[glhs#116]

Originally Posted by Cliff R

There is nothing wrong with your HEI's mechanical advance and it's not the reason you are getting light throttle ping. Pontiac HEI's actually have set-ups in them that bring the timing curve in pretty quick, but not all-in right off idle with some of it in at idle like the junk aftermarket weight kits.

My HEI starts adding timing right off idle around 900-1000rpms and all in by 3000, with most of that all-in by 2500rpms. It uses stock weights, center cam and strong stock springs on it. The last little bit of it sneaks in a few RPM's later. It's been on 5 Pontiac engines to date and all of those engines have been flawless for performance and no ping whatsoever.

My vacuum unit is a very early "adjustable" unit that adds or takes out how much is added by turning the screw inside of it. It was purchased and installed back in the 1980's and still working fine. I've never even tested the spring tension on it and don't care, it's adding what I want at light part throttle as I use ported vacuum to it.

You simply don't have enough camshaft in the new engine and LSA is tight so it's not going to want a lot of timing anyplace. I saw that coming and mentioned it at least once thru all of this.

It will still work fine with correct tuning. Start out by doing this:

Get the engine fully warmed up and heat soaked. Set the idle mixture screws and idle speed best you can, down around 700-750 rpms. Loosen the distributor slightly and advance the timing well up off the scale till the engine smooths completely out. Then retard the timing until it just starts to slow down some and listen to the engine's idle quality. When you reach a point where it just starts to slow with a "deep/heavy" sound plus it sounds happy and still making good vacuum stop and see where it is at. Hopefully it's not up around 20 degrees but down around 4-12 degrees. Search for the sweet-spot and lock it down. Hook up the vacuum advance to ported vacuum and do some testing.

With 455 CID and roughly 10 to 1 compression with relatively tight squish plus your 703 camshaft I doubt if it will like, want or need much more than 26-30 degrees total timing plus another 8-10 from the vacuum unit. It may not even want quite that much, but whatever happens tune it for ZERO ping anyplace.

I doubt if the carb is the problem, if it were too lean at light part throttle you'd feel it surging, or at least the engine would be anemic, "flat" and down on power. If it runs good and not surging of down on power it has enough fuel in that range.........Cliff

Thanks, Cliff. That helps a lot. So, I knew (never doubted) that this cam was on the small side. It's just that I had it and needed to control costs. I will see where this noise (the "tick") goes and be led by that. If it tracks down to something non-cam or lifter related that I can fix I will tune this setup.

On the other hand, if there is anything even slightly up with this cam or lifters then they are OUT like last week's dinner. What would you put in (other than a roller)? Crower 60919? Something else? Do you think Rhoads are required for 60919 or similar with my heads and squish (I have the thin 1016 head gasket and pistons are about zero deck)?

Sam

[Cliff R]

What we get into here with these things Sam is that I do it for a living, and 95 percent of your other helpers don't. I saw this coming and knew that you would run into some minor tuning issues.

Right to start with FORGET any specific numbers for timing and tune the engine for ZERO ping anyplace. Even if you end up at 4 degrees initial and 25 total plus 6 from the vacuum unit. We don't need to pound the rod bearings out of this thing while you sort out ticking issues and determine that the cam is just a tad too small and LSA too tight for what you are doing.

You may find that with very close control of timing and fuel curves you can live with it.

I've done two builds for myself years back before I had the time under my belt to figure all this out and they were FAR from optimal but ended up working fantastic once I nailed the tuning down with them.

The first one was a 400 SBC build I did for my 1979 K-5 Blazer. I didn't like the factory type dished pistons so order flat tops for it. Teamed them up with a set of heads that yielded over 10 to 1 compression, and put a really small cam in it. That thing pounded like SLEDGEHAMMERS with "normal" timing in it. It also "bucked" the starter so hard I thought it was going to bust the nose off of it!

I retarded the timing little by little and settled in on zero for initial timing. I could only add about 22 more degrees to it and 10 from the vacuum unit. It idled dead smooth even at zero timing, and pulled like a locomotive at full throttle, plus very efficient for "normal" driving.

One of my early experiences with high compression and pump gas but I put nearly 200,000 miles on that engine over many years and it never grumbled once, plus nailed down 13-15mpg's and TONS of power in the "normal" driving range.

