing) check your time. Set you time where you want it. Then its carb time. Its tough to tune and almost impossible when the engine is still breaking in. Timing is now set, now the carb. Idle down as low as possible and hit it with the vacum gauge. If you have it set at factory which is usually 1 1/2 to two turns on the adjust screws kick it over and let here idle (already warm choke plate all way open). Give it an 1/8 turn at a time and give it a few seconds to catch up after you adjust. Do this until you get your highest vac setting. Use same amount of turns on both sides. Then set your your idle and readjust your timing. You will be pleased. Breaking in I usually idle'm around 800 to keep the cam greasey. Good luck.

Author:	64ValiantVert [ Sun Aug 28, 2005 7:43 pm ]
Post subject:	Tuning help after rebuild
I've rebuilt my 225. Everything looks good so far I'm still having a bit of trouble getting it to purr. It goes like a hot damn, but It idles a bit rough. Lets see what I can come up with to describe the sound. It's that sort of intermitant low bubbub.....bub.......................bubububub...bub..bub.....bub etc.etc. I've hooked up a vacuum gauge and its a steady 20 and drops to 19 on the "bubs" As I said the "bub" is completely intermitant and random, leading me to believe that it's not a particular valve or guides. Any ideas?

Author:	CrAlt [ Sun Aug 28, 2005 8:02 pm ]
Post subject:	Re: Tuning help after rebuild
Quote: I've rebuilt my 225. Everything looks good so far I'm still having a bit of trouble getting it to purr. It goes like a hot damn, but It idles a bit rough. Lets see what I can come up with to describe the sound. It's that sort of intermitant low bubbub.....bub.......................bubububub...bub..bub.....bub etc.etc. I've hooked up a vacuum gauge and its a steady 20 and drops to 19 on the "bubs" As I said the "bub" is completely intermitant and random, leading me to believe that it's not a particular valve or guides. Any ideas? Try rechecking for vacuum leaks..clamp off the power brake booster. Try just driving it...mine has a slight random miss when its cold but i drive it for a wile you cant even tell its running.

Author:	64ValiantVert [ Sun Aug 28, 2005 9:13 pm ]
Post subject:
Hmm, no power brakes. There's new gaskets all around, but of course I could have messed something up. New - points, plugs, wires, carb rebuild, timing sprocket and chain, pistons, rings, bearings, valve grind, water pump, starter, fuel pump... My real problem I suppose is that I've done so much to the motor in the last while it's impossible to troublshoot it by asking "hmm, what have I messed around with lately" It doesn't seem that vacuum is the cause and the slight twitch from 20 to 19 at the "bub" is more of a symtom. But I could be wrong. I usually am

Author:	DusterIdiot [ Sun Aug 28, 2005 9:53 pm ]
Post subject:	Hmmm...
Have you rechecked the valve lash if mech. lifters, just to make sure that it is still spot on after breaking everything in? Are you using EI or points? How do your plugs look? (have you got one that's a little sooty?) Check the basics something might just need a little tweak, or it may need to warm up a bit. good luck, -D.Idiot

Author:	64ValiantVert [ Tue Sep 06, 2005 11:25 am ]
Post subject:
I've set the valve lash to the recomended 10 and 20 and rechecked it after a couple hundred miles. It should be pretty close. It has mechanical lifters. I'm using points. All new stuff there. Plugs look ok. If I'm going to retune it from scratch after a rebuild can someone give me a sequence to follow. e.g. Rough timing first, then valve lash, then carb idle... etc. It's just that I feel like I'm chasing my tail

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Author:	skraecken [ Tue Sep 06, 2005 11:33 am ]
Post subject:
PCV valve?

Author:	71satelite [ Tue Sep 06, 2005 4:18 pm ]
Post subject:
I have found its hard to get the bub out with the points. Get an electronic set up and she will smooth out plus better top end. Have you set your dwell on your points, I think its like 35 for a slant. It will make the most difference. After you set your point/air gap (same thing) check your time. Set you time where you want it. Then its carb time. Its tough to tune and almost impossible when the engine is still breaking in. Timing is now set, now the carb. Idle down as low as possible and hit it with the vacum gauge. If you have it set at factory which is usually 1 1/2 to two turns on the adjust screws kick it over and let here idle (already warm choke plate all way open). Give it an 1/8 turn at a time and give it a few seconds to catch up after you adjust. Do this until you get your highest vac setting. Use same amount of turns on both sides. Then set your your idle and readjust your timing. You will be pleased. Breaking in I usually idle'm around 800 to keep the cam greasey. Good luck.

Author:	Dennis Weaver [ Tue Sep 06, 2005 4:49 pm ]
Post subject:
Quote: I have found its hard to get the bub out with the points. Get an electronic set up and she will smooth out plus better top end. Have you set your dwell on your points, I think its like 35 for a slant. It will make the most difference. After you set your point/air gap (same thing) check your time. Set you time where you want it. Then its carb time. Its tough to tune and almost impossible when the engine is still breaking in. Timing is now set, now the carb. Idle down as low as possible and hit it with the vacum gauge. If you have it set at factory which is usually 1 1/2 to two turns on the adjust screws kick it over and let here idle (already warm choke plate all way open). Give it an 1/8 turn at a time and give it a few seconds to catch up after you adjust. Do this until you get your highest vac setting. Use same amount of turns on both sides. Then set your your idle and readjust your timing. You will be pleased. Breaking in I usually idle'm around 800 to keep the cam greasey. Good luck. 41 to 46 degrees dwell on /6 points. D/W

Author:	SlantSixDan [ Tue Sep 06, 2005 5:34 pm ]
Post subject:
Also getting harder to buy good quality breaker points. My favorites are the NAPA Echlin CS-851 (not the CS-851P). I put them in a smooth-jaw vise and very carefully squeeze the bushing along its axis to eliminate side float in the movable point arm. It takes a careful touch to squeeze 'em just enough to eliminate side float without squeezing so hard that you cause the bushing to bind up. These points, thus prepped, work very well and last a nice, long time.

Author:	Dart270 [ Wed Sep 07, 2005 6:43 am ]
Post subject:
If you are getting 19-20 in Hg vacuum, you don't have a vacuum leak. Lou

Author:	53plym [ Wed Sep 07, 2005 5:55 pm ]
Post subject:	Bub.....Bub..BubBub...Etc....
Sticky valve??????

Author:	64ValiantVert [ Thu Sep 08, 2005 2:28 pm ]
Post subject:
Quote: Sticky Valve?? I don't think so. The "bub" is intermittent. If it was a valve it would be a uniform "bub"no?

Author:	64ValiantVert [ Thu Sep 08, 2005 5:58 pm ]
Post subject:
Re gapped the points (of course they were out )and set the timing again, she almost purrs. Tomorrow I'll monkey with the carb to see if I can't get rid of that last little "Bub" Um, ... so "bub", will that be going into the /6 Rossetta Stone then?

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