#81  
Old 07-18-2019, 03:04 AM
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Originally Posted by Cliff R View Post
I know what it's supposed to be and what they are telling him it is. The symptoms all indicate that the octane is much lower than advertised, or his timing marks have slipped about 8-10 degrees.

NOTHING about the issues make sense for the combination of parts being used. Not being able to run more than 22 degrees total timing tells me something in this deal is fundamentally wrong.

Right to start with what method is being used to determine total timing, an indexed balancer, measuring and making a mark at 22 degrees, dial back timing light?........Cliff
Cliff,

It's a big mystery to me too. One thing I can tell you is that the balancer is correct. Not only have I been through two recent partial rebuilds where I found TDC with a gauge and then slid the balancer on to have 0 lined up with the mark but I can also guarantee the cam is installed dot-to-dot since I took pictures. Now, sadly, I didn't degree the Crower since the cam swap was in-car and outside in the dust and heat and humidity. But, again, the cranking compression numbers are correct for that cam spec at its advertised ICL. Also, I can guarantee that if I go down to, say, 5 degrees initial it becomes very hard to have enough vac to run a vac advance and I'm having to add throttle stop to keep the idle solid when dropping in gear.

As far as that balancer, it's a really nice SFI-approved unit with timing marks on a long scale built in. And, yes, they match, so that if I see "12" at the "0" mark on the timing cover I also see "0/TDC" mark at "12" on the timing cover. Oh, and I use a non-dialback light.

So, last night I did a bit of careful grinding with some screws and eventually worked out an arrangement that limits my mechanical advance to 10 crank degrees. Yes, ten.



I also closed the stop on the vac advance to a hard limit of 14. Here's where that leaves me:
8 initial. 22 with vac at idle. 18 total mechanical. Yes, 18 (centrifugal advance limited to adding 10 degrees plus the inital 8).

And the result? At full throttle I _think_ I have no more pinging above 3000. I _know_ I still had pinging at 3500 at full throttle with 20 degrees total mechanical. With the limit at 18 total I still have some ping noise at less than full throttle, say 3/4 throttle also at that high RPM. I'm assuming maybe I pick up a degree or two from vac at that point? Dunno. No ping now at all in any normal driving modes (under 3000).

As far as the fuel quality, I never seem to have had an issue on the old 197 heads and 068 cam but I know that was a much gentler combo. I also know that they knocked the "super" down from "97" octane to "95" octane in 2016. I'm putting the octane in quotes because it isn't "US" octane numbers but the RON numbers that most other countries use. In the UK, for example, we have 95 RON as our "regular" grade and 98 RON as our "premium" grade. Here in Qatar the top grade is 95 RON.

Also, if the balancer were simply off then I presume my car would idle happily at, say, 0 initial (if 20 were really 30 then 0 would really be 10). That's not the case. I genuinely need less advance _gain_.

Now here's the other weird thing. The car is pretty damned happy like this. With the vac and mechanical set up like I have it now it scoots like a go-cart and it definitely has a lot more on tap than with the previous heads and cams. Maybe it is fuel. Maybe, as Jay suggested, this cam is also a bit smaller than what it says on the cam card.

With that in mind, I figured some samples of the idle were in order.

Here's a cold idle. Keep in mind that cold here is like 100ºF+. I think some would say there is some lope here
https://youtu.be/-Q9EHlfOiS4

Here's a warm idle. Also a rev in the company parking lot just for Jay (with tick of course)
https://youtu.be/EzGGxHzywKQ

Also, speaking of the company parking lot, there's a nice echo on the U turn at the end
https://youtu.be/6a82h0g5vIY

And just to give you guys a feel for the place, this is about five minutes into my drive home
https://youtu.be/Vb4CQdPvURU

Any thoughts welcome.

Sam
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Last edited by glhs#116; 07-18-2019 at 03:34 AM.
  #82  
Old 07-18-2019, 03:22 AM
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Just for giggles, here's the carb info. My carb is a 1972 unit for a 455 with auto but is not the HO unit. It's 7041262. I rebuilt it with a kit from Cliff a little less than two years ago. At the time it was still the old cam and heads.

