First time readers can mosey to page 2, I have used the piston stop now and balancer is dead on. Ok, I have the 347 stroker running, have driven 80ish miles. Just cant seem to get a grip on the timing. I did NOT install the cam, so maybe its not degreed right?? I brought the engine to 11* BTDC on the compression stroke. How? I hand rotated the engine until #1 was blowing my thumb off the hole. I then stopped it at about 11* BTDC on the balancer. Of course ***uming 0 on the balancer is true TDC. *NOTE* I changed the timing cover a while back and while in there I aligned the chain dot to dot and the balancer was on 0 when aligned dot to dot. *NOTE* I noticed that when aligned dot to dot, it was set at R2 and not 0. This was "how it was supposed to be installed" I was told. It was a custom ground cam specifically for this engine. So whats the problem? When I dropped the dist in at 11 BTDC, pointing towards #1 on the cap and rotor pointing in the direction of #1, it cranked right up and ran. I put the timing light on it and it reads 5-6* BTDC. WTF? Why?? This of course with vac advance disconnected and plugged off. Is it because of the R2? There is a 5-6* discrepancy here somewhere, at least from what I think it is and what the timing light says it is. So then I revved the engine till advance was all in and set it about 36* total. My initial is now sitting 10-11* BTDC. But this would probably be sitting at about 16-17* according to the balancer (allowing for the 5-6* discrepancy). BG and many here say initial should fall in 14-16 maybe a tad higher. BG tech says the 650 demon I have will not run right unless 14-16 initial. However if I set my initial to be 14-16 at this point, my total would be in the 40's, not good. Why is my timing so "off" and with it being like this, how in the world do I find and decide what the optimal timing should be? This is where I am confused. When my timing light says my total timing is 36* (or whatever), is it REALLY that, or would that be "off" as well, if my initial is also "off" from what I think it is? I just want to know if I am really at 36*, regardless of what the initial is and not knowing if the cam is degreed correctly. I dont want to think I am at 36 (by the light) and it really be 30* or 40* or who knows what.
TDC is when the #1 piston is at TDC, not when the flimsy sheetmetal pointer is pointing at TDC on the rubber-insulated OEM balancer. Check TDC with a piston stop. Basically it replaces the spark plug in #1 and you hand-spin the crank until the piston bumps it. Then, you spin it the opposite direction until it stops again. Halfway between those two points is exact TDC. Compare that with the balancer and adjust your marks as needed. One other thing. Fords are awful for trying to find TDC, since different years and front accessories required different timing pointers and timing marks. If you have any mismatched parts, it can be a disaster. But usually it's REALLY far off, and it doesn't sound like you're out 40* or more. Not sure if this helps, but good luck. Oh, and let dragstrip performance determine your spark advance settings, not some book.
Good info gotgas, thanks. I guess I need to get a piston stop to be sure. I know its not off that much, because this thing will put you in your seat . I can tell its not perfect though, before I was getting some dieseling run on, adjust it, thats gone, but high rpm its not quite right. So I agree, no book can tell me, I just havent done this enough to listen and drive and say yep, thats dead nuts right there. And also the carb needs to be dialed in, which you need your timing set before doing that. So just playing with the timing until its right seems hard to do since the carb hasnt been adjusted either. So I wanted to get it real close to what it should be, then adjust the carb and be done. I have also heard some people say run it up to temp, shut it down, let it heat soak a few, fire it up. if it doesnt labor to start, give it a little more timing, run it, shut it down, do this untill it does labor to start, then back off 2 degrees and call it good. dugan, yeah the timing cover I used is exactly the same, I just needed one with the fuel pump provision and dipstick hole. otherwise it was an identical swap. This is what my pointer and damper looks like, its a professional products damper and I believe a 302 mustang pointer setup.
Your timing is not off, or is it is, it is not by much. It is either the wrong timing tab for the balancer, or vice-versa, or the balancer's outer ring has slipped. Go with what Gotgas says, and you will be just fine. As per your picture, your timing chain is set at the R2 position, which means that it is set up 2 degrees behind the "normal" position, in relationship to the crank. Advancing or retarding the cam in relationship to the crank wont make more or less power per-se, but it will "move" the power and torque peaks up or down a bit in the RPM range. It should not have a large effect on initial timing.
if the cam is installed retarded, thats gonna throw the timung back a few degrees regardless of what the balancer and pointer says... any particular reason it was installed retarded?
This is how the cam was installed. Jay ground the cam and this is how he installs them. http://www.camshaftinnovations.com/FTT_InstallingCam.htm
Care to explain? The balancer and pointer have NOTHING to do with where the cam is timed. TDC is TDC and the balancer and pointer, if properly set up will read correctly even if there is no cam in the motor - they are not related. Since you then use the marks that are now considered correct and you move the distributor to get the proper timing, all will be well. The ONLY thing that could make your sentence remotely correct would be if someone timed the motor and then retarded the cam without resetting the distributor, then yes the timing would be retarded from where you started - but the balancer and pointer would show that it was now retarded.
