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Old 06-09-2016, 10:14 PM   #26
davepl
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Re: Pinging after 40-45 mins of driving?

Nah. It's not a "good idea" but I think the amount of heat you'd see rubber-rubber transfer is very small.

I recommend no more than about 4" of rubber line in the whole vehicle, but that's me.

Do you remember our static+mechanical == total discussion? You've got a lot of initial, you might have to have someone lock out some mechanical. Or try less initial if you can get away with it.
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Old 06-09-2016, 11:29 PM   #27
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Re: Pinging after 40-45 mins of driving?

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Originally Posted by davepl View Post
Nah. It's not a "good idea" but I think the amount of heat you'd see rubber-rubber transfer is very small.

I recommend no more than about 4" of rubber line in the whole vehicle, but that's me.

Do you remember our static+mechanical == total discussion? You've got a lot of initial, you might have to have someone lock out some mechanical. Or try less initial if you can get away with it.
I do, and I'm actually grinding on a machine screw right now. It's gonna take some trial and error grinding on the head of the screw because the amount limited will depend on the size of the head, but I'm starting with just a little off one side making a flat spot. Then that screw goes in the plate that's under the weights and springs. I'm hoping to limit the mechanical to around 12-14* so I can run 18-20* of initial. The drawback is that I'm probably going to have to wire in a switch to my ignition so I can get the engine cranking for a second or two, and then close the circuit letting it fire up. That much initial makes it a little tough to start when it's already warmed up or hot.
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Old 06-09-2016, 11:38 PM   #28
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Re: Pinging after 40-45 mins of driving?

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Originally Posted by davepl View Post
Nah. It's not a "good idea" but I think the amount of heat you'd see rubber-rubber transfer is very small.

I recommend no more than about 4" of rubber line in the whole vehicle, but that's me.

Do you remember our static+mechanical == total discussion? You've got a lot of initial, you might have to have someone lock out some mechanical. Or try less initial if you can get away with it.
I do, and I'm actually grinding on a machine screw right now. It's gonna take some trial and error grinding on the head of the screw because the amount limited will depend on the size of the head, but I'm starting with just a little off one side making a flat spot. Then that screw goes in the plate that's under the weights and springs. I'm hoping to limit the mechanical to around 12-14* so I can run 18-20* of initial. The drawback is that I'm probably going to have to wire in a switch to my ignition so I can get the engine cranking for a second or two, and then close the circuit letting it fire up. That much initial makes it a little tough to start when it's already warmed up or hot.
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Old 06-10-2016, 07:21 AM   #29
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Re: Pinging after 40-45 mins of driving?

Been there and ended up buying a programmable MSD box with a small body distributer. That made life much easier and kept the distributer phasing correct.
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Old 06-10-2016, 12:28 PM   #30
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Re: Pinging after 40-45 mins of driving?

Have you considered that there might be carbon build-up in your combustion chamber that is increasing your compression ratio? Additionally, that carbon can act like an ignition source for fuel when it gets red hot. The increased compression ratio and ignition source from the carbon can cause pinging and/or detonation. I recommend running a good quality top end cleaner, ATF, or water through your carb to clear out any carbon, and take this possibility out of the equation before you do anything else.
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Old 06-10-2016, 01:37 PM   #31
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Re: Pinging after 40-45 mins of driving?

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Have you considered that there might be carbon build-up in your combustion chamber that is increasing your compression ratio? Additionally, that carbon can act like an ignition source for fuel when it gets red hot. The increased compression ratio and ignition source from the carbon can cause pinging and/or detonation. I recommend running a good quality top end cleaner, ATF, or water through your carb to clear out any carbon, and take this possibility out of the equation before you do anything else.
Can you tell me exactly how to clear it out with water? I did the fresh top end rebuild a few months ago so I'm not sure how much carbon could be built up
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Old 06-10-2016, 01:49 PM   #32
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Re: Pinging after 40-45 mins of driving?