Carb had been 73 jet with 45 rods and BU secondary rods

Kit came with new idle tubes which were installed. Also two drill bits which were I believe:
.0625 idle channel restrictions
.1015 idle bypass air
Both were used. Afterwards I found it was too much idle bypass air and I partially filled the enlarged idle bypass holes with pieces of a roll pin which brought it back to a good place.

Kit came with 42 rods which proved too fat. I went up to 43.
Kit came with DA secondary rods (these are long taper, the BU are short taper). I installed these but they made the car fat and slow and I put the BUs back in.

So carb was 73 jets, 43 rods, BU secondary rods.

A few days ago I figured that Cliff knows his stuff and probably the new heads and cam move a lot more air so I tried the DA secondary rods again. With the new combo the DA rods are a BIG improvement on the BU secondary rods. However, since I've been mostly trying to dial out ping I haven't touched anything else in the carb yet. I will say, however, that "seat of pants" it runs and drives very nicely in all scenarios. I'm sure there's something to be gained on the primary side but as it is it's working well.

Also, since the detonation is the main topic here I should add that with the DA secondary rods the car picked up a lot of _power_ in the secondaries and was nicely responsive (it wasn't with the DA rods and the old cam and heads) BUT the swap had zero effect on the tendency of the car to _ping_ under full throttle versus the BU rods. The only difference was power. The ping sensitivity under full throttle was exactly the same from BU to DA rods.

Just in case it rings any bells for anyone regarding the whole ping thing.

Sam

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  #83  
Old 07-18-2019, 05:33 AM
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One thing you are not doing with the mechanical advance is adding a positive stop for it.

They can, and will add timing at high RPM's. I found this out decades ago and have been putting a mechanical stop in all HEI's we build here.

I have never once found the need to modify the stock weights or center cam with Pontiac units. They did a darned good job of setting them up from the factory. 99 times out of 100 I use the stock springs as well, and find that if they are in good shape, the timing curve starts right off idle and is all-in around 2800-3200rpm's.

I will on occasion "work" the spring eyes a tad if/when I want the curve in a little quicker or to reach total timing a tad earlier. Aftermarket springs are nothing but pure garbage these days, as are the weight kits they come with. As for the vacuum advance I do NOT recommend a can that starts sooner than about 5" vacuum. The one we use here starts around 5-6" and all in around 10-12".

As mentioned previously, ALWAYS tune full throttle and total timing first. No need to get all the timing in quickly or a lot of it. The more efficient the engine combo the LESS timing (and fuel) is needed at every RPM to make best power.

For about 2 years now I've opened up my Saturday mornings for custom tuning troubled set-ups. Folks make appointments and bring cars here, often from great distances. I've had them brought here as far away as Georgia and even had one customer stop in on a road trip for Colorado.
About year and a half ago I had a PRESTINE Buick GN Stage 1 car brought here, and a few weeks later a 1968 Hurst Olds. Since then (the word got out) I've had half a dozen more of those cars brought here. Interesting part is that the cure for ALL of them was to remove the "goofy" advance kit in the distributor and put stock weights and springs back in them. I also replaced the rubber advance pin bushing with a stainless steel one. Once I got the timing under control (all of them were adding timing at idle and some when cranking) I went into the carburetors and put them back where they should have been.

Each time the owners return to the shop after a test drive grinning from ear to ear! I'll also add here that I also remove the Petronix and put points back in them. Yes, we go back to the original set-ups. I've found WAY too many defective Petronix units in recent years and refuse to run them.

Just had a customer (actually the dyno shop called me) a few weeks ago. I built a custom Q-jet for a "high end" restoration, 1970 Chevelle 454 SS car. The engine "builder" stroked it to 496 CID, ported the heads, bigger valves, higher compression and flat tappet solid cam (my contribution). The goal was 550hp or so and still using the flat intake, Q-jet, stock distributor, exhaust manifolds, etc.

