Cam degreeing: I USED to think it was a waste, but now IT RUNS !!!

[Kern Dog]

....Now.
I've been working on cars as a hobby since I bought my first car, the 69 Dart in 1982. I built my first motor in 1992, a Chevy 350. Since then, I've built many more. Chevys, a few imports, then in 1998 I built my first 360 Mopar. Since then, I've only built Mopar stuff because it was all I wanted to own.
I've built 4 440 engines. The one in the 70 Charger is actually a 493. I love that car. The bodylines, the styling... These cars just ooze "cool". I built this engine in 2004 with a 4.15 crank, edelbrock heads, an 850 carb, 2" headers.... and what I thought was a decent choice for a camshaft: The 292/509. I had a buddy help me degree it in. With the dots aligned and the crank gear at the ZERO setting, it came in at 1.5 degrees retarded.  Ah well, close enough, right?
Well, over the years, I've dealt with an engine that runs okay in cold weather but detonates when it warms up. When using 91 octane pump gas, I cant push it past 3/4 throttle without knocking. If I run 100 octane gas, it will not ping. For quite some time, I've felt that the engine was performing well below its potential. I've read here and there that these "500" inch engines can make 500 HP or more even without head porting, 14 to 1 compression or radical camshafts. My car registered 369 HP on a chassis dyno in 2005. Even accounting for a 20% HP loss through the drivetrain, this still equates to 442 HP. This isn't very impresssive to me.
I've been busy on the internet asking about what can be done. Mine is a two-fold problem: Eliminate the detonation and increase the power. The majority of the responses related to a camshaft swap. The 509 cam was deemed to be too mild to be a good match for both 493 cubic inches and 10.7 compression.

[Kern Dog]

.....So on the advice of many online car guys, I picked a cam. Most guys said I needed MORE lift, MORE duration and most important: a later intake closing.
I went with a Lunati solid flat tappet. Some said I should get a roller cam, but I just couldn't justify the expense.  The cam is pretty rowdy to me, but may seem tame to others. It is the 316/326 with 261/271 degrees INT/EXH @ .050, .558/.578 lift with the 1.6 rocker arms after deducting the valve lash. The intake closing isover 11 degrees later than the 509 too.
With this cam, I was advised to degree the camshaft. I have made some misguided moves in the past so I was determined to do this right. I asked more questions, read in the archives on several forums and watched YouTube videos on Camshaft Degreeing. I bought a degree wheel kit, a crank hub with a 1/2" drive and went to it. This is my first time degreeing a cam on my own, and I have encountered several obstacles.
First up, the piston stop included in the degree kit is/was a flimsy POS. It is a 14 mm "plug" that threads into the spark plug hole. It is threaded inside for a 3/8"x 16 bolt.  The bolt is supposed to be screwed in until it touches the piston. (More on this in a moment)
I followed the instructions to the letter. I attached the crank hub and rotated the engine to establish TDC. I bent the piston stop, so I removed it and straightened it out. I bent it again. HOW you may ask? Well, the engine was hard to spin over with the compression it has. I couldn't tell when I was hitting the stop because the resistance to turning was so much. THEN I read in one of my threads online that the spark plugs are supposed to be OUT when doing this! Okay, some may think I am stupid for not knowing this, but I never read it written anywhere before or mentioned in the videos. Also, I was later advised that the rocker arms should be removed.

[Kern Dog]

Okay, so here I am: The cam is in and the timing set is on in the ZERO/dot to dot position. The cam card shows a 108 LSA with an installed centerline of 106 for a 2 degree advance. I have the dial indicator set up and it checks out at 110. Okay, I see that it means that I am 4 degrees retarded. I called it a day and figured to recheck the next day. After all, I've read that you need to be able to repeat your numbers to know that you have it right.
Next day I get the same numbers. The timing set has 3 settings. 4 degrees RETARD, Zero and 4 degrees ADVANCE. Since the numbers came in as being 4 degrees retarded, I figured to switch the crank gear to the 4 degree ADV setting, thinking that it should put me right on the 106 number. Well, this change put me at 103. Huh? Yeah, the simple change made a difference of 7 degrees. Obviously I cant leave it at either setting because they are both outside an acceptable "margain of error".
It is odd though. The dot-to-dot setting was off by 4 degrees. The 4* ADV setting (In a perfect world) should have resulted in a 102 number, instead it was off by a single degree. The discrepency had me looking for something to blame.
The crank hub slips over the snout and has keyways to fit around the Woodruff key. I am on the smallest notch and it still has some play in it. I've tightened down the set screw to the point where I thought I'd snap my allen wrench, but I still was getting about 2 degrees of slop when alternating between a clockwise rotation and a counter-clockwise turn. I feel that this 2 degree + or minus slop is partly to blame. I decided to pull the hub and mount the degree wheel to the crank directly using the dampner bolt. As I was trying to determine TDC for the umpteenth time, I bent the piston stop again. At this point I was pissed and sweaty, so I called it a day.

