Cam is in, car is running, now the TUNING begins!

[67Satty]

Did you check your reluctor gap in the distributor? Make sure it's set to .008"? When mine was off it made my car sputter above 3,000 rpm. Maybe you are confusing a sputter from that with spark knock?

 

[Kern Dog]

I did check the reluctor gap. It was at .010, but I went ahead and tightened it back to .008 wit the brass feeler guage. I had the gap slip once many years ago. It ran great until I floored it and then it would pop and sputter.
The car now shows no sputter, no hesitation, just detonation at WOT.

I rejetted the 850, going back to #86 primaries. Still have the 3.5 PV and #94 secondaries. It idled well and drove well. The A/F numbers were a bit rich but not terrible. It ran like before, fine up to 3/4 throttle, then detonation. I came home and added 5 gallons of 100 octane unleaded. I had 5 gallons of 91 still in there, so I figure the mix works out to around 95. I drove it a few miles to use up the 91 fuel in the lines, pump, filter and carb. It still knocked at the same point as before.

I may revisit the search for vacuum leaks. The valley pan was put on bare. I also put the intake directly on the valley pan with only gaskicinch around the intake ports of the valley tin.

 

[Meep-Meep]

A small vacuum leak will not make a hill of beans worth of difference at WOT or near that. If you put a new valley pan on, and you don't have a huge mismatch between the intake and heads, then you don't have a significant vacuum leak.

It only takes one bad cylinder to detonate but often the assumption is made that the entire engine is to blame. I pointed out long ago in one of your threads that detonation is caused by many factors not limited to compression alone. Fuel distribution is a big factor and that is largely controlled by the intake manifold. Maintaining good wet flow from booster venturi to the chamber without fuel/air separation is what works, but that can get completely screwed up by the cam, flow CFM, temperature, fuel composition and jetting (too rich or too lean).

The only way to check for proper fuel distribution is to get an EGT or O2 sensor reading at each exhaust port. Have you tried a different intake? That monster cam might very well be suited for a single plane. It's possible you have a major mismatch of parts going on here or as simple as too much compression for the available fuel.

 

[Sweet5ltr]

It is funny.. Why not just buy some thick head gaskets, knock the compression down 1/2 point and get in realistic pump gas territory other than borderline? Mine is barely pump gas friendly with 10.25:1 and the 312/590 solid in a 440 based combo.. Can't tell me that doesn't bleed off a heck of a lot of cylinder pressure. I am also only running 32* timing.. Car used to have serious dieseling with my old hyd. camshaft's (meaning, engine still running after car is shut off).. No more dieseling now with the .590 but on very rare occasions.

 

[Kern Dog]

That monster cam might very well be suited for a single plane. It's possible you have a major mismatch of parts going on here or as simple as too much compression for the available fuel.

I'd love to try another intake. The Holley steet dominator is a popular one. I may look for one at the next swap meet!

- - - Updated - - -

It is funny.. Why not just buy some thick head gaskets, knock the compression down 1/2 point and get in realistic pump gas territory other than borderline? Mine is barely pump gas friendly with 10.25:1 and the 312/590 solid in a 440 based combo.. Can't tell me that doesn't bleed off a heck of a lot of cylinder pressure. I am also only running 32* timing.. Car used to have serious dieseling with my old hyd. camshaft's (meaning, engine still running after car is shut off).. No more dieseling now with the .590 but on very rare occasions.

I asked a BUNCH about reducing compression with thicker head gaskets. The majority of responses I got advised against it because of the loss of quench. When I mentioned that I am at .056 now and am just outside of what is ideal, ( .035 to .045) Guys still told me the engine would detonate more due to lost quench.
I actually tried the thicker head gaskets in 2006. I was dealing with this exact same problem. I pulled the '509 and installed a Comp cams XE285HL. I also installed .060 thick Cometic MLS head gaskets. I wrote in my Charger notebook that the car ran great without any knocking.

