Signet-ficant Other

[Dr.Jass]

The biggest difference between 2- and 4-corner idle is that you're individually tailoring each throttle bore's output to what the engine wants. It's definitely fussier, but anything more precise generally will be.

On a 2-corner idle, you still have four idle outputs, you're simply adjusting them in pairs. Each screw is adjusting two throttle bores. Since each screw takes longer to affect the idle (you're using half of each orifice for one bore), it seems easier because the screws don't affect things so quickly. It's simply a less-precise "band-aid" to simplify things at the dealer level, so to speak. Remember: the original 1957 Holley four-barrel was a factory Ford carburetor.

This is the part where I remind you that all this nonsense started with a 2-corner-idle carburetor. I still had the same issue, it just took more turns of the mixture screws to have an effect, little effect though it was. This leads me to believe this situation would exist regardless of which carb I use.

When you build an engine, you slap your AFB on it, tune the idle, and it runs however well it runs. That's good enough, because it idles and drives pretty well. I, on the other hand, have more than a year tied up in just figuring out my valvetrain. After all that work, I intend to get exactly everything out of this engine that I can: every tenth, every MPH, and every MPG (all five of them ). "Good enough" doesn't exist. I started this project with a stated goal and I don't intend to start half-assing things now.

Regardless of our differing opinions on AFB carbs, the fact remains: There isn't one large enough to feed this engine, nor was there ever. In fact, no square-bore Carter (or Edelbrock) carb exists that's large enough. I cannot use a spread-bore carb. A 750 might work, but it's awfully close. I'd rather not risk what may well be my sole shot at the strip on having the engine lay down several hundred RPM shy of the shift point because it ran out of carb. Remember, if all goes well the car will quarter well into the "rollover protection required" range (11.99), and since I have none I'll be duly punted from the track.

After a lot of consideration and conferring with both friends and people more knowledgable than I, the friend solution is "Just run it at the higher idle and be happy"* while the expert opinion is "There's a fundamental issue you're missing; the carb should be very close." So I'm going back to basics, checking and re-checking everything: Float levels (yes, this can affect idle on any carb, and adjusting it yesterday did clean things up noticeably), mixture-screw baseline, spark timing, potentially even valve lash (which I did set tighter than the card, based on Lunati tech's suggestion). I'll check anything and everything that comes to mind. If I find nothing, then I'll probably tinker with the primary idle air bleeds to allow more air into the idle wells. If nothing else, it should dampen the effect of the mixture screws a tad, giving me greater range of adjustment.

It's something simple. It has to be.

* This does not include Stretch or Kevin, both of whom are well aware of my intent with this car and have brainstormed with me trying to determine the solution. I've stopped bothering either with it at this point.

 

[restoman]

I did right up until last night. I cut it in half with the Sawzall, then a friend and I loaded it on his trailer for its final journey to Jacuzzi Valhalla.


This far north, they're a ridiculous purchase. Put it inside the house and it'll eventually destroy the place with humidity. Leave it outside and it'll drive your power bill through the roof. Then its heater dies mid-January, at which point it freezes and self-destructs. That's actually how I got mine, but after discovering how someone had attempted to fix it, including but not limited to bypassing the factory wiring with a household light switch and ceiling-fan speed control, it turned into "thirty-six square feet I no longer have to mow or rake" pretty quickly. It would've been safer to make toast in my bathtub.

We got our hot tub in '17. Trouble free except for the warrantied display screen on the control panel, I've tracked a $9 increase in the electric bill through the colder months since new, and a $4 increase through the warmer months.
Maybe we're lucky, but my RA wife sure loves it!

 

[Dr.Jass]

I talked with a couple of fellas online yesterday, and both suggested trying more timing... like, a lot of timing. It's at 25° initial now (36° total); they seem to think it might want more because of the 106°LSA camshaft. Essentially, "Keep advancing until it smooths out, then you should be able to back off the idle screw." One of them told me I might simply have an engine that won't idle happily below 900-1000RPM. His won't, and he has less cam and more cubes... so there's that.

It's worth a try. I'm sure I'll end up locking out the advance if I go much further.

 

[71dusterman]

You'll get it figured out. We have faith.

 

[Dr.Jass]

Strange things are afoot at the Circle K.

