Advancing Timing Sbc

It has a mid-range Crane cam with cam timing @. The first step in adjusting engine timing is to disconnect the vacuum-advance unit. SBC's normally run 32-34 degrees total Mechanical advance. Distributor as to be advanced so that the timing mark, at idle, is almost at the 12 o'clock position to compensate for the timing retarding when accelerating. Thus running the timing completely locked at let's say 37* degrees. Which way do you turn it to advance and retard with the hold down clap slightly loose. Remove the spark plug wire on the original distributor cap that the engine timing is set from, and install it onto the UNILITE® Distributor cap post above the mark on the UNILITE® Distributor housing where the rotor had pointed. Chevy 350 block checked over, machined and set up for Marine crank, mild cam, stainless valves, roller rockers, rollered timing set, brand new cylinder heads etc etc. GM Chevy V8 HEI Distributor Mechanical Advance Re-Curve Spring Kit This H. The ECM ( computer ) controls the Spark Advance once the engine gets above 400 rpm. I have cleaned the engine but it's aged, because of this I cannot use a timing light to adjust the. If it pings at high rpm, you may need to retard the timing a bit. When you here the phrase "advance/retard the cam", it simply means to change the position of the intake valve closing point. I would also make sure you have everything setup correctly. What Happens When the Timing Is Advanced It has long been held, and demonstrated at the Club's Dyno Days, that advancing the timing to 13 to 14 degrees before top dead centre (BTDC) is a cheap way of achieving lower rpm performance in the Mazda MX-5 1. The distributor timing curve and initial advance settings were designed to accommodate a wide range of operating conditions, such as driving habits, weather, altitude, maintenance schedules, and gasoline quality. If this procedure is missed by even one tooth, engine damage can result. Initial Advance: Initial advance is just that, initial timing. I would also make sure you have everything setup correctly. A detonation limit is always the. I would second that on the thermostat being suspect. Valve timing is set when you degree your camshaft, and is not adjustable through the distributor. more importantly you should set the total timing which should be about 32-36 degrees. Its a cloyes true double roller and maybe had 1/4 inch of deflection with opposite side tight, so I think that is within tolerances, but not 100% sure. In this Hagerty DIY, Kyle Smith walks you through the process of adjusting timing on a Chevy small-block engine. This kit comes with 3 sets of advance springs to allow you to adjust the rate of spark advance from quick (Brown), to super-quick (Silver), to ultra-quick (copper). Or,get a copy of the 1927Capitol AA/1928 National AB repair manual,and it will tell you how to do the timing too. Restart the engine, and give it 12-15 degrees of advance at idle, and go for a spin. CAUTION: You must recheck your piston to valve clearance after advancing or retarding you camshaft timing. In order to increase an engine’s total timing, this slot must be elongated with. It is also known as vacuum advance, distributor advance, distributor spark control, automatic spark advance, distributor vacuum advance, and advance timing mechanism. This article will be especially helpful on non-stock engines or engines with a non-stock distributor. Setting initial timing on a small block Chevy (SBC) John Milmont on October 20, 2012 — 7 Comments This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run. Effect Of Changes In Cam Timing And Lobe Separation Angle The following tables illustrate how variations in lobe separation angle and cam timing will effect the behavior of the engine in which the camshaft is installed. Adjusting Timing for Ping If you are experiencing "ping" at specific locations (TPS vs RPM), this document explains how to make timing adjustments to remove that pinging. The amount of advance added by the distributor, combined with initial static timing, is “total timing” (i. Dial indicator,. I was watching my timing advance in real time yesterday. The amount of advance added by the distributor, combined with initial static timing, is "total timing" (i. The valve seat timing of the Z-80 is intake opens at 57 and closes at 93 and exhaust opens at 93 and closes at 57 checked at. 5:1 compression make peak HP with 38-42 degrees total advance. A popular crate motor for repowering classic trucks on a budget is the 350 Chevrolet small-block, PN 10067353. and start the engine. Chevy Silverado 5. Its no different than a Chevy, don't worry about initial timing at first, get a dial back timing light and set advance to 36 degrees at 2800 RPMs then see where the idle timing is but if you want to just set the timing mark