A few years later I did a 327 for my 67 Impala SS and didn't put enough cam in it. Ended up with initial at 4 degrees, 20 from the mechanical and 10 from the vacuum advance. That engine again was flawless and nailed down mid-20's for fuel economy after I put a 4L60 trans in the car.

So don't worry about numbers for timing, tune for results.

You might find that you can effectively tune the new combo with the parts already in it and live with the results. Just take the timing out and sneak up on the ideal tune for it, rather than pinging it with a lot of timing and going the other way. NOTHING harder on a new engine build that detonation, it will destroy the best prepared short blocks........FWIW......Cliff

[glhs#116]

Well, I ended up around 6 base with the vac can pulling in 8. But of course with the initial down around 6 the vacuum was getting marginal and the vac number bounces. Means I also had to add idle stop. But at least it was almost totally ping free.

Jay got in touch and pointed out that my plugs are on the hot side. Managed to get some more "normal" heat range plugs in town that are OEM spec for some Nissan: NGK BKR6E
NGK do their heat range from like 1 to 12 and lower number is hotter. So these are still on the hot side but not as bad as the Autolites I had.

I put them in and sure enough I could get back to 8 base with 8 added and no light throttle or no-load ping. This was better because at least at 16 degrees (8 + 8) idle there is enough vacuum to hold the advance vacuum steady and it runs smoother off idle. Anyway, did a little full throttle and it was pretty sweet up to around 3000 where I clearly heard pinging. At full throttle. Not something I really wanted to experience. The car is parked pending the arrival of the 60919 cam and me changing the cam. Hope I didn't pound those rod bearings too hard..

Sam

[Cliff R]

Not good news that you pulled out that much timing and still have full throttle detonation. Time for a larger cam on a wider LSA. That will tame things down and lower cylinder pressures across the RPM range and push peak torque up in the RPM range. This really helps with managing pump gas.

It will also "soften" up the power curve some. Instead of throwing a LOT of power at you early and narrow RPM range the power will be smoother and more "locomotive" like. Initially you may think you cut the balls off the engine if you are evaluating engine power and vehicle performance "by the seat of your pants".

Don't be fooled by that deal, every single time with ZERO exceptions any parts I tested that yanked power down in the RPM range, and/or narrowed it up, had me thinking the car was faster but my time slips showed otherwise.

I'll date that testing all the way back to the late 1970's when I spent a sleepless weekend installing a HUGE "high performance" aftermarket cam in the 440 that powered my Roadrunner. I also removed the factory intake and installed an Edelbrock Tarantula, big 850 Holley DP carb, etc. I pulled the car out in front of the farmhouse I was living in and it blasted thru the gears leaving two black marks clear out of sight! I was stoked and ready for the track. Man did it feel "strong", especially in the upper mid-range and top end. It was like adding a nice shot of nitrous over the previous very close to "stock" set-up.

Went to the same local track I always raced at, jacked up the car, installed my slicks, did a "John Force" burnout and staged. The car left "soft", rolled out decent then GAME ONE! It ran thru the gears so quick I had trouble shifting below 6000rpm's. I could hardly stand the long drive up the return road to get my time slip. Got the slip and my heart SANK! I lost a solid 3 tenths over the mostly "stock" set-up I just removed. Yes, all that work and slowed the car down, even though on the street my "seat of the pants" testing told me the car was now WAY faster and making a BUTTLOAD more power. I tuned and tuned and tuned on that deal and ended up removing all those parts and back to where I started.

My first lesson followed by many, many more with this sort of thing......FWIW.........Cliff

[glhs#116]

Well, interesting results.. Interesting..

I got the Crower 60919 installed and broken in. It claims to be on 108 ICL when installed "dot to dot". Which corresponds to Crower saying that "four degrees of advance is ground in to the cam". I used my Melling link chain since I was going dot-to-dot. Just as a side note, I changed out the fuel pump cam thing because I had a new one and I could see some cracking in the outer shell on the stock one.

Anyway, after getting things broken in I set about finding what timing was needed. My factory vacuum can was not working well. It gave me nothing at idle and then a bunch under part throttle vacuum. I ended up going back to the adjustable can. I set the can softest (fully turned in) then ended up at 2.5 turns out. The happy place ended up like this:

base: 3 (yes three)
vac adding 22 at idle
idle with vac: 25

This works everywhere part and full throttle and trailing. Even at 5 degrees base, however, I was getting detonation at 4,000rpm or so full throttle. At 3 it seems good.