Well, I get the call while they are on the dyno and this thing ain't making chit for power. Stuck around 420hp and EVERYONE right down to the guy who takes out the trash is blaming the Q-jet. The builder is telling my customer the carb isn't big enough for his engine and to get that POS off of there and put a Holley on it. He's also recommending to take the "flat" iron intake and make a door-stop out of it. I'm trying to convince them to keep the Q-jet/stock intake and try to help by telling them in try more fuel pressure, larger inlet seat, etc. I get all caught up in trying to fix the carb and didn't even think about the distributor. After going no place with the carb I asked them how the timing was set-up? They said it's "all-in" by about 2800rpms and that the engine does fine till about 4500rpms then just quits pulling. I asked them about the points, and they said they eliminated them and put a Petronix in it.

BINGO, the light goes off........I told them to remove the Petronix and put the points back in it..........................the next pull was 548HP!

Just a reminder that a lot of these parts we are getting these days aren't up to par. That's about the 3rd or 4th time I've ran into issues in recent years with those parts.......FWIW.......Cliff
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Last edited by Cliff R; 07-18-2019 at 06:10 AM.
  #84  
Old 07-18-2019, 06:13 AM
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Quote:
Originally Posted by Cliff R View Post
One thing you are not doing with the mechanical advance is adding a positive stop for it.

They can, and will add timing at high RPM's. I found this out decades ago and have been putting a mechanical stop in all HEI's we build here.
Those two silver screws in the picture with their sides shaved are a positive stop. I didn't modify the centre cam. I abandoned that idea after hearing how hard it is to get right. That's my 394 centre (numbers down) with my 045 weights (numbers down) and the two beefiest springs I could find. All old factory stuff from junk parts.

I should add, just not to be confusing, that this was not the final shape of those screws. I had to shave them more to get the rotor to mount squarely and I had to do some fine tuning to get the right amount shaved for 10 degrees. A little material more and you are limited to 4 degrees. A little less and you are back at 14 or 16 again..

Quote:
Originally Posted by Cliff R View Post
I have never once found the need to modify the stock weights or center cam with Pontiac units. They did a darned good job of setting them up from the factory. 99 times out of 100 I use the stock springs as well, and find that if they are in good shape, the timing curve starts right off idle and is all-in around 2800-3200rpm's.

I will on occasion "work" the spring eyes a tad if/when I want the curve in a little quicker or to reach total timing a tad earlier. Aftermarket springs are nothing but pure garbage these days, as are the weight kits they come with. As for the vacuum advance I do NOT recommend a can that starts sooner than about 5" vacuum. The one we use here starts around 5-6" and all in around 10-12".

As mentioned previously, ALWAYS tune full throttle and total timing first. No need to get all the timing in quickly or a lot of it. The more efficient the engine combo the LESS timing (and fuel) is needed at every RPM to make best power.

For about 2 years now I've opened up my Saturday mornings for custom tuning troubled set-ups. Folks make appointments and bring cars here, often from great distances. I've had them brought here as far away as Georgia and even had one customer stop in on a road trip for Colorado.
About year and a half ago I had a PRESTINE Buick GN Stage 1 car brought here, and a few weeks later a 1968 Hurst Olds. Since then (the word got out) I've had half a dozen more of those cars brought here. Interesting part is that the cure for ALL of them was to remove the "goofy" advance kit in the distributor and put stock weights and springs back in them. I also replaced the rubber advance pin bushing with a stainless steel one. Once I got the timing under control (all of them were adding timing at idle and some when cranking) I went into the carburetors and put them back where they should have been.

Each time the owners return to the shop after a test drive grinning from ear to ear! I'll also add here that I also remove the Petronix and put points back in them. Yes, we go back to the original set-ups. I've found WAY too many defective Petronix units in recent years and refuse to run them.

Just had a customer (actually the dyno shop called me) a few weeks ago. I built a custom Q-jet for a "high end" restoration, 1970 Chevelle 454 SS car. The engine "builder" stroked it to 496 CID, ported the heads, bigger valves, higher compression and flat tappet solid cam (my contribution). The goal was 550hp or so and still using the flat intake, Q-jet, stock distributor, exhaust manifolds, etc.

