Tuning with jets, Power valves and an O2 guage

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I'm building a stroker.got it from Hughes Engines. They said that even with aluminum heads, the gas in the northwest is so bad that they recommended 10.0 not 10.5 compression. Have Az. Cell #. When they saw my shipping address they told me lots people were having issues running pump gas. That said, usually a bigger can helps lower cylinder pressure...
 
Are you saying to clean all of the oil and grease off the valve cover gasket mating surface before you adhesive seal the gasket to the valve cover? Sorry, just a little confused with the sentence structure.

moper said:
I'm talking about the valve covers... Not the intake. I don't use paper gaskets and do use a little ultra grey or ultra black around the ports. I've never had an issue that way.
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I've been thinking over the past few days that maybe I really do need to reduce the compression. All of this stuff with bigger cams, reduced ignition timing, high octane fuel, race fuel....
It would have been better to drop my compression ratio to 9.5 to 9.8 and run a milder cam. I could have run 89 octane. I could have driven it in Arizona at 120 degrees and hammer it without trouble. These claims of...." Well, I have run 11.0 to 1 on pump gas..." may be true, but I must have really screwed up to have this much trouble.
I've been working out of town and have yet to take the car out since replacing the intake gaskets. I sent an email to Don at FBO. He pretty much considered my combo a mess. Too heavy vehicle for the converter I have, too big a cam for the converter, "race" cam that won't make any power until 3500 coupled with an GV overdrive.....
He suggested several things including a smaller cam. I am as confused as ever.
 
Desmo - yes - sorry - I thought with the prededing post talking about sealing the valve covers being a problem for Fraken that "Get all the oil and grease (including oil from your skin) and take 3M yelow weatherstrip adhesive and glue the gasket to the cover" would be clear.

Franken - the more people you ask the more approaches you will encounter. Frustration always comes with casting a wide net. I'd suggest you take one approach and follow just that - whomever you chose - and let us know how it goes. I do think what you have is on the hairy edge of "ok", which means there's some tweaking to make sure it stays in the safe area.
 
Regardless of what the problem is, take ONE approach and follow it completely THROUGH. From what I have read, you've not done that yet, regarding the distributor advance and that could fix your entire problem.
 
Today I spoke with Jim at Racer Brown cams. He has many interesting things to say.
First off he blamed the wide .056 quench and 10.7 compression for the detonation. He thinks that with quench, the compression wouldn't be a problem. He thinks I should zero deck the block and use a .039 gasket to obtain optimal quench. I told him I am not against pulling the engine if it comes down to it but I'd prefer to look elsewhere for a fix.
Jim suggested going with a thinner head gasket to tighten up the quench distance. This would close it to .044 while raising the compression to 11.03 to 1. He said the same thing I've heard before: Quench gives benefits that overshadow the common reaction to high compression. Every time I hear this, it sounds like the TV claims of "Eat more cake & pizza and lose all the weight you want!" It just seems too good to be true.
I've asked many people about quench. I've started threads about it asking "At what point of piston to head distance is quench no longer effective?"
I don't recall many clear answers on that topic. If I knew with scientific proof that at my .056 distance I had NO quench, I'd just default to the thicker gaskets like I did in 2006. It seemed to work then.
Jim said that the thinner gasket would get me into an effective quench and probably stop the knocking. He also spoke about another angle I never considered: There are cases where a bigger solid cam can actually increase cylinder pressure over a smaller hydraulic cam when you consider VALVE LASH. The Lunati cam has bigger lift and duration numbers but when the lash is figured in, it may be opening the valves later and closing them sooner. This could explain why the Lunati cam increased the cranking compression.

Finally, I added about 3 1/2 gallons of 110 leaded Sunoco and drove the car. This sucker is SCARY fast compared to before! ZERO detonation and more power than ever.
Okay, I've determined that the car will run stong without knocking. My goal still stands: Getting it to run on 91 octane knock free.
Head gaskets, thicker or thinner? Maybe both would help. I've tried thicker in 2006 and it worked then. Maybe going thinner would also work while making more power?
 
