Bbc total timing. move up by 2 degree at a time.
Bbc total timing Now if one is serious about total timing, and one does not own a distributer machine one is only guessing with a dial up timing - Summit racing BBC distributor with vacuum advance connected to ported vaccum above the throttle plates - running 93 octane pump gas Have not touched the carb yet with the exception of the idle set screw. Believe it's a 290crane cam. idled at 1200 with 4. If you have an adjustable timing light, this is very easy to check. 17° on the other hand seems high to BBC's like 40 to 42 degrees total timing due to large diameter pistons (long way for the flame to travel). but 45 is to much total mechanical timing. With only 9. You have now set the timing for On the Israel-Gaza border - Timing is a critical factor in war. Jump to Latest 19K views 21 replies 6 participants last post by 154567 Jul 20, 2012. Set the timing with the vacuum advance hooked up so you can do vacuum and mechanical advances at the same time. Tags advance timing. Im at a total of 38 degrees and didn’t want to go any higher without some insight. This will give you 36 total and 4 + the vacuum advance at idle. If your total timing say in all in at 3000 rpm, hook up vac advance and go to 3000+ rpm to get total with vacuum advance. (Usually, 3,000 - 3,500 rpm will do it. I recently upped it to 42* total and the car seems to have gained a pretty decent amount of power. Start with 14-15* at idle,without the vacuum advance hooked up. The next thing to consider would be inlet temps. Reactions: hirschdalechevy and bucket. 035 with points. 20* initial and limit the total timing to 30 or 32* until you see what the car likes. Many, many engines run less than 20* under load, just look with a digital timing light on an old 366/427 tall deck in a 3 ton truck. 38 and 39 total timing was the same HP. I?ve read this is not uncommon, 540 BBC + 15psi Boost via Single Garrett GTX Stock looking, and fairly stock sounding HP and ET not determined yet! Mechanical advance, 11 crankshaft degrees (this is confirmed by the 35 degrees of total timing Starts coming in at 2000rpm and all in by 3000rpm, WAY TOO SLOW Now, with a moderate 540, I'd shoot for 10 to 12 initial 1967 Olds Cutlass 468 BBC/T400/type O, 3. Is this what people have found as what does actually work best? "Start the engine and adjust the initial timing. try getting a BTM unit for the 6AL and pull timing as boost increases. 050. No ping and starts good hot tells you you're at max initial timing for your motor. 25/1. Jump to Latest Not sure what total advance to use. 5:1. to 36@3000RPM, and a total with vaccum of 46-51@3000rpm, didnt know a big block was so much lower (first big block), so total adv. We found 80 horsepower From what I have read, it seems that 18 degrees initial timing is a good starting point for a BBC. You can adjust that as well by limiting the travel of the vacuum slot. R. Let´s say I have (vacuum advance unplugged) an initial timing of 10° BTDC at idle and set the HEI mechanical advance to stop at 36° BTDC. This parameter is used such that ignition timing does not under or over-advance as engine speed is increased. Somewhere around 737 737 lift. patrickonb wrote: ↑ Tue Feb 27, 2024 8:46 pm If you go to YouTube and look up "Ben Alameda Racing", Ben put out a really great video on timing chain vs gear drive vs belt drive about a year ago. Best of 5. This shows the power potential of a positive-displacement blower combined 1967 Olds Cutlass 468 BBC/T400/type O, 3. 0 diamond pistons Howard cam , duration 279/291 114 ls centerline 110 . Joined Aug 8, 2007 Messages 418. If this is the case set the initial to 4 and put your vacuum advance on a manifold source. Your idle will clean up and you can tune from there. Bigger cams need more initial timing and a richer fuel mixture at idle. 5" vac. When the numbers stop increasing, At 750 rpms it was in fact at 6 degrees btdc. The 2:1 ratio is from the difference in the diameters of the timing gears. e. 90@113 MPH Turned out I have my initial timing set at 20* BTDC and have the idle set at 1000 rpm. We usually set initial timing to between 12 to 16 degrees, far from the 22 to 24 the 4engine wants at IDLE. if you are having trouble with the starter make sure you have the battery grounded real well, alot of times that's what it is. Mar 21, 2021 #5 WFO The BBC would do well with A total advance of 36 degrees, and an initial of around 8 I've ran 38* total, LOCKED, timing with no vacuum advance, off and on since I built the 439 BBC that's in my car, and installed a year ago. Jump to Latest If you do end up with 32 degs in the dist (36 total - 4 initial) you may not want to run the initial at 12 as that would give you 44 degs total. This engine starts and runs GREAT at 20-25 initial timing. 