John Scott

I've used the custom grind a few times, but for applications where only a few were available. Case in point, late 80s before the 4.3 became popular, there were no options, CC was the only company with blanks, not regrinds, willing to custom grind for my NA motor, 108 lsa, and then later for a supercharged application, 114 lsa. Now with a gaZillion profiles availible, one is bound to be a good match. Its still a good idea to call with your engine and vehicle specs to get a good match, but typically get a slightly different recommendation day to day.

It looks like a cogged belt? Not sure of the traction of the drive system, but I second the additional reinforcement. Its amazing how much stress a belt supercharger puts on the mounts. You can see in my personal photos, the custom brackets I made, though V6. With an 8 rib ATI, I was using 1/2" aluminum, mounted to three points on my head, the front of the SC, and the SC housing.. Then adding more angle bracing, turnbuckles etc, above 14 psi, I still had deflection and belt slip. I was using my weight and a 2' breaker bar to set the tension. Try and see? Always make it beefier.

So until database is back why not just start a new thread for timeslips only?

Yeah, that's like showing up as the only guest to a hot tub party of naked super models and saying "darn there are only 8 instead of nine!" Well, nine would be better, but...John

Wow, just saw your signature Z 30 years ago. WOW...I guess I said that already. John

Really..REALLY, you don't need the vacuum advance with a HEI or any other distributor. Its not going to give you more advance at wot when your vacuum is 0 anyway. I haven't used it on my last four motors. Don't know anyone who does. Only for part throttle response and slightly better mpgs. You can tune it to tame a bigger cam, but need to use it with discretion and manifold vacuum only. I'll dig up the article later by David Vizard, He likes it when its used correctly. With my procahrged motor, I modified my HEI to have 18 initial and 4 more mechanical for 22 total. Made my own stops on the advance. Took of the rotor, made a bushing that fit in the advance slot, checked with timing light and filed a couple of times, done. No big deal. No I'd never recommend using a locked out advance, I thought that's what you meant by "no advance". Have friends that do, but mostly drag cars with plates. Almost every NA chev V8 will use around, 36 total. Cam and compression will determine initial. BG= Barry Grant. Here it is By David Vizard reviewing the Crane Distributor: Cylinder Pressure: The Number One Influence The reason an engine requires an ignition advance curve is that the speed of combustion varies greatly with the prevailing circumstances. As rpm increases, there is less time for the charge to burn. This, for optimum results, calls for the combustion process to be started earlier. Countering this is the effect of mixture agitation, which increases with rpm. These two factors leave us with the basic advance curve concept. In essence, the timing has to advance as rpm goes up but this levels off as the effect on increased mixture agitation speeds the rate of combustion. The overriding influence on ignition timing requirements at the prevailing rpm is the cylinder compression pressure. To get a handle on what might be needed for an advance curve in a normally-aspirated engine, we need only look at the two biggest factors affecting the compression pressure. These are the compression ratio and the cam timing, and here's how they affect the burn rate. The higher the pressure of compression, the faster the charge burns. Higher burn rates produce optimum results with less advance. The primary factor influencing compression pressure is the engine's static compression ratio. The influence the compression ratio has is also closely allied to the cam duration, or more accurately, the point of intake valve closure (Fig. 1). If the compression ratio goes up while all else remains constant, the amount of advance for maximum output will come down at all points in the rpm range. If a short cam is used, increased compression can have a substantial effect on the advance curve at low speed. If the compression ratio is increased and the engine uses a short duration cam then the initial advance needs to come on much slower as well as total advance being less. If the cam's duration is increased the compression pressure will drop. This slows the burn, so calling for more advance is the preferred move (until pressure wave and ram filling of the cylinder at higher rpm cause the compression pressure to increase). The effect of the longer cam is to bring about the need for the initial advance to come on quicker but total advance may not change that much. Vacuum Advance All the aforementioned applies to an engine operating at wide open throttle (WOT) with the advance curve being totally rpm related. (That's what we would have called mechanical or centrifugal in a regular distributor.) At less than WOT (idle, cruise etc.), the amount of air entering the cylinder is reduced which in turn reduces the compression pressure. As manifold vacuum increases the amount of advance needs to increase. At idle and low-speed operation, the amount of advance required to most effectively utilize the air and fuel entering the engine can be as much as 50 to 55 degrees. This is handled by the vacuum advance; a function many hot rodders believe is not needed because their favorite drag racer does not use it. Now is the time to listen up and listen up good. A functional vacuum advance is the single most effective camshaft tamer you can get. By taking the time to hook up the vacuum advance to a manifold vacuum source you can get a big cam to idle as if it were about 20 degrees less than it really is. Conversely, if you are looking for a decent idle the use of vacuum advance will allow you to use a cam of, at the very least, 5 degrees more duration/overlap than would otherwise be the case. ...so if you are convinced to use the vacuum advance make sure you have a way to limit how much it will advance. Old style distributors usually have too much. Drill and pin the actuating arm so it has a positive stop. I was inspired by the article and gave it a try. Mallory vacuum canister adjust 1 full turn for every 2 degress. 8 degrees additional vaccum at idle, Conclusion? Slightly perkier part throttle tip in. Car is too loud to know if any part throttle detonation. Really don't see a big difference. Your choice. John