[Kern Dog]

I came inside and sat a short time, then ordered a solid brass piston stop from Summit racing. This one threads in like the other one, but it is robust enough to NOT bend when I spin the engine up to it. It is from Crane Cams and cost $13. It has a hole in the center to allow compression to escape too.
That was Tuesday. I've been busy with other stuff the last 2 days. I'm still thinking though about what to do to get the cam in at the 106 number. Lets say that I can get the degree wheel set in place and can spin the engine with zero slop. Lets say that I establish TDC and now that I dont have that 2 degree slop, it results in a 108 installed number at dot-to-dot. Would YOU leave it there? If I try the 4* ADV notch and it comes in at 104-105, is that preferrable?
Would it make sense to start with a tad more advance given that the timing chain will stretch and retard the cam as a result?

[ws23rt]

Are you taking your two degree measurements (before TDC and after TCD) while rotating clockwise (engine rotation)?
If you don't than the backlash in the chain and sprockets will affect the results.
Also 2 degrees of slop in the damper to crank key fit seems too much.  Set screw on key?  Need picture.

[Kern Dog]

I can post a picture today. The engine turning hub is an aluminum collar that slides over the snout of the crank sorta like the balancer. It has a tapped hole with a screw that is supposed to tighten and positively lock the collar to the crankshaft. The problem is, the Woodruffkey in the crank is a fraction smaller than the groove in the collar, and the hub slips even with the set screw really tight.

[HPP]

It is odd though. The dot-to-dot setting was off by 4 degrees. The 4* ADV setting (In a perfect world) should have resulted in a 102 number, instead it was off by a single degree. The discrepency had me looking for something to blame.

The timing set is probably the culprit. Talk to any engine builder who has been in it for a while and they will tell you that some timing sets are machined like a horeshoe set, ie, close enough, let it go. This single facet of building power is enough to necessitate degreeing. As you discoverd, simply setting it up dot to dot produced a margin of error that likely could contribute to later driving manners that are not what you expected and could cause problems with detonation.

I also agree with ws23rt, you reading all need to be in one direction when taking measurements. Backlash in the timing set can produce varied results and as you noted, you cannot tighten the turning socket to be perfectly solid either. If you do reverse things, at least back them off far enough tha tyou can take of the slack again before reaching reading key points.

[oldschool]

those keyway chain sets are never accurate. they are still nice thou as you can move them around to many combinations. if you are sure of 103*, I would run it at that. as the chain set wears, it will naturally retard. 3* advanced is not bad at all......

[cdr]

in your case run it at 106,you have already had a detonation problem with the other cam.

[oldschool]

in your case run it at 106,you have already had a detonation problem with the other cam.

he could not get 106*. he was either 110* or 103*. his new cam should bleed off more cylinder pressure than the old one.....

[cdr]

http://chucker54.stores.yahoo.net/ofcamkey1.html

[Kern Dog]

The intake closing of the Lunati cam is around 11 degrees later than the MP 509, so I would think that even with this cam advanced a bit more than what is recommended, I still should see an improvement.
I hope to get back to it tomorrow.

[fy469rtse]

  huh , still waiting to see what happened , please post result

[Kern Dog]

I am anxious to get the car started, but as is often the case, LIFE gets in the way.
I parted out a 68 Plymouth station wagon. I started in on it late last week. Over the weekend, I cut it up and stowed away the parts that will get saved and sold. Today was cleanup day. I took the scrap metal in to the recycler. Tomorrow I'll take in the aluminum trim, stainless and other non ferrous stuff. I should be able to get back to it in the afternoon if the weather isn't too hot. I love the long days of summer, but 103 in the shade can be hard to take!
I'm looking forward to making some 11 second quarter mile passes soon.

[Kern Dog]

Cooler weather is coming....
I was able to get out and establish TDC today. That solid brass piston stop is bad ass! I was able to get it right on the first try. I rechecked myself twice to make sure that I was right on. I'm back at it again tomorrow. Hopefully my luck with the numbers will be better than before.

[Kern Dog]

Stung by a bee yesterday while mowing the lawn, so I called it quits afterward.
TODAY though....
The cam card calls for a 108 LSA with an installed centerline of 106. I degreed it today and the first number came in at 73. The second was 139 for a 212 total. Divided by 2, I am EXACTLY at the 106 number with no additional work needed. I am at the ZERO/Dot-to-dot setting too. That crappy loose fitting crank turning hub resulted in a 4 degree difference in the settings. I was dead on with the cam timing though the sloppy tools showed that I was off by 4 degrees. GOOD tools make a huge difference.
Next, I have to finish up the cam install. I'm changing valvesprings, swapping in a 6 quart oil pan and a few other things.