 

[Kern Dog]

A guy on another Forum by the name of "DODGEM" mentioned he knew a guy that had similar problems with a 496 mill. He found out that his Fel-Pro head gaskets had one or more of the "fire-rings"that were over into the combustion chamber. These rings had burned, causing detonation. He didn't say, but i wonder if the knocking was the result of the wire ring being a HOT spot?
I went out to the garage and laid a new Fel-Pro 1009 gasket on the deck of a .030 440 block. The engine in my car is also a .030 440 so I figured it is an accurate mock up. The guy was right: The fire ring is very close to the edge of the top side of each cylinder, right at the quench side. I wonder how much closer it gets when it is compressed when the heads are torqued down. DODGEM wrote that his buddy replaced the 1009 gaskets with others with a larger bore size. I looked on the Summit site and saw these:


http://www.summitracing.com/parts/edl-7325

I like that the compressed thickness is similar. The bigger bore size would result in a slight reduction in compression without any loss of quench.
I wonder though how to determine if this is part of my problem or all of it. The detonation was getting worse with the 509 cam and now it is as bad as ever. Since we're playing the "what-if" game....WHAT if the heat I had during the cam break in made an already bad situation even worse?
I wish I knew how to determine if my gaskets are failing. I'm not against pulling the heads, but I am getting tired of chasing dead ends.

 

[IQ52]

If you pull the heads, the Fel Pro 8519PT1 has a larger diameter than the 1009, is the same thickness, and we have used the 8519PT1 at compression ratios to 12:1 without them failing. Plus you should be able to get them for $20.00 each or less.

 

[Sweet5ltr]

If it worked in 06', why can't it work in '13?

 

[Supershafts]

Supershafts,

I never doubted an 850 Holley or 1050 Dominator would make 'additional HP'.. as we all know, more airflow equals more power. Some of us (not insulting) use common sense when we think of "hp per/dollar". I picked up my race tuned and modified 750 for $150 from a friend... I couldn't imagine spending $500-$700+tuning costs for an 850 in order to gain an additional few HP if any at all. For a street car, you would NEVER notice 5-10HP at the crank. Many aren't running 6,000+RPM from stop light to stop light. An arcing plug wire can cost you that much horsepower! In the second article, the 440 made 550HP. That is no typical street combination with a lil' sub .500 lift flat tappet cam... Many of us don't plan on placing really radical cams in our street dedicated cars, as they are just going to wipe out and go flat in a matter of months with the spring pressure they recommend while we idle down main street in heavy traffic. I ran big lift cams in my SBF's, but they were all hyd. roller and their duration was pathetic! Heck, I run slightly below the recommended spring pressure with my .590 in order to further my durability over the minimal power gains; and it has a slow ramp rate to begin with...

If you want to pay the dyno time, i'll be more than happy to show you that a 750 is more than 1 hp loss on both my motors, and again showing with proof RR is very important on how it effects breathing and how what you do for a 1.8 440 you do not do for a 1.6 490.

Many people aren't running 6k light to light, maybe, i do and beyond, i do not know Greg at all, im surely not going to give him advice ONLY to get SOME perf up to and nearly at a determined rpm and NOT all of it. . .

The motor in that article by my standards are just off stock

For me, street manners means the ability to run fine on 91 octane and not overheat. It means having the ability to idle in traffic yet still run clean. No clouds of black smoke on startup or full throttle. No vapor locking in 100 degree weather. I'm willing to deal with the vibration and noise. The smell of some unburned fuel is cool. I don't want to deal with knocking, dieseling or the engine being hard to start when it is cold or hot.

My cars don't over heat, no black smoke, idle, cruise, no vapor lock, no start up issues, no vibration and all my motors are mounted with ears no block mounts and no rubber except at the trans.
Both my BB are using solid rollers and are larger than yours and there are no issues with any driving conditions, other than rain when traction becomes non existant with the lightest touch of the gas pedal, so so responsive those big doms are, the throttle response is better than my f.i. 408 jeep.
Starting either one, without chokes in 10 degree weather only issue are a slow idle for a few mins until the motor gets some heat into it.
Both are using what would be considered race cams, both large solid rollers

Besides all that, everything you described are just poor running motors with people that aren't tuning them right, or putting the entire piece together right, you can follow my cars all day and there is no smoke

261 / 271 @ .050" with nearly 100 deg of overlap is not exactly the type of cam that epitomizes street manners.