After work tonight, I decided to play with the car a bit. After initial warm-up (doing anything with the carb prior to that is just pissing windward) the idle stayed at about 1,100RPM... but it seemed just a little cleaner. I'd touched nothing on the car since Saturday. I broke out the timing wrench and just eyeballed about 5° of advance. As expected, it picked up some RPM and I was able to back the idle speed screw off more than a quarter turn. It's definitely off the transition circuit now, as 1,100RPM is much choppier than it was the other day. It's got a definite lope to it, even up there. It's smooth and consistent, it just sounds gnarly. But holy crap, it went super-rich after that adjustment.

Out came the vacuum gauge, and it read more where I'd expect: about 8" of suck, with much less needle flutter. Smoother signal is a good thing, and I don't think I'll ever get a steady needle with that camshaft. Messing with the mixture screws again (which now had greater, although still very narrow effect), I managed to pick up almost an inch of vacuum... but it was still too rich. There's not much left in the mixture screws: the fronts are 1/2 turn out, and the rears are only 1/4. What passes for common sense in my head tells me those should be averaged out to about 3/8 turn each, but it wasn't fond of that. I lost a bit of suction, so I put it back the way I had it.

Wary of increasing the idle speed, I decided to give it just a touch of secondary idle screw (I put a topside conversion on the carb during the rebuild). It liked about 1/4 turn past screw contact, smoothing and cleaning up a little with no change on the gauge, but any more than that and I started losing idle speed. I was probably starting to expose the secondary transfer slot, which is not desirable.

Flashback to 1991: I'm running wild in a '78 Trans Am with a RA-III. The car's a beast (for 1991), slapping down all takers and running 12s on 87-octane pump gas. Life's good. The car was even nastier at 26°BTDC base timing, but hot restarts are nearly impossible, so I'm running it at 24°. Total timing was "It doesn't detonate" because I didn't have a dial-back light. In other words, I have no idea... but on those glorious summer days where the temps were above 80 or so, a hot restart still required jumper cables despite the car's 31-series, 1,300CCA battery. Asking strangers if they'd give me a jump-start in the mall parking lot on a sunny summer day? To quote Coach from Letterkenny, "It's f__kin' embarrassing!" [Please kick the nearest trash can] The subsequent owner of the car pulled 10° of timing out so the car would always start. Sadly, it was nowhere near as quick that way, and I didn't hesitate to point that out.

Returning to the present, I had you endure that flashback because I'm now facing a similar concern: I don't care to live that hot-start nightmare twice. The Trans Am had low-9 compression; the Valiant has a tick over 10:1. I'm being told to just advance the hell out of the timing (and I assume lock it down, although that hasn't been actually said yet). With those horrible memories of humiliating moments still vivid, hot restarts are a serious concern to me... so it seemed prudent to check that since I'm approaching 30°BTDC initial. I let the car heat-soak for close to half an hour and it started just fine. Plenty of cranking speed; no worries. It cranks over as fast or faster than the Magnum V8 for which the starter was intended. Then I tried a 5-minute, and later a 10-minute restart. Still no issues, so running up the timing doesn't worry me much. Between a starter that's not GM direct-drive garbage almost sitting on the header primaries, and 4° less LSA, I don't think I'll have problems.

But this is where things got a bit strange: On the initial 30-minute restart, once back up to full temp, the idle was now at 950RPM. I stabbed the throttle a few times to clear it, and each time it went back to 950. It's a consistent, rock-steady 950 now with a great lope. Problem is, I touched nothing to make that happen. It just... did. I didn't even open the hood! Same thing after the shorter-wait hot restarts; a 950 idle to kill for (it sounds awesome) other than still being richer than Jeff Bezos. The idle just went ahead and adjusted itself. The vacuum advance is not currently connected so that's not involved, and the car wasn't any hotter on the restarts than it was whilst I was fiddling under the hood. The VDO mechanical gauge is rock steady at 180°, and the factory gauge is dead-nuts in the middle as always.

I'm not sure what happened.