Well, I get the call while they are on the dyno and this thing ain't making chit for power. Stuck around 420hp and EVERYONE right down to the guy who takes out the trash is blaming the Q-jet. The builder is telling my customer the carb isn't big enough for his engine and to get that POS off of there and put a Holley on it. He's also recommending to take the "flat" iron intake and make a door-stop out of it. I'm trying to convince them to keep the Q-jet/stock intake and try to help by telling them in try more fuel pressure, larger inlet seat, etc. I get all caught up in trying to fix the carb and didn't even think about the distributor. After going no place with the carb I asked them how the timing was set-up? They said it's "all-in" by about 2800rpms and that the engine does fine till about 4500rpms then just quits pulling. I asked them about the points, and they said they eliminated them and put a Petronix in it.

BINGO, the light goes off........I told them to remove the Petronix and put the points back in it..........................the next pull was 548HP!

Just a reminder that a lot of these parts we are getting these days aren't up to par. That's about the 3rd or 4th time I've ran into issues in recent years with those parts.......FWIW.......Cliff
Just a reminder, Cliff. I am also a believer in stock parts wherever possible. My HEI is all factory except for the adjustable vac advance. And it's six turns out, so fairly stiff. Just not quite as stiff as a factory can (or at least any of the ones I have). None of my cans would start at low enough vac to be stable at idle.

No junk rubber bushings in the dist. All factory weights and springs and cam. I have a positive stop, it's those two screws. That's how I got the mechanical to limit at 10º. I've got nothing against welding, I just don't have the equipment or knowledge.

Carb, again, as you know is factory QuadraJet, good rebuild parts from your own inventory. No funny stuff. The heads are common in this hobby and the larger chamber size available (87cc). The cam is a pretty commonly used 041 clone (Crower 60919) well recommended for my compression ratio and heads. Like you said, you see a lot of combos like mine. And mine is set up pretty close to how you would. No funny X cam, no junk advance kit, no funny carb tricks, factory carb and intake..

Anyway, I appreciate any thoughts on my situation. I'd also appreciate your advice on the idle videos as to if this sounds like the right sort of idle quality for what the cam and combo is supposed to be. Words like "lumpy" and "smooth" sometimes don't convey what they should.

Sam

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  #85  
Old 07-18-2019, 06:21 AM
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If you verified 87 cc chambers, have tight squish, correct cam, timing is under control and carb bowl isn't getting sucked low on hard pulls, then you have CHIT for fuel over there!......IMHO......Cliff

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  #86  
Old 07-18-2019, 06:21 AM
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Just as a general statement, I like to drive fast as much as the next guy but I also daily drive and value reliability. It has been my sixteen year experience with this car that I ALWAYS prefer the factory part and the near-factory configuration where possible. One of the challenges of having to run the new head and then a new cam was that it pushed a lot of things out of the area where factory stuff (at least the factory stuff I have available to me) is geared to work. That's why I'm trying so hard to understand everything going on here.

Sam

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  #87  
Old 07-18-2019, 06:28 AM
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Listening to the clips above doesn't sound like you are lacking timing anyplace, or fuel delivery.

If the engine didn't like the conservative timing specs it would have a much "deeper" or "heavy" sound to it. It's clean, and doesn't sound like it's working hard so pretty happy with what you've done....IMHO......

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  #88  
Old 07-18-2019, 06:39 AM
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If you verified 87 cc chambers, have tight squish, correct cam, timing is under control and carb bowl isn't getting sucked low on hard pulls, then you have CHIT for fuel over there!......IMHO......Cliff
Are the chambers verified volume? Well, no. I didn't fill them with water. But they are the Edelbrock CNC chambers so one would expect a certain level of accuracy. Also, as far as I'm aware, if I accidentally got 72cc units then they would have been missing the exhaust crossover port which mine have.

Is the cam on spec? Well, according to the card. And the cold cranking pressures suggest it. But really, who knows, I guess.