I'll bite on a few. Start with your ignition, then go to carburetion. Initial with a cam that big should be around 18-20 degrees. A good rule of thumb is to set the timing at 3000 rpm, either with retard light, or degreed balancer, to 34-36, then see what your initial is. At least at this point you have the proper full advance set. Starting with the initial, you might find that you have way too much total, ususally the case, causing predetonation. Get the right bushings stops, what ever and get into the advance mechanism of the distributor and make sure your total then is limited to around 34-36 at full advance, find a spring combination that starts your ignition curve 100-200 rpm above idle, all in by 2500. Again, you can use a touch more if you are up in the clouds, I run 38-40. Locked out is ok for some, but not as nice starting or street manners. I swear by BG's advice for initial timing: 10-12 for cams less than 220@ .050, 14-16 cams less than 240, 18-20 cams less than 260. I'm using 19 right now with my 244, but add a touch for altitude. Amazing how many people with a big cam bitch about the performance, and don't run enough initial, or take the time to get the distributor curve right. At low speed high overlap, low cylinder pressures take longer to burn need more advance. Vacuum advance can be touchy, most don't even connect it on a performance engine.If you do, limit to around 8-10 degrees at idle from manifold source only. If you are using locked out advance disconnect it. Its only for part throttle response and slightly better mpg.The old ported theory doesn't work well with performance engines. Usually makes pinging at part throttle. Most of the guys I know don't run it. Your solid cam should wind out till it blows, so cutting out after 5000 might indicate weak springs, (new?) , poor ignition system, timing, jetting? I'd guess your hp peak to be close to 5800-6000? Guessing the rpm range should be around 3000-7000. You didn't mention the lsa, but Circle track cams usally are around 108-110. Nice tight power band. HEIs with the right parts can rock! IMO, with a nasty cam like that, streetablity and mpgs aren't a big concern, I'd pony up and get a Holley double pumper and pick up a little more hp. Edlebrock is a great street carb, but Vic jr himself admits they are not intended for really hot set ups, and you can gain hp with the Holley. With wideband afr tuning, wide open should be around 12.8-13.1. Best for drag only 12.5-12.9. Without a wide band, holley stock jetting is really close at sea level. Subtract 1 jet for every 2000'. Primary side I tune for clean cruising w/o lean surge. If you feel lean surge go back up a couple. Access to a track? go for best MPH indicating hp in the secondary side. Then you can go back to timing and add a touch up or down and see if anything picks up. Better heads would really wake up the combination, as the small valves and stock floww are a roadblock to the potential of the cam. You results may vary! I bet the .030 lash makes a nice mechanical noise. Isky? Mine is .028, no hiding a solid!

