360 timing

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No ridicule or name calling. But again, "bleed off" is incorrect terminology. Overlap also does not lower cylinder pressure. It's dependent on when the intake valve closes. A later intake valve event will lessen cylinder pressure, because the cylinder starts to build pressure later in the compression stroke, conversely, an earlier intake valve closing event will raise cylinder pressure, all other things being equal. Most of the time, camshafts with a great amount of overlap also have a later intake valve closing event, but not always. It depends on the grind. But a later intake valve closing event will cause less cylinder pressure every time, all things being equal because it makes the cylinder build pressure later in the stroke. The cylinder simply starts filling later in the stroke, so less mixture is compressed. I didn't say you were wrong. You are essentially right. Just not right in the terminology, because all of this has to happen before TDC, not after.



funwithfuel said:
Perhaps I stated what I was trying to convey incorrectly. Let me explain my statement, and I am by no meens trying to invite an argument on engineering, cam theory and all other things mechanical. I am just explaining what worked for me I built a lowly H-D sportster engine. Originally an 883cc . I converted it to 1200ish . I replaced the 3" cylinders and pistons for 3.560's . Now I didn't try to cram all that extra volume into the same tiny combustion chamber. I used heads with higher cc combustion chambers. It was still too much compression for the factory cams. I installed a set with greater overlap which "bleed off" some of the static compression Allowing me to step down from 105 to much more affordable pump premium 92 without retarding timing and without melting plugs and scoring cylinders. Keep in mind this is an air cooled engine that ran mufflers and sat in traffic quite often. I'm not totally "ignorant" to theory and application. And more often than not I do agree with you. Perhaps 9.08 :1 is a bit extreme. So..... what is factory compression for 5.9 magnum engine out of the box truck engine?.I await the ridicule and name calling..... Rant off.
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ted0161 said:
wow was just looking for some initial settings. This has really taken an odd turn. GOD BLESS AND GOOD LUCK WITH LIFE. I am out.
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You're takin all this personally and it's not meant as such. I am ignorant of so many things, it's pathetic. I got no problem with somebody sayin it or me admittin it.

You be "out" if you want to, but that's your mistake. This is a great discussion and one you can learn from if you can come down long enough. You asked for help. You're getting it. Just because we're not pamperin and powderin your butt while we're doin it ain't our fault.
 
i do appreciate the time and replies. It appears that 10 degrees btdc is the initial number that i was looking for. I plan to do a compression test when i get the time. I am going to get the numbers for the timing and post them before i change anything.
 
10 degrees wont be NEAR enough initial timing.... Here is something else to consider, if you have to dial back your total timing due to spark knock, (and you will!) that engine is gonna be awfully soggy feeling by the time you get it to run on pump gas. The absolute best thing for you to do, is swap the pistons to something more street friendly, and swap the cam to something else as well. The cam in there makes best power where? Its a oval track grind, POOR choice for the street imo
 
Well it might run on pump gas...... at 6000plus ft elevation. I run 87 at 900ft at 10.7 static with aluminum Eddys and a Hughes 230@.050. I seem to remember the dynamic was in the mid 8s. Maybe 8.7? I forget.Ran around 185psi when fresh with filefits.
-Yeah for sure a compression test can help determine fuel type.And aluminum heads suck a ton of heat out. I ran a tick over 200 on 93 with flattops and .020 quench, for a while. That motor flew.
 
i understand whats been said. After i get the compression numbers and check the heads to see if they match the build sheet. I will go from there. If it means changing the cam and or pistons then that is what i will do.
 
thanks for asking. It's going to be a little bit before I can get the timing and compression readings. I will post them as soon as I get them.
 
finally got my new timing light. The mark on the balancer is no where near the marks on timing chain cover. Can't see it at all. I guess my next step is ''timing tape''.
 