040-. Currently i use the vacuum advance, so my question is should I sue the vacuum can also (no i dont set the timing with it hooked up , i know that much lol) Visit BBC News for up-to-the-minute news, breaking news, video, audio and feature stories. without knowing anything about the motor i'd say a rough guess would be 14* initial with around 20* of mechanical advance for a total of 34* should be a safe place to start with. I recommend the Delco Rapid Fires, #4 gapped at . Help I just had a engine builder tell me over the phone that my 454 setup should have about 10-12 deg initial timing advance, with maybe 35 deg total advance. Single plane 1050Dominator. wgwarren Discussion starter. " I think it's a great video with good info. C3 Tech/Performance - 454 mild build initial and total timing? - I'm not trying to bring up the whole timing issue. I am setting timing on my engine 396 BBC w/750 Holley Double pumper. e85 helps a bunch. COMP Cams® Three-Piece Billet Aluminum . So, how do we get the 24 IDLE Here’s the issue: somehow or another my timing went askew - after checking it last night, there was 22 initial and 44 total. Wildcatracing, Sep 30, 2012. Currently run 31 degrees and figuring on taking out 8 or so to be safe and tune form there. Those stock BBC heads have very slow flame travel and that big piston is a long way to travel across. My 454 runs best with 40. BBC's like 40 to 42 degrees total timing due to large diameter pistons (long way for the flame to travel). BBC Timing. I see most folks with Vortec heads say their engines like 34-ish degrees total. BBC advance timing. _____ Ok but with a 15. I believe the base timing was set at 14 but maybe it was 13 or 12. run 6 to 10° of initial advance (static timing advance) with about 22 to 24° of mechanical advance in the distributor, for a total of 28 to 34° of advance, which should be all in by 2500 RPM. ADVANCE @ 2500 RPM's, which is quite quick. Sep 5, 2012 #3 Re: Thunderbolt IV ignition questions and timing Thanks so much! P. BBC timing 32 degrees here too 11:1 static (only 30 lb boost though) #5. I have 28 degrees initial and 10 degrees of advance (vacuum advance disconnected). What timing should i aim for on initial You could then set your initial timing to 20° and still maintain 36° total mechanical advance. Runs great. Timing 454 BBC questions. Every other rotation the marks will line up at 6 and 12 and the other time at 12 and 12. 060 with Accel electronic no vac distributor. Jeff 64 El Camino Pro street, 496, T-400, 9" 3. This will give you 40 total. The shape of the combustion chamber (ie sbc vortec heads), domed pistons in a bbc, etc. Let me try to answer you. 8K views 16 replies 12 participants last post by johnmc Nov 27, 2015. What total timing should I be looking for. As for 540ci BBC Street/Strip motors in particular, 37* total is often the best. A typical street engine with a compression ratio of 9. Depending on the chambver and piston and quench area I would personally start at 14-16 degrees total at 16psi with a fat tuneup. Especially one that is fairly mild. Total timing requirements are dependent upon many variables. . 72 Chevelle. 28 to 1 compression, and with the motor being new, the builder said to only run 32* total for now. BBC L88 cam vs ignition timing differences. Timing is directly related to valve angle and the size of the dome on the piston and the SG of the fuel. Doug . If uncertain as to what the initial ignition timing should be for a particular engine, set the timing to the lower figure for initial start-up. This is the hottest setup possible with the Looking for peoples ideas on what is a safe number for final timing on a BBC, I'm currently running 20 static and have a final of 38/40 at around 4000/4500rpm. You will reach a point of detonation as well. I run 34 degrees on 565 BBC with BB2xtra cnc heads that have been angle milled 2 degrees. 663/. I appreciate your Every other rotation the marks will line up at 6 and 12 and the other time at 12 and 12. They set the base timing at 12 degrees BTDC & total timing is 34 degrees BTDC. That should get you in the ballpark and running. 250 stroke)Dart Big "M" 4 Bolt Race Prepped Block w/Splayed Caps, GM iron square port heads, solid roller camshaft (286@. Will be adding a small plate kit, 100 to 150 HP. 5 to 1 comp. Academic Achievement = Look around you 3. THIS SHOULD BE A GOOD SAFE PLACE TO START. No vacuum advance, minimal base timing, sometimes down as low a 8*. move up by 2 degree at a time. 045 some will say . Bottom line is set it where the engine is happiest 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. This is determined by using the timing light and raising the engine RPM until the timing stops advancing (and noting what it is). Jump to Latest IE does it limit the vac advance to only 10 degrees or total advance to 10 degrees. It would be big help to know what these motors like for total timing N/A. He suggested putting the engine in car and see how it does. 600/. I would suspect a starting point for total advance (initial + full mechanical} might be in the 34-36 degree range and go from there depending upon C. 38 -40 total mechanical is good. I brought the timing up slowly and noticed it got better and better as I did that. I've got a . Nothing wrong with 20 degrees advance at idle unless starting hot becomes an issue. I At 15*-18* initial timing, I get about 15" vacuum but the needle bounces up and down 1" or so (i. BBC News provides trusted World and UK news as well as local and regional perspectives. When you bump the initial timing up, the total timing can get out of hand. Question is, Initial Timing: 8 Degrees BTDC Total Advance: 32 Degrees . 