I certainly saw that I could go down two steps on the plug heat range and it was fine. Probably as Jay says I need to go further. But it is kinda hard to believe that I will put in 11s and suddenly the motor will take 30 degrees. I mean maybe. I'd love that. But it's hard for me to imagine.

In the same way it's pretty clear to me that by the numbers the highest grade of fuel here is equal to the lowest grade of fuel in the UK and about equal to near the lowest grade of fuel in the US (since it's probably around 89 US octane). But then again, I'm hearing a decent set up combo should run 89 octane with a cam like this (although, who knows, maybe I need more rocker ratio). Still, kinda hard for me to imagine that I pull up to the pump at home and put in slightly higher octane fuel and suddenly it likes ten more degrees of advance. Again, maybe. What do I know? I'm definitely a baby in this stuff compared to the more experienced guys here but something seems fundamentally shifted.

Again, I can't escape the fact that it's not just that it wants less _overall_ advance. It's that it wants less advance _spread_ between low and high RPM. To me this points to a very quick burn for some reason.

I also feel like I'm not buying the temperature and mixture factors much. I've just had quite a bit of experience that if x degrees cause ping cold it will cause it hot and vice versa. Likewise that if x degrees cause ping lean it will still cause it with more fuel. Not that these factors don't matter at all. They are definitely very real factors for the fine-tuning. I just can't see ten or more crank degrees of advance hiding in any of them.

What makes sense here? I dunno. From what I can gather my possible options seem to be:
• Cam grind with way smaller lobes than card -- here is where I hoped that experienced ears listening to the idle videos might help
• Compression way higher than I think -- and I take it this would have to mean chambers are smaller than advertised
• Something glowing in the chamber -- but since I know the piston tops are in good shape and the heads are new that leaves only plugs. Hence me trying to work down the heat range
• **** fuel -- Well, sure, could be. And most of the new cars here would never notice since the computer would just work around what was available. Still, I know the old combo took the expected timing. And, yes, that was a mild low compression factory combo

And the reason I want to know is that if it's anything I can fix I want to fix it.

Again, the other strange thing is that with this weird tune with a very short advance curve that comes in slowly the car drives pretty great. But 18 total. And it may even want a smidge less.. Well, I never heard of that and it doesn't sound like it should be that way.

Lastly, I guess, there's the climate. It is, indeed, pretty extreme. But I'm sure there's places in Florida and south Texas, for example, that get something close to this heat and humidity. Well, not this bad. But certainly high.

Sam

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  #89  
Old 07-18-2019, 06:41 AM
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Quote:
Originally Posted by Cliff R View Post
Listening to the clips above doesn't sound like you are lacking timing anyplace, or fuel delivery.

If the engine didn't like the conservative timing specs it would have a much "deeper" or "heavy" sound to it. It's clean, and doesn't sound like it's working hard so pretty happy with what you've done....IMHO......
And does that sound about the amount of "lumpy" you would expect 10.2:1 Edel head, 041 clone cam, 1.5 rocker 462 Pontiac to sound like?

Indeed, I've driven the car in a lot of different tunes over the years. The DA secondary rods with the old heads and cam, for example, were "heavy". And the stopwatch showed it liked the slower fuel curve of the BU rods with the old 068 and 197 heads. But on the Edel heads and the Crower cam it LOVES the DA secondary rods. The car drives really nice. It lifts the nose at the lightest tap of the throttle from idle. It pulls strongly and smoothly even in top gear from low RPM. It feels pretty "happily" tuned. But it's weird how little timing it wants and it's frustrating how little total timing it will take.

Sam

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  #90  
Old 07-18-2019, 07:10 AM
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Quote:
Originally Posted by glhs#116 View Post
And does that sound about the amount of "lumpy" you would expect 10.2:1 Edel head, 041 clone cam, 1.5 rocker 462 Pontiac to sound like?

Indeed, I've driven the car in a lot of different tunes over the years. The DA secondary rods with the old heads and cam, for example, were "heavy". And the stopwatch showed it liked the slower fuel curve of the BU rods with the old 068 and 197 heads. But on the Edel heads and the Crower cam it LOVES the DA secondary rods. The car drives really nice. It lifts the nose at the lightest tap of the throttle from idle. It pulls strongly and smoothly even in top gear from low RPM. It feels pretty "happily" tuned. But it's weird how little timing it wants and it's frustrating how little total timing it will take.