Now, according to my notes my centrifugal advance gives me 14 degrees all in around 3000rpm. So this is total timing of 17degrees. That seems really low versus what I read others getting.

Now, I know that the Crower 60919 is a 112 LSA copy of the RAIV and I think it might have faster profile. I know that Jay told me the Melling copy is a "bigger" cam (more like 113.5 or 114 LSA) still, I'm surprised. Idle is smooth like stock.

The cam does pull quite hard. Definitely more in there than the 703 ever had, but the timing numbers puzzle me.

Now, on the one hand I am in quite high heat and humidity here. But would that be enough to make such a difference?

I'm absolutely sure the balancer is correct since I just did a cam swap. TDC is TDC for sure. I know the cam was dot-to-dot. Not only the position of the dots but I even (by now) have a good feeling for where the keyway goes. For sure the cam is in straight. I was wondering if the plugs I have are still a bit "hot". It does slightly like to try to run on occassionally on shutoff. I am currently running NGK BKR6E plugs which are also known as 6962. I've heard others have run this plug on these heads. It's OEM for some Nissan which is why I was able to find them in town.

So, she's running well. But the timing numbers puzzle me.

Old timing set before removal


New timing set (the Melling link chain gears, non adjustable)


The new fuel pump cam (it's a slightly different design)


Sam

[glhs#116]

Oh, with the 25degrees at idle I'm pulling around 17 degrees of vacuum. Obviously a lot less with the vacuum advance disconnected. I don't think I wrote that value down..

Sam

[mchell]

What’s your total timing with vac advance disconnected?

If your initial is 3 with vacuum advance disconnected, your total timing should/would be very low........somethings cocked up

[Cliff R]

Sam, do you have a pic of the cam card for the 60919?

[glhs#116]

Originally Posted by Cliff R

Sam, do you have a pic of the cam card for the 60919?

Yes



Sam

[Cliff R]

Same as the last couple we put in except our cam cards say 113LSA and ICL to be installed at 109.

Dating back to around 1999-2000 Crower has had that cam on their website advertising 112LSA, but every single one we purchased said 113LSA/109ICL on the cam card. I guess they finally got around to correcting their error.......Cliff

[Jay S]

Originally Posted by glhs#116

Yes



Sam

Crower must like to change the cam card too drive us crazy. I have never seen the 108 Icl on this cam before. First they were 113 lsa and 109 Icl, then 112 lsa and 109 Icl, now 112 lsa and 108 Icl.


My guess is you should be at 8 on the heat range for that plug due to your lower altitude, heat, humidity.

[Jay S]

Got to thinking Sam, I can’t think of a reason this N/A engine would want anything colder than a BKR7E, the 8’s are probably to cold. Those BKR6E are close to the right heat range, if the car was in my region those would be fine. My knee jerk reaction is to go to cold on plugs. Mostly because if the plugs are to cold they just fowl out, but to hot they can cause preignition. I have had a couple engines the spark was even sniffed out under load when the plugs were to hot.

That is me anyway. I experiment with the plug heat range before I start splitting hairs on the rest of the tune.

[ta man]

Originally Posted by Jay S

Got to thinking Sam, I can’t think of a reason this N/A engine would want anything colder than a BKR7E, the 8’s are probably to cold. Those BKR6E are close to the right heat range, if the car was in my region those would be fine. My knee jerk reaction is to go to cold on plugs. Mostly because if the plugs are to cold they just fowl out, but to hot they can cause preignition. I have had a couple engines the spark was even sniffed out under load when the plugs were to hot.

That is me anyway. I experiment with the plug heat range before I start splitting hairs on the rest of the tune.

If anything the plug heat range is too hot..I'd pull them out and look..most run 8's or 7's. I can bet they are burnt all the way down to the threads.

[Jay S]

Thanks TA man.

If I remember correctly, one heat range for most spark plugs takes out approximately 200 degree F out of the combustion chamber. Then those projected Autolite plugs Sam started out with adding another 70 degrees F in addition to the high heat range. They were never close to working. Those 6’s are a heat range about what most OEM plugs would be. The voodoo cam needed 8s for sure, the crower should be fine 7 or 8s. Jay

[glhs#116]

OK, so just doing due diligence here. Now that the car is running fairly well mostly (although with weirdly retarded ignition timing to get there) I thought I would see what the plugs looked like and take a compression reading across the engine. Now, new rings only about 100 miles ago and some fair amount of pinging in the early runs so I am sure my rings aren't totally bedded in yet. Anyway..