to the top of the tab and drive to check for pinging and starting issues then move down the tab 2 degrees until it don't ping and it starts when hot. Total timing, theoretically, is then the initial + mechanical. Also, what should a small block Chevy 350 idle at? I heard about 700-800 RPM but just wanna be sure that is correct so I can finish up with all the timing issues. Advancing the timing of an engine means that you are moving the combustion up in time. The rotor turns in a clockwise direction in a sbc so to advance the timing you turn the body of the distributor counter clockwise, and to retard the timing you turn the body clockwisethat is what you want to do. Ignition Timing for Modified Engines An often neglected but important area when tuning an engine is the ignition system. For a given RPM, there is an optimal ignition timing. i would set the initial timing at least 12. Can be any size, Larger is more accurate. Dial indicator,. Timing And Vacuum Advance 101 SPARK TIMING AND CENTRIFUGAL AND VACUUM ADVANCE IN TERMS THAT NON-ENGINEERS CAN RELATE TO B Y J O H N H I N C K L E Y I n this day and age,when modern automotive powertrains are com-puter-controlled and engines don't even use distributors anymore, the knowledge of what distributors did and how they operated to. 1988 chevy silverado K1500 5. Everyone says that the amount that the vacuum will add to the timing is fixed and that adjuster just determines at what vacuum it starts adding the timing. Worn centrifugal advance bushings can cause excess mechanical advance. Advance Curve Kit is designed to fit all GM & Chevrolet H. Valve timing is set when you degree your camshaft, and is not adjustable through the distributor. -Subtract the minimum (initial) timing (step 1) from the maximum timing as recorded in step two. At 2000 I'm still at 0, so now my spark is igniting when my exhaust valve is already open!. I recently rebuilt my 1990 k1500 350 tbi and upgraded to vortec heads. In order to increase an engine’s total timing, this slot must be elongated with. You really need a better timing light to fully determine what is going on here. 3: Timing marks are often difficult to see; this engine is equipped with a magnetic probe holder which may be used with special equipment On later model vehicles equipped with EST, the electronic spark timing must be disabled or bypassed to prevent the control module from advancing timing while you are attempting to set it. 5 compression and timing advanced as far as possible but still not pinging on 85. The Chevy 216/235/261 Tuneup Guide As with all of the content on this website, you can simply click on any picture to get its largest size. The motor is a stroked 350 (368) and has a wet sump. An example of total timing would be 12° initial plus 24° of mechanical which equals to 36° total. this vehicle is also a manual trans. 4 (July/August) of Pontiac Enthusiast. Setting the timing on your engine is one of the most misunderstood adjustments, the information on these pages will help you understand and answer all of your questions about ignition timing. It is a single wire sealed connector that has a tan with black stripe lead. The easiest way is to buy a timing light with an advance dial. The ideal ignition timing for power and fuel economy is just short of the point where detonation or pinging occurs, the correct ignition timing (the initial timing plus the advance from both mechanical and vacuum advance mechanisms) will cause the pressure created by the fuel being burned in the combustion chamber, that is pushing the piston. He reported that it gave a lot more low end torque and power but that there were other problems. When added together, these equal the total spark timing advance. Related Questions. The first pass at Bonneville was faster than we had ever been, 223 mph. Adjust the Timing and Throttle Stop until the Idle Speed and Timing are correct. i dont have the veci label on the fan shroud anymore. 4 and was still happy at 31 deg with 15 lbs boost. DISTRIBUTORS & HEI INSTALLATIONS Section 2 “Identification of HEI Ignition Systems" authored by Schurkey. To insure proper alignment of the distributor, perform the following: With the ignition OFF, connect the scan tool. It is a single wire sealed connector that has a tan with black stripe lead. Of course at Zero timing the motor will have a hard time starting so we need to advance it to about 15*-20* , so if we think about this the position we have it set at the distributor should have already fired #1 plug so study your rotation and think about which direction it rotates and turn the housing so that it indicates that the distributor. Timing covers all will bolt up, but you need to use the matching dampers and water pumps for '67 and '68. At idle it was varying 5-6 degrees. Valve timing is set when you degree your