Anyhow, I'm at the point now where I can feed it still more timing, or pop the carb and try opening up the primary idle air bleeds a couple of thousandths to see if that helps things. The Boys (which is how I'll refer to my more-knowledgable resources from here forward) seem to have reached consensus on the timing aspect of it, but damn it, I'd rather not run a locked distributor on the street. I have considered the idea of locking out the mechanical and leaving a functioning vacuum canister, simply because vacuum advance makes such a huge improvement in overall street manners. I don't know if it's been tried, but I'm not afraid to make the attempt.

The carb's not the only job on the roster. I still need to swap out the rear axles, change the oil, freshen the plugs, install exhaust cutouts, and Lord knows what else. Oh, and the radio doesn't work yet. There's that.

'Course, the axles being out would be an optimal time to install the 4.10s, but I'm not sure I want to commit to those just yet. We'll see.

 

[69.5CUDA]

the fact it changes itself makes me question the "why"..did something shift in the timing? did something "settle in" somewhere(cam, lash, valve seat, something timeing,lodge in the carb), worse...whos to say it wont settle back out of it

as far as timing...hear me out...do the ole hot rod power timing trick for now and see where it puts you...put the bastard in gear and wind her up with the brakes on in gear and turn it up till it pings then turn it down till just before it doesnt, and see where your at, imo theres only 2 ways for an engine to tell you what it ones for timeing..do it this way or do it on a dyno with feedback ...if nothing else it will give you a better "baseline" on it...worse your fighting fuel AND timeing AND idle...you gotta find 1 which..imo starts at timing, anything else your just chasin your tail till you accedentily land on one then you can spiral out and find the rest

id dial it all back till its not pig rich and then tweak the timing till happy then go back at the carb for everything else,

 

[Dr.Jass]

as far as timing...hear me out...do the ole hot rod power timing trick for now and see where it puts you...put the bastard in gear and wind her up with the brakes on in gear and turn it up till it pings then turn it down till just before it doesnt, and see where your at

I've never done it against the brakes, but it's impossible with a 4-speed regardless. I always used to do it on a very steep hill (usually Park Ave, which seems like a 45° angle when you're on it). I tend to experiment with timing now starting from a baseline total timing number, since "the ragged edge of detonation" is not where engines make the most power.

id dial it all back till its not pig rich and then tweak the timing till happy then go back at the carb for everything else,

In case you haven't been paying any attention to what I've already written: That's what I've been trying to do from the very outset. There is no "dialing it back until it's not pig rich". It was pig rich with the mixture screws completely closed last year. Now doing that will stall the engine, but it's still burning nostrils with the rear screws 1/4 turn out and the fronts 1/2. That's where I get maximum vacuum, which is about 8.5" (and all I really expected with this cam).

With so much cam overlap (low LSA number), getting it "clean" per se is probably impossible. The amount of time the intake and exhaust valves are open simultaneously is enough to allow the scavenge of the exhaust to pull fresh charge right through the cylinder into the header. That works wonders at higher engine speeds where the valves are open for less time per revolution, but at idle it means rich-smelling exhaust regardless. I just don't think it should be as rich as it is.

I'm going to tinker with the timing a bit more and try opening up the IABs a little, but as yet-another friend with considerable race-engine experience told me after I explained the situation, "With that cam in that size motor, using that intake and those heads, you're essentially asking the impossible. And 7,500 seems a bit low on the shift point." I'll get it as good as I can and deal with the results.

 

[restoman]

Strange things are afoot at the Circle K.

After work tonight, I decided to play with the car a bit. After initial warm-up (doing anything with the carb prior to that is just pissing windward) the idle stayed at about 1,100RPM... but it seemed just a little cleaner. I'd touched nothing on the car since Saturday. I broke out the timing wrench and just eyeballed about 5° of advance. As expected, it picked up some RPM and I was able to back the idle speed screw off more than a quarter turn. It's definitely off the transition circuit now, as 1,100RPM is much choppier than it was the other day. It's got a definite lope to it, even up there. It's smooth and consistent, it just sounds gnarly. But holy crap, it went super-rich after that adjustment.

Out came the vacuum gauge, and it read more where I'd expect: about 8" of suck, with much less needle flutter. Smoother signal is a good thing, and I don't think I'll ever get a steady needle with that camshaft. Messing with the mixture screws again (which now had greater, although still very narrow effect), I managed to pick up almost an inch of vacuum... but it was still too rich. There's not much left in the mixture screws: the fronts are 1/2 turn out, and the rears are only 1/4. What passes for common sense in my head tells me those should be averaged out to about 3/8 turn each, but it wasn't fond of that. I lost a bit of suction, so I put it back the way I had it.