[cdr]

how did you come up with those #s,,,,at what lifter lift.

[Kern Dog]

I followed the instructions in the degree kit. You crank the engine until the intake valve gets to maximum lift, then set the dial indicator to ZERO. You then turn the engine CCW intil the dial indicator reads .100. Then you turn the crank clockwise until the indicator reads .050. Look at the degree wheel and record that number. Mine was 73 degrees. The engine is then spun CLOCKWISE until it reaches zero and up to .050 again. Record that number. Mine was 139. take the 2 numbers and add them, then divide by 2. I got 212 which averages to 106.
Score!

After the degree work was done, I changed the valvesprings, installed the pushrods and rocker arms, then set the lash. THEN I remembered that the lash settings were supposed to be set HOT. Uhhh... okay, the engine is cold because I havent ran it in a few weeks. So I guess I need to add a couple of thousandths to the lash, right?
The cam card calls for .020/ .022 for the lash INT/EXH.

[Kern Dog]

I had my thinking wrong.
I checked the Lunati site for help, but they had zero info on setting lash. I checked tech archives and found that most guys agree that with aluminum heads/iron block, the lash should be .006 tighter than the "hot" settings. This means that my .020 and .022 HOT settings can be set cold at .014 & .016 cold.

[Kern Dog]

Its almost ready to fire.
I went and reset the valve lash to .014 INT and .016 EXH. In theory, this should be spot on when the engine warms up and the lash widens. Valley pan and intake are on. I changed the PV from a 3.5 to a 6.5. The 85/93 jets were changed to 86/94.
Trouble with the oil pan install though. I pulled the chrome pan I had on there along with the steel MP windage tray. I bought one of the Jegs molded plastic windage trays to replace the steel one. The Jegs tray has twin rubber ribs in place of conventional gaskets. It is similar to the plastic 727 and 904 trans pan gaskets from Mopar.
The Jegs tray didn't fit. It hit the rod caps! Turns out the one I had was for stock stroke. I have the 4.15 crank. The long stroke tray won't be available until mid October, so I reused the steel one. The Milodon 6 quart pan fit great. The sump extends a bit closer to the K member as well as rearward. The area over the steering link is shallower on the Milodon pan, giving more clearance.
Still need to install the plugs, wires and distributor cap. Oh... I'm going to need another radiator cap too. Mine got lost during all of this!

[2Luke2]

Glad to hear you're getting everything back together! Can't wait to hear the results! Thanks for keeping us updated.

[mauve66]

you done yet???   

[Kern Dog]

Life keeps getting in the way! I have help coming over tomorrow. I always have a helper when I break in a cam or a new engine.
Today I wanted help from the wife, but she was busy with work and not very friendly.

[Kern Dog]

The cam and lifter break-in is done!
I will readily admit.. I have been pretty nervous about this whole thing. I have had some good luck and some bad with camshafts. This is my first solid lifter cam and my first time degreeing anything. I spent a good chunk of money over the past few months on Rocker arms, Lunati solid cam, Howards lifters, Crower pushrods, Milodon oil pan, Edelbrock timing set and the tools to degree this dude right. I used a good quality break in oil, Moly lube on the cam and lifters and a bottle of the Comp cams supplement. This afternoon I preoiled the engine with the hex rod in a drill, then waited for my brothet in law.
Jeff showed up and we got to it. I did all the usual stuff along with what Rick Ehrenberg wrote in the "First Fire" article in this months Mopar Action article. The engine started within 2 seconds and Jeff brought it up to 2600-2800 rpms while I checked for leaks. I was happy to find none anywhere. The exhaust sounded great from behind the car. Oddly, it smelled cleaner than it has before. No stinging eyes from an over-rich condition, thats for sure. Oil pressure was 80 when cold, dropping to 58-60 when up to temp. Fuel pressure was between 7-8 lbs. By the 15 minute mark, the furl pressure dropped to below 3 lbs and the engine stumbled. I looked at the fuel filter to see it was nearly dry. I had Jeff shut it down. We let it cool and came back 2 1/2 hours later. The filter now had some gas in it and the fuel bowl in the carb had gas!
I started it up and ran it again, now up around 2900 rpms. BY 10 minutes in, the fuel pressure dropped again to below 3 lbs and as the engine started to stumble, I shut it down again. I have a Holley mechanical pump part # 12-440-11 rated at 110 GPH. At idle, this pump shows between 7-9 lbs now and before with the '509 cam. I drive this car at freeway speeds, doing 2600-3000 rpms and have never had a fuel starvation problem. I guess I need another pump, huh?