camshaft, and is not adjustable through the distributor. I was told from my father a while ago that far advanced timing is hard on the heads (valves). I think a basic description of timing might help sort out a lot of this. 3 liter engine i cant get a answer on my timing mark when setting with a timing light also my engine has a miss in it i cant get rid of. I am troubleshooting a 1970 Chevy truck with a 350 small block. Just got the exhaust on the 350 sbc and now I am hearing a ticking noise from under the valve cover for the first time. This advance is just the effect of the location of the magnets in the sleeve relative to the Hall-Effect sensor in the Pertronix module. The centrifugal advance adds advance up until about 3,000 - 3,200 rpm, and is not attached to vacuum advance. As you advance the cam you open and close both intake and exhaust earlier in relation to the crank / piston position. For instance, for most rotary and Ford TFI engines, we prefer to set the Fixed Angle to 20. 50 years of camshaft and valve train innovation. If the lobe center comes up as 110 deg. I would also make sure you have everything setup correctly. THE IMPACT OF VALVE EVENTS UPON ENGINE PERFORMANCE AND EMISSIONS Summary This paper seeks to provide an overview of the basic parameters used in the specification of valve timing in spark ignition engines. This is a discussion for the topic Big Block Chevy guys. hook up a timing light ,remove the and plug the vacuum line to the distributor and check timing,then with light still on,hook uo the vacuumm line,it should advance the spark at idle still,if not then vacumm advance is not working,just remove and replace. com FREE DELIVERY possible on eligible purchases. Ignition Systems Cheat Sheet for the Chevy Small Block For our budget-oriented purposes we find that conceptually at least, GM's HEI distributor is a near ideal choice in terms of practicality. , that only affect the efficiency of the spark, but the actual ignition advance supplied by the distributor. Prices will vary from state to state and from car to car, but they should give you a rough idea of what you can expect to pay. The vacuum advance- while important- is usually considered separately from total advance in most discussions on setting up a performance timing curve. As engine load or throttle position increases, the vacuum decreases, and so does vacuum advance timing. First, you should know that there are two types of timing in an engine: cam timing and ignition timing. Should be "all-in" by about 2,500-3,000 RPM's. Hang out at any race shop or racetrack for a while and you'll see somebody setting the ignition timing on an engine. Get the job done with the right part, at the right price. Chevy Small-Block V-8. The first step in adjusting engine timing is to disconnect the vacuum-advance unit. Ignition Timing with Modern Fuels Getting the ignition timing of your classic's engine right is a critical part of getting it to run properly. The adjustable knob helps you measure computer advance, as well as centrifugal and vacuum advance with the same device. Spark timing retarded to far will cause late combustion, losing the opportunity to take advantage of the most efficient part of the power stroke, at the top where the highest pressures occur. Can be any size, Larger is more accurate. "B" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1) What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles, including but not limited to Toyota, VW, Honda, Chevrolet, Hyundai, Audi, Acura, etc. In this way, we can maintain the clearest definition to make it easier for you to see the detail. If you have any questions, please call 1-877-ADVANCE (238-2623) or visit any Advance Auto Parts store. thank you. is in the fully advanced position. Low octane fuels ignite faster, thus require less timing advance. P0021 is the OBD-II generic code indicating that the Engine Control Module (ECM) has determined that the bank 2 intake camshaft is more advanced than what the ECM has commanded it to be. One reader advanced his cam timing by slipping the timing belt by one camshaft gear tooth. What is your timing set at? on the board The No Wake Zone. The ignition timing can be checked with a timing light. GM Completes Rollout Of Variable Valve Timing In Its Truck Small Block V-8 4. I have chevy s10 blazer 4. 