Is it bad/dangerous to use a screw in piston stop with these aftermarket alum. heads. I read another guy say it was because "Some cylinder heads, especially AFR, have the plug pointing right at the exhaust valve and PARALLEL to the piston face. Bad news. Been there." I sure wouldnt want to make things worse here. I am using canfield heads, which are very similar to the AFR. This would be OK if I "disabled" both rockers/valves on #1 during the test wouldnt it?
If you take it easy while doing this, it will be fine. Take out all of the plugs so you can turn it more easily. If the stop would make contact with the valves, by all means, pull the rockers for the test. If the plugs were truly parallel to the piston face, the insulator would have to be pointing down at a 45 degree angle. I have yet to see a set of heads like that. They may be out there, I have not seen them all. Or, advance the timing until it pings under load, and then back off until it stops. That's the way my g-pa taught me.
Yeah I am going to probably go with that method for now. Reading about the piston stop, seems like its best used with a degree wheel to... I was/am just scared of detonation and dont want to advance it to much and then go get on it and bad things happen. What is the best way (or how do you) to know or tell before driving it that you could have to much, since we are unsure of the pointer being correct?
The piston stop is used to confirm balancer/timing cover markings to show where TDC really is compaired to the marks. That allows you to make correct marks if needed. Degree wheel is not needed or wanted for doing this.
maybe i should have said VALVE timing... but that shoulda been remotely obvious... cam installed retarded= valves opening later than if it were installed straight up. correct? balancer installed correctly and lined up with timing tab means at TDC the the valves are opening later so consequently, the pointer would be pointing at a different spot on the balancer as the valves begin to open.. correct? if i'm "remotely" right it's a miracle. correct?
Flyer : The question here by the OP was IGINION timing. Cam timing has no bearing on the iginion timing pointers/marks.
I wondered if the OP was adding to his own confusion and I think you've hit the nail on the head here. Cam timing is relative to the crankshaft. Ignition timing is also relative to the crankshaft. But cam timing and ignition timing are independant of each other. Ignition timing by "ear" and by "seat-of-the-pants" can work OK most of the time. But there's something re***uring about knowing how much mechanical advance and vacuum advance your distributor has. Combine this advance with your initial static advance and now you know exactly what your total advance is. Just remember that increasing initial advance is going to effect the total timing as well. It may improve your idle and off idle driveability but give you too much total timing when you've really got your foot buried in it.
It seems that nothing is simple. Finding TDC seems simple enough, and it is if you rely on the balance marks and never have a reason to doubt their accuracy. But if you step out onto the slippery slope to verify true TDC, the piston stop method seems to be the most accurate. Since all other timing will be related to crankshaft position it's nice to have it correct. It's always easier to check TDC against the balancer/pointer you intend to use during ***embly- If not - it'll turn your hair gray. Good luck
I don't know about you guys, but I prefer using the tried an' true method for locating TDC.... With the heads off and a mag base with a .0"- 1." travel indicator... Once you bring #1 piston too TDC, check the balancer pointer and the TDC mark on your balancer.. If they don't line up, either tweak the pointer so it does line up or replace the balancer with a new one,,, Another way would be to "remark" "0" on the balancer if it's just off a degree er two... It's your call! That's my .02 cents worth for today..
Ok, thx for the info. On the piston stop. I have read around about piston stops not being long enough for some aftermarket heads, or certain pistons, etc.. I am running canfield alum. heads, think it will work ok? The other major question I have is this, how do you know how far to screw it in? Accurate TDC can only be as accurate as you are setting up the piston stop, right? Friend of mine said he thinks its more accurate to pull the valve cover and watch the 2 valves and make your 2 marks when the one stops (mark 1) then the other starts (mark 2) take the center of that. (I simplified that a lot figuring you know what I mean)
I see you have one of the double yoked bister packed superduper with lightning holes timing gear set ups.I now just put them in the garbage when people bring them here. I had one out 7 degrees from realitiy and one as bad as 11 degreees. The 7 i fixed with some creative key work but the 11 I finally put an end to this **** anf filed it in the round file. I use now only Cloyes ot Melling OEM set ups single keyway preferred and if I need to move it I use the i old methods. It appears the quality of these fancy dingdangs is not there. It is mpressive that you sort have have that figured out already in a round about way. You know something is wrong and you know most likey where. A simple swap to the old stock style roller truck chain and gear set up will provide an instant cure for cam timing erros If you need to advance it for the cam an offest key or a offset ****on works fine. If you insist on using the triple keyway set up a then use a cloyes 3 way as cloyes has some of the highest standards for accuracy in the industry. I often wonder how many folks have an otherwise good engine but not up to snuff performance simply because of one of these fancy timing setups. I am betting 1000s. If it wasnt degreed in no one would ever know. First one I thought maybe it was just a fluke and just that one. After a few more were off more than reasonable I said to myself I am wasting hours fixing something that doesnt need to be fixed simply because of an inferior inaccurate part. NO MORE! Sure it is nice to be able to advance or retard the cam without the extra work but if the keyways are not cut at 0 +4 and -4 but some other close by spot then the engine will never run quite right. Since we specialized in squeezing extra ordinary performance from relatively ordinary parts we double check everything we can. Otherwise it might have gone unnoticed in a regular rebuild shop. Don
a lot of the timing chains are set up for retarted cams,emmision thing. get a good aftermarket timing set with the o degree set up and try setting the cam straight up and see if the engine runns better.advancing the cam creatates low end power an retarted cam will produce upper end power.i have seen stock cams retarted as much as 16 degrees
All good information and remember, never trust a cam gear as right, lots of lost power right there! And alot or lost power if you don't set the curve correctly in your dizzy, most hot street engines depending on compression and combustion chamber/piston dome will like 14-18 initial and 32-38 total all in around 1800-2400. And last, if using MSD boxes, do not use adjustable lights and use either a self powered light or a seperate battery to power it up as these can/will cause inaccurate readings. (From MSD techs) Good luck with the tune.
