John Scott

Morgan,nothing to add, just laughing at your topic header. I can't tell you how many times I've felt the same way! JS

ATI's tech Mark, will defend the Holley for blowthrough. He is running a 351 in his daily driver mustang pulling over 700hp. He claims the flow through the Holley, as modified above) will flow linearly and not experience the overly rich conditions below max boost. His jetting on the seconday side is 30(!) steps above the stock jetting. So maybe my 89 jet I'm trying next will get some good results. Of utmost importance is the fuel pressure 7+ psi above boost. He recommends the Aeromotive pump and regulator for high boost applications. "The Mallory 140 is an excellent performance pump for naturally aspirated engines". The carbshop offers a big step above, but I'm going to work on what I already have to see what can be done.I need a different pump!! JS

The Holley with minimal mods works pretty well for a blow through. The bonnet, or hat came with the supercharger. Only need plastic floats, air horn milled and the choke linkage hole plugged with jb weld. Simple! I've been running mine for a few years now with few complaints. I think the higher you go in boost, the bigger the spread in primary/secondary jetting become, the more desirable the carb shop's units become. I don't have any problems as far as drivability, but It sounds like the Carb shop takes care of some inherent problems with the blow through. Its not anything I can afford right now, but would give them a go if I had the spare $$. I encourage anyone interested to give them a call. They are very willing to give information. JS [This message has been edited by John Scott (edited December 20, 2000).]

You need to call them, Brodix directly. They don't list them in the catalog either. I have part #s if you're interested. Last I checked $1700.00 for a ready to run set. JS [This message has been edited by John Scott (edited December 20, 2000).]

The information from the fuel injection posts is pretty amazing. Also got me thinking..actually worrying about my fuel pressure. My budget Z has never had a visible fuel gauge to see whats really happening under boost. I have no question that my Mallory 140 can supply enough fuel, but I've been reminded now that I'm seeing some pretty high boost #s, the importance of having 7# over your boost psi. There is no way the Mallory can deliver 23 psi! This is an issue of line pressure overcoming boost, not flow rating. So now I need to shell out another $300 for a pump that can push mid 20 psi, or is there a cheaper alternative? Anyone know what the Mallory maxes out at? At ANY boost level my wimpy 15 psi gauge is pegged. JS

Since my last bout of carburetor woes, I've had a lot of time to ponder the good and bad side of a blow through system. As I stated in another post, it seems the carburetor can only handle two sides of the supercharged curve. Cruise speeds with no or little boost and overly rich secondaries that finally come into their element at max boost. Everything in between is probably going to be running too rich. I've been hashing this over with other members, a Nascar carb guru, ATI, Holley and even posted the problem on other performance oriented boards. No one seems to have a good solution for a blow through carburetor...until now! I finally found a carb shop that not only understands a blow through system, but will pit their carburetors against any fuel injection for hp, and still provide excellent drivability. One of their personal commuters is a 383 producing in excess of 700hp! The Carb Shop www.customcarbs.com will completely re-do your Holley to very specific engine specs. They claim to drastically change the flow for a dedicated blow through carb. The end result is a carb that produces big hp with a balanced delivery throughout the rpm/boost range. As usual, this comes at a high cost. I was quoted roughly $500 for the upgrade to my 600. I don't want to start a FI vs carb issue here and agree that FI is the best solution for precise metering in most conditions. This is just the first time I've encountered a carb shop that really addresses the blow through system with excellent results. JS

At the upper end of the intended hp ratings, 300-350 for engines with 14.-29 psi boost???? A naturally aspirated 4.3 with the old style raised runner heads and a Holley 650 pulled 300 hp. Come on holley, I think 350hp, with lets say brodix heads and 14 psi is going to run a "bit" over the 350 mark! If not, there is always a primitive carburetor that can. JS

YIKES 2 grand for the even fire. Mark you have a gift for finding cool information! JS

Follow the discussion on the fuel delivery board. Also has the link posted. Its not often a munufacture makes a move like this for the 4.3. I had to beg Edelbrock for years to make the performer in a dedicated 4.3 model. Thanks for the tip Z-Dreamer! JS

...and as Z-Dreamer informed me it will fit 4.3 with aftermarket heads. Plenty of applications all the way up to mega boost w/nitrous!! Gotta find that money tree! JS

A local transmission owner and fellow hot rodder was talking to me a few weeks ago about how the Lencos would be the ticket for high powered steet machines. Due to the racers using a different style transmission now, the used market has come down considerably in price. They have any # of gears and ratios availible, easy to work on, light weight, and can handle just about any engine's hp. Relatively compact too. Just have to deal with a plethora of shifters sticking out of the console

Sometimes on older Qjets have leaky fuel wells. A dab of epoxy underneath sometimes gives them more life. I agree to check your plugs and jet to cruise surging, then back richer a number or two. Secondary bogs are usually the airvalve tension spring. Mini hex lock on passenger side of rear butterfly air valve. Loosen and with screw driver in spring adjustment tighten slightly 1/4 increments for bog. When you get a clean transition to idle to power, driving conditions, not winging it in neutral that is, then play with the hangers/ rods. Usually don't need to get into the primary side. If you can get the book(s) on Qjets. They really do make nice street carbs. JS

Sounds like something is out of alignment. I've never had to shim either, but the dang things are common. Must happen sometimes. Since your starter gear is destroyed you might want to check the condition of the teeth on your flexplate as well...all the way around. If any are in poor shape and since they are a harder metal, they'll eat on the new starter too. I've cleaned up minor flaws with a small file. I've never used a starter that was a universal fit for both diam. befor, maybe someone else can add here. Good luck! JS