1. 5 comp. out of box. * Whats total timing with vac adv unhooked/plugged at 3k rpm & higher to ensure total isnt higher at over 3k rpm? This engine was dynoed before it shipped and is rated at 454 HP at 5,800 & 477 torque at 4,200 RPMs. Even with 26 initial timing, the motor turned over easy and fired up on with only a blip of the starter. don't have the Crane kit then install whatever springs you have and check the advance curve with a dial back timing light and a tachometer, swapping springs until you get it close BBC timing, need expert advice, short novel. Yes, if anything 12 is conservative with that cam. Is it just The intial timing is what you have at idle and the total is what the timing is when your distributer has reached max advance, usually 2500 rpm or more. Souldnt the total timing reach 36-38 later, when the cam starts to "run" (above 4000 rpm) ? with less than 18 it doesn't idle ( this with the L88 cam) Now I use the comp cam Zl1 nostalgia cam and it needs more than 18 initial and 38 all in Hopefully the mechanical advance will be in the 20* range and put your total (without vacuum advance) to be 34-35* at around 3000 rpms. 5 c/r. Start at 10 initial and then check total and see how the car responds. You bring the engine up slowly to the highest reading you get. 48 to 52 degrees total with the vacuum advance will be good for highway mpg (low load, high vacuum, low rpm) Need som help with total timing with nitrous on my sbc 406 stroker . I have seen them with as little as 26* total timing, with no load. I would switch it back to running mechanical advance and get total timing somewhere around 36 degrees. 5 to 1,Torkker II intake with a Holley Put your timing light on it, read it and then pull your timing back 2 degrees. Don't have paperwork on hand right now. bbc timing. The base static timing is to get the engine to idle well. 427 BBC by S&S Speed Center, AFD, Enderle MFI by Spud Miller Sepanek Racing T400, Dynamic converter, Autoweld, Update: set timing to 40 total, been driving it around have not sprayed it yet! I have been through 2 sets of plugs so far, champion rc9yc first, We set the distributor up with the black bushing which allows a total of 18 degrees additional advance mechanical. I was out messing around with my timing the other day and I unplugged the vacuum line and the initial timing was around 12 I think. To find out what your mechanical 36 total is probably just fine, but it will probably wake up with more initial timing, so you're going to have to limit the total advance. All i know about it, 10:1 compression, Lunati Cam 110 lobe seperation 264/276 (i believe), light porting on iron heads. The more efficient the head and chamber the less total timing needed to produce this. The My bbc with mild perf cam little more agressive FT perf cam then yours & approx 9. I need to re-curve my distributor, so I can get more initial timing with the new cam, which is supposed to run best on 18-20* base timing. 8 posts · Joined 2014 Add to quote; Only show this user #1 · Nov 24, 2015. It’s a Motown bore 4. My 468 BBC on Methanol likes the timing best at 42 degrees. - As an example our old combo was a conventional 600ci BBC, and with a good bit more flowing nitrous than what it sounds like you have(we were around 3100pph) we were ~14* on total timing. And most likely you will be throwing a decent amount some boost at this. 88) AED 850 HO carb Straub cam, 288/300 . The only reason Hahahah Mark you pointed very interested questions. Tags 496 bbc bbc timing. We've found (dyno testing) that most of the engines we've done in the past 20 years or so have made disconnect the vacuum advance from the distributor and plug the line. The thing that you have to consider, however, is when you start to get beyond 12 degrees static base advance you need to know what the amount of centrifugal advance is and rope that in if the total gets beyond about 34-36 degrees. 3° per pound of boost, so say if it pumped 6 lbs, it would pull timing back to around 28° total. 641/. The block doesn't care where to install the marks (6/12 or 12/12), as long as they line up. I’m ditching the MSD timing computer & will leave the 6AL box & separate coil. and check setting on dist bench to which it is right on to manufacturer spec 24 degrees total mechanical advice starting at 800 rpm and in by 2800 rpm. It seems you have 20 in the distributor, so 36 plus 20 would be 56, which a way too much mechanical. 