Wary of increasing the idle speed, I decided to give it just a touch of secondary idle screw (I put a topside conversion on the carb during the rebuild). It liked about 1/4 turn past screw contact, smoothing and cleaning up a little with no change on the gauge, but any more than that and I started losing idle speed. I was probably starting to expose the secondary transfer slot, which is not desirable.

Flashback to 1991: I'm running wild in a '78 Trans Am with a RA-III. The car's a beast (for 1991), slapping down all takers and running 12s on 87-octane pump gas. Life's good. The car was even nastier at 26°BTDC base timing, but hot restarts are nearly impossible, so I'm running it at 24°. Total timing was "It doesn't detonate" because I didn't have a dial-back light. In other words, I have no idea... but on those glorious summer days where the temps were above 80 or so, a hot restart still required jumper cables despite the car's 31-series, 1,300CCA battery. Asking strangers if they'd give me a jump-start in the mall parking lot on a sunny summer day? To quote Coach from Letterkenny, "It's f__kin' embarrassing!" [Please kick the nearest trash can] The subsequent owner of the car pulled 10° of timing out so the car would always start. Sadly, it was nowhere near as quick that way, and I didn't hesitate to point that out.

Returning to the present, I had you endure that flashback because I'm now facing a similar concern: I don't care to live that hot-start nightmare twice. The Trans Am had low-9 compression; the Valiant has a tick over 10:1. I'm being told to just advance the hell out of the timing (and I assume lock it down, although that hasn't been actually said yet). With those horrible memories of humiliating moments still vivid, hot restarts are a serious concern to me... so it seemed prudent to check that since I'm approaching 30°BTDC initial. I let the car heat-soak for close to half an hour and it started just fine. Plenty of cranking speed; no worries. It cranks over as fast or faster than the Magnum V8 for which the starter was intended. Then I tried a 5-minute, and later a 10-minute restart. Still no issues, so running up the timing doesn't worry me much. Between a starter that's not GM direct-drive garbage almost sitting on the header primaries, and 4° less LSA, I don't think I'll have problems.

But this is where things got a bit strange: On the initial 30-minute restart, once back up to full temp, the idle was now at 950RPM. I stabbed the throttle a few times to clear it, and each time it went back to 950. It's a consistent, rock-steady 950 now with a great lope. Problem is, I touched nothing to make that happen. It just... did. I didn't even open the hood! Same thing after the shorter-wait hot restarts; a 950 idle to kill for (it sounds awesome) other than still being richer than Jeff Bezos. The idle just went ahead and adjusted itself. The vacuum advance is not currently connected so that's not involved, and the car wasn't any hotter on the restarts than it was whilst I was fiddling under the hood. The VDO mechanical gauge is rock steady at 180°, and the factory gauge is dead-nuts in the middle as always.

I'm not sure what happened.

Anyhow, I'm at the point now where I can feed it still more timing, or pop the carb and try opening up the primary idle air bleeds a couple of thousandths to see if that helps things. The Boys (which is how I'll refer to my more-knowledgable resources from here forward) seem to have reached consensus on the timing aspect of it, but damn it, I'd rather not run a locked distributor on the street. I have considered the idea of locking out the mechanical and leaving a functioning vacuum canister, simply because vacuum advance makes such a huge improvement in overall street manners. I don't know if it's been tried, but I'm not afraid to make the attempt.

The carb's not the only job on the roster. I still need to swap out the rear axles, change the oil, freshen the plugs, install exhaust cutouts, and Lord knows what else. Oh, and the radio doesn't work yet. There's that.

'Course, the axles being out would be an optimal time to install the 4.10s, but I'm not sure I want to commit to those just yet. We'll see.

I worked for an Olds lover in the mid-late eighties. He had a very healthy 455 in his '71 Cutlass - '70 engine out of his wrecked W-30, cam, headers, think he had C.J. Batton heads on it, etc. Starting that b*tch after a 15 heat soak was next to impossible with the factory starter. I swapped in a starter from a diesel Olds at his behest. I didn't know enough to say "No f*cking way!" Hoisting a starter that seemed to weigh 100lbs and was most definately physically larger wasn't much fun for 22 year-old me.
But it sure cranked over that hot Olds.
Not! He still had to carry booster cables with him wherever he went... the diesel starter was better, but nowhere near enough to get anywhere near cranking speed.
Fun times...