See Rob? Nobody is to blame here. Sometimes a situation comes along that defies good logic. I've asked many questions, received some good advice and still face problems. THINK of how this thread may help another Mopar guy once I do figure it out!!
Don at FBO told me that a point of compression is only worth a few HP at 6000 rpms but a single degree of timing could be worth 25 HP ! He felt that a 11 to one engine that has to run retarded timing to avoid knocking would make less power than a 10.5 engine with proper 34 degrees.
I absolutely hold no grudges on any advice I have received. I appreciate everyone that was cool enough to take the time to respond. RustyRatRod: Did you read what I wrote about the way the car ran on 110? It is faster than ever! I'm feeling that with the head gasket change, the car will run great and I'll chalk this stuff up to a learning experience. Old timers with knowledge got there by trying things, making mistakes and moving on. I plan to do the same.
 
72BBSwinger said:
Quench can actually have a cooling effect in the chamber.
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I have read that. Lots of smart engine builders have said the same thing.
Also, many of them saying this live on the East side of the USA. I am saddled with a max of 91 octane unless I go to a specialty gas station for 100. I wonder how these quench engines run after some carbon buildup from idling, low rpm cruising and many miles of regular use. I may be wrong, but it seems that running so close to the limits of detonation in terms of a tight quench means that detonation may creep in within 10,000 miles and I am back to all of this again.
I am not going to make a decision on this today, but while looking at head gaskets and a compression calculator, I found this:

http://www.summitracing.com/parts/cgt-c5464-075/overview/make/dodge

This Cometic has a 4.50 bore, a .075 thickness and drops my compression to 9.89. If I already have no quench, (Or so little that it is not helping) this gasket would surely make a difference.
 
72BBSwinger said:
Quench can actually have a cooling effect in the chamber.
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So I've read.

duster, I think Rob's a little flustered because you ask for advice, then they give you advice and you don't really follow it up with results of said advice...but then solicit advice elsewhere, then come back here and report it in deference to other advice. Take one and stick with it, I think is where he was going with it.

I don't really have a dog in this race, but I would tend to agree that if you close up your quench to about .040", then a large amount of your problems will depart, and if you still have pinging, it's more a matter of correctly tuning/curving your timing.

As far as 'how close is too close?' with quench question, too close is when parts start touching. I know at least three guys that build Ford mod motors (4.6, 5.4, etc) and they run sometimes as low as .024" piston to head clearance. Granted, that's an engine who's assembly weighs less, but a 3.54" stroke swinging 7000-7500 rpms, that's close.

Just my 0.02...
 
RustyRatRod said:
Regardless of what the problem is, take ONE approach and follow it completely THROUGH. From what I have read, you've not done that yet, regarding the distributor advance and that could fix your entire problem.
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Take one approach and follow it through? Actually, I have. The UEGO guage & 02 sensor was used to get the A/F ratios in the proper range. I've upjetted and down jetted the carb, I've changed power valves. After much work, I figured that the carb isn't the problem.
The engine ran hot during cam break in. I added a fan shroud.
The fuel boiled during cam break in. I tested the fuel pressure and found that it isn't an issue. I later read that an engine often runs hot during a break-in session because the carburetor isn't under a load. It runs lean because the power valve rarely adds additional fuel. Don at FBO suggests to UPjet a carb for the breaking in of a new cam or engine assembly.
I thought that the leaking intake gaskets could have led to oil getting into the chambers, so I replaced the gaskets and valley pan.
I have tried using another MP distributor. It had heavier weights and a slower curve. I narrowed the total advance too. Maybe I didn't take it far enough with the tuning of it, but I did try. I read about how to map your curve with the distributor in the car. This is still on my list of things to do. A guy sent me a link to a Mallory tuning kit I might get to mess with.
I know that sometimes I look like I am wandering around randomly with no direction. I'm not too proud to admit when I make mistakes. Some people have suggested that I find ONE person that I know and trust and follow the advice of that person. That sounds great, but I do not know anyone with a similar car and similar engine in my town. The engine builders I know are not performance guys. The guys in my car club are mostly into stock stuff. The racers in my car club have stuff way beyond my car. I'm sorta in the middle on this one.
THIS is why I ask questions online. I hoped to cast a bigger net and sift through the responses to find a solution. If some get bent because I don't do exactly what they suggest, I'd tell them that there may be several reasons for that. Maybe I missed their response because I read it while the wife was talking to me. Maybe their suggestion wasn't in my price range. Maybe the advice didn't feel right. I appreciate the efforts though.
 