My .02 is carbs are second rate to a good FI. Don't get me wrong a carbureted system can support plenty of hp, but not as precisely as FI thoroughout the rpm and boost range. I've been running a blow through (centrifugal) system for 5 years. My conclusion is even though it works very well, it only really addresses two ends of the fuel/air mixture spectrum. First you jet the primary side for cruising around with no or low boost. Since as air density increases, so must your fuel, the secondary side must be jetted for maximum boost, which occurs of course for mine at max rpm. Detonation at high boost due to lean mixtures tends to hurt your expensive reciprocating pieces. Everything in between is a compromise. The system works pretty well, but a FI that adjusts throughout the boost curve would be superior. Now if I only had lots of $$ laying around I could advance into the computer age. In the meantime I'll live with a carburetor's shortcomings. JS

Thanks all, for the good info. I'm 6'0 and want to remain that height. Your mods should give me plenty of room. JS [This message has been edited by John Scott (edited December 07, 2000).]

I find it disturbing that when I sit with my helmet on, it is firmly against the headliner. I suppose the only alternative is a lower seat height. What are the recommended distances between the roof and your head, also distance behind for rollbar? JS

#3#4, If I had to do it all again I'd get the MSD distributor. Mallory unilite has come a long ways, but I like the MSD's pick up better than Unilite's expensive to replace eye. The Mallorys, when they say vacuum advance, have both mechanical and vacuum. Mechanical is w/o vacuum canister. Their mechanical adjustments used to be a flimsey tab, but have improved to two locking set screws on the distributor plate. As long as your shaft is in great shape on the HEI why not just get a good aftermarket module, coil etc. The weights wear grooves on the pins on the HEI's advance causing rough advance curves. Some kits come with nylon bushings to eliminate wear. Look closely at that area. JS

colored water, tubes, milk jugs and supersoakers all wired to the Z?? I'd like to see the look on the arresting officers face with 150mph displaying on his speed stalker. Morgan, thanks for the info and nerve to do it! Keep it coming. JS

Fosta, Welcome to the fastest Z site around. You came to the right place. Great ideas, information and people. So,...what'er your plans? JS

Having run a 700 since the 80s,a common misconception is the 700's TV cable is ajustable. It is not a down shift cable like on a 350. The TV cable is designed to operate the shift feel, fluid pressure and points. The TV cable is designed to operate from ONE setting. With the cable fully retracted (push release button and pull cable back until it stops) it is SELF adjusted when you open the throttle to wide open and it ratchets back to the correct location. This is where it is suppossed to be. Changing it from that location only puts the transmission at risk for improper fluid pressures. If its really off, there goes your transmission. The auto setting is foolproof. Once in a while its good to recheck it as new cables stretch a little. JS [This message has been edited by John Scott (edited December 02, 2000).]

Yes you need yo do some hammering. Just part of the deal when "hybridzing" I was suprised how little I needed to do, 72 240. Biggest area for mine was for slave cyl. I studied a previous T56 swap and made some good notes. Nothing is even close to rubbing on mine. Part of an afternoon is all thats needed. Gets rid of the day's frustration Haven't heard too many problems with the Centerforce Dual friction clutches. Plenty around here with big nasty hp are doing fine. I'm suprised. JS

Finally found a manufacture for anyone building a maximum effort chev 90 degree V6. Callies manufactures a 4340 steel oddfire crankshaft that can be orderd with 6" plasma treated rods. Don't let the oddfire scare you away. Distributors are still avil. from Chev. suprisingly the oddfire is easier on everything especially at the really high rpms. I didn't get a price, but one of these in a splayed cap four bolt bowtie block would be killer. If I'm not mistaken these can be stroked up to 5.2 litres 320 cu in! OH PLEASE SANTA PLEEEEASE! JS

Pete, The F-body T56 w/2.97 1st has the same 400 lb-ft rating. I think the lower rating is based solely on the the 1st gear. You'll notice the lower numeric gears (1st 3.35=350 ft/lb, 2.97=400 vs 2.66=450) are stronger. (this is why drag racers often do their burn out in 2nd or 3rd, they can take the shock better when the tires grab) I think this is the only difference. I believe only the Viper was treated to better gear metallurgy. Still a 400 lb-ft rating is figured for what weight of car? Fast frog has probably one of the highest hp street Z engines (and supercharged engines almost always have much higher torque than naturally aspirated, his Z while under way will roll on wheel spin in 3rd!) his WCT5 305 lb-ft(?) has lasted for quite a while. Figure in the price of the T56 only fly wheel, clutch, bell housing, slaves, special pull style t/o electronic speedo, shifter (after market includes one) etc and maybe the price difference won't be that big. T5 parts are probably cheaper and way more plentiful. For me the peace of mind of new was worth it. How was that used one treated before you got it? Short of opening the case and knowing what to look for... Came from a perfomance car? Not knocking used, but with my my luck... JS JS [This message has been edited by John Scott (edited November 29, 2000).]

Or you can get rid of a little more $$ and have a brand new aftermarket T56. $2100+ Has regular speedo hookup and uses the T5 bell housing and slave, clutch (stick to the center force dual friction). No rocket science to install either. 400 lb/ft as opposed to the stronger 450 lb/ft of some models. JS

ZD, I don't think there is a forged even fire crank for the 4.3. I don't even think the raw cast odd fire is still avail. from chevy. I heard someone is making a odd fire forged, but need to dig and find who. I'd bet the stock one, if prepared well and a splayed 4 bolt would hold up nicely. JS