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PostPosted: Mon Apr 16, 2018 7:26 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Hello,

I've cured most of my driveability issues by replacing the Holley 1945 with a Carter BBS. However, with both carbs, I've had this clattery noise between 2k-4k rpm or so, especially decelerating or coasting. Full throttle occasionally clatters at that RPM, but not consistently. Higher and lower RPM does not seem to make the clatter noise.

I removed the distributor and cleaned out the weights. The timing seems to advance at higher RPM and usually comes back down. Vacuum advance is disconnected (carb has no port, don't know why) and I've tried anywhere from 8BTDC to 12BTDC, no change. Tried a bottle of octane boost, no change. Still clatters. Oil pressure is great, doesn't overheat, 19-20lbs of vacuum on my old gauge, voltage is fine, everything seems fine otherwise.

Could it be valve lash? It doesn't tick at idle, I've just adjusted the valves. It's a fast clatter - it would be more than one cylinder detonating if it is that. Anyone have any ideas? Should I even be worried about it, or is this one of those "turn up the radio" kind of problems?

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Mon Apr 16, 2018 7:57 pm 
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Supercharged
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Joined: Sun Nov 03, 2002 9:20 pm
Posts: 12102
Location: Fircrest, WA
Car Model*:
Have you confirmed oil flow to the rockers? I once installed a rebuilt head on a 225 but later removed it because I thought the head had been milled too much and the motor had bad pinging at 2500-3000 RPM. When I pulled the head I found that I had installed the rocker arm shaft upside down. This means the rocker arms were being starved for oil and i suspect making excessive noise at higher RPMs. I haven't reinstalled this head on any motor to test my hypothesis, but I hope to.

My point is you might want to verify that the rocker arm shaft is installed properly because installing it upside down can lead to oil starvation and excessive valvetrain noise.


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PostPosted: Tue Apr 17, 2018 3:51 am 
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SL6 Racer & Moderator
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Joined: Sat Oct 19, 2002 12:06 pm
Posts: 6893
Location: Silver Springs, Fl.
Car Model*:
Are you sure it is not an exhaust leak?

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170


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PostPosted: Tue Apr 17, 2018 11:00 am 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Charrlie_S wrote:
Are you sure it is not an exhaust leak?


I just fixed a ton of them, and it doesn't sound like one to me, but I suppose I could've missed something. There is a crack in the exhaust manifold, but it doesn't seem like it's all the way through yet - nothing comes out of it, even cold.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 11:11 am 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Reed wrote:
Have you confirmed oil flow to the rockers? I once installed a rebuilt head on a 225 but later removed it because I thought the head had been milled too much and the motor had bad pinging at 2500-3000 RPM. When I pulled the head I found that I had installed the rocker arm shaft upside down. This means the rocker arms were being starved for oil and i suspect making excessive noise at higher RPMs. I haven't reinstalled this head on any motor to test my hypothesis, but I hope to.

My point is you might want to verify that the rocker arm shaft is installed properly because installing it upside down can lead to oil starvation and excessive valvetrain noise.


It wasn't getting any oil to the rockers when I got it, but after cleaning everything out I've verified that revving it shoots oil out of the top of the rocker arms, so I think I got it all back together straight. It might be worth pulling the valve cover off again and taking another look, though. I'll give that a shot in a bit, just fixed a leaking needle seat and a warped bowl not sealing. (not affecting fuel level in the bowl, just sloshing out when I stopped hard)

While the carb was out, I adjusted the power valve level a bit. If I'm understanding correctly, the mid-range fuel should come in a little sooner now. If that doesn't do it, I think I'll stop looking at fuel as the problem until I can get my hands on an o2 sensor.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 11:42 am 
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Supercharged
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Joined: Sun Nov 03, 2002 9:20 pm
Posts: 12102
Location: Fircrest, WA
Car Model*:
Hmm. That kind of valvetrain noise is not something to ignore. If it is quiet at idle but is audible from inside the cab when you are driving then something is wrong.

If you are positive that there are no exhaust leaks (did you check UNDER the truck, too?), then I would go back to the valve lash. I like to set the lash by getting the engine good and hot (fully warmed up after a drive), turning the idle speed down as low as I can get it with the engine still running, and then adjusting the valve lash while the motor runs. On a truck the recommended lash on a stock cam is .012 intake and .022 exhaust. Don't forget the valve order changes after #3. Front to back it is E-I-E-I-E-I-I-E-I-E-I-E. I have goten 80% through a valve lash adjustment and then remembered the valve order switch and had to redo a few valves.