Sam
Not weird to me. Same here as there. Then I add octane booster and I'm good to go.

  #91  
Old 07-18-2019, 09:36 AM
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I hope it did not come a across that I was bashing the 60919. It has been and still is one of my “go to cams” .

I think these timing issue are probably a combination of the low altitude, heat, humidity and fuel quality. I think Cliff made a similar statement.

Lol, I get the feeling I am alone on an island when I mention spark plug heat ranges. That is fine, it may not work. I am guessing, but base on experience, you can keep going colder and use your adjustable vacuum advance to advance the time more cruising to keep the plugs in the self cleaning range so they don’t fowl.

One of the more difficult engines we tuned. We have a 455 Olds we run. It was stock 1970 10.0:1 w-34 400 hp factory rating engine with headers and a 214/224 @.050 cam like many common grinds. It is in my 1971 chevelle, my first car (still have it!) When it was first built we looked up the factory spark plugs and used them since it was more or less stock. It pinged, ran hot, and would bog when the secondary’s were kicked it. We thought it was fuel at first, an issue in the qjet. We went through everything on the ignition and the carb trying to sort the problems out. We decided to drop a heat range on the spark plugs and noticed right away improvement. We ended up dropping 4 heat ranges. We can run that engine on 87 octane gas, with 10:1 compression with cast iron heads. I probably have about 25000 miles on the car with those same spark plugs in it. We had a predator carb on it for a while and the needle stuck open and the electric fuel pump filled one cylinder with gas and bent a rod. It had about 15000 miles on it at the time. We took it apart, inspected everything, replace the rod, ported the heads, reused all the bearings because they looked like new yet. It went from about 350hp to 430 hp., it still runs.

All our Pontiacs 455s have 10:1 or higher with cast iron heads, a bigger cams than the Olds, and we run r44 plugs. Most guys run r45 and r46. That Olds would be compatible to an r43. It is probably 100hp short of the hp the 455 Pontiac we have, but it needs a colder plug. The Pontiacs take 91 though, that Olds will run on 87. I also have a mopar 510 cid 10.5 compression cast iron headed engine that is 530 hp and run on 87 octane. Have also done a 429 10:1 ford we dropped the heat range on the plugs.. Several others too, quite a few were mopars though.

We do not work on other people vehicles anymore. It is hard to find time for our own stuff. But when we did, people bought their vehicle in and expected to get it tuned and drive it home that day. I am sure the other guys like Cliff probably run into the same thing. Rarely did we ever get the chance to drop the plug heat range, they all wanted the timing pulled out or jets changed so it wouldn’t ping and drive it home that day. The ones that we changed the heat range to transfer some more of the cylinder temperature out were consistently better outcomes and happier customers.


Last edited by Jay S; 07-18-2019 at 09:43 AM. Reason: Edit
  #92  
Old 07-18-2019, 10:41 AM
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Heh, don’t worry Jay. I definitely am going to try colder plugs when I can put another order in. Thanks for the NGK racing part number. This stuff is so hard to find it’s like a secret. Thanks for the benefit of your experience. And your piston and rod. And your dowels.

I am so indebted to your help and expertise at this point that you could probably tell me to put rainbow stickers on the car to fix it and I would try it.

Sam

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  #93  
Old 07-19-2019, 08:38 AM
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I watched your videos. It sure runs and sounds good. Neat to see the environment the car is running in. It sounds like the last 455 we did with the 60919 that measured up on the small side. A little choppy cold and smooth idle when warm. Yours is a little choppier cold than the one we did, but it had roads vmaxs tightened down to .010 lash, they are not doing much versus a stock lifter set that tight. It also has 1.65s on the exhuast only. Your probably aware, I will meantion it anyway, you can do the 1.65s on the exhuast without worrying about the push rod clearance, that’s what we did. It was an in vehicle cam swap. Not sure what it gained but it certainly did not hurt.