 

[b-body-bob]

Starting that b*tch after a 15 heat soak was next to impossible with the factory starter

Before we were driving age, this friend of mine got his hands on a 396 in a 65 Impala SS 4-speed. I don't know the details of who paid for what, but he was/is a mechanical genius and had rebuilt the engine. Problem is, it was so tight it took two batteries to start it.

There was a loop of sorts where he lived that he'd rip and tear around. Jeez we were nuts.

 

[restoman]

Before we were driving age, this friend of mine got his hands on a 396 in a 65 Impala SS 4-speed. I don't know the details of who paid for what, but he was/is a mechanical genius and had rebuilt the engine. Problem is, it was so tight it took two batteries to start it.

There was a loop of sorts where he lived that he'd rip and tear around. Jeez we were nuts.

Sarnia Speed Center once built a FE engine for his Econoline pick-up... "It's going to pick the fronts on launch" was Freddie's famous line.
It spun a bearing on initial start-up, and while he dorked around trying to figure why it didn't have the oil pressure it should have had, the crank was ruined.
It never did run after that... and the only time the fronts were picked up is when the next owner came to get it.
Fred never lived it down.

 

[Dr.Jass]

Sarnia Speed Center once built a FE engine for his Econoline pick-up...

Right there I knew it wouldn't end well.

My old RA-III engine, on the other hand, was quite the happy accident. I never bragged it up during the build because I didn't know until right near the end what the combo would even be. All I really cared about was "no smoke" and "not shamefully slow". One store in the chain had a set of forged pistons, another had a vintage Crane Cam on the shelf. The virgin-bore block and RA heads came from a friend, another friend had a '72 455HO intake lying around that he couldn't recall even getting. It was quite the slapdash affair from the start and much greater, somehow, than the sum of its parts. Near the end I'd guessed it would be a pretty good engine, but was astonished at how good it actually was.

Tinkering with the Valiant the other night, I had the base timing all the way to 60°BTDC at one point--the absolute limit of my dial-back light. The richness didn't improve, nor did the vacuum... but it still started. Before you ax: yes, I verified the timing marks when I degreed the camshaft. When I put the dial on the timing light at zero, the marks stamped into the balancer (by a previous owner) agree with what I'd set via the dial.

I'm not 100% sure where I left the timing. However, starting it on Wednesday night showed it will now idle on its own starting below 140° coolant temp. The weather went south quickly, though, so I never got to mess with it after it was up to operating temp. Last night it was downright cold (around 40° when I got home), so I didn't screw with it a'tall.

Anyhow, not convinced of the advice I was given by one fella to "keep adding initial until the idle doesn't increase"--since I managed to go that high and was still gaining RPM--I did a little more research. I found an old (1990s) MP bulletin suggesting 35° total mechanical advance with W2 heads, then how to go about setting the vacuum to be around 50° at cruise. I believe I'll follow that advice as a baseline and see where it lands me. The curious thing about that bulletin is its complete lack of regard for timing at idle. Of course, the burn rate of a combustion chamber design doesn't change significantly with cam timing, so it makes sense.

Once that's set, I'll probably dabble with the primary idle air bleeds a bit... but as this project wears on, I'm pretty certain an overly-rich-smelling idle is just part and parcel of the wild cam. So be it. As noted above, there's still a lot of other things left to do. I don't want to waste half the summer tilting at windmills.

 

[restoman]

Fred's son did put together a FE-powered Mercury Comet that was pretty potent. Fred had nothing to do with the engine building, though... but did insist on welding on the rear quarter skins himself. With an oxy/acetylene set-up. With steel rod. The result sent out tsunami warnings across the Great Lakes Basin.
I think I spent something like 14 hours with my shrinking disc, torches, and hammers trying to get some semblance of proper shape back into the poor little Comet. Fred wouldn't talk to me after that. Can't blame him: I think I called him every name in the book...

Sorry for the hi-jack, Doc.