Perhaps your title should read: For all that think Centerforce clutches are bad. You always hear plenty about the bad apples. The majority that think they are good won't be agreeing with you anyway. Maybe my torque and 6500-7 grand shifts aren't a true comparison to your set up. Most 383s have at least 400 lb/ft throughout the 3-6000 rpm. Many 500 peak. So far so good. Same clutch and pressure plate since 99! Wonder why Big name aftermarket tuners for Corvettes would use them if they were junk?? But, again maybe your driving style isn't a good match. Make sure you post it when you find the right one. John

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You might look for the whole rear end assembly. I thought all Buick, Pontiac, Olds, Chevy, had interchangable rears, coil spring, as long as it was from the same "Family" of cars i.e. Skylark/GS, Chevelle, LeMans/ GTO, Cutlass/F85/ 442, . My 68 442 ended up with a 10 bolt rear with aftermarket 5.13 Zoom gears from a Nova, (blew the ring gear bolts out the cover) and later a 12 bolt from a Chevelle with 4.11s. A '65 442 with a pathetic 2.56 rear and a powerglide(!) was upgraded to a 3.42 rear end from a 68, and a variable pitch T400 from a buick. All swaps were a direct bolt in. Sometimes there was a u-joint difference, but no big deal. If you have the knowledge or sources to set it up properly, aftermarket gear sets are available for the popular rear ends, GM 10 bolt, GM 12 bolt etc. Look at http://www.Summitracing.com ring and pinion sets. John

When I was in my teens, early 20s I worked 5 years saving and acquiring parts for the "ultimate" 455 Oldsmobile engine. $1700 in head work when a rebuild cost about $600, custom rods, Arias pistons, lots of Mondello parts, a hard to find 425 Toronado block, Dyer blower drive, job at the local speed shop. The shop owner turned out to be a big time coke dealer, after months fired me when I refused payment in drugs, spent my $$ on ?? instead of investing in performance parts, a new hot machine shop butchered my block crank, rods, into a pile of scrap, then left town, and I was left without a job and a hard lesson. Fast forward almost 20 years, think I learned my lesson? My V6 Blower motor had a cam walk trashing the valve train due to a builder's oversight, along with a oil pump that wasn't tightened. This was a guy with a solid reputation who built top fuel motors! At least he admitted his fault, rebuilt everything for free. Later I had a tension rod come loose after some strut work at one of the local shops, right after a really fast run down the highway. Since then I don't trust anyone to tighten my lug nuts, work on my brakes, mess with any suspension parts, or change my oil. Now I turn every bolt I can, and make sure when someone does anything they come with a long long list of great recommendations. I now have a short list of great shops for balancing, head work, engine builds, and crankshaft machine work. It took a lot of years to build the trust of these. On the positive side, websites like this can save you a ton of heartache. The members who are truly experienced and willing to share, are priceless. John

In my metal work, I use a few acids for cleaning, etching etc, keep lots of water and baking soda near by. I keep one water bottle easily accessible for emergency eye wash. Respirator! Corrosive lung burns suck! Take the crud to your toxic waste disposal. Even our podunk town has a place to bring paint, solvent, acid, batteries, mystery goo, etc. At the very least neutralize the acid with baking soda. John

Earned most of my living there until recently. Glad it was something simple. Nice to see another HybridZ in the area. Loveland has some nice cars. Been over to your A&W on Friday summer cruise nights. Most of the locals don't get it until you pop the hood. Have to get together some time. John

http://www.thedirtforum.com/pushrodlengths.htm Most big cam companies have good articles on their tech pages. With new rockers and heads, I used a CC pushrod checking tool, centered my roller tip over the middle of the valve stem at 1/2 lift. There are better ways since this doesn't account for the geometry of every engine. If you like to sweat the details and are looking for that last hp, peak piston velocity is between 73-78degrees ATDC, max lift at 75 degrees ATDC will give best results. John

The only thing off the top of my head I could think of is to visually check the dentents of the linkage on the transmission compared to what your shifter is doing. Sometimes a shifter will indicate a "click" but the linkage is between positions. Are you sure the ears of the converter are engaging the pump? I've overlooked the obvious on more than one occasion so I'll throw this out to check the fluid level again. Hope you find the problem and its something simple. Where in Colordo?