So here are my notes. I did all eight (after a short warmup drive and about ten minutes of sitting). Then, after noting the low reading on #6 and the high reading on #7 I thought I would just run through them all again. I cranked with the throttle wide open and all plugs out to five audible compression pulses for each reading.

2019-06-08. Compression 5x
1. 155psi
2. 158psi
3. 155psi
4. 152psi
5. 163psi
6. 142psi
7. 171psi
8. 158psi

1. 161psi
2. 174psi
3. 159psi
4. 153psi
5. 164psi
6. 144psi
7. 162psi
8. 153psi

So, a few things are clear. First, number 2 read in the middle of the range first time then went very high to 174psi the second time. Second, #7 which was highest first time round at 171psi came down to a still-high 162psi for the second reading. Third, #6 is consistently low. This is the sleeved cylinder with Jay's piston in it. I'm guessing that since I had to hone this cylinder to size and it is less of a perfect cylinder shape than the others the rings might take longer to seal nicely on this one. At least, that's what I'm hoping.

For the plugs.. Well, to my eye I don't see anything all that alarming. A little oil from new rings. A little carbon from the retarded ignition timing. A little normal ash.. But let me know if anything jumps out at anyone..

Strap on a representative plug


Top view


7, 5, 3, 1


2, 4, 6, 8


Somewhere there has to be a clue why my particular engine just won't take hardly any timing on a cam that seems to have often been used in this setup..

Sam

[Cliff R]

"Somewhere there has to be a clue why my particular engine just won't take hardly any timing on a cam that seems to have often been used in this setup."

The answer may lie between the hot climate and the quality of the fuel. Your "ping" at full throttle may also be related to fuel delivery and sucking the bowl low on the carb leaning it out just a tad. I've seen that deal play out over and over and over with these engines. Folks increase the power levels WAY beyond the capabilities of the factory fuel delivery systems with big CID, good flowing heads, bigger cams, then wonder why you get a bloody nose at the top of first gear when you bounce it off the steering wheel on a hard run! That's easy, the fuel pump is sucking thru a tiny 14' straw and when you are pinned against the seat all the fuel is pinned against the gas cap. If you look at a factory tank and pick-up location they are backwards.....the engineers never even took into consideration those cars would ever be that quick or they would have changed the shapes of the tanks and used a rear located sump, not a front one.

Anyhow, I have no idea whatsoever the actual octane rating or quality of the fuel you are using but it may be a key player in your results. You have an engine with known components that should be fine on 89 or higher octane with "normal" timing curves, but it still isn't overly happy.

You also have some common denominators with all the set-ups in that arena.

Something else that raises an eyebrow with me is the persistent "ticking noise", and wiping out cam lobes with known components. Hopefully the current set-up doesn't go that direction.

What I would do, and this is just some basic advice. I would NOT run the engine hard until you leave that climate. You've mentioned moving soon so it would be a really good thing if the "new" engine is working well enough to move the car around until that happens. If you put some rod bearings or cam lobes in the oil pan or bust some rings or piston lands out it will probably be a logistical nightmare for you as far as shipping the car, etc.

Your timing numbers defy all logic with the current set-up.

All the 60919 cams I've installed have NOT had any advance ground into them. They have all came in closer to 112 ICL than 109 as dubbed on the older cam cards. I've always suspected the 60919 cam is nothing more than a re-boxed 041 grind for this reason. Your cylinder pressure numbers are actually a tad low for that cam, CID, those pistons and the heads being used. So for sure it's not advanced a bunch and it shouldn't be having any pinging issues.

WAY back when I was using that cam in my own 455 with 91cc iron heads it squeezed over 170 PSI with the ICL at 109. I street and track tested the cam at 107ICL, 109, 111 and 113. It ran fine on the street at all those settings, didn't ping, didn't run bad, just felt a little "lazy" at 113ICL and a little slower at the track. It also ran slow at 107ICL, but equally as well at 109 and 111ICL.

I went on to run the same cam with the new (at that time) KRE aluminum "D" port heads flowing 260cfm and 10.48 to 1 compression and no issues anyplace on pump fuel of any octane. Cranking pressures jumped a little over 10psi as expected and we were rewarded on the dyno with another 40 something HP. The car picked up a couple of tenths at the track and a solid 2mph.