No you haven't Not with the distributor curve. Ant that's where I think you may could cure the problem. Could more quench solve it? Maybe. But which is cheaper and easier to try? Tearing the engine back apart, or removing and curving the distributor? Just trying to stick with the simplest methodology first. You've already gone back into it once and it seems to not have change it. You say there are times it does not spark knock, so you HAVE to be close. Yes, I saw where you said it runs good on 110. What does that prove? That it has too much compression? How do you know? Have you ruled out too much timing yet? NO.
 
You want .039 gasket thicknee up to .040 and an 84-80 or 75 chamber. Then get a cam with 112-114 lsa and yore there.
 
RustyRatRod said:
No you haven't Not with the distributor curve. Ant that's where I think you may could cure the problem. I saw where you said it runs good on 110. What does that prove? That it has too much compression? How do you know? Have you ruled out too much timing yet? NO.
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How about THIS:
Running the engine in 2nd gear at 3500 rpms. ALL the timing is in and has been for several hundred rpms. The timing is set to a total of 31 degrees. I floor it and it knocks. Please, please explain how this can be related to the distributor! The timing curve is moot once the maximum degrees are reached, right?
If I ease into the throttle it knocks. If I roll along at any RPM and floor it, it knocks.
 
I narrowed my advance curve by 2 degrees, then backed total up 2, and went 2 heat ranges colder all AT THE SAME TIME and it went from PING CITY to almost zero. If I floored it in 4th gear at 20 mph it would still ping. Frank its the 2's at a time method.
 
I am not trying to insult people or frustrate anyone. If my understanding of the ignition issue is wrong, I'd appreciate knowing what is right.
 
C300 said:
I'm building a stroker.got it from Hughes Engines. They said that even with aluminum heads, the gas in the northwest is so bad that they recommended 10.0 not 10.5 compression. Have Az. Cell #. When they saw my shipping address they told me lots people were having issues running pump gas. That said, usually a bigger can helps lower cylinder pressure...
Click to expand...

Hughes is telling the truth. If I had the engine out and apart, I'd build it to a 9.5 to 10 ratio to have some wiggle room. I've read that ignition timing is worth more HP than compression is.
Regarding the "bigger cam" method, I am starting to think that it would be much better to build the engine to the right compression ratio, THEN choose a cam that is appropriate for the driving style. I have very little interest in drag racing this car. I've been on 3 1000 mile road trips since Spring 2011 and I want to do more. What happens if I get a sorry tank of fuel in the middle of nowhere? A tempermental high compression engine isn't any fun, I've learned that firsthand.
The cam I have now isn't much different than the one it replaced. If I went more radical, this theory may have worked. If I took it too far, the tradeoff would have been soggy low rpm performance and crappy street manners. I'm glad it didn't go that way.
 
wow what a cluster... 190 cranking pressure will run like a raped ape for sure! sounds like you just built to much compression into it for your gas... if it were me I would leave the head gaskets as if you make the quench less (or in the case of where you will be none) it will get worse... quench is a strange deal, its all or nothing...

you have swapped the dizzy a couple of times but have you ever curved it? you should probably be 16-22 initial, 34-38 total all in pretty early. by pulling timing your lessing cylinder pressure which tells you you have to much for a given fuel/combo.

I would try a colder plug and see what it does, if no dice then retard the cam or put a race gas mix high test pump and 110 mix for 100oct
 
and get rid of those crappy champs and go NGK's, you would be surprised what a real plug can do...
 
No. He needs his timing in later. That's his problem. It's coming in too soon now.
 
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