Good regulator. The picture shows it being the one with the reference port. I'm using similar, but 4 port, with -8 in and out then dual -6to the carb. I think mine was rated to 22 psi. 1/1 rise with boost. I just plug the vacuum/boost port. I really don't know what the stock lines are cabable of, so I won't chime in other than make sure your return is of equal or larger than supply. I'm pretty sure NHRA requires solid or braided lines, so its a good move. John

I’ve always enjoyed how ScottieGNZ and a few others take a car’s observed performance, run it through their supercomputers and give us tangible numbers relating to horsepower, torque, and time. Maybe Scottie is some kind of savant and can do this by counting on his fingers and toes. Regardless how calculations are made, it helps me to appreciate the relationship of power and its application to performance cars. Very Cool! Sometimes we try and go the other direction in making predictions based on dynos, magazine articles, and the most famous of all, seat-of- pants or butt dynometer.. This has many valid applications, but more likely “$h!+ that car is sooo fast it must have like 600 horspower and do 1/4s in 8 flat,” when in reality it had 290 and went 13 seconds. Depending on your ability to hear B.S. It makes for either entertaining or annoying conversations. My favorite subject of late is wheel horsepower so I throw out this question. Do your formulas account for aero drag, and can they be modified for differences in Cd and frontal area? I just wonder about an early Z with it’s notorious aerodynamics of a water buffalo in reverse, and frontal area of a sheet of plywood, pushing 130+ mph. This has to require way more hp than a say new Corvette doing the same speed, even if they were the same weight. Maybe you guys are making even more power than the formulas indicate. Just a thought. I know many disregard the Gtech, and I'm not touting all of its virtues, but I liked the idea that the instrument gives results that are affected by rolling and wind resistance, unlike a stationary wheel dynometer.. If you know your vehicle’s frontal area and Cd, I found a cool link for aero drag hp calculations. http://www.gtechprosupport.com/support/AeroDragCalc.htm In the meantime, keep the numbers coming. John

http://centuryperformance.com/fuel.asp Dead heads require a bigger rated pump than return style, hp for hp. They don't call them dead heads for nothing One source recommends -6 or 3/8 lines up to 375 hp, 550 with -8. Make sure the rest of your system is up to the task.Running a return style regulator is a pain, but worth the effort. Your pump will thank you by only working hard when it needs to, your pressure is stable, fuel cooler, and you can concentrate on the next problem. John

Nevermind

The metal T5 slave has been around for a few years. I think I had mine in the late 90s with the Procharged V6. Thanks for putting up the part# as I need to update the list. I'm using the Ford F150 master and line (Juju's idea many many years ago) so both ends use the roll pin. The slave is for the T5, and GM aftermarket T56 using the T5 bell housing. Not sure about the T56? John

I've had cleared cookies, logged in, made post then won't accept. Login again, make post, won't accept. Sometimes if I make post, log in, won't accept I hit back button until I get to the post then it accepts. Me thinks There's a ghost in the machine. John

Entertaining! Turbos, imports, domestics, its fun to have a little rivalry. The old Cavin pissing on brand X used to make me laugh as I saw a guy walk up to a car he particlarlly hated and said "watch this I don't even need Calvin... "I don't know how your area is with police enforcement, but after years of trouble free street racing I eventually received two suspensions, my last included a two page ticket worth 40 points, cuffed & stuffed, and my girlfriend going home in a police car. 20++ years later she still rides with me. It took many years to wipe the record and get the ultra preferred insurance rates I now enjoy.Yes my driving still gets a little out of hand, but usually just to make a quick point. Invitations to the track are not usually accepted, but allow a little dignity when you know better. Just something to think about, a video is pretty hard evidence to dispute. Sorry, enough preaching, Great car, nice video work. I like the HybridZ plug at the end. John

....really I don't watch the show, wife and kids are watching it on in the lower computer room.Tonight started at Redrocks amphitheater...real close to Bandimemre the Mile high nationals. Too bad they couldn't take a shot of the track! Laughed at all the people gasping and complaining about the air. Sounds like most engines I know. John