It ran best at 30 degrees total timing just like it did with the iron heads. I add a little timing from the VA but it really didn't care all that much. I even forgot to hook up the vacuum hose to the distributor a few times and couldn't tell until next time I had the hood up and noticed it. The current engine enjoys the VA more, probably because it's got a larger cam in it and bleeding off more cylinder pressure at lower RPM's.

Anyhow, it's nearly IMPOSSIBLE to tell much reading plugs, especially if you have an efficient carburetor that isn't dumping TONS of fuel on the engine in the "normal" driving range. I recommend tuning for best results vs what the plugs look like, and just a minute of idling time will typically darken them up some flawing the results considerably........FWIW.......Cliff

[Jay S]

A couple of the plugs looked like they were burning hot, but not overly so. Just judging that by the white color showing up more down into the ceramic part of the electrode on a couple of them. But really the only thing they tell me is you have done a good job pulling your timing back to keep them running to hot.

Your compression test looked good. I recall you used a little bit undersized dingle ball hone to give 6 some extra clearance. It will probably take a little time to brake that in. Exactly like you mentioned.

There are not necessarily signs that you need a colder plug by reading them. If you just tune a car by ear there will almost never be a sign calling for a colder plug because you are pulling the timing out to manage the hot plugs. The sign is when you put a timing light on the engine, have it tuned by ear with no noticeable pinging, and are way down on your initial timing and the centrifugal timing. When you drop to the next range colder plug the colder heat range let’s you run more advance. Keep dropping the heat range on the plugs until you can get up above 32 full mech advance. Because heat ranges are broad on the hotter plugs you will find were your engine wants it’s full timing in at. If the plug is a bit cold it may want 38. To hot it may want 28. Once you get the heat range right then I would say it is time to start reading plugs and start focusing in on the AFR ratio.

[Cliff R]

Just a note on reading plugs.

IF you took a look at the plugs pulled from my engine you'd IMMEDIATELY comment that it's running way to lean because they are very light tan to almost white.

Folks in this hobby are used to tuning and using components that aren't overly efficient in the "normal" driving range. This ranges from cams with a lot of overlap, "lowering compression ratios for pump gas", carburetors that are very "generous" for fuel delivery at idle and light load, distributors W/O vacuum advance, and many combinations of the above.

With a well thought out engine build, good compression, well chosen cam, very close control of fuel and timing curves we shouldn't be looking at sooty dark or black spark plugs, they should be clean, free of carbon deposits and very light tan to almost white. So for the most part the better the engine is doing in the efficiency department the cleaner the plugs will look when removed for inspection. That fact is a LOT more commonplace with this new fuel, whatever formulation it is, there isn't much left behind to tell us which direction to go with our tuning.

Here I tune for results, best idle quality, smooth right off idle, and best power across the loaded RPM range.

Matter of fact I just came in from custom tuning an engine for a long time customer. He had an 350 SBC engine built for his 1982 Chevy truck to replace his tired 305 with 312,000 miles on it. The engine builder did a wonderful job, not a drop of oil leaking anyplace, but he told the owner the carb I did for him 8-10 years ago needed to be "rebuilt" because it will not help the new 350 engine idle well. In reality there was nothing wrong with the carb, the engine builder used a cam on a much tighter LSA than he should have, even though it's a tiny cam. He dubbed it his "torque" grind, and customers love it. It's nothing more than a modified 350/300hp cam pulled down on a 104LSA.

Well that tiny change puts some "rumble" in the exhaust at idle and this air conditioned truck with stock carb tune wasn't overly happy with it. He just pulled out a few minutes ago and is very happy with it. We had to do a slight distributor recurve, and open up the idle system in the carburetor to make the engine idle down and smooth out below apprx 700rpm's. I also went up one jet number for the larger 350 engine and aftermarket cam combo.

Not a big deal but seemingly minor changes to things can result in needed changes in other areas to make the entire unit work like it's supposed to.

Nothing much different that what Sam is doing here. With all the changes there will be some tuning required along the way, and I'm betting improved fuel delivery to keep up with the new found power as well.........Cliff

[ta man]

When the cam was installed and the engine was at TDC, did you check to see if the balancer and timing tab line up at TDC?

[glhs#116]

Originally Posted by ta man

When the cam was installed and the engine was at TDC, did you check to see if the balancer and timing tab line up at TDC?

Yes