707 exhaust 109 LSA),Brodix single plane intake for a 4500 carb, Holley 1050 cfm dominator model # 9375, 2 inch primary Hooker super comp Depending on engine specs, cam timing, compression ratio, I'd like to see IDLE timing of 20 to 24 (initial and full manifold vacuum timing), and total (initial and mechanical) of 36 or so. I've got a 1970 Chevelle with a 1978 454 truck motor. Most instances 50 to 52. Jump to Latest 8K views 18 replies 8 participants last post by peterfilly Sep 22, 2009. Disregard the stock timing specs. performer rpm heads, bowtie/ rpm intake. Check it If it's a bone stock 71 BBC the OEM calls for 8 deg BTDC or 12 deg BTDC if it's 425HP with Auto Trans. In that situation, you do not want a bunch of ignition lead. The motor doesn’t really like it; runs hotter, and the idle settings on the carb are hyper sensitive now. 43 static compression ratio and even the c-16 fuel that was ran on the dyno I would have thought that much timing would rattled the hell outta that poor motor. Since he didn't mention it, I'm guessing maybe pump gas? If so, 35 degrees seems a bit much with 7 psi of boost. The total timing of 38* is all in at 3000 rpm. How much timing would a 427 Like to see? Initial, mechanical advance, and vacuum (when applicable). Joined: May 22, 2010 Messages: 11 Likes Received: 0. PowerAddict Chief Petty Officer. Set it for the total and let the initial fall where it may. I run 24 initial and 36 total, and i am at 14 pounds of boost right now. Rev the engine past the point where your mechanical advance is fully engaged. Have a 12 degree 632 combo on gas, single carb. Your cam needs at least 1000 rpms to idle. I'm pretty sure you want to start in the 16-20 deg BTDC for initial (no vacuum advance - no centrifugal advance) keep the RPM at like 7-800 when setting initial. What's the best Start at 32° and work up in 2° increments. I am happy 😎 This is how I set the timing on a sbc My 427 with 550 hp wanted 34 degrees total timing. Adjust the distributor to bring the mark you made inline with the "0" mark on the timing tab. Able to get the total down to 38, which is fine, but now the initial is 12. 5 DEGREES PER POUND TO START . Basically initial and total timing please. will have an effect on the total timing / advance used, I assume you have verified your TDC / timing marks as you indicated ECU and knock sensors. 700 net lift with 1. The carb is rated at 750 cfm. peterfilly Discussion starter 10 posts · Joined 2009 Add to quote; Only show this user #1 · Sep 17, 2009. Correctly setting it, however, Most BBC's like a bunch of timing, usually 38-40 total, very little advance and light springs so it jumps to it's happy place quickly. Also, dont set timing for total only which is best suited for race motors that see mostly mid to upper rpms not seeing any or very littl idle or low rpms use,setting timing for total only often results in the initial/base timing being substantially retarded which is no good for a street perf Need som help with total timing with nitrous on my sbc 406 stroker . Try 38 total mechanical, try 40 total, and try 42 total. Got a BBC Big chief with tunnel ram and dual quads. Joined Oct 20, 2018 · 1,315 Posts #21 · Oct 27, 2021. Now suppose you wanted set your initial timing to somewhere in between 14°- 20° BTDC but still maintain a total mechanical advance of 36°. I use a 10 degree bushing for 32 degrees total. The more initial the more it will blow the tires off on the bottom end, but you will run out of motor Blown BBC underdriven, MSD 6AL and magnetic pickup dizzy. no mixture or other adjustments have been made. I WOULD RUN 3932 OR VPOWER 10 PLUG SOMEWHERE AROUND 27-28 TOTAL TIMING THEN TAKE OUT 1. Basically it's a 454 version of your L-88. You'll also need to find out what your total timing will be, generally 16 BTC initial timing finished at 36* If you get pinging or hard to start when hot drop it a couple of degrees, but most BBC's run great at 16 initial. 454, 9. W. " So its in the ball park of what you guys say, maybe a little more conservative. 569 109. Anything under 40 degrees and it is So for 36* total timing you would mark your damper at 2. At 2,500 rpms it was only at 12 degrees btdc. 30 over 454, 049 oval heads, speed-pro hypers running about 9. MSD 8360 billet ready to run. I have the vacuum advance disconnected. 2. Any advice would be helpfull. I'm running 40* TOTAL timing with no problems on 110 octane gas. You want to aim for 34 degrees total at 3200 rpm. It contiunes to diesel on me. 04-16-2019, 10:25 PM More timing at idle can help but you will then need to limit total advance. Aluminum bb2 Brodix heads. With vacuum advance disconnected and plugged to set timing, I am at 17 BTDC idle timing and 37 BTDC total timing. 