As the motor gets larger and the characteristics of the motor change that cam isn't going to react the same as it would in a regular 440. That cam would be on the small side to what i use yet i have no street use issues

Yeah, but this isn't a daily commuter car.
The 750 idled great. It has some lope, but I was able to get it to idle at 600 in gear. I was impressed with how docile the engine sounded and felt. The 850 wanted to flop around and stall below 700 rpms. I drove it and found the Air/Fuel numbers were pretty close to the prescribed goals.
It STILL detonated at 3/4 throttle and above. From a standing start, from a roll, from 3000 rpms it didnt matter. Light black smoke and spark knock. This totally defies any logic I have. I have tried different jets, power valves, carburetors, timing settings, distributors...I've tested it on a warm engine, a cold engine, under 85 degree weather and 94 degree weather. Everything I have tried has resulted in spark knock except retarding the timing.
I am damn near out of ideas. Now it seems like a case of...."When the logical solution does not work, time for the illogical".
I have a few stock 440 distributors I can try. I have different spark boxes/ECUs. I have a 5 gallon can of 100 octane unleaded fuel.
I don't know what else to try.

How bad is the detonation, maybe you need to try 93 instead of 91, i have used 93 in mine twice but i usually mix for others.

.

 

[Sweet5ltr]

Never disputed you would lose horsepower.. Never disputed you wouldn't gain power by a bigger carburetor. The power gained/lost is not enough to notice on the street, but dyno junkies would be all over it and condemn you for 5-10HP lost at 6,500RPM with an 850 over spending a grand on a tuned, custom dominator. I have put thousands of miles on my Mopar in the past two years idling and driving in heavy traffic.. Do you really honestly believe roller lifters and the valve train they require would last in these street conditions? If you do, you are being very, very unrealistic.

 

[67Satty]

I say it is the distributor. You've changed the cam, problem not solved. You've changed the carb, problem not solved.

You said before somewhere that you have a vacuum advance distributor but that you don't run the vacuum line. You said before that someone recurved your distributor. These two things are a red flag to me. Did the guy who reworked your distributor know you were going to be running your vacuum advance distributor without the vacuum pod hooked up? From what I understand that will make a big difference in how you set up a vacuum advance distributor and if he did it wrong or did your distributor not knowing you wouldn't be running the vacuum advance it could just be the cause of all these problems.

A new distributor set up for your exact combo would be cheaper and easier than a lot of the other stuff you are trying.

 

[Sweet5ltr]

I have been running a Mopar vac. advance dizzy forever without the vacuum line hooked up.. no issues.

 

[67Satty]

Well, it's something for him to try that's easier than tearing his heads off to change the head gaskets that may or may not be the problem. I like to try the easiest stuff first.

A couple seconds of searching old Moparts posts and I found this regarding disconnecting the vacuum advance:

"I have done this mod since the 70's. It takes a little longer than just changing the springs. The counter weights have to be limited so you do not get too much advance. The slots have to be filled in or welded a 1/8" or so to stop the weights from advancing all the way.The vacum advance pot stays in place to hold the plate from moving but disconnect the hose. If you search the web I am sure you will find info on this mod. Hope this helps"

Getting "too much advance" . That's sounds familiar to me from all his posts, he seems to be getting too much advance and detonating no matter where he tries to set his initial timing.

Were the above mods done to the OP's distributor???

 

[19polara64]

"I have done this mod since the 70's. It takes a little longer than just changing the springs. The counter weights have to be limited so you do not get too much advance. The slots have to be filled in or welded a 1/8" or so to stop the weights from advancing all the way.The vacum advance pot stays in place to hold the plate from moving but disconnect the hose. If you search the web I am sure you will find info on this mod. Hope this helps"

Getting "too much advance" . That's sounds familiar to me from all his posts, he seems to be getting too much advance and detonating no matter where he tries to set his initial timing.

