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10-14-2011, 09:02 PM | #1 |
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BB Valve Adjustment (made it worse)!
My mid 70's 454 only smoked if it idled to long and then I'd leave a nice big cloud for the cars behind me to drive through. I decided to adjust the valves thinking that's the problem but it only made it worse. I did the traditional (engine running) adjustments, you know loosen one rocker arm until it starts tapping then tighten until it stops plus 1/8 or 1/4 or 1/2 turn. Well over half of them needed to be loosened between 2 to 4 complete turns before they started tapping and the others were around 1 turn. I thought that was quite odd so I finished thinking the guy before me must have tightened some way too tight and that was my problem BUT now it started smoking faster than before and even smokes when first started! What should I do now???
P.S. I haven't drank in a long time but a cold one sounds good right now! |
10-14-2011, 10:26 PM | #2 |
Formerly- 1972SuperCheyenne
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Re: BB Valve Adjustment (made it worse)!
Sounds like you need to replace the valve guide seals. Its a fairly common issue. If theres alot of miles, valve guides could be worn too.
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10-14-2011, 10:44 PM | #3 |
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Re: BB Valve Adjustment (made it worse)!
I've done the valve guides on a 2.8L v6 Foorrrrd before with the heads on, once the pistons on TDC I pulled the plug and stuffed the cylinder with small gauge rope so the valve woundn't drop when the valve spring keepers were removed with a spring clamp but I've never done them on a BB Chevy so any tips to point me in the right direction? What are the chances of the rings making it smoke like that??
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10-14-2011, 11:19 PM | #4 |
Formerly- 1972SuperCheyenne
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Re: BB Valve Adjustment (made it worse)!
You can do the BB the same way. Rings will definately make one smoke. Usually all the time though. If it smokes a little at idle and smokes out people when pulling away from a light then its more than likely the valve guide seals.
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--Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with. |
10-15-2011, 01:21 AM | #5 |
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Re: BB Valve Adjustment (made it worse)!
Wouldn't the valve guide seals also make it smoke when first started in the morning or is that just the valve guides and could simply adjusting the valves have make the seals leak?
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10-15-2011, 09:27 AM | #6 |
Formerly- 1972SuperCheyenne
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Re: BB Valve Adjustment (made it worse)!
Yes valve guide seals would make it smoke on first startup.
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--Josh My Build Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=799218 A good crossthread is better than Loctite any day. Life is not about what you have, but who you have to share it with. |
10-15-2011, 09:35 AM | #7 |
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Re: BB Valve Adjustment (made it worse)!
Smoke on first start is seals, but after idling I'm thinking rings. I had a 350 years ago that was like this. Friends called the smoker malibu. (car was a 78) The motor was rebuilt and ran real strong, heads where rebuilt too. But idling for too long would make it smoke like crazy and if too long would foul the plugs. Warmer it got the worse it got.
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10-15-2011, 12:57 PM | #8 |
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Re: BB Valve Adjustment (made it worse)!
I'm going to try to give an answer to why it smokes more now, see if this makes sense. By loosening up the valve adjustment it has decreased the valve opening depth and time a little therefore it's not sucking as much fuel and air into each combustment chamber. The amount of oil that's getting in there hasn't changed (bad valve guide seals, rings) just the way it's being burned off. With less fuel and air it appears to be worse but really hasn't changed. Does that make sense?
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10-15-2011, 11:47 PM | #9 |
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Re: BB Valve Adjustment (made it worse)!
Looser adjustment makes for a little longer piston stroke time, creating more vacuum. And hense sucking more oil trough the valve guides and rings.
The reason your valve adjustments may have been tight is the the valves are very seated in or well worn. Tell me do you have stock valve covers, or aftermarket chrome or aluminum? I have found where some aftermarket valve covers do not have a baffle or an adequate baffle for the PCV valve. No baffle for the PCV means the oil is being sucked up by the PCV and going directly to the intake. I was acused of installing someones rings upside down over that. But I knew better. |
10-16-2011, 07:15 AM | #10 |
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Re: BB Valve Adjustment (made it worse)!
Three things can help
1. install a set of "umbrella" style valve seals , NOT the OEM style 2. change the oil to something heavier like 20w 50 NOT synthetic (until cold weather) 3. purchase a can of "Engine Restore" for 8 cylinders at you local parts store I did this to a friends truck and he went 2 more years on the engine Desert |
10-28-2011, 05:20 PM | #11 | |
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Re: BB Valve Adjustment (made it worse)!
Yes that does make since but if the rings were bad wouldn't it smoke no matter what if the was cold or warmed up? It does have chrome Moroso valve covers with a baffle but that's no where the PCV is, the PCV is in the other valve cover without the baffle.
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10-28-2011, 05:23 PM | #12 | |
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Re: BB Valve Adjustment (made it worse)!
I know there's a lot of suction on the PCV valve but would the rocker arms squirt enough oil up there for the PCV valve to suck it up?
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10-28-2011, 06:11 PM | #13 |
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Re: BB Valve Adjustment (made it worse)!
you can also do a cylinder leak down test and also look into a compression test wet and dry
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10-29-2011, 01:50 PM | #14 |
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Re: BB Valve Adjustment (made it worse)!
You want the pcv in the cover with the baffle, the baffle is there to make it harder for oil to get sucked up.
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11-06-2011, 12:35 PM | #15 |
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Re: BB Valve Adjustment (made it worse)!
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