0:1 runs very well with around 36 degrees of timing (initial plus mechanical) for a rough total of 15-55 degrees of timing at light throttle I would think that before anyone can recommend a (total) timing number, you would have to know what type of fuel he will be running. Let´s assume I aim for maximum advance at around 3. 25:1 Compression 840 Rec Heads (2. 050, . Jump to Latest 21 - 39 of 39 Posts. It depends on your set up/ specs, but for most blown small blocks I would think 18-22 initial, with 32-36 total. Total timing (not total advance) can be in the 50 degree range with the vacuum advance hooked up when under cruise - As an example our old combo was a conventional 600ci BBC, and with a good bit more flowing nitrous than what it sounds like you have(we were around 3100pph) we were ~14* on total timing. 73 All the football fixtures, latest results & live scores for all leagues and competitions on BBC Sport, including the Premier League, Championship, Scottish Premiership & more. Base timing and centrifugal timing you set with vacuum advance disconnected. I agree that 5° initial timing seems way too low. BBC's like timing. - then keep the total around 35-40 deg BTDC, but I'm no expert. So, option 1, at the 22* initial setting plus the 21* bushing in my dizzy I 12-1 compression 565 BBC Shafiroff short block(4. Guess how its running! 35 total and 39 total make within 3HP on a wheel dyno and it gets better MPG at 35 total which was the 3 HP loss. I am drawing a blank and need to ask my buddy. You need to limit your total mechanical timing to 32-34 degrees by using a bushing in the dizzy. 636 lift and 256/266 duration @ . The simple trick is to lock out the dizzy and set total timing to 30*. Also It seems like I should work on fixing my vacuum issues first once I've corrected my vacuum then move to the vac advance? 2. , comp cam XM270 cam. With vacuum advance hooked up I have a all in timing of about 52 degrees at about 2700rpm. blownalcohols10 New Member. 6 rockers intake/exhaust . 17 at idle is good. 21 Every time I drop a distributor into a motor I always get the same questions and comments. Jump to Latest 9. With the blower pulling through the caby it is possible to get a high vacuum signal with the throttles wide open and under boost This "false" vacuum signal may pull on the vacuum You don't check total timing with distributor vacuum disconnected. alt 6153 Member. Jump to Latest I'd prefer 36* total, but I have 10. Suits BBC, Big Block Chevy. Read plugs and repeat. Motor makes about 1200 without the juice now and has about 14. Just some numbers. All, this video was designed to help others. Only show this user Old thread but I find 52 What would be a good number for total timing without Vac can connected? I've read as much as 40 for BBs. What is the best Timing for a Big Block Chevy with an aftermarket Comp Performance Cam Specs below ? I am using a NOS Delco Points Distributor and replacing Points with a Pertronix 1181 I, I changed the Vacuum Advance (Specs below) to a VC1765 starts @ 5-7 max adv 8 @ 11-13 and replaced the mechanical advance springs to Moroso medium springs. I recently had rebuilt a 1967 396 with iron heads, 60 over KB pistons, Comp 280H cam. Water bypass closed. But inlet temps will have an effect on total timing. Then hook up the vacume advance to the distributor and set your total timing to usually 32-34 degrees at 3000rpm. 7:1, Scat forged rotating ass'y, AFR 265 CNC's, Lunati 249/255@. Its fine for a naturally aspirated street motor that rarely sees the high side of 5000 RPM. If you're using the scale on the damper, whatever the reading that lines up with the 0 mark on the timing tab is your total at whatever RPM the distributor stops advancing. But once the engine is running, the engine should (safely) be run up to 3000-4000 RPM, and timing be checked such that it matches the commanded value. With a 4k stall etc it wouldnt matter because the engine would never be running at less rpm than where you would have full mechanical advance anyhow. and when i plugged the vacuum line back on it went about an inch off the scale sorry if I am confusing you guys i dont know what degree it is when its of the scale. I have a MSD Pro Billet Distributor with a black (18*) advance stop bushing and with 1 heavy silver spring and 1 light silver spring. "I would recommend idle timing between 8 and 14 degrees advance and total timing at 30-34 degrees advance. They might be small, but their personalities aren’t, and trouble is never far behind them! It would have 55° of total timing at Idle. If that is the I've changed out the cam in my 427 and now have a 286H (560lift/286duration), stock specs, 780 dual feed, power plus intake, 2" headers and flowmasters. 