high compression and a small supercharger



high compression and a small supercharger

Postby grumpyvette » August 23rd, 2013, 9:12 am

Carbd84 wrote:Hey all. Within the next week or so I will be ordering a 142ci weiland blower to sit atop my engine and I will begin the prep to do so tonight. So, I figured I would start my build thread now, since I do already have a few goodies to go along with the blower sitting in the garage ready to install.

I realize I am new to this specific corvette forum, I'm also a member on corvetteforum.com, but I grow tired of the trolls over there.



just a question, having been down this road several times in the past?
are you really trying to get decent performance or just add a bit of extra low rpm torque?
and is your goal to keep it hidden under the hood?
The reason i ask is that a 142cid roots style super chargers going to run out of boost on a 350 displacement engine well before your engine speed reaches about 5500rpm
if your serious youll go with a 871 or better yet a centrifugal super charger
youll obviously need to match the cam timing, compression, injector size or carburetor size and the torque converter stall speed , and rear gear ratio,to the intended power and rpm range



before you waste cash buy and read a few books it will save you a great deal of time, cash and disappointment

http://www.ebay.com/itm/Superchargers-Guide-to-Street-Supercharging-/280619790192?pt=Motors_Manuals_Literature&hash=item41563e2f70&vxp=mtr

http://www.ebay.com/itm/Supercharging-Turbocharging-Nitrous-Oxide-System-Design-Installation-/380457191829?pt=Motors_Manuals_Literature&hash=item5895040995&vxp=mtr


http://forum.grumpysperformance.com/viewtopic.php?f=86&t=3803&p=10069#p10069

http://forum.grumpysperformance.com/viewtopic.php?f=86&t=4633

http://www.montygwilliams.com/

http://www.enginebasics.com/Advanced%20 ... ooler.html

http://cherry84.joby.se/

http://www.airflowresearch.com/articles/article122/A-P1.htm

just making the point that a 142 or 144 supercharger on a 10.5:1 compression engines a rather useless combination, don,t get upset, just step back mentally a second and consider the facts ,think about what your trying to accomplish and the fact that by the time a 350 engines spinning at about 4500rpm a superchargers like thats already peaked on efficiency and starting to drop boost rapidly at the same time in the rpm range that your trying to maximize power. and your running a significant risk of detonation damage, at only 2 pounds of boost your effectively running a 11.9:1 compression ratio, put an engine under significant loads like rapid acceleration on a hot day with 11.9:1 effective compression, running pump high test fuel and its going to run a significant chance of detonation damage, kick the boost to 4 psi and pistons melt easily.
so what youll have is a combo that is very likely to break parts in the mid rpm range from detonation issues and run out of torque where you want it the most in a performance engine .
look my one goal here is to help you avoid an expensive learning process, a supercharged corvette could be a great deal of fun, but put the research into planing thats required to pull it off and get it running correctly, and in this case youll need lower compression and a larger capacity super charger. a 3000rpm stall speed converter and a 3.73:1 rear gear will allow the super charger to build boost quickly

Image

http://forum.grumpysperformance.com/viewtopic.php?f=86&t=9078

http://forum.grumpysperformance.com/viewtopic.php?f=86&t=7976


viewtopic.php?f=55&t=7751&p=26449&hilit=aviation+gas#p26449

viewtopic.php?f=55&t=2718&p=12119&hilit=calculate+octane#p12119

viewtopic.php?f=55&t=613&p=817&hilit=octane+booster#p817

now on a side note!
if your willing to change over the fuel supply , system,fuel lines,fuel pump, use a matching carb, or the correct fuel injectors and sensors and youll need too run an effective inter-cooler. and related parts in your fuel supply and induction and sensors,too run E85 fuel and use a bit larger supercharger you can get away with a high compression ratio, with a super charger