 

[restoman]

The Olds guy I worked for let me daily-drive his other '71 Cutlass quite often.
Stock '67 425 power, with supposedly-the-best-factory C heads, and one of Cliff's massaged Q-Jets on top.
I used to get a huge kick out of watching the vacuum gauge needle bounce just by just touching the go pedal. As fast and as lightly as I could touch the pedal, the needle would move. It was cool to that 22 year old kid.
That was the most fun beater car I'd ever driven: it would light that single rear tire at will, even up to 25 mph if you times everything right. Also cool to that 22 year old kid.
It did manage a best ET of low 14s at Ubly Dragway, hazing the right rear a third of the way down the track. The final-drive was something like a 2.76. Loved that car!

Sorry again, Doc.

 

[Dr.Jass]

Three things have become painfully evident about this engine:

1. A rich odor at idle is going to be a fact of life. It'll improve a bit, but it's outside the realm reality to expect it to idle cleanly.
2. I need to restrict the oil flow to the heads or find some way to stop oil loss through the shafts.
3. The timing gears have got to go.

Reasons for above:
Point 1: The cam has too much overlap to do what I'd normally expect from an idle. I'm well past Chrysler's timing recommendations on iron W2 heads, but I think that'll be OK with the cam timing and (relatively) low compression.
Point 2: Above ~1,500RPM for any length of time the engine turns into a mosquito fogger. I expected some smoke due to having left the exhaust valve seals out, but it's much worse than expected. The oil pump pushes oil so fast that I think it's pooling in the heads and submerging the guides. Excessive shaft leakage would also explain its inability to develop more than 55PSI hot at elevated RPM.
Point 3: I have always hated the sound of gear drives. They sound like an empty steering pump or some other mechanical issue. They do not sound like a blower. The constant droning whilst tuning this thing really grates on my nerves, which are further grated by the memory of what a pain in the ass it was to configure in the first place.

Solutions:
Point 1: I'm already well beyond Chrysler's recommendations for total timing. With the tight LSA and (relatively) low compression, I think that'll be OK. Testing is the only real way to find out. I'll have to modify the vacuum canister to pull in even more advance at idle; it's "all in" vacuum-wise at idle, adding 11° of advance at idle for a total of 31° and wants more. Total mechanical is currently 42°; I think it'll take more but again: testing. It belched smoke like a refinery fire while setting this, which leads us to...
Point 2: This is a bit tougher. Generally speaking, for dual-purpose use with needle-fuclrum rockers the recommendation is to install a .090" restriction in the head. I don't have needle fulcrums, though, so I'm flying a bit blind as far as restriction size, if any. Part of the problem here is that Harland Sharp shafts are a wee bit oversize compared to OE or MP. That means some leakage around the shafts using OE-type shafts with HS stands, which is my current configuration. The enormous slots I made in the rocker shafts probably aren't helping. Possible solutions include:

• Harland Sharp offset rocker shafts, which would fit the stands correctly and have the correct bolt offset. Drawbacks: The $300 buy-in and having to slightly hone the MP rockers to fit them, and the HS shafts are slotted all the way through the side of the shaft (intended for use with needle-fulcrum rockers and doil restrictors), meaning the improvement in actual shaft leakage comes only from better fit in the stands (the current shafts are not sloppy, just looser.
• Finding my NOS .100" DC stands and having them modified with a set of .180" offset holes by drlling through the undrilled sides. Drawbacks: I'm not sure this is even possible, have you seen the state of my basement (I'm not sure where they are in that disaster)?
• Further modifying my existing shafts by finding a way to close up those slots somewhat and possibly installing plugs between the last rocker on each end of the shaft and the end bolts. Drawbacks: Continued poor shaft fitment in the stands, possible welding required (which could warp the shafts), "Aren't those shafts hokey enough already?"
• Installing a restriction in the cylinder head oil passage. Drawbacks: I've no idea what it would need to be for pressurized rockers (but I bet stock size isn't far off), continued leakage issues at the rocker shafts resulting in wiped or broken rockers, I might have to pop the heads which involves both removing the master cylinder and making new intake gaskets (a process I truly dread).
• Some combination of the preceding two, not involving $300 shafts. Drawbacks: I'm so freakin' tired of messing with this valvetrain.