050 ex . I have removed dist. Dean- I'm not sure how the cam is dialed-in. Vacuum advance should not be connected and your power valves must be boost referenced. Set ignition timing at around 18 degrees initial, with 32 degrees total timing. a retarded timing reading). C3 Tech/Performance - 69 427 Total timing - Want to make sure Im setting the total timing correctly. Most BBC dyno tunes use 38 to 42 total mechanical timing for max power. Trying to come up with the right starting point for my mild build. P. That's what mine likes, and so do quite a few others that I'm familiar with. These motors typically run solid roller cams with around 265* to 275* or so X2 on what Bucket said, I don't think your dealing with a timing issue, but it wouldn't hurt either to check total timing to make sure the vacuum advance and mechanical advance are functioning. 050 cam, 1050 carb, 10. I had a roots blown bbc at 5lbs and made 20 dyno pulls testing timing. BBC's generally like 34°-36° total advance. You would still need to limit the VA as mentioned above. A: We would shoot for 34 to 36 degrees total timing at 2,800-3,000 rpm. Best power was also found at 36 degrees total timing. Joined: Among things, i decided to come on here and ask about timing, As im used to buicks. I am setting the initial timing at 18 degrees BTDC at about 750-850 RPM. Get all the latest news, live updates and content about the World from across the BBC. Believe they are 345's. Usually the engine is "all in" by 2800-3000 rpm. Small block Chevys (and most other GM performance V8 engines) perform best when the total timing (full centrifugal advance plus the initial timing setting with vacuum advance disconnected) is all in by C3 Tech/Performance - BBC Likes High Initial Timing - Hello everyone! Before anyone says: YES I?ve researched this before posting, but just want to solidify my findings. You set vacuum advance after you know you total timing. What is the total timing and at what rpm should it all be in at? What would you suggest the idle timing be at. , combustion chamber shape, iron or aluminum cyl heads, fuel, timing curve, etc. The builder says he regularly sees BBC start to float at that point due to the weight of the valves. With that number you'll likely need to limit the mechanical timing in the dizzy. Engine specs are; 540ci BBC, Dart 355 CNC heads, Solid roller cam, CSU 850 carb, F2 Procharger, air to air intercooler, 2900lb '57 Chevy. BTW,With the cam your running in a bbc 18 deg base + 18-20 deg mech in dist all in by 2500-2600rpm for 36-38 total is a great place to start where it should run well with minimal/+ - couple deg adj in timing to fond sweet spot. 050 with HEI . IH Scout/buggy-496" BBC, 10. With the initial timing set, lock down the distributor and have a friend bring the engine RPM up. I run 22 degrees initial but I have a much larger cam. I would be inclined to run the motor up to 3500 -4000 RPM's and recheck total mechanical advance just be sure. Thanks!! Edit: Found a pdf on the HT502 that says set for 4 degrees initial and 26 total. 1967 Camaro SS/RS Convertible L78 396 (MJ496) M20 (M22). Should we start with 36 and go up till it pings? So for 36* total timing you would mark your damper at 2. Sold 69 COPO clone, 461" BBC 11. Then rev the motor slowly until you have full mechanical advance. I changed the springs on the MSD billet distributor to the two lightest silver springs and the largest black bushing to limit the advance. Gear drive vs. 71malibuu · Registered. Is it common for roots supercharged engine to like that much at Idle, or would I likely have to limit the Vacuum Advance going that route? I could then pull 1. I know how to set the timing properly, I'm just looking for where guys run their 454's. Total timing relative to cruise RPM. Once C3 Tech/Performance - Timing a friends BBC 496 Stroker - HEI on ported vacuum with this cam https: What would be a good number for total timing without Vac can connected? I've read as much as 40 for BBs. My camshaft is a Crower mech roller with a . Get it warm again and retest. msd ignition should be adjustable so set the advance to 2 degrees, which will give you 4 at the crank, and set the initial to 36. Sep 6, 2012 This video shows how to set Initial Timing and Total Advance Timing on 350 Small block engine. Having chosen with great skill the moment to start its onslaught on the crowded Palestinian territory, there are signs that Israel's 10 deg initial is retarded by approx 8 deg for that cam which requires approx 18 deg base timing. I have it set at 12 degrees advanced at 750 rpm idle? Thanks JP Westech gets this 540-inch Roots-blown big-block Chevy on the dyno, where it makes over 930 hp and 880 lb-ft of torque. Look at the plugs after you beat on it, the timing burn mark Almost 43 degrees total advance at 6500 rpm. Should we start with 36 and go up till it pings? I just want to set it and let initial fall where it may for right now. 600 boreX4. Total timing, which refers to the maximum amount of ignition timing applied to the engine, is easy enough to calculate. Title is: "Timing chain vs. This shows the power potential of a positive-displacement blower combined C3 Tech/Performance - 502 ran at 46? total timing - Hi there, this is a :willy: experience report :ack: Had my new zz502 engine installed at a vette-specialist with more than 20 years experience and known for doing good work 396 bbc timing help The 1967 - 1972 Chevrolet & GMC Pickups Message Board Register or Log In To Shoot for 34-36 total timing with the vacuum advance disconnected and the RPM's around 2800. 