Teddys back.
-Hey Ted, would that be at idle? (Please reread post#5) If so, what is the most timing it gets at what rpm? Keep reving it up until it quits advancing.( with the vacuum advance disconnected) Do not exceed 36*. If it goes past 36*, retard the distributor, and retest. Note that rpm (of maximum advance) and the advance number of degrees. You are probably looking for 34*,plus/minus 2*, at something like 3800 to 4000ish.If you had the right fuel for that motor you could run 2-4 deg more, and bring it in a lot sooner(like 2500 to 3200ish). But Im thinking with 93 octane you better play it safe; so 34* @4000 is a reasonable number for now.
-If the max is not 34ish, you need to make it so.
-Then check the idle timing and report all the numbers here.
-If the max comes in before 3800ish, it may have to be delayed, depending on the roadtest.
- Disconnect the vacuum advance hose at the dist. and plug it.Now, find a safe road and take it for a roadtest. If its quiet in 1st gear,try 2nd.Do not test 3rd gear yet;thats speeding ticket territory.Try it at various rpms and throttle settings.Have a passenger write down the rpms at which any rattles occur and the throttle settings at time of rattle. We are looking for ZERO RATTLE, period, but especially at WOT(Wide Open Throttle).When you encounter rattle;BACK OFF immediately.Stop the car and retard the dist. a tiny bit(no T-light at this time), then retest.Repeat as many times as necessary to achieve zero rattle.After zero rattle, go back to the shop and see what the max timing is for zero rattle.If it ends up at less than, say 30*,you will have to decide if the power loss is acceptable, and it may have a tendency to overheat.And if it ends up in the basement, like 26*,you will have troubles. But.......
-If at 4000rpmWOT, its quiet at 34*, you can try 36*.( it might pick up a few hp).
-If the idle timing isnt at least around 20* after adjusting the maximum, then the distributor-cam will HAVE to be modified.
-Every hotrodded motor has to have this worked out. Do not despair.It has to be done.
-And finally; We really need to know how much compression pressure that beast is making.
-Also; it would be very helpful to see the camcard, especially the intake closing point @ advertised duration, and where it was installed at. I read that the dynamic was 9.03; I would just like to verify that. A 9to1 Dynamic c/r would be do-able with aluminum heads and 93 octane E-10, at 1000ft elevation. I did it for a few years. No problems. And I rode it hard. Youre talking about cruising. I think it MIGHT be do-able,for you. What elevation are you at? Im assuming your heads are NOT aluminum? Whats the stall on your convertor? What gears in your diff? If you dont know the gears, can you give us a mph to rpm comparison in 3rd gear( eg.60mph=3000rpm,etc)? What size rear tires? 14s? 14what? Say;245/50-14s? Or 235/70-14s? Or?
-Ok, thats it for now. Will await progress report.
 
ok its raining here. I did run out and at 3500rpm its at 45 degrees. The 25 was at idle. I did not disconnect the vac advance. I am going to get the compression numbers and the timing numbers that you asked for, but it will be this weekend at the earliest. I do not have a camcard but the paperwork says ultradyne 252/261 @ .500 560/570 lift, standard lash at .026. The heads are not aluminum. A previous owner that i spoke with had the transmission rebuilt and said that they removed the high stall converter and replaced it with stock. I take it that he was unhappy that the car wouldnt spin tires unless revved really high. I dont know the rear diff gearing. And it has 14 inch tires
 
Man, no disrespect, but this just keeps getting worse.....stock converter? 14 inch tires? 13 to 1 with iron heads? You need to put down the timing light, and get out the cherry picker and REMOVE this engine, sell it to someone with a race car, and buy or build something suited to what you need...you are going to ruin this engine on the street.
 
Replicar, I see you are concerned for Ted. But Im not ready to throw the towel in just yet. Lets wait for the compression test and roadtest results first. It might not be the most ideal set-up for the street or for you, but consider that Ted just wants to cruise it around. Im pretty sure that we can make that do-able, with this long-block, and this car, with these parameters.
-Now, Ted you need to back that timing off, PRONTO. I see that you have 45* max timing and 25* idle timing. Doing the math that means you have 20* in the dist.(45-25=20) We are shooting for 34* max so you will have to retard the dist. 45-34=11*. you currently have 25*. So 25 -11=14* Reset the idle timing to 14*, then check the max timing. Adjust as necessary to get the max to 34*. Then note and report at what rpm this max timing first occurs.You may have to rev it to 4000rpm or more, to make sure no additional sneaky degrees are up there.If it doesnt change from 3800 to 4400 that should be high enough.
-It wont idle very good at 14*.Dont worry about that right now. You will have to increase the idle speed to keep it running.We will fix that after the max timing is worked out. Please reread post #5
-.Do you know how to adjust the idle speed? Its the only one screw on the drivers side of the carb that moves the throttle lever.
-That motor shouldnt have any trouble spinning any 14 inch tires, with any convertor, and nearly any ratio SG. Hi-stall TCs take a little getting used to on the street.
-Do you know how to do a stall test?
-Plz provide a 3rd gear Mph to Rpm comparison; eg 60 mph=3000rpm,etc.
-Plz provide the whole tire size. eg. 245/60-R14
-Do you have a hood scoop providing fresh cold air to the carb?
-Do you have a direct drive cooling fan, a 26 inch fully shrouded rad, and all underhood air seals installed(cowl strip and rad-core strip)?
 