As the chain stretches, it retards the timing. Are you sure that motor only has 80 miles on it, it doesn't look that fresh in the pictures. No offense intended.
tiredford, I agree, doesnt look new, but it is. The engine is all new built by an engine shop, other than cam install and heads, top end etc.. It just sat for a year after being built, which is why it looks that way. Still had all the ***embly lube on the parts, never had any oil in it. I am the one that put the 80 miles on it, I had to finish the build and then I dropped it in and ran it. Oldgaurd you bring up an interesting point here. I am use a sears adjustable light. I am not running a MSD ignition box and coil with a duraspark distributor, but I did have this problem when running an HEI distributor and no MSD also. I could try another light, I have an old school one that has a plug wire on it to plug onto #1.
I have a suggestion. I had my carb on the 368 rebuilt by Pony. The old T-pot had boiled over too many times. Pony insists that we should all throw our timing lights away and simply hook up a vacuum gauge. There are two simple steps. Adjust idles screws for maximum vacuum. Reset idle stop screw. Then advance spark until highest vacuum is reached. Reset idle screw stop. Do this twice. Then take it for a test drive. If it knocks the spark is too advanced. Reduce advance until knock goes away and you're done. Obviously this won't work if you're a tooth off, but has worked extremely well on the dozen or so cars I've tuned by vacuum alone.
I'm thinking you issues are more distributor advance curve issues than anything else. If you set max advance to 36 degrees, and it drops to 11 degrees at idle - you have 25 degrees mechanical advance - if you want to idle at 16 degrees, you need to restrict the mechanical advance to 20 degrees - which is about right for a performance engine. Vacuum advance should not be used when you set timing like this - vacuum will probably over- advance your engine . I set up racing SBC engines to 36 deg total, 20 degrees mechanical all in by about 300 rpm - as recommended by GM Race guys - works great . I don't believe in the "set it where it sounds good" method for modified engines - you are going to be off of optimum everywhere except where you listen......
fms, I am learning as I go here, so bare with me but, I dont think my whole problem is the curve. My problem is dropping the dist. in at 11* BTDC (according to the balancer) and then having the timing light tell me its 6*. I agree about the curve and mech. advance, which I will address once I feel comfortable that I know where TDC truly is in relation to my pointer/balancer.
One more time !! Use a piston stop to physlicaly confirm where the timing pointer/marks are in relation to each other. Once you have a true zero install the dist and set the timing to whatever you want with the light. You can not just flop the dist. in at a certain degree # and expect the light to exactly agree. I run nothing but points iginion and do my intinal static setting with a test light in series with the points. I still use a piston stop on every new build to comfirm the marks relationship.
I am I am Just bought one at lunch. Unfortunately they didnt have one with the bleeder hole to let air out though. My plan is to bring it up to TDC and go just a hair past it (watching the piston or using an long dowel in the hole), once slightly past TDC and piston comes down slightly, put in the piston stop and screw it down gently until it makes contact with the piston. Mark the spot. Then rotate by hand clockwise until it hits again, mark it. Split the difference and see where it is in relation to balancer. Doing it this way will avoid having to turn counter clockwise and possibly loosening the bolt. Sound ok? Also will loosen the #1 rockers to be sure nothing gets bent in the process. The only thing scary to me is denting/marring the piston head. I know, easy does it, but sometimes when hand turning it will get tight then "jump" for lack of a better word. I will probably pull all the plugs to be safe and remove compression, but still... This is where I was reading about the procedure http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center
Remove ALL the plugs ,then do it the right by turning CCW till you touch the stop again. If the engine is so stiff that the crank bolt comes loose with the plugs out you got other problems ***uming you tighten the bolt up correctly in the first place. Bleeder HOLE ?? WTF ? I've made several stops out of a olg plug body with a nut welded on and a piece of alltread, enough clearance around the threads for any air to escape. If you are not a Gorrilla you will not damage the piston by touching the stop.
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