It's not just the smoke that's an issue; in fact that's of secondary concern. With that much oil going up top, it can only mean the crank and rods are suffering to some extent. I don't think supply is an issue at all with that pump; pressure is my main concern. I would not feel confident at nearly eight grand on only 55-60PSI. The engine has yet to see over 5K at this point, unloaded no less, so I feel well within my safety net. If you've got any suggestions on this issue, fire them across the bow... it might save me some time.
Point 3: The timing cover is coming off and the gear drive will be replaced by a higher-end Cloyes double-roller chain and gears. If I have to change, remove, or do any other service to the camshaft it'll literally save me an hour. I'm all about precision, mind you, but I just can't live with constant whining. It's why I'm single.

Indecision regarding Point 2 and lack of parts for Point 3 have kept me from accomplishing much of anything with the car since Friday, along with not feeling particularly well the last couple of days. I'd rather not mess with further timing and idle stuff until I get the oiling concerns addressed.

It's also hard to get motivated when you feel like you're back to Square 1.

 

[69.5CUDA]

wasnt there...at one point anyway....a vac canster that had an allen screw inside the vac nipple to change how much timing it gave or something...i remember reading about it at some point in some manual long ago...hell it may not even be a chrysler thing but it might be something one could addapt?

i get the concerns on the oil but why leave out the exhaust seals?

seems to me you may need to do something messy...ie have a valve cover off while cranking at the very least and see if you can figure out the where and why you have excessive flow up top, that should give you a better direction to follow or atleast give you a better ballpark with some visual proof so to speak...one of the ONLY cases where one of those stupid 2 piece eddy VC's would actualy come in handy especialy with a plexiglass top..visual inspection while running..not something to run "long term" but a diagnostic tool

what about restricting just the stands?..just spitballin it out there

whatcha gunna do with the gear drive?..i always wanted to try one

 

[Dr.Jass]

wasnt there...at one point anyway....a vac canster that had an allen screw inside the vac nipple to change how much timing it gave or something...i remember reading about it at some point in some manual long ago...hell it may not even be a chrysler thing but it might be something one could addapt?

During that era, most Chrysler vacuum canisters were adjustable. However, it's a spring-rate thing that determines how quickly the advance is applied rather than adjusting the total amount of advance. I've got mine adjusted so it's pretty-well all-in at maybe 10", which means there's a little adjustment left. The amount of advance it can apply can be adjusted by grinding the stops in the arms (or, if you want less, shimming them). The amount of advance a canister can create is actually stamped right on the arm itself, i.e. "11".
I've nearly reached the limit of the "rate" adjustment, which means I'm going to have to start grinding stops to pull in more advance. The tension screw can, to some extent, limit the total amount of advance by adjusting the spring so there's more tension than the amount of vacuum the engine generates can overcome.

i get the concerns on the oil but why leave out the exhaust seals?

To make sure the exhaust stems get oil. It's more common than you'd think on race engines.
On the intake side, there are positive-lock seals, and there were on the exhaust when I got the heads. I left them out simply to ensure that at the kinds of engine speeds this thing would see, it would get oil. With posi-lock seals, oil might be a rarity in there at near-eight-grand speeds.
Normally, when the intake valve is open the valve stem/guide has a vacuum pulling on it, so it'll suck a lot of oil without seals. On the exhaust side, there's pressure on the stem/guide due to the exhaust being pushed out of the cylinder, which pushes oil back up out of the guide. The only time oil gets down the guide is when the valve is closed.
With a lesser cam and oil pump, the only time I'd have smoke is on startups. However, I think I have the dual issue of the overlap allowing a little bit of vacuum on the guide as the exhaust valve is closing, and so much oil up top that the guides are drowning.

seems to me you may need to do something messy...ie have a valve cover off while cranking at the very least and see if you can figure out the where and why you have excessive flow up top, that should give you a better direction to follow or atleast give you a better ballpark with some visual proof so to speak...one of the ONLY cases where one of those stupid 2 piece eddy VC's would actualy come in handy especialy with a plexiglass top..visual inspection while running..not something to run "long term" but a diagnostic tool

what about restricting just the stands?..just spitballin it out there

I'm 98% sure my issue is excessive oil flow, just based on the mods I've done to the valvetrain. The problem is, all valvetrain oil is provided per head through only one stand (same as OE): Second from front on the driver's side, second from rear on the passenger's. That feed is what Harland Sharp recommends restricting for use with their rockers, but as I mentioned theirs don't require pressure to operate--just lubrication. The Mopar/Crane arms that I have do require pressure, as do OE arms. My fear is that by restricting the feeds, there won't be enough volume of oil in the shafts to maintain pressure with all the leakage.

