I just got done rebuilding my 364 nailhead and I put a TAperfromance cam it is the ta112 model. I had a machine shop degree in my cam and they said it was fine to install it with no advance. Right now it is running well at 14 degrees adv. but smells really rich. Is this a problem if it is how should I fix it.
??? Did the machine shop mean they did not need to advance the cam? I would not think that they would tell you not to advance the distributer. I assume you have 14 degrees total advance on the distributer, I would move it up into the 28-32 range. This has been covered on several threads in the past. I would check with the machine shop to make sure they did not mean the distibuter needed no advance.
Yeah sorry if i wasn't to clear about what i was saying. The Machine shop did not feel they needed to advance my cam. But I have been trying to set the timing by advancing the distributor. In the past I have always worked on stock motors and set the timing according to the manual. With this new cam I have to throw that all out the window. I am not sure on how to find out the total timing or anything like that. I went out and bought a timing light with the advance dial on the back I am just worried something wasn't done right at the machine shop and i am having to make up for it somewhere else. I may just sound like a fool but I just started working on cars about a year ago and am just little paranoid about messing up my dream car.
Ignition timing I use a 'dial back' timing light as well. I just set the dial to the desired amount(i run near 40 degrees total) and keep rotating the distributer until it reads at '0' on the crank. The light makes up the difference in degrees. You will notice that the advance will increase with engine speed until you get up around 22-2500 rpm (depending on how your distributer is set.) There are different weights and springs you can purchase for the distributer to adjust how fast and at what rpm your timing advances (mechanically through centrifical force) but if you don't have much experience with that I would leave it up to some one who really knows what they are doing. There used to be one or two guys on this board who set up distributers for a living. You might want to do a search for distibuters or ignitioin timing on this board and contact one of them. Good luck, If I can help at all, just ask.
could you give me a little bit more of a detail on how to exactly do this i have a dial timing light at what rpm do I check for total advance. And do i leave the vaccum advance hooked up. I really appreciate your help.
Hook up the dial back timing light. Then disconnect and plug your vacuum advance. At wide open throttle, engine vacuum is near 0, and vacuum advance is nonexistant. You want to set up the mechanical advance, so that at wide open throttle, you have maximum performance. Most Buick V-8's like between 30-34 degrees total. If you turn the dial to say 32*, and point the light at the balancer, you will see the timing mark a good distance below the timing tab. As you rev the motor, the timing mark will move upwards towards the tab. This is the mechanical advance working as engine speed increases. At some point as you rev the motor higher and higher, the timing mark will move no higher. This is the point when all your advance is "in". If it reaches the 0 on the timing tab, you have 32* total. If it falls short, you need to move the distributor so that the mark reaches the 0. For maximum performance, you want all your advance in before or at 2500 RPM. A stock distributor will not allow all the advance in until approximately 4600 RPM. To change this you need to replace the stock springs with lighter ones, that allow your advance in earlier. When you bring in your mechanical advance in earlier, and then hook up your vacuum advance it may ping. To remedy this, you have to limit the vacuum degress to 8-10* Normal is 14-18* The best way to set up your distributor is to buy the Crane adjustable vacuum advance. It comes with 3 sets of color coded springs, and an adjustable vacuum cannister. The Jegs part number for the points distributor is 270-99601-1, 22.99. I would install the springs in this kit first, so that you can rev the motor safely to where all your advance is in. I don't think you want to rev the motor up to 4600 to adjust the timing. If you use the two silver springs in the kit, your timing will all be in around 2200 RPM, which will make it easy to adjust your total timing. Get the kit first, and we will go from there. Hope that helps.
It isn't, just the Crane kit part # is different, 270-99600-1, same price. Another good idea for the HEI is to use an external coil. Get the MSD coil cover, Jegs part # 121-8401, and get the 121-8200 coil. The coil in cap runs hot, and can limit spark.
I have pertronix ignitor 2 installed i think I know the answer but just wanted to make sure. That this kit will still do what i want.
Yes, it will. Depending on which pertronix you have, it may be more difficult to get to the weights and springs. I believe the early pertronix used a ring with magnets, that attached to the rotor mounting screws. Then there was a lobe-sensing model. In any case the Crane kit will work for you. When you get ready to limit the degrees in the vacuum cannister, post again. There is a better way than what Crane recommends.
Use the slowest idle speed you can without stalling or objectionable roughness. It's up to you to set it up the way you like.
There is a possibility, that IF your new cam has produced a lopey idle, that you may be down on manifold vacuum, and therefore subject to carburation problems, paticularly at idle. The type of carb used will also have a lot to do with this kind of problem. Another factor is compression ratio. If you have a cam with any amount of "overlap" (intake and exhaust valves open at the same time) and not enough compression (too low for the cam) you will encounter all sorts of idle problems,including running rich at idle. One way this is often manifested with a semi-radical cam is the need to increase base, or "curb" idle speed. If you go too far with the idle screw (not idle mixture screws) you will move the carb into it's off idle/transition phase, and will have an unstable fuel mixture--too rich. I have seen this many times. The 112 number in the cam grind probably indicates the lobe centers of the grind. 112 degrees isn't that radical, but depending on lift and duration, it could be if you have a low compression engine (below 9:00 to 1). Ignition timing won't have that much affect on basic fuel mixture, if it's close to correct. If your figure of 14 degrees was at idle, and before top dead center, then that should suffice, to begin with. Advancing the cam can help matters if you have a cam with lots of overlap, and a (relatively) low compression engine, advancing the cam timing will boost low end torque. ----Zach Collie.
hey zach thanks for your info I bought 10 to 1 pistons from egge. I have gotten to the point where the motor will idle but is a little lumpy i let it run for about 2 hours the other day no problems sept for it is not all together yet and can't leave the garage. I it is just hard for me to time the motor because the it runs alot different now. I am just looking for some more info on fine tuning to get the most bang for my buck. I have gotten it close but just want make sure I am on the right page the TA112 is not much different then stock they told me it would give me about a 20hp gain i kind of wish now that I would of stayed stock but once it is tuned correctly it will all be worth it. Thanks for your help I really appreciate it.
larry, I just got done playing with the timing a bit more I messed around with the carb mixture screws and was able to get the motor to run at stock timing it sounded really lumpy and vibrated like crazy the motor seemed to settle down around 12 degrees advance I kept advancig it until about 20 degrees where it just shutdown. I set it back to 12 degrees set the idle to 600 and it starts up quicker without hesitation like it did around 14. I am wondering if you still think i should use that kit it should be here tommorrow. Will I be able install everything and tune it with my little experience. Thanks again.
Yes, The kit will work, and it is very important to know your total timing. Initial timing of 12 is good, but what does it advance to? If you put the lightest springs in and rev the motor to 2000 RPM, you'll be able to see exactly what your total timing is (initial+mechanical) Aim for 32*. Then see where your initial is.
Hi Larry, i am still waiting on my kit from Jegs then I will need to ask you a few more questions too. thanks Bill
hi larry i just recieved my kit from jegs. It looks really easy to install I will the springs in right that sounds easy but the vaccum advance part with the limiter plate sounds a little difficult. If you could please give me some info on this portion i would really appreciate it.
Crane suggests that you mount the limiter cam onto one of the cannister mounting screws. Then the cam is pivoted so that one of the notches on the cam actually pushes the link further into the cannister. The total vacuum advance is limited in this way, because the link moves a shorter distance from it's starting point. Unfortunately, this also advances the base timing, by 2*(for each notch). It also preloads the spring which controls the rate of vacuum timing. What this means is that for every notch you move the cam, you have to retard the timing 2*. BUT, there is a better way. If you mount the cam in between the cannister and the arm, it will restrict the the links movement into the cannister, and not move your base timing. To do this, you drill a 9/64" hole, and then tap it with an 8-32 tap. Use a short screw to mount the cam as shown. When you rotate the cam one way it locks out the vacuum advance totally, the other way restricts it. 8-10* is usually best. Leave the vacuum advance disconnected, and experiment with different total advances, and spring tensions. Get the advance in as quick as possible without detonation. You'll be able to feel the difference by the seat of the pants feel, and by listening for detonation ping. Once you have optimized that, add the vacuum advance and limit it to 8-10*, run off full manifold vacuum. Check for part throttle ping. Use the allen wrench to adjust the spring tension inside the cannister. This spring adjustment controls how fast the vacuum degrees go away when you snap the throttle open.