[Kern Dog]

I expected the solid lifters to make more clatter. I expected the cam to sound more lopey. I'm not complaining, I just expected it to sound more radical. I didn't drive it yet. The fuel pump may be okay for some breif street action, but I may have to upgrade it. I have had fuel starvation problems before that came down to kinks in the fuel line. I wonder if the demands of this cam will result in the need of a higher rated fuel pump?

[firefighter3931]

Good Job getting the cam installed and broken in. 

I'm sure the fuel system is fine....it sounds like fuel boiling/vapor lock based on the symptoms you've described. You need to insulate the carb from conductive & radiant heat.

http://www.dodgecharger.com/forum/index.php/topic,52284.0.html



Ron

[Kern Dog]

I think Firefighter is right.
Last night in my sleep, I began thinking about heat soak. My 75 Power Wagon runs great in cool weather but bogs and sputters when I drive and idle it in hot weather. Getting up to speed helps a bunch. I guess with the truck, it is a matter of getting airflow.
Yesterdays breaking-in was in 94 degree weather in my garage. I do not have a fan shroud on the car and my helper fan wasn't very big. The fuel was bubbling in the filter just as the pressure was dropping. After cooling down, it ran great again.
Has anyone ever put a rubber hose over their fuel line to insulate it from heat?

[firefighter3931]

I think Firefighter is right.
Last night in my sleep, I began thinking about heat soak. My 75 Power Wagon runs great in cool weather but bogs and sputters when I drive and idle it in hot weather. Getting up to speed helps a bunch. I guess with the truck, it is a matter of getting airflow.
Yesterdays breaking-in was in 94 degree weather in my garage. I do not have a fan shroud on the car and my helper fan wasn't very big. The fuel was bubbling in the filter just as the pressure was dropping. After cooling down, it ran great again.
Has anyone ever put a rubber hose over their fuel line to insulate it from heat?

Todays fuel formulations are designed for high pressure fuel injection systems that often operate at 50psi or more. When that junk fuel is subjected to heat and low pressure (carburator) at 6-8psi....it just starts to boil. When i ran a mechanical pump I used the DEI tubing to insulate my fuel lines and it seemed to work well....never had an issue with vapor lock  

But....I also had the carb well insulated and i'm sure that helped as well 

http://www.summitracing.com/parts/dei-010415/overview/



Ron

[Kern Dog]

I haven't had an issue with vapor lock on this car since 2003.
I think that I must be running excessively lean. I must have screwed something up when I worked on the carburetor. The distributor is the same. The fuel line is routed the same way. Same fuel pump. All that was changed was the cam and the guts of the carburetor. Are all Holley and Demon carb bowl and metering block gaskets the same? Are there any gaskets that have holes where others do not? I ask this because I am amazed that it ran like it did.
Here are the stats:
It ran hot during the Cam break in and boiled the fuel.
The exhaust smelled clean, zero smoke.
The engine detonated at 30 degrees and approx 25 degrees. Not heavy knock, but it was there.
I used new jets but a used power valve. 
Setting the total timing to 30 ( Initial 16) resulted in a great idle and throttle response, but spark knock.
Backing off the timing to 20 total ( About 6 initial) resulted in an erratic idle, lazy low rpm performance, glowing headers but NO spark knock.
Some say to pull the plugs with a hot engine, then read the plugs. Uhhh... 2" headers and all that heat? No thanks.

I have no

[firefighter3931]

What carb are you running on this engine ? It definately sounds like you're running lean and need more timing. With no load you should be able to run with 35* at 2500 rpm and no detonation. 

I think you're on the right track with the carb being too lean 


Ron

[Kern Dog]

Hey Ron,

The carb is the same Barry Grant Speed Demon 850 Vacuum secondary unit I have had for many years.
The engine ran fine under no load. I heard zero detonation during break in or at any other time when the car was sitting still. Even at 30 degrees, it sounded fine and ran great until 1/2 throttle when light detonation was heard. Oddly, I'd lift off the gas, the detonation would stop, I'd get into it and at about 3/4 throttle it did NOT knock then at full throttle it came back.
Read that last sentence again.
Today I set the timing to 19 initial, 33 total. It ran great while sitting still. I checked the vacuum in neutral at 1000 rpms. 10 inches in Park, 4 inches at a 700 rpm IN GEAR idle. I have NOT touched the idle mixture screws. With a PV of 6.5, having an in gear idle
vacuum number that is LOWER than the Power Valve is obviously backward. I plan to get that wideband guage in tomorrow. This will give instant data to every change I make. I read that the goal is to jet the carb to read 14.7 Air/Fuel for cruise and 12.5 to 13.0 at WOT.