whatcha gunna do with the gear drive?..i always wanted to try one

I'll most likely sell it, but be forewarned: It won't be "cheap" per se. A new one (13600) is $490 new, and mine has very little run time on it. I'm not going to dump it for $50 or $100. I like the concept and the execution, but it is a bit of a pain to initially set up--there are no dots to align, you have to degree the cam--but the built-in precision is pretty impressive.

 

[69.5CUDA]

i get the volume concern, thus why "if" one could get even a single eddy pop top vc and toss some pleci on it you could see whats going on...i too would be worried about volume with restriction, thus why i was wondering about doing it via the stand vs the head specificly so it could be done and undone without head removal

i really think you need to see exactly where your volume is going to truely find an answer....hell pull the passenger VC, pull the dizzy drive and run the pump via drill so you can see whats going on

 

[Dr.Jass]

I have old valvecovers I could sawzall, so that's not a big concern. As far as restricting the stands themselves, I don't think there's enough material/room in them. My plan was to restrict the oil passage just below the stand, still in the cylinder head but accessible from the top side. It makes sense to restrict the heads themselves, since they're the sole source of the issue I'm having. I could slap one of my other sets of W2s and a different intake and be done with it in half a day... but those wouldn't have the "Chunnel" intake ports, would they?

 

[69.5CUDA]

my concern here would be you have too much leakage in the valvetrain that restricting the input would be bad, thus a visual may be in order before you run something dry

can the pump be spun up to "idle speed" with a drill tho?

 

[Dr.Jass]

I guess I should've been clearer in my previous couple of posts. If I was going to restrict the oil to the valvetrain, the only real option is doing it somewhere along the feed path. That means in the block or head passage (and the head makes better sense) and there's only one per bank. However, for exactly the reason you stated ["before you run something dry"] I backed away from the idea of restricting oil flow into the shafts themselves.

Pressure is nothing more than a measure of resistance to flow. If I gain more oil pressure restricting the feeds to the rocker shafts, it's because there's less oil getting there. It also means there's less pressure after the restriction, i.e. less oil film (hydrodynamic barrier) to support the rockers. Non-needle shaft rockers operate the same way a main or rod bearing does--the parts survive because a pressurized layer of film prevents contact between the two parts, so pressure is critical.

I think that pressure is being lost through the ginormous bolt holes in the rocker shafts, which I had to oval significantly to offset the shafts back toward the valves. I'm trying to determine a functional way to block or fill the areas of those oval holes not needed for the hold-down bolts. Welding might seem the obvious answer, but there's a good chance that would warp the shafts (and if nothing else, damage the hardening) so I'd like to keep that to a minimum if not avoid it entirely. The slightly-loose fit of the HS rocker stands on OE-style shafts exacerbates the leakage situation; the wider gap provides little resistance to flow. Short of custom stands, I don't have a good solution for that (at least not one that's easily implemented). I think if I can shore up those ovals in the shafts, though, the shaft-to-stand clearance will be of significantly less concern.

Right now, my current plan of action is to insert sections of 5/16" or 3/8" steel rod--clearanced in sort of a "crescent moon" cross-section (see below, blue highlighted)--into the original bolt-hole locations. I'm not sure if I'll tack-weld or use an epoxy to secure them, but it should close up most of the leakage path. It will also be an enormous pain in the ass since I don't have a mill (which would shorten the clerancing job by well over half).




To lessen the pain-in-the aspect of that project, I'll attempt to relocate the shafts' end plugs (highlighted below) about 1" further inboard. That would put them inside of the outer bolt holes--no need to oil those--but shy of blocking the outermost (exhaust rocker) oiling holes. That would eliminate plugging four of the ovalled holes. That may or may not involve reaming the ends of the shafts to allow the plugs to travel that far.




That's my current best idea. I'm absolutely listening if anyone's got something better.