7 rebuilt in a shop and installed it back into my truck a couple months back. , that only affect the efficiency of the spark, but the actual ignition advance supplied by the distributor. This marker has numbers stamped on it representing degrees of crankshaft rotation before and after top dead center. you will also need more inital timing, all of my cams liked about 14-20 degrees inital and 36-38 total. Vacuum advance has absolutely nothing to do with total timing or performance, as when the throttle is opened, manifold vacuum drops essentially to zero, and the vacuum advance drops. Restart the engine, and give it 12-15 degrees of advance at idle, and go for a spin. Timing covers all will bolt up, but you need to use the matching dampers and water pumps for '67 and '68. Most Small Block Chevys like about 32-38 degrees total advance at WOT. You may need to adjust the Ignition Timing to 6 degrees first, then check the Tachometer. the only exceptions would be very high compression motors. can any one give me some advise on these problems. Since we know already that the HEI has 20 built into the stock mechanism the first thing we need to do is set the initial advance correctly- that means you need an initial advance between 12 and 18 degrees (you might want to retard it 2-4 degrees for daily street use just to. Remember that there are several small block timing covers and the timing tabs are welded on in different locations. Engine builders can refer to these characteristics often to determine the likely effect of any cam timing alterations they may contemplate. Other vehicles may require a bit more advance. if it has a points dizzy make sure the dwell angle is also set right. So if you go from a mixture of pump gas to straight 110, it'll want even more advance. Set it the same 34 - 36 total if you are not using vacuum advance, you will just have more initial timing at idle. To insure proper alignment of the distributor, perform the following: With the ignition OFF, connect the scan tool. so the vacuum advance can (connected to manifold vacuum, not "ported" vacuum - more on that aberration later) is activated by the high manifold vacuum, and adds about 15 degrees of spark advance, on top of the initial static timing setting (i. The ideal place for the timing to be is in the advanced region of the graph. The distributor is driven directly off the engine camshaft. Ignition Timing. The key here is to enter a reasonable timing advance for your engine while we verify that our commanded timing is the same as our actual timing. Vacuum advance has absolutely nothing to do with total timing or performance, as when the throttle is opened, manifold vacuum drops essentially to zero, and the vacuum advance drops. I would also make sure you have everything setup correctly. Since we know already that the HEI has 20 built into the stock mechanism the first thing we need to do is set the initial advance correctly- that means you need an initial advance between 12 and 18 degrees (you might want to retard it 2-4 degrees for daily street use just to. Wiki User 08/03/2010. We provide incredibly reasonable prices on quality parts. , if your static timing is at 10 degrees, at idle it's actually around 25 degrees with the. Also note negative values wont work. Shop online for original OEM & replacement parts. On 2003-09-19 18:28, supportTHEezln wrote: well back to the timing issue. At Ignition Engineering in Anaheim, California, we specialize in distributor rebuilding and curving, blueprinting and custom timing advance curves on aftermarket and OEM distributors including AC Delco distributors, Bosch, Mallory and other brands for your GM, Ford, Mopar cars, trucks, boats, race cars and more. At 2000 I'm still at 0, so now my spark is igniting when my exhaust valve is already open!. 40mph fast ball is like 87octane. Additionally, eliminating vacuum and centrifugal advance results in a simpler and more reliable distributor. Shouldn't they be much closer to each other in tuning?. if the motor is running an after market cam you may need to play with the timing to get it right but around 5 degrees should be good. Valve timing is set when you degree your camshaft, and is not adjustable through the distributor. As soon as the engine starts and a vacuum is produced, the vacuum advance mechanism advances the spark to about 18 degrees BTDC. Boost plus over-advance equals disaster at high fueling levels. If an engine will not run, but then starts after advancing the ignition timing A LOT then the timing chain has probably skipped a tooth and is about to fail altogether. 1988 chevy silverado K1500 5. the only exceptions would be very high compression motors. To establish the correct advance curve, the vacuum advance and mechanical advance in the distributor must work properly with no binding. , that only affect the efficiency of the spark, but the actual ignition advance supplied by the distributor. If it pings at high rpm, you may need to retard the timing a bit. should be idling around 30. A popular crate motor for repowering classic trucks on a budget is the 350 Chevrolet small-block, PN 10067353. Also note negative values wont work. advance line, hook up a timing light and read the timing while you or a friend opens the throttle a little. Before computers the distributor had at least a mechanism to advance