Try retarding the timing 2 degrees at a time til the detonation goes away. It will probably idle like crap but at least you'll know if you need to limit your advance. Rene'

 

[Kern Dog]

Try retarding the timing 2 degrees at a time til the detonation goes away. It will probably idle like crap but at least you'll know if you need to limit your advance. Rene'

After the cam break-in, I let the car sit overnight then changed the oil and filter. I warmed up the car and took it for the first road test. I had the timing set to an initial of 16 degrees and the total was 30. The vacuum advance was plugged. My thinking was that these setiings would surely be safe since the new cam should allow far more advance than the old cam. The engine started knocking about 1/2 throttle! This was at 30 degrees total timing. I stopped and backed off the timin g THREE times until it could be driven at wide open throttle without spark knock. At home I checked the timing with my dial back light. It was down to 6 initial, 20 total. It idled terrible, it was lazy at low to midrange and the headers started to glow red.

I have other carburetors here but I am starting to doubt it is the problem.
I have other distributors too, but all of them are vacuum advance types. I have another MP unit. I have a couple of stock 440 ones. I have a stack of ECUs ranging from stock, parts store replacement and one REV-N-NATOR I bought last year.

 

[67Satty]

Was all of this stuff done to your distributor when the guy reworked it?:

"The counter weights have to be limited so you do not get too much advance. The slots have to be filled in or welded a 1/8" or so to stop the weights from advancing all the way.The vacum advance pot stays in place to hold the plate from moving but disconnect the hose."

Or you could send the distributor plus $89 to Don at FBO. You give all your engine's details, all your car's details and he will curve and phase it for you.

http://www.4secondsflat.com/Ignition.html

Call him or use the chat feature on his website, he's always been really helpful when I have questions.

I still say it is the distributor.

 

[Kern Dog]

The Mopar Performance distributors like mine were supposed to be equipped with internals from Mallory. To change the amount of mechanical advance, there are 2 screws to loosen then the baseplate is clocked. The screws are in a slotted opening that allows adjustment to either totally lock out all advance or set it up to 25 degrees of mechanical/centrigugal advance.
I just found this out the other day. I had no idea how easy it was to make that adjustment since everywhere else I've read that welding the slots was the norm.
When I had the car "tuned" on a dyno in 2005, the guy said he "worked" the distributor. What he probably did was just adjust the limit of advance, not change the springs or weights.

 

[Kern Dog]

*************************************************************************************
I may have found the problem here.

I went out and checked the cranking compression. Earlier I wrote that I got a 173 reading from Cyl # 6. That was a mistake. I meant #5 and the 173 number was wrong. I duplicated the testing methods I used with the 509 cam in place: Cold engine with the plugs removed. The test on # 5 earlier were on a warm engine with the other 7 plugs still in place.


509 cam:
#1: 188 #2: 188
#3: 185 #4: 190
#5: 188 #6: 189
#7: 185 #8: 190

Lunati cam:
#1: 190 #2: 190
#3: 189 #4: 190
#5: 192 #6: 195
#7: 190 #8: 192.

The Lunati cam actually increased the cranking pressure!
I thought that the Lunati had a later intake closing than the '509. Maybe the specs I had on the '509 were wrong. The engine knocked with an average psi of 188 with the '509 cam, so the 191 average with this one surely didn't help. I am shocked at these numbers, but I ran them twice. Now I am back where I started, too much compression for the octane. I might go buy a jug of 110 leaded and try that. Of course I'll pull the O2 sensor and plug the hole for this test.
Since I fought this problem with the 509 cam without much success, I guess my next move will involve a reduction in compression somehow.

 

[Meep-Meep]

I think you just need to pull that 493 out and put in a 383 2 BBL.

 

[67Satty]

There's GOTTA be a way to make this thing work. I still say spend another $89 on getting your distributor curved/phased by Don at FBO. At least call him.