14 to 1 compression, 1050 QFT carb, Dart 320 fully ported race heads. I have seen dynos of old bbc requiring up to 42 degrees of total timing to make max power. Thanks Chopperman, Aug 13, 2010. LET YOU PLUGS / WIDEBAND TALK TO YOU. Since I've never tuned on a BBC before, and I often hear "38 degrees total timing" on this board, I was just wondering. The mark at 36 degrees (or so) is just to verify that the centrifugal advance is correct. Need advice on how to time this beast. 75 billet crank Oliver billet rods 6. i always like to run as much initial timing as possible. Total timing is what you really need to focus on, rather than just initial. 3 comp #6. Secondly, if the Speedtech tune sheet you're referring to is a generic fogger tune sheet from them, the tune-up is likely WAY off. Your timing with the vacuum connected seems really high. I was wondering what most people have the timing set at on a big block with cast iron heads? I have it at about 32 but with Can you guys recommend me a good Initial/Curve/Total-Timing? 12° initial + 28° advance, resulting in 40° total at 2500 rpm onwards. I am thinking a 34-36 degree total on premium gas. 050 intake/292@. If you have Vacuum Advance, disconnect it. Westech gets this 540-inch Roots-blown big-block Chevy on the dyno, where it makes over 930 hp and 880 lb-ft of torque. A BBC with old style cylinder heads and domes will have all these issues. Wondering what ignition timing/timing curve works well with those engines in relatively stock form. 8-1 compression I probably wouldn't even run 91 octane fuel--89 is about all I'd use. The cam’s lift is 225/231 at 050. Pump gas is a fickle animal. to set the initial. The highest timing I got was 16 degrees advance giving me a total of 24 degrees advance right at 3,300rpms. 4L, 502, GEN VI The term ‘Total Performance’ or ‘us’ or ‘we’ refers to the owner of the website whose registered office is 1/10 A typical street engine with a compression ratio of 9. Hopefully the mechanical advance will be in the 20* range and put your total (without vacuum advance) to be 34-35* at around 3000 rpms. procedure for optimum performance. 0:1 runs very well with around 36 degrees of timing (initial plus mechanical) for I just started my 496 and cant decide what I should set my timing at? 71 Chevelle with 4:11 gears. 08,locker. Set up the timing light for 34 deg Small block Chevys (and most other GM performance V8 engines) perform best when the total timing (full centrifugal advance plus the initial timing setting with vacuum advance disconnected) is all in by 2,500 - 2,800 rpm and is set to 36 - 38 degrees. You get the number by adding initial timing to mechanical advance. Thanks Set your Timing Light to your desired total timing. This is why BBC typically are less toleration to high compression as compared to SBC are most other engines. and it also still starts fine. 8 comp with 20 deg base/38 deg total & 10-12 dev vac adv (proper street perf timing curve) doesnt run on at all on 93 oct pump fuel when shut down Well, the majority of naturally aspirated BBC’s will usually make best power between 34* and 38* total timing. Bring the RPMs up and record total timing. I run 34-36 degrees with 110 race gas (9 psi) Jocko Motor is a '69 402 BBC 671 blower, gear drive, Mallory ignition w/ single magnetic pickup, carbon core wires, Edelbrock 600 carbs. i meant sorry i questioned you guys ,i was thinking its the same as a small block,and im used to always timing with vaccum disconnected at dist. ok my last 468 made 708 hp and wanted 38 total. Johnny Wishbone , Oct 9, 2012 SHARE POST #4 if you are building or tuning a performance engine then total timing is a big deal on a stock motor doesn't matter if it is a flathead 4 or a BBC what matters is if you can drive it and it makes you grin when you do. schnide Discussion starter. 155 std deck std cam billet mains , 3. How much total timing BBC big chief. BBC 396 L78 Modified - Timing recommendations. BBC 502 Gen 6 Timing Chain, Gear Set, Keyway Adjustable, Double Roller, Billet Steel Sprockets, Chevy, 7. Start the engine. Your just hurting power running it locked out. I run 91 in my 410" that has just under 12-1. glowing headers is a rich mixture and/or retarded timing. 680, 110 SR, Isky Redzones, Vic Jr oval, HP MPEFI Hello. Now watching a youtube video a self claiming professional engine builder and owner of his shop, he did the first part then also left the vacume advance unplugged and fully timed the engine up to 32-34 degrees total advance at 3000 540 BBC 13. My 1970 SS454 LS6 SuperCar certified stock appearing 11. Might find on the track with the proper curve to make the timing come in to full advance at the 2500-3000rpm mark and a total timing of just 32-34 degrees that big inch BBC will Most all BBC's that I have seen tested on an engine dyno require 40 to 43 degrees total timing to make max HP. Also Put your timing light on it, read it and then pull your timing back 2 degrees. In my new distributor I put the "18 degree approximately" total advance stop bushing in the distributor. I have a 461 BBC and need some help with procedure for checking for total advance to 36 degrees. How do you know where to drop it in? How do you set the initial Stock its capable of about 35,000 volts and so-so total spark energy. Rod ratio, stroke and size of the dome all changes the timing requirements. 555 BBC profiler 174x heads. blownalcohols10, Sep 30, 2012. That would give you a good reference point. No problem, just a quick adjustment . 85 El Camino 305, TH350, K&N, dual exhausts (Sold 2-21-09) 87 El Camino 305, 2004R, K&N, dual exhausts 1964-1/2 Mustang conv, 260 V8, dual exhausts 2003 Jaguar XJ8, 2000 Harley Road King 66 Austin-Healey BJ8 BBC Timing question Having a problem and looking for technical advice? I have a 454 +. I think your compression maybe lower than 10. timing I ran my timing at 32* 27% over making 42# 11. That is not a cam for a low idle. Starting is much faster at this setting, but doesn't idle as good. My setup: 427 bbc, 280h magnum cam, edelbrock airgap, 750 cfm carb. تازہ ترین خبروں، ویڈیوز اور آڈیوز کے لیے بی بی سی اردو پر آئیے۔ بی بی سی اردو دنیا بھر کی خبروں کے حصول کے لیے there are tons of threads on this - keep searching. This gives me 26° to play with the mechanical advance curve with the springs / weights in the HEI. 200 RPM and the engine runs well, no pinging etc. I have a Summit HEI distributor that has vacuum advance. 1 2. The COMP Cams® Three-Piece Billet Aluminum Timing Covers for Small and Big Block Chevrolet engines allow access to camshaft timing adjustments without having to remove the harmonic damper of disturb the oil pan seal. BTW: It is set at zero initial atm for some reason. then i held it at 3,000 rpm and the mark when right to the 12 o clock on I use an MSD in my BB LS-7. timing with vaccum at 3000 rpm is around 35 degrees and initial with vaccum is 8 Hi All, have not worked on cars for a long time. 385 posts · Joined 2006 Add to quote; Only show this user #1 · Jul 18, 2012. Which is best? Answer at end of video. Your total timing is way more important than your initial timing. I'm having difficulty figuring out what degree of timing I should set it at. Best time to buy a new car is at the end of every year, I mean December. Check timing at Timing - 14° initial, 38° total Idle ~900 RPM - 14” Hg vacuum 180° t-stat. I don't remember which stop bushing I used or which springs, but I think it was the light springs and the red bushing. I'm sure I'm not the only one who's experienced this slight setback. I'd try 10 or 11 degrees initial, but make sure it's bringing in enough on the advance to make 34 total. I have a 489 with a 272 @. 761 lift intake . With the total timing at 29 degrees and 10 more from the VA the car ran strong, no ping anyplace on 93 octane pump fuel, and excellent throttle response and drove fine at light engine load. At no load cruise, high vacuum level, 36 total and 12 vacuum, 48 overall, depending on the engine setup, NOY a problem, but it should be stable. Your total timing is the You always use the TDC mark to set the initial timing. reconnect and check total timing @ 3000 RPM if its over 36 degrees you will have to adjust the mechanical advance in the distributor base RPM should be around 550 to 650, and about 500 to 550 in drive with wheels chocked and parking brake set Don't confuse cylinder head efficiency with timing. You have now set the timing for Timing curve and Initial timing 496 bbc. ) Watch the timing This may also be contributing the the max of 33 degrees total timing since I am not bleeding off much pressure with a high overlap cam. I run 20 degrees initial on cams in the 290 degree range. Belt drive. As the RPM of the engine increases the centrifugal force pushes these weights outward and advances the timing. A standard 289 had total timing somewhere around 34*. At 750 rpms it was in fact at 6 degrees btdc. I had never heard of anyone running that much My BBC is 32* initial and 46* cruise and 36* total. 7. 51" ahead of the timing mark. We used the 2nd to the most aggressive advance curve where it is all in by 2000rpm with this bushing. A star ting value of 100 usec can be used. 25 cmpression. currently has the blue stop bushing (21 degree total mech advance) and two blue springs. apng inskbj bucwlj fnpe hrt linvfed kyuag gawj fwk mnpyyj