[Kern Dog]

*******UPDATE*******UPDATE*********UPDATE********

I got the wideband guage installed. I haven't jumped into tuning much yet, just wanted to pop in to post this:

Engine as is without touching anything: 9 1/2 inches idle vacuum at 1000, 4 in gear at 700-800. Idle mixture screws were only 1 1/4 turns out from being seated. IN GEAR the guage reads between 15.0 and off the guage which tops out at 18.0. When I revved it above idle, it pegged past 18.0!
I had a feeling it was lean!
I seated the idle mixture screws, then backed them out a full 2 turns. Idle vacuum went up to a solid 10+ with 5+ in gear. At idle, the guage reads between 14.0 and 15.0. It still pegs when I lean into the throttle.
Here is a thought: The primary side is running lean with the 86 jets. Being that I have 5.0" of vacuum and a 6.5 Power Valve, I think the PV may be covering for the UNDERjetted primaries. When I rev the engine, there is no additional fuel to keep the Air/Fuel ratio in check.
Sound right so far?

[Kern Dog]

I switched the 3.5 PV back in. The idle readings went down to 13.0 to 13.6. Kinda odd for it to richen up when I went to a smaller rated PV. I turned the idle mixture screws in to where they sit at 1 1/4 turns out again and the A/F reading came back to the 14.5-14.9 range.

NOW it goes off the charts lean when I put it into gear or hold the brake and ease on the throttle.

I thought I knew a little about carburetors, but tell me if i have this right:
* The IDLE circuit works when the primary throttle blades are closed. The main jets are NOT in play when in the idle circuit.
* The primary jets begin to function when the engine is put under a load and the primary throttle blades open.

If the above is true, would that mean that my primary jetting is still too lean? I understand that you are supposed to make only one change at a time which is why I only changed the power valve when I had the bowl off.
Looking at the gaskets I used, they actually are fine. They are a rubber like red gasket that came in a Demon rebuild kit I had.            

[Kern Dog]

I changed the primary jets to #88s. The in gear idle numbers hovered around 16.0 but the guage still pegged lean when I eased into the gas, power brake style.

I know that something is off here. Jets this big should not allow an engine to run so dang lean. I have been curious as to what jets others use in their 500 inch engines. This lead me to look at this:

http://www.summitracing.com/parts/hly-0-81870?seid=srese1&gclid=COP_-4CDrLkCFYU5Qgod8VsAzA

This was confusing. The Holley Street Avenger 870 uses  #78 primary and  #84 secondary jets along with a 4.5 Power Valve. This is a carb with a higher CFM rating but with leaner jetting. I'm wondering if my carburetor is AFU.

[firefighter3931]

Hi Greg,

The idle circuit is independant of the main circuit. If the throttle blades are too far open at idle it will expose too much of the transfer slot and the engine will be pulling fuel from both circuits at the same time. 

Often with long duration cam profiles the carb will need some additional air at idle. One thing that helps is drilling small holes in the primary throttle blades to allow additional air into the venturies. A 1/8in hole on each blade is what i use. 

I'm not that familiar with Demon carbs but i've heard that they use a different numbering system for their jets. What works for a Holley might be different for a Demon. 

It's definately going lean as the A/F is showing on the wideband....you need to address that to keep the engine healthy. 

The other thing to consider is the carb itself and the fuel curve calibration. With bigger cam profiles and high flowing cylinder heads you need a more agressive fuel curve. A vac secondary carb is not what i would run on a build like yours. You might be able to get it better but it will never be as good as it could be with a double pumper carb.



Ron

[Kern Dog]

The symptoms with this engine are a bit conflicting. The guage reads that it is lean. The pinging even with mild timing tells me it is lean. It has NO stumble when the throttle is snapped open even though the guage JUMPS to the lean.
I'm wondering if there is something wrong inside the carb itself. I tested for vacuum leaks. I sprayed Brakleen around the base of the carb and the intake ports. There was no change in engine speed until I sprayed it across the throat of the carb.

[Kern Dog]

I have 2 Holley carbs I can bolt on to test, a 600 and a 750. The Summit Racing CFM calculator shows for a 493 with a 6200 max rpm, a 751 CFM carb for street and a 972 for race. I might bolt on the 750 to see what A/F numbers I get. I'll report back soon.

[cdr]

when tuning with a wb,when you crack the throttle it will go lean for an instant.the only way to tune it is to drive it.

[Kern Dog]

I tried running the engine with a stock Holley 750 from another car I have.
The vacuum numbers came up at the same 1000-1100 idle rpm, from 10.0 to 11.5. The IN GEAR idle numbers came up from 5.0 to 6.5.
Also, the Air/Fuel ratio is now within tunable range. 
* Idling in Park @ 1100  13.8 to 14.2
* Idling in gear @ 850    14.2 to 14.6
* Pwr brake in gear        13.8 to 14.5

This shows something. The 750 actually richens up under a load. The 850 goes lean every time the throttle is opened under a load.