ok. Ease my mind. To much advance can cause a cracked piston or a hole. But backing it off some should be relatively safe?
 
before i do any of that i am going to plug off the vac advance and figure out the total. And post it. Hopefully this weekend.
 
p225/70r14 98s rear tires.*direct fan with shroud has cowl gasket but front gasket was removed and is in trunk. Will measure rad. Size this weekend. No scoop. The aftermarket temp gauge isnt working at all. I just bought a replacement for it. The dash gauge barely comes up but i believe it is working. My non contact thermometer reads about 145 at thermostat/top rad hose area. My guess is that the thermostat has been removed. I have a 195degree one that i hope to install this weekend. Sunpro Tach says 2000 @ 50 mph but at times it can be jumpy. I plan to replace it.
 
Expect it to run like **** at 14 initial.

Fix the fricken distributor so it has the initial timing the engine wants, NOT what determined by the excessive curve un the distributor setting it by the total method. That's the WORST method to use if you plan on street driving ANY car. If it runs OK at 24 initial, get it set up so it runs there with 10* in the distrubutor. I bet it would even run locked out.

Getting any timing reading with vacuum advance hooked up is worthless as it will be pulling timing in at almost any point above idle.
 
Ted; That car looks like a pretty nice score.
-That one sheet appears to be a work-sheet, projecting end results much like the old "desk-top dyno". The numbers on it seem to all be theoretical, or projected.
-With the numbers you provided as to tire size and rpm/mph, the math comes to about 3.23 rear gears.Probably not the best for that engine, but for you, may be acceptable. And yes, too much timing at full load WOT will quickly wreck stuff. Esp.pistons
-As to the thermostat, 195 may be a little high for that engine, especially until we get the timing worked out.
-Yes, at 14* initial, it wont perform very well until it gets wound up some.And we could just take the dist. cam out now, take some timing away from that 20* dist., and start from there. But the thing is A) HE doesnt seem to know his way around engines, much less dist.cams, and B) WE dont know what his engine will accept for power-timing with his available fuel and C) Once we know what max timing will be limited to, we will be able to very closely figure out how much to take out of that dist.-cam,for a nice idle and off idle tip in; instead of guessing at it. Im thinking "baby-steps" here.

Now, to crackedback: I see that you are a senior member, with nearly 14000 posts. I have also seen that you give excellent advices. I would not question your skills as a mechanic, a tec, or a teacher. We both know that in the time it takes to produce some of these posts, in our driveways, we could have had this beast running like the champion it was built to be.So if you like,I will bow out, and you may take over.Respectfully, AJ.
 
Nope. you can have the fun in this one all to yourself. Even at the suggestion I just made, I bet that thing starts at 36* initial, so if he had to wind it up to 38* total, still not going to be an issue starting at 28*.

I've provided input early on, that last post was my last input. Other than this...

Fix the fricken distributor!!!

Have at it.
 
Keep at it Ted, there is some good advice being posted here. It would be disappointing to see this engine blow up, due to not knowing what the engine is or what it "needs".
Follow the advice and go with the "baby steps" here.
The whole timing thing used to confuse the **** outta me as well.
Hang in there and post pics, progress.
 
yea. When he says ''fix the distributor'' that means to unhook and plug the vacuum advance correct? This car does start and run on 93 pump and has for years -as a cruiser- set right where it is. However i feel that if tuned properly it will start and run better. 4spddragtop i am confused ha. I am thankful to everyones patience and help.
 
Ted my bone stock 360 in my 84 1/2 ton wants initial timing at around 18-20 degrees. That is with engine idling at about 600-700 rpm and the vacuum hose to.distributor unhooked and plugged. Start with that.
crackedback helped me with my timing...he speaks the truth...lol
 
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