the spark with increasing RPMs. However, when the engine heats u. I cant get timing set correct on my chevy truck it it 93 1500 4wheel drivewith 4. The reading will drop off if you advance too far, so turn the distributor counter-clockwise (retard timing) to go back to the peak reading on your gauge. Power production isn't our main concern, longevity is. If youíre looking for a small-block Chevy that makes big-block power, weíve got the engine for you! For the ultimate GM Performance Parts small-block crate engine, choose the ZZ383óa combination of Fast Burn aluminum performance heads and a 383 stroker small-block that can add up to 425 horsepower and 449 lb. Timing Chain Cover Vortec Oil Filter Housing & Bolts Cam Sprocket & Double Roller Timing Chain Accessory Bracket If interested or have any questions please text or call Ray at show contact info. The Causes of Internal Engine Knock, and How to Eliminate it. The Advance Auto Parts core charge presented to you online today with your item is representative of the most common core charge. the only exceptions would be very high compression motors. The vacuum advance canister, located on the side of the distributor, provides additional timing only when the engine is pulling vacuum. Checking the timing yesterday, I found it at 8 deg BTC, where spec is 6 deg. Shouldn't they be much closer to each other in tuning?. If either are worn the timing can be erratic at certain rpms and steady at others. Because there is no distributor adjustment, the only way is the mechanical adjustment with our IPP Cam Gear here. Advancing overall cam timing: Advancing overall cam timing is better for low-RPM power. The motor is a stroked 350 (368) and has a wet sump. 7LT Timing Advance Wire ? Well I am trying to set the timing but there is only one problem, I can't find the timing advance wire and NO! it is not near the distributor and no it is not tan with a black strip, I also checked behind the glove box and near the fuel pump relay on the fire wall so where the heck is it?. Most Small Block Chevys like about 32-38 degrees total advance at WOT. advance line, hook up a timing light and read the timing while you or a friend opens the throttle a little. timing curve when used with 12° initial timing set at engine idle. As stated above I run only centrifugal and no vacuum advance. Dial indicator,. THE IMPACT OF VALVE EVENTS UPON ENGINE PERFORMANCE AND EMISSIONS Summary This paper seeks to provide an overview of the basic parameters used in the specification of valve timing in spark ignition engines. , the 34-36 degrees at high rpm that most SBC's like). The COMP double roller timing chain and GM distributor are brand new as is the MSD coil. For example only, we will use the ISKENDERIAN 283-350 Chevy Z-80 cam in describing the proper cam-degreeing procedure (Figure 13). The Advance Auto Parts core charge presented to you online today with your item is representative of the most common core charge. Retarding is like swinging to late. What is your timing set at? on the board The No Wake Zone. I would also make sure you have everything setup correctly. Turn the crankshaft with a ratchet until the timing notch is visible. to advance timing rotate distributor body counter-clockwise, thereby moving each contact. I set my initial timing the same as you. Check to see what your total timing is when it's fully advanced. I don’t know much about Chevy engines so any help would be greatly appreciated. Most also have one or two vacuum advance mechanisms. more importantly you should set the total timing which should be about 32-36 degrees. Spark timing retarded to far will cause late combustion, losing the opportunity to take advantage of the most efficient part of the power stroke, at the top where the highest pressures occur. Below are some sample costs for having the timing chain replaced at some of the leading garage chains in the country. First, try the initial timing at 8 degrees, and change nothing else until you try it. Looking at the engine from the front of the car, Which direction do I turn to advance the timing on a small block 340? That was a serious post. Now, you can have our championship winning technology in your Camaro, Corvette, Chevy Truck, other LS or new LT equipped vehicle. Now that I have it back together it will only run with the timing advanced to over 25 degrees PTC and when it does it runs terrible. I’ve got a knocking sound and it seems to go away when I advance to timing. 