[firefighter3931]

I tried running the engine with a stock Holley 750 from another car I have.
The vacuum numbers came up at the same 1000-1100 idle rpm, from 10.0 to 11.5. The IN GEAR idle numbers came up from 5.0 to 6.5.
Also, the Air/Fuel ratio is now within tunable range. 
* Idling in Park @ 1100  13.8 to 14.2
* Idling in gear @ 850    14.2 to 14.6
* Pwr brake in gear        13.8 to 14.5

This shows something. The 750 actually richens up under a load. The 850 goes lean every time the throttle is opened under a load.

A few posts back i mentioned the fuel curve calibration differences between carburators being a factor. The 750 definately has a more agressive fuel curve and is a step in the right direction. 


Ron

[Kern Dog]

I just changed the primary jets in the 850 to #90s. I also sprayed carb cleaner through the idle air bleeds. They were CLOGGED! I got the outer 4 to clear to the point where spraying through the top it exited at the idle transfer slots. The inner 4 sprayed though but I think they lead to the metering blocks or somewhere else inside the carb.
With these changes, the A/F numbers changed a bunch.
Idle in park:  13.0 to 13.8
Idle in gear:  12.8 to 13.5
Pwr brake:    12.0 to 12.9
Before with this 850 carb, any movement off idle resulted in a terrible lean A/F reading. Now it is too rich. GREAT news, now I can go back one jet size and fiddle with the idle mixture screws to get it right!

[firefighter3931]

Good work Greg 

The outer holes are the idle bleeds....inner holes are the high speed bleeds. 

It'll be interesting to see how well that carb can be dialed in for your particular combo 


Ron

[Kern Dog]

I've read that it is recommended to set the initial timing at a point where I get the highest manifold vacuum. What if that results in a 25 degree setting? Wouldn't that make it hard to crank over, especially when the engine is warm? With an initial at 25 degrees or so, I'd certainly need to modify the distributor so it is limited to 33-35 total. I guess this is just another part of tuning. Before this engine, I never degreed a cam. Fuel pressure was never an issue in the past. I never used an Air/Fuel guage either.

[Kern Dog]

I tried running the engine with a stock Holley 750 from another car I have.
The vacuum numbers came up at the same 1000-1100 idle rpm, from 10.0 to 11.5. The IN GEAR idle numbers came up from 5.0 to 6.5.
Also, the Air/Fuel ratio is now within tunable range. 
* Idling in Park @ 1100  13.8 to 14.2
* Idling in gear @ 850    14.2 to 14.6
* Pwr brake in gear        13.8 to 14.5

I am going to try this carb again tomorrow. When I had it on the engine on Monday, I didn't get to road test it. The numbers above indicate that the 750 already runs pretty close to the goal A/F numbers. I know that a 750 is way too small for this engine, but if it runs without detonation, I can consider the Demon 850 to be the main problem here.
*******************************************************************************************************

[Kern Dog]

I am damn near out of ideas here.
The 750 ran pretty good. It idled smoother than the 850 and the A/F ratios were pretty close to the goal. The engine still detonated at anything over 3/4 throttle. From a stop, from a roll, from 3000 it didn't matter. Spark knock and light black smoke. I am baffled as to how after everything I have tried, it still knocks.
I've tried different jets, Power valves, timing settings, distributors, carburetors. The only time the engine didn't ping is on the first test drive after breaking in the cam when I backed the timing off until the knock went away. The timing at that point was 6 initial and 20 total.
I really do not know what to make of this. It defies logic. The cam swap resulted in a 15 lb drop in cranking compression which should make it knock LESS.
****************************************************************************************************
Grasping at straws here, but here are the only variables between the 509 cam setup and the current one.
Cam-lifters-pushrods-timing set. Different timing cover and oil pan.
Intake was installed with the valley tin only compared to using the paper gaskets last time.
*****************************************************************************************************
I may reinstall the 850 with totally stock jetting and see what happens. I really do not expect any improvements.

[RECHRGD]

Bad gas?

[Cooter]

What style intake?
I know no matter how well that carb is tuned, some cylinders will show lean and screw with your sensor..
This is why these work best with port FI...