Other possibilities-
loose torque conveter nut hitting the inspection plate (if it is an automatic)
fan hitting something
maybe a u-joint



I bet your carb does have a port for the vacuum advance, but the nipple might have pulled out of it. See here: https://app.box.com/s/vazo197yglpelw6110p2


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PostPosted: Tue Apr 17, 2018 1:42 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Reed wrote:
Hmm. That kind of valvetrain noise is not something to ignore. If it is quiet at idle but is audible from inside the cab when you are driving then something is wrong.

If you are positive that there are no exhaust leaks (did you check UNDER the truck, too?), then I would go back to the valve lash. I like to set the lash by getting the engine good and hot (fully warmed up after a drive), turning the idle speed down as low as I can get it with the engine still running, and then adjusting the valve lash while the motor runs. On a truck the recommended lash on a stock cam is .012 intake and .022 exhaust. Don't forget the valve order changes after #3. Front to back it is E-I-E-I-E-I-I-E-I-E-I-E. I have goten 80% through a valve lash adjustment and then remembered the valve order switch and had to redo a few valves.

Other possibilities-
loose torque conveter nut hitting the inspection plate (if it is an automatic)
fan hitting something
maybe a u-joint

I bet your carb does have a port for the vacuum advance, but the nipple might have pulled out of it. See here: https://app.box.com/s/vazo197yglpelw6110p2


I'm almost sure there are no exhaust leaks - I was very thorough checking for those this time, my inspection station was a bit picky about it so I've sealed everything off. Thing is, the tick doesn't sound like it's coming from the exhaust direction at all - definitely sounds higher. I noticed today that it only happens after it's warm as well - verified that it's not overheating, steady at 185 on the new gauge, but still clattering.

Thanks, I'll give that a shot this afternoon and see if it's just a lash issue.

There isn't a cover under the bell housing right now (manual trans) so I'll look up in there, maybe something is rattling just right. Definitely not the fan or a u-joint - fan is miles from hitting anything, and the rattle happens if I rev it up without the truck moving.

Thanks for the link, I've been looking for a good manual on this thing. I'm sure someone just blocked off the port, it looks like they blocked off a few different things.
I hate problems like this :( thanks for the help.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 3:22 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Well, I need to slap the idiot that did the last valve adjustment (me). A few of my exhaust valves seemed extremely tight. Granted my fender sticker says .010/.020 rather than .012/.022, but I still think they were tight. Valves are definitely noisier now, but I didn't notice any rattle when I revved it up. Maybe I had one floating or something.

One more question for you though - how much side-to-side movement should a rocker have when it's up? I feel like there's a little more play than I expected, wondering if maybe some of my little bolt-spacer things aren't correct. Maybe I'll go measure them, if they're different it's possible I didn't put them back in the right spots.

I also plugged the PCV hose when I took the valve cover off, and noticed that the idle dropped significantly and my vacuum went up to a solid 20. Maybe plugging it made it run richer (less vac leak) and solved the pinging? I'll try a few things when I get it back together - if it's as simple as plugging the PCV, that's fine with me.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 3:43 pm 
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Supercharged
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Joined: Sun Nov 03, 2002 9:20 pm
Posts: 12102
Location: Fircrest, WA
Car Model*:
sqeeek wrote:
Well, I need to slap the idiot that did the last valve adjustment (me). A few of my exhaust valves seemed extremely tight. Granted my fender sticker says .010/.020 rather than .012/.022, but I still think they were tight. Valves are definitely noisier now, but I didn't notice any rattle when I revved it up. Maybe I had one floating or something.


The stock adjustment is .010/.020, but running them a little looser helps a bit with torque. However, even that loose the valves should not be noticeably very loud.

sqeeek wrote:
One more question for you though - how much side-to-side movement should a rocker have when it's up? I feel like there's a little more play than I expected, wondering if maybe some of my little bolt-spacer things aren't correct. Maybe I'll go measure them, if they're different it's possible I didn't put them back in the right spots.


This is possible. Rocker arms should have a bit of side-to-side play in them when off of the lobe, but I don't have a number. I think about 1/8 of an inch is normal, if memory serves. It is possible for the rocker arm spacers to be reasembled in the wrong order, but that usually leads to binding, not excessive looseness. Have you verified all spacers and washers are there? All the holddown bolts properly torqued?

sqeeek wrote:
I also plugged the PCV hose when I took the valve cover off, and noticed that the idle dropped significantly and my vacuum went up to a solid 20. Maybe plugging it made it run richer (less vac leak) and solved the pinging? I'll try a few things when I get it back together - if it's as simple as plugging the PCV, that's fine with me.


You should always run a PCV valve. You may need a new one. What is your current vacuum at idle with the engine warmed up and the PCV installed?


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PostPosted: Tue Apr 17, 2018 3:58 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Reed wrote:
The stock adjustment is .010/.020, but running them a little looser helps a bit with torque. However, even that loose the valves should not be noticeably very loud.


Ah, that makes sense. Well, I wouldn't say they're "very loud", just more noise than before. A little bit of sewing maching noise, but nothing I'd consider out of the ordinary.

Reed wrote:
sqeeek wrote:
One more question for you though - how much side-to-side movement should a rocker have when it's up? I feel like there's a little more play than I expected, wondering if maybe some of my little bolt-spacer things aren't correct. Maybe I'll go measure them, if they're different it's possible I didn't put them back in the right spots.


This is possible. Rocker arms should have a bit of side-to-side play in them when off of the lobe, but I don't have a number. I think about 1/8 of an inch is normal, if memory serves. It is possible for the rocker arm spacers to be reasembled in the wrong order, but that usually leads to binding, not excessive looseness. Have you verified all spacers and washers are there? All the holddown bolts properly torqued?


I've got at least 1/4" of play on some of them. It looks like the only spacer that is larger than the rest is in the center, which I think makes sense. Moving that spacer anywhere else would probably cause binding. [EDIT: whoops, 1/8" is what I meant]

None of the hold-down bolts are loose, but I'll go find my torque wrench and do it right whil the valve cover is off anyway.


reed wrote:
You should always run a PCV valve. You may need a new one. What is your current vacuum at idle with the engine warmed up and the PCV installed?


What's the downside of no PCV? More condensation in the crankcase?
It's about 18-19lbs with the engine warmed up and PCV on. Seems to lose about 2lbs if I hook up the PCV. I'll admit I don't actually know how that should work, should it be partially open at idle like that?

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 4:28 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Just went and zipped around the block with the PCV both on and off. Still light clattering at part-throttle coasting but it does seem like there's less of it. Can't hear it when parked anymore, only under load. Also a lot more responsive, thanks for the tip on the looser valve clearances.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 6:01 pm 
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Board Sponsor

Joined: Wed Oct 23, 2002 7:57 pm
Posts: 5371
Location: Waynesboro, Pa.
Car Model*: 65 Valiant 2Dr Post
You really want vacuum advance on a street vehicle. It will run better and get better Gas mileage

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2 Mopars come with Spark plug tubes. One is a highly refined, record setting, world class, racing machine. The other is a 426 CI. boat anchor!
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PostPosted: Tue Apr 17, 2018 6:17 pm 
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Joined: Tue Oct 29, 2002 8:27 pm
Posts: 9523
Location: Salem, OR
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Quote:
Still light clattering at part-throttle coasting


Coasting and light or no throttle pressure is not good for the engine..... on manual tranny vehicles
this allows the throttle plates on the carb to shut and create high vacuum... at the same time the
only fuel circuit available to the engine is the idle circuit which is like a squirt gun compared to the fire hose
the main jetting provides... if it leans out really good, the engine will backfire (some guys call it "shooting ducks").
The factory solution was to install a dash pot which keeps plates open/slowly shuts them to compensate,
or sometimes in late vehicles a vacuum solenoid.

FYI.


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PostPosted: Tue Apr 17, 2018 7:24 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
Rick Covalt wrote:
You really want vacuum advance on a street vehicle. It will run better and get better Gas mileage


I found the port under a bolt and hooked it up. Problem is, it seems to draw too much vacuum at idle - idles like garbage. Did drive better though.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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PostPosted: Tue Apr 17, 2018 7:28 pm 
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4 BBL ''Hyper-Pak''

Joined: Mon Apr 02, 2018 9:07 pm
Posts: 32
Location: Waco, TX
Car Model*: 1980 D150 225 4spd
DusterIdiot wrote:
Quote:
Still light clattering at part-throttle coasting


Coasting and light or no throttle pressure is not good for the engine..... on manual tranny vehicles
this allows the throttle plates on the carb to shut and create high vacuum... at the same time the
only fuel circuit available to the engine is the idle circuit which is like a squirt gun compared to the fire hose
the main jetting provides... if it leans out really good, the engine will backfire (some guys call it "shooting ducks").
The factory solution was to install a dash pot which keeps plates open/slowly shuts them to compensate,
or sometimes in late vehicles a vacuum solenoid.

FYI.


That's good to know, thank you. Maybe I'll see if I can find the dashpot that was on there, I think there was one at some point anyway. Whatever the case, I'll try not to part-throttle it too much.

Still don't understand the noise on acceleration. It sounds too fast to be anything but valvetrain. It's intermittent, too... I really have no idea. It's frustrating. The most infuriating part is that my last truck, an '89 Ford with a 2.3T swap, made almost exactly the same noise at the same time, for a year until I sold it. Maybe I'm just cursed.

_________________
1970 Olds Ninety-Eight (great grandpa's old car)
1980 D150 225
1989 Civic - high-power SOHC project (advice: don't)
1989 Integra
... and a Prius, because none of those ^ run.


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