  #94  
Old 09-10-2019, 07:01 AM
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So.. It seems like forever ago but is probably just two months. I ordered some colder plugs and also a new cap and rotor. The carbon tracking on the old ones were beyond what I could ignore. I bought the more expensive AC Delco items. The rotor, in particular, is about twice as thick material as the old one.

Anyway.. Today at lunch I thought maybe I could get away with going one down on the heat range since the "8s" didn't foul out yet. I pulled out #7 and at first glance it looked like a sooty mess. In the dim light of the parking garage I thought no way could I go colder. I put it back in and replaced the cap and rotor instead.

But on the way back up I looked again at the pics of the plug and I'm not so sure. To my eye it's the brown "fuel additives" coating on the plugs, not black soot. The firing portion is bright. Also, from my dim understanding of such things, the "high tide mark" on the strap is pretty far down. I've always understood that to mean the plug is running with too much advance. Well, since my advance is in the basement, I would also interpret that as "might like a colder heat range".

But what do you think?

I should add that the car is a glorified commuter vehicle in current use. About a third of my commute is fast highway. Maybe a quarter of it is idling at red lights.

It's an Iridium plug because that was the only flavour of "8" I could find. I didn't have the race plug part numbers yet. I have 9s and 10s that I can put in.

Just a reminder, I can't get any high octane fuel and the only octane boosters sold here are the snake oil ones that hardly make a difference. It almost certainly needs more cam but that can't happen right at the moment.

By first impression, a sooty mess


Tide mark looks almost to the base ring to me


Side view


Actual ignition point looks bright. Forget what those raindrop marks are meant to mean..


Sam
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  #95  
Old 09-10-2019, 07:56 AM
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Sam to check your new Balancer out if its the same OD as the factory one then once you confirm number 1 is at TDC 36 degrees with then be 2 1/8" around and every 1/8" within that 2 1/8" will be 2.25 degrees pretty much.

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  #96  
Old 09-10-2019, 08:13 AM
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Quote:
Originally Posted by steve25 View Post
Sam to check your new Balancer out if its the same OD as the factory one then once you confirm number 1 is at TDC 36 degrees with then be 2 1/8" around and every 1/8" within that 2 1/8" will be 2.25 degrees pretty much.
Yeah. I understand the reason for suspecting the marks are off. So, here's what I can say to that: The balancer is decent and not that old. The crank was at TDC during assembly and when the balancer was installed the TDC mark lined up with 0. When the indicated timing drops below where it is currently set (around 8 initial without vac advance, 22 with) it doesn't really want to idle without more throttle and has a big drop in vac. For any number of reasons I'm pretty sure the timing is what it says it is. As far as marking the balancer, my balancer is marked already along a pretty broad range. It's one of those nice ones that just give you a bunch of extra numbered timing marks. I use a non-dialback timing light on it. I'm pretty sure my timing is really where it is indicated. I'm pretty sure that the mere 18 degrees of total timing it will take is a real mere 18 degrees. For another example, I had to also limit the mechanical advance to only add 10 degrees before I could get both a decent idle and a non-pinging WOT. Pretty sure it's just making too much cylinder pressure at low RPM for the quality of fuel.

Sam

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Last edited by glhs#116; 09-10-2019 at 08:24 AM.
  #97  
Old 09-10-2019, 12:10 PM
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The plug looks a little hot since about 4 threads are colored. Shoot for having more like 2 with color. The color change on the electrode is close to the base of the plug which means it has more advance than it needs.

What heat range are these? It's just my preference but I don't like using the modern Iridium plugs in these old engines, just regular old copper core.

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  #98  
Old 09-10-2019, 03:35 PM
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Hey Sam I read your email, I thought I would respond over here on your thread so others can add to my thoughts or members can throw eggs at me if I get something mistaken or point you in the wrong direction.