[Kern Dog]

I'm running an Edelbrock RPM intake. It is a dual plane.
I took the 850 and put the #86 primary jets back in. It actually idled pretty good. Better than it has in awhile and the best it has since the cam swap. The A/F ratios were better than they have been, though a bit on the rich side. I still get knocking at 3/4 throttle and more. It doesn't matter whether I'm at a roll or from a dead stop. Up to 3/4 throttle, it barely pings at all, but once I get to the secondaries @ 3/4 throttle it pings.
I came home and poured in 5 gallons of 100 octane unleaded that I was saving. I considered it a last resort. I still had about 5 gallons of 91 in the tank, so without a degree in petrochemical science, I can only guess the mix results in about 95 to 95.5 octane. I drove the car 4 or 5 miles to use up the 91 octane that was in the fuel line, pump and carb. When I tried to hammer it, it still knocked. I tried it a few  more times in the next 3 or 4 miles and I got the same results.
I am still confused as to how an engine can react this way. When I ran a 40/60 mix of 110 and 91 in the car with the '509 cam, it didn't knock one bit. Even if I had my numbers wrong and the cam timing is off by 4 degrees either side of the 106 number, I still wouldn't expect it to knock.
A guy on another forum wrote about a  496 that had the same problem. His Fel-Pro head gaskets had burned "Fire-Rings" that  were hanging into the combustion chambers. He put in larger bore head gaskets and solved the problem. I wonder how you determine that they are burned. I guess I could pull the heads to check, but I'm getting tired of chasing dead ends!
http://www.summitracing.com/parts/edl-7325

[Kern Dog]

****************************************************************************************************

Update:
After chasing all sorts of possibilities, I decided to do a cranking compression test. It turns out that my numbers now are actually 3 lbs HIGHER per cylinder than they were with the '509 cam.
Yeah, that is what I found out. I did the test like I always do:  All plugs out, engine cold. I had an average of almost 188 before, now the average is 191. I wrote that the engine knocks more now than before, THIS may be the reason. I am totally baffled at HOW this cam can produce MORE psi when it has a later intake closing. It just defies logic.
509 cam                    Lunati cam
#1 188  #2 188       #1 190   #2 190   
#3 185  #4 190       #3 189   #4 190
#5 188  #6 189       #5 192   #6 195
#7 185  #8 190       #7 190   #8 192

I reinstalled the plugs. Tomorrow I'm going to run the tank down a bit then pour in 5 gallons of 110 octane leaded fuel. I'll have to unscrew the O2 sensor to keep from damaging it.

[Cooter]

 I told you in the beginning you will have to lower that compression.

[Kern Dog]

Guys are running at this ratio on pump gas, Cooter.
"I told you so" isn't the way to fix it.
There is something wrong here that is getting in the way.

[Kern Dog]

This morning I found some oil in the valley pan. There was some below the intake and some toward the rear. Also, both valve covers were wet on the sides that face the intake. I Figured that there was some possible oil seepage. The intake bolts felt as if they had loosened up. I was able to tighten them at least 1/4 turn more! I wiped the valley with a rag & solvent.
I rigged up a long fuel line and attached a guage to the windshield so I could read the fuel pressure while driving. I got 7-8 lbs at idle and cruise and at WOT it went down to 5 but didn't go below that. The first 2 WOT blasts actually had NO detonation! I was all wiggly thinking that it was gone!
The next 3 WOT attempts, the detonation came back. At home, I noticed that the valley pan had some oil on it again. I pulled the intake and found oil all around each port. Oil was also around the intake ports on both sides of the valley pan and the heads. I've been pulling oil into the cylinders! Each intake port had oil film on the walls. When I installed the valley pan, I left the paper gaskets out but smeared Gaskacinch around the ports. Obviously it was inadequate. I replaced the valley pan and used the thin paper gaskets on both sides of the ports on both sides of the intake. This made it a bit more difficult to thread the bolts in, but I got it done. I went a bit tighter on the bolts this time. I'll drive it tomorrow and report back.

[Kern Dog]

I am still at it, trying to get the engine right.
I replaced the valley pan. This time I used the thin paper gaskets on both sides of the tin. I replaced the valve cover gaskets at the same time. Unfortunately, all I had here were the flimsy rubber VC gaskets. Here is an odd discovery: The MP aluminum valve covers have a gasket rail that is over 1/4" wider than the gasket rail on the Edelbrock heads. The MP valve cover mounting holes are big enough to allow a degree of slop. THIS caused the squishy rubber gasket to distort, causing leaks on both sides. I replaced them again with the firm black fibrous gaskets. No leaks now.
The leaky valley pan had me thinking that my detonation may have been from oil getting into at least one cylinder. A test drive showed that it still knocked.
I added 5 gallons of 100 octane to about 5 gallons of 91. I estimated the octane rating to be around 95 1/2. Yeah, it still knocked. I drove it around awhile until I was down to about 5 gallons again, then added 5 gallons of Sunoco 110. The knocking is gone and the car hauls ass! It feels faster than ever.
I DON'T want to rely on race gas to enjoy this car. I ordered a Mallory distributor tuning kit and replaced the springs in my original distributor and another MP I have as a spare. I need to wait until the tank is almost dry, then add 91 octane gas exclusively. If i drove it now with the race gas in there, there is no way to know if the recurve in the distributor did anything. I'm not very optimistic though. The full advance is all in by 2000 rpms. If I hold steady at any rpm above 2500, it knocks at WOT. To me, if it knocks at any speed AFTER the distributor advance is all in, then the advance curve isn't the problem.