030 over 350 ) seems like it doesnt want to run as well if i advance the timing - ie turn the distributor counter clockwise. There has been a lot of mail concerning how to set timing with an unknown engine. Vacuum Advance With Roots Style B&M 144 Supercharger Hi, I know this is mainly a blow-through board,as we own a couple,but I have a question about the Vacuum Advance with a "roots stlye" B&M supercharger on a 350 sbc. In this way, we can maintain the clearest definition to make it easier for you to see the detail. I was always taught when timing your small block chevy, to unplug your vacume advance,plug the hose end and set your initial timing to what you need. The timing couldn’t have been more ideal as SBCA’s Best Way to Frame website was just taking off. Its a cloyes true double roller and maybe had 1/4 inch of deflection with opposite side tight, so I think that is within tolerances, but not 100% sure. Turn advance knob until moving mark is aligned with stationary “0” degree timing mark (Top Dead Center). The dots in the gears where lined up when in stalled. The difference is the number of degrees of advance timing the Mechanical advance system is adding. The rotor turns in a clockwise direction in a sbc so to advance the timing you turn the body of the distributor counter clockwise, and to retard the timing you turn the body clockwisethat is what you want to do. can any one give me some advise on these problems. Setting initial timing on a small block Chevy (SBC) John Milmont on October 20, 2012 — 7 Comments This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run. Press and hold down button. DIGITAL TIMING LIGHT When connected to the battery, the timing light defaults to the 4-cycle, tachometer. Usually for stock chevy around 4-6 degrees btdc at idle. Tuned and modified engines have different. Also, it's good to look at the timing through a sweep of RPM, at idle a loose distributor gear or timing chain will usually not show up. If it is 36 to 38 degrees BTDC you are all set. this vehicle is also a manual trans. , that only affect the efficiency of the spark, but the actual ignition advance supplied by the distributor. See details! Digital Timing Light Gun with Tach LED Screen | Auto Timing Light. Disconnect and plug the vaccum advance hose. Dial indicator,. Effect Of Changes In Cam Timing And Lobe Separation Angle The following tables illustrate how variations in lobe separation angle and cam timing will effect the behavior of the engine in which the camshaft is installed. There is nothing special about this ignition advance, it happens in all cars, all the time. The vacuum advance works best when connected to ported (or part-time) vacuum source, that is why the port is there. This kit comes with 3 sets of advance springs to allow you to adjust the rate of spark advance from quick (Brown), to super-quick (Silver), to ultra-quick (copper). 7LT Timing Advance Wire ? Well I am trying to set the timing but there is only one problem, I can't find the timing advance wire and NO! it is not near the distributor and no it is not tan with a black strip, I also checked behind the glove box and near the fuel pump relay on the fire wall so where the heck is it?. timing, and is not a good procedure for optimum performance. If either are worn the timing can be erratic at certain rpms and steady at others. thank you. There is nothing special about this ignition advance, it happens in all cars, all the time. I was told from my father a while ago that far advanced timing is hard on the heads (valves). Set it the same 34 - 36 total if you are not using vacuum advance, you will just have more initial timing at idle. What's the Difference Between Cam Timing & Ignition Timing? Contrary to what a lot of people think, cam "timing" and ignition "timing" have nothing to do with each other, anymore than a timing "belt" and a fan "belt" have anything to do with each other. As stated above I run only centrifugal and no vacuum advance. For instance, for most rotary and Ford TFI engines, we prefer to set the Fixed Angle to 20. The dots in the gears where lined up when in stalled. Ignition Timing. Ignition timing SBC w. advance or retard the whole curve but that should not change more than 5 degrees either way because rotor phasing will be affected. Start the engine. Another good tool for timing is a vacuum gage. Usually for stock chevy around 4-6 degrees btdc at idle. The COMP double roller timing chain and GM distributor are brand new as is the MSD coil. The timing of the spark is measured as the number of degrees by which the crankshaft is short of. The easiest way is to buy a timing light with an advance dial. 4 and was still happy at 31 deg with 15 lbs boost. i have a sum-1104 cam in a sbc and it only. With the vacuum advance disconnected and idle around 700 set the base timing at 4-5 degrees before tdc. Displacement. Domed pistons and poor chamber shape/size block flame travel and hurt mixture motion. The Causes of Internal Engine Knock, and How to Eliminate it. Advancing the timing will lean out the A/F ratio of an engine. An example of total timing would be 12° initial plus 24° of mechanical which equals to 36° total. The "A" camshaft is either the intake, left, or front camshaft. It has a mid-range Crane cam with cam timing @. It’s all in the timing. Since then the service light has come on for a few days at a time then goes off. You do have to be careful on a street car at high vacuum part throttle not getting too much vacuum advance to cause detonation. Also, it's good to look at the timing through a sweep of RPM, at idle a loose distributor gear or timing chain will usually not show up. As soon as the engine starts and a vacuum is produced, the vacuum advance mechanism advances the spark to about 18 degrees BTDC. Remember the value that you set here. Boost plus over-advance equals disaster at high fueling levels. Initial Advance: Initial advance is just that, initial timing. Ignition Systems Cheat Sheet for the Chevy Small Block For our budget-oriented purposes we find that conceptually at least, GM’s HEI distributor is a near ideal choice in terms of practicality. If this procedure is missed by even one tooth, engine damage can result. This ad-vance was similar to “centrifugal advance” in that it is purely RPM-related; there is no provision to mimic vacuum advance. , the 34-36 degrees at high rpm that most SBC's like). tower on the distributor cap,and the points are just starting to crack open. 7L Vortec, Timing advance connector C/K Car Forums. I suspect it is an after market or upgrade system, since the bell housing tag on the engine has point gap and dwell specs. See details! Digital Timing Light Gun with Tach LED Screen | Auto Timing Light. The Cad is a bullet compare to the Sub. Tools required: Timing light, 3/32 allen wrench, vaccum gauge with long hose, vaccum source ("Mighty Vac"), and a friend or helper. Advancing overall cam timing: Advancing overall cam timing is better for low-RPM power. The Chevy 216/235/261 Tuneup Guide As with all of the content on this website, you can simply click on any picture to get its largest size. Ford 351 Cleveland Engine Ignition Guide: Timing- Covers Engine Building and Performance Updgrades to the 351C, 351M, 400M Ford Cleveland Engine. A street/strip car that runs on pump gas may “ping” with this much spark advance and will require less initial advance or heavier springs to slow down the “curve. I have chevy s10 blazer 4. My personal opinion is if your engine is operating under optimal parameters on gasoline, then based on the flame speed of ethanol and the testing I've personally done, the engine should develop max efficiency on E85 with slightly LESS advanced timing. Shop online for original OEM & replacement parts. DodgeCharger. Adjust the Timing and Throttle Stop until the Idle Speed and Timing are correct. This is because the valves are closing a little sooner. com FREE DELIVERY possible on eligible purchases. There is nothing special about this ignition advance, it happens in all cars, all the time. You can then turn the distributor 1/4 of a turn clockwise to advance it enough for the motor to start. Unlike the SBC and other motors with adjustable distributors, where you can adjust the total timing so that the events take place earlier for mid to high RPM use, this cannot be done on the Chevy Cavalier. The engine speed operating range affects where the timing is the best. Remember that there are several small block timing covers and the timing tabs are welded on in different locations. When I rev it up it starts advancing the timing with the vacuum hooked up which is normal. The distributor timing curve and initial advance settings were designed to accommodate a wide range of operating conditions, such as driving habits, weather, altitude, maintenance schedules, and gasoline quality. Vacuum advance has absolutely nothing to do with total timing or performance, as when the throttle is opened, manifold vacuum drops essentially to zero, and the vacuum advance drops. 28 degrees is max recommended advance on vortecs, and 32 degrees on older heads. I just installed a timing tab and it look like the balancer has slipped because good clean idle sits at about 50 BTDC (almost at the very top of the balancer). Start the engine. Keep adding 500 degrees and writing down the information until the timing no longer advances further with increasing RPM. The adjustable knob helps you measure computer advance, as well as centrifugal and vacuum advance with the same device. The ECM does all of the timing for you and uses the reference of "0" or "6" degrees to properly deliver the correct spark angle. When the load on the engine is light. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. It’s all in the timing. Fuel is not timed. The reading will drop off if you advance too far, so turn the distributor counter-clockwise (retard timing) to go back to the peak reading on your gauge. The ignition timing can be checked with a timing light. Advance Timing.