The carb jetting and metering rods are probably lean. I think a 73 with 43 primary and a DA on the secondary is closer to how a 400 would be jetted than a 455. A place to start by changing the secondary to something closer to CC, or on the rich end of the scale. DA is about in the middle. The engine can have crisp throttle response and run lean as long as the accel pump and air door do their job. Rich conditions generally make the throttle response a little less crisp. The brown color all the way down the electrode might be some indication your on the lean side, I know your not suppose to use that for jetting though. That plug shows no signs anywhere I can see of being rich. Best I can do without holding the plug in my hands. It looks like the plug had some heavier deposits opposite from the strap, I don’t know if that is something that will start to be an issue if you go colder, or if that is from the direction the plug was indexed, or something else.

Other than that I do not see much for signs that you could not go colder yet on the plug heat. I can’t see much looking at the strap. With the small amount of advance your at now the colder heat range should not cause it to immediately fowl so long as the heat range helps move the advance of the right direction. But if you go colder and it does not effect the timing then preignition is starting somewhere else in the chamber and you would need to go back to the hotter plug. I have never ran iridium plugs on a carbureted engine that I can think of, copper core is all I have ever used. So I do not know if there will be a bigger than normal step when you jump from the iridium 8 to the copper core race -9. I know reading the iridium tend to run hotter, it might be like jumping more than one heat range.

The two cams you mentioned, that crane 308/316 246/254 112LSA and the HOracing HC-03 sounds a bit on the big side. Those are really big cams for a commuter vehicle. I have never ran a cam like that HC-03 with the 120 lsa. I was thinking something in the upper 230s at .050 with more lift than those with a 114lsa and maybe pull the exhuast duration split back some and look for something with as much lift as you can find for the 1.5 rockers.

  #99  
Old 09-12-2019, 02:37 AM
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OK. So, I bit the bullet after work yesterday and swapped the Iridium 8 heat range NGKs for the copper 9 "race" NGK plugs I had. I'm not convinced it was a step forwards.. Even with my current very conservative ignition timing and even running a bottle of the p*ss water octane boost with every tank (there are none of the effective ones for sale here. Just STP, GAT, Cyclo..) I have some part throttle conditions where I can reliably induce a little ping. Changing to the 9 heat range didn't affect my ability to induce some ping. However, it did noticeably take the crispness out of the throttle response that had returned the day before when I put the new cap and rotor in. This morning, cold, it even wanted to die out during braking which I'd never had before. I did a short full throttle blast on a short open stretch and it cleared up a bit but I think I'm obviously too cold here with the 9s. Gonna throw those 8s back in when I get a chance.

Anyway, having them all out let me see them better. The little bit of oil you see is from my valve cover gaskets. I have thick ones glued to the valve covers for good clearance. They just don't ever seem to seal up nicely. The engine is a mess at the moment with the oil seepage doing a great job at binding all the road dust to everything..

1,3,5,7 with parking garage light


1,3,5,7 with flash


2,4,6,8 with parking garage light


2,4,6,8 with flash


Sam
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  #100  
Old 09-15-2019, 06:10 AM
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OK, so I'm not sure if I really gave the 9 range race plugs enough of a chance. Frankly, I was worried about them loading up and stranding me in traffic somewhere. That can be bad in this place. A lot of temporary roads with barriers either side where you simply can not get off the road and a stuck car blocks all traffic.

Eniway.. What I did in fact to was throw in the 7 range copper plugs that I still had. They were unused since I originally went straight from the copper 6 to the Iridium 8 range. Here are my not-so-expert conclusions:

The heat range seems to have a SLIGHT effect on ability to ping and knock. There is a bit more part throttle ping sensitivity with the 7 plugs but it is slight. There is a larger effect on throttle response. Those "9" race plugs were not great for transitional load. But also part of this might be the "race" design. The "standard" plugs are much more projected. The "race" plugs are very low profile.

Anyway, imagine my surprise. The 9 race plugs that felt to me like they might be fouling actually looked pretty good. They have the colour change right in the middle of the strap and no funny carbon, just good normal fuel deposits. They actually look like I was worrying about nothing.

1,3,5,7


2,4,6,8


Close (in fact, too close) shot


Anyway, I'm just going to keep the 7s in for the time being. If I swap it will probably be to put the 8s back in.

Sam
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