[Kern Dog]

Hello again.
******************************************************************************************************
UPDATE:
After much deliberation, testing, parts swapping, etc....I decided that the problems that I was having came down to one fact: The compression ratio I had was too high for the 91 octane fuel. TWO options: Use higher octane fuel or lower the compression ratio.
I chose to pull the heads and go with a thicker head gasket to lower the compression ratio. I have heard about all the benefits of quench, but after rechecking the numbers, I found that I was already at the edge of 11.0 to one, I had a quench distance of .051 and no amount of distributor tricks could stop the detonation. Only 110 octane stopped the knock.
I removed the heads and had them cleaned, ported and a valve job done. I cleaned the carbon from the tops of the pistons and rechecked the deck clearance. I thought that I was .017 in the hole but every hole came in at .012. This moved the CR up a bit from what I previously thought. Also, I have had these heads lightly resurfaced approx .005 4 separate times to clean them up after using the Fel Pro gaskets that left a slight imprint after use. The resurfacings also must have raised the CR a little bit. Before, I had calculated the CR at 10.73 to one, but I could have been at or above 11.0 to one. After posting about my intentions to use a thicker head gasket to lower the CR, many advised against it. They felt I was going to lose the "quench" effect. My thoughts? If I had to use a THINNER gasket to gain quench, this meant I was also moving the Cr to the 11.5 range as well. Would this be a smart move? To me, it was a gamble that was hard to feel comfortable with.
The heads measured 83 ccs. This is after several resurfacings AND the unshrouding of the valves, opening up the chambers and the valve job.

[Kern Dog]

The calculations show that with the Cometic .075 gasket, my Cr will be at 10 to one. The .086 moves me to 9.77 to one.
All these moves should improve the driveability of the car. The lower Cr will allow the use of 91 octane fuel and a more aggressive spark curve. The porting will improve power. I sure am anxious to see how much difference it all makes!

[firefighter3931]

Hopefully these modifications work out for you....a one point reduction in compression will make a difference. 


Ron

[BSB67]

It is unfortunate as for a little or no more money, no more work, you could have had 0.040" quench and any reasonable compression ratio you wanted. 

You should be successful at getting ride of your detonation, but I only wonder how much power you've given-up. 

[Kern Dog]

Do you mean by changing pistons? Yeah... I have been stubborn to pull the engine to do that. It would have probably been a better choice in the long run, but that was a move that would have surely cost me $1200 at a minimum when you factor in the pistons, pressing them on the rods, rings, oil, filter, gaskets, engine block honing, cleaning, new cam bearings.... then I'd still need new head gaskets anyway.
This way I at least have had the heads ported which should allow more power for any configuration I ever plan to run.
The machinist did the surfacing, valve job and assembly while another guy did the porting.

[Kern Dog]

He gasket matched the huge 2 inch TTI header gaskets too.

[BSB67]

Do you mean by changing pistons? Yeah... I have been stubborn to pull the engine to do that. It would have probably been a better choice in the long run, but that was a move that would have surely cost me $1200 at a minimum when you factor in the pistons, pressing them on the rods, rings, oil, filter, gaskets, engine block honing, cleaning, new cam bearings.... then I'd still need new head gaskets anyway.
This way I at least have had the heads ported which should allow more power for any configuration I ever plan to run.
The machinist did the surfacing, valve job and assembly while another guy did the porting.

No.  That is not what I mean. 

Have the combustion chambers milled on a CNC to 90 cc.  Anyone with a CNC porting program for the heads can do it. If you have them do the porting, they probably won't even charge you for the chamber, as it will be milled anyway.

[Kern Dog]

I guess I could have gone about it differently.
Living in Northern California, there isn't exactly a reputable performance machine shop on every street corner. I read good things about Dwayne Porter, Jeff at Modern Cylinder Head and Jim LaRoy but my work schedule made it difficult to deal with "out of town" machinists. By the time I was off of work, they were already home for 3 hours.  I was limited to dealing with people locally. I went with a referral from my regular machinist. I like the idea of opening up the chambers and running a thinner gasket though. I'd be willing to spend a few more bucks to have that done if I knew more.....

[Kern Dog]

Just waiting on the head gaskets. I hope to have them this week.