Basically you get the motor up to temp then raise the RPMs up. From there either dribble water out of a bottle through the carb or use a spray bottle and mist it into the carb. The RPMs will drop off so don't let it stall. It will literally steam clean the piston tops and combustion chambers. This is an old racer trick but be careful as to much water to fast and bad things happen. You can hydro lock the motor if you go nuts. Going slow you can put gallons off water through the carb but it really only takes a 20oz coke bottle to get the job done.
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Old 06-10-2016, 02:41 PM   #33
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Re: Pinging after 40-45 mins of driving?

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Can you tell me exactly how to clear it out with water? I did the fresh top end rebuild a few months ago so I'm not sure how much carbon could be built up
I had a fresh motor that got a quick carbon build up when I used some valve covers that didn't have good oil baffles. My PCV valve was able to suck in enough oil to create a nice carbon crust in just a few weeks. Just saying its possible. I ended up going the water route to clear out the carbon, and then put on another set of valve covers with good oil baffles. No problems since.
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Old 06-10-2016, 03:57 PM   #34
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Re: Pinging after 40-45 mins of driving?

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Basically you get the motor up to temp then raise the RPMs up. From there either dribble water out of a bottle through the carb or use a spray bottle and mist it into the carb. The RPMs will drop off so don't let it stall. It will literally steam clean the piston tops and combustion chambers. This is an old racer trick but be careful as to much water to fast and bad things happen. You can hydro lock the motor if you go nuts. Going slow you can put gallons off water through the carb but it really only takes a 20oz coke bottle to get the job done.
Ok I'll do that today so I can at least rule out the possibility. I decided to lock out my distributor today and set the total timing at 34*, this makes the truck run great and also rules out a timing curve issue. Now I'm trying to figure out where to set the adjustable vacuum advance so I can run that with the locked distributor.
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Old 06-10-2016, 03:58 PM   #35
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Re: Pinging after 40-45 mins of driving?

I felt the fuel filter today as well just to see and it was scalding hot, any thoughts on that?
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Old 06-10-2016, 05:37 PM   #36
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Re: Pinging after 40-45 mins of driving?

Is it possible you have a vacuum leak after it warms up?
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Old 06-10-2016, 06:38 PM   #37
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Re: Pinging after 40-45 mins of driving?

I.think your way off , your running it so advanced trying to track down another 50 horse power that's just not there , now what's up with the hot fuel filter ? I'd be chasing that issue first it just may become the cause of many of your issues . Back it down to basics and while your at it back up the timing and let it live until the engine you really want is ready . Nothing's worse than a blown engine with a ton of shiny parts sitting in the garage .
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Old 06-10-2016, 08:09 PM   #38
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Re: Pinging after 40-45 mins of driving?

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I.think your way off , your running it so advanced trying to track down another 50 horse power that's just not there , now what's up with the hot fuel filter ? I'd be chasing that issue first it just may become the cause of many of your issues . Back it down to basics and while your at it back up the timing and let it live until the engine you really want is ready . Nothing's worse than a blown engine with a ton of shiny parts sitting in the garage .
I thought it may be too much timing as well because I was tinkering with that so much a while back looking for a tune that would run good with my combo. But I've checked it 4-5 times in the past week and it's 34* TOTAL, which is conservative for a motor like this.

As far as the filter goes, you can see it in the pic a few posts back, it's one of those clear view filters made out of metal and glass. Never considered that could be the problem but maybe those are junk.
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Old 06-10-2016, 08:10 PM   #39
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Re: Pinging after 40-45 mins of driving?

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Is it possible you have a vacuum leak after it warms up?
It could be, I haven't checked yet either so I'll spray some brake kleen and see what happens. I hadn't considered that there could be one after warm up
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Old 06-10-2016, 08:19 PM   #40
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Re: Pinging after 40-45 mins of driving?

Also if your engine is running lean it will get hot and ping.
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Old 06-10-2016, 08:45 PM   #41
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Re: Pinging after 40-45 mins of driving?

I'll say one last time because I don't want to be a dork about it, but if you've got manifold vacuum connected to vacuum advance, that's your cause. You've got a bunch of initial timing and then soon as you foot-brake it, which won't take manifold vacuum very low at all, you've got vacuum+initial == detonation.

Before you start pouring water into your engine or other last-ditch attempts, put it back the way GM built it (if it's not).

In brief: big cams like lots of timing so people "discover" that they idle better with manifold vacuum on the vacuum can, but you can't drive it because it'll rattle like crazy with detonation. Don't do that (if you are).

I could go into a giant manifesto about vacuum advance, how it works, and so on, but I'll leave it at "Hook it up like GM did".
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Old 06-10-2016, 09:25 PM   #42
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Re: Pinging after 40-45 mins of driving?

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I'll say one last time because I don't want to be a dork about it, but if you've got manifold vacuum connected to vacuum advance, that's your cause. You've got a bunch of initial timing and then soon as you foot-brake it, which won't take manifold vacuum very low at all, you've got vacuum+initial == detonation.

Before you start pouring water into your engine or other last-ditch attempts, put it back the way GM built it (if it's not).

In brief: big cams like lots of timing so people "discover" that they idle better with manifold vacuum on the vacuum can, but you can't drive it because it'll rattle like crazy with detonation. Don't do that (if you are).

I could go into a giant manifesto about vacuum advance, how it works, and so on, but I'll leave it at "Hook it up like GM did".
Right after I read your post about switching it over I went ahead and did it, and it got much better. I also adjusted the vac adv can down so it's not putting in as much advance, and it coming in later as well.
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Old 06-10-2016, 09:27 PM   #43
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Re: Pinging after 40-45 mins of driving?

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Also if your engine is running lean it will get hot and ping.
The carb that's on there is an Edelbrock 650 AVS, how do I richen it up a bit? I assume you're not talking about the air/fuel mixture screws because those are only for the idle circuit correct?
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Old 06-10-2016, 09:32 PM   #44
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Re: Pinging after 40-45 mins of driving?

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Is it possible you have a vacuum leak after it warms up?
This has got me wondering a little, because about a month ago I was fiddle fartin around with the truck and had the carb off. When I put it back on, I BARELY over tightened the passenger rear bolt (didn't get carb studs like I shoulda) and the corner cracked but stayed on, so I left it alone. The crack goes all the way through for sure, but I don't know if it's causing a vacuum leak.
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Old 06-10-2016, 09:33 PM   #45
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Re: Pinging after 40-45 mins of driving?

The picture is sideways...but you can still see the crack
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Old 06-10-2016, 09:53 PM   #46
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Re: Pinging after 40-45 mins of driving?

DUDE , and I mean this in a nice way , toss that carb you killed it . That's a huge vacuum leak , and the pretty chrome and glass fuel filter is the absolute worst filter ever made ,Toss that in the trash along with the carb and get a plain old steel filter ! Before your standing back and watching it go up in flames !! Take all the performance books and threads you've been reading and toss those too !! Back it all down and drive the truck . Your tossing $100.00 bills at it weekly and getting no where . Carbs don't have to torqued down that hard . And trying to get that engine where you want to be isn't going to happen .enjoy it for what it is ,don't drive yourself INSANE trying to make it something it's not . Hug the kid and take your girl out for dinner and walk away from it for a few days .

And dump that carb spacer and get studs and a phenolic spacer .
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'71 - 350 / 4bolt / 487 heads / Edelbrock C3BX
Muncie M-22 4 speed / Hurst Comp plus
Factory 12 bolt posi 3.73 / 255-70-15
Smoothed firewall / Factory cowl induction
Power disc brakes / power steering / 3.5-5" drop

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Old 06-10-2016, 11:06 PM   #47
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Re: Pinging after 40-45 mins of driving?

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Originally Posted by Grumpy old man View Post
DUDE , and I mean this in a nice way , toss that carb you killed it . That's a huge vacuum leak , and the pretty chrome and glass fuel filter is the absolute worst filter ever made ,Toss that in the trash along with the carb and get a plain old steel filter ! Before your standing back and watching it go up in flames !! Take all the performance books and threads you've been reading and toss those too !! Back it all down and drive the truck . Your tossing $100.00 bills at it weekly and getting no where . Carbs don't have to torqued down that hard . And trying to get that engine where you want to be isn't going to happen .enjoy it for what it is ,don't drive yourself INSANE trying to make it something it's not . Hug the kid and take your girl out for dinner and walk away from it for a few days .

And dump that carb spacer and get studs and a phenolic spacer .

These posts always crack me up lol I haven't spent a dime on this thing for a while, and yesterday is the first time I've touched it in weeks because I've been working and doing the family thing.

I will get a new filter though and a nice shiney polished oversized carb and then I'll install it using my David Vizard performance books Bwahahaha! Just ribbin ya
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Old 06-10-2016, 11:24 PM   #48
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Re: Pinging after 40-45 mins of driving?

Finding a vacuum leak is great, but the problem I'm having is with pinging and detonation. So does a vac leak cause that to happen??
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Old 06-10-2016, 11:27 PM   #49
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Re: Pinging after 40-45 mins of driving?

Lots of online mechanics have never touched a wrench , send their truck out to be worked on and can tell you everything you ever wanted to know about building engines according to whatever book their reading at the moment ! I used to chuckle when I'd over hear a new owner brag about the new truck he brought to a show and how long he worked on it when all he did was sign the check and hand it to me ! Put a Pontiac quadrajet on it 850 CFM and it will run just fine. I wish you lived closer for 2 reasons , 1 being you would be buying me a LOT of Heineken , and 2 I'd love to see your face when a little 292 smokes your big old bad V8 . Bhwaaaa .... Bhwaaaa...Bhwaaaa .....and gone !

Weight and balance ....Weight and balance ............100 ft burnouts are easy in any truck , getting one to launch correctly with 75 % of the weight in front is a whole nother ball game
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1967 Factory short bed - Old school
'71 - 350 / 4bolt / 487 heads / Edelbrock C3BX
Muncie M-22 4 speed / Hurst Comp plus
Factory 12 bolt posi 3.73 / 255-70-15
Smoothed firewall / Factory cowl induction
Power disc brakes / power steering / 3.5-5" drop

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Old 06-11-2016, 12:52 AM   #50
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Re: Pinging after 40-45 mins of driving?

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Lots of online mechanics have never touched a wrench , send their truck out to be worked on and can tell you everything you ever wanted to know about building engines according to whatever book their reading at the moment ! I used to chuckle when I'd over hear a new owner brag about the new truck he brought to a show and how long he worked on it when all he did was sign the check and hand it to me ! Put a Pontiac quadrajet on it 850 CFM and it will run just fine. I wish you lived closer for 2 reasons , 1 being you would be buying me a LOT of Heineken , and 2 I'd love to see your face when a little 292 smokes your big old bad V8 . Bhwaaaa .... Bhwaaaa...Bhwaaaa .....and gone !

Weight and balance ....Weight and balance ............100 ft burnouts are easy in any truck , getting one to launch correctly with 75 % of the weight in front is a whole nother ball game
That would be fun, and afterwards I'd wanna ride in the 292 because that's gotta be one fast I6! And I love Heineken! You have a pretty awesome job Grumpy, I mean, getting checks made out to you for building really cool trucks is about the coolest job I can think of. I'm not great at wrenching yet, but since that first thread I made where I took apart the motor the very first time to identify the cam which lead to all sorts of work, I've definetly improved 300% (not to toot my own horn lol) Maybe when I get the Gear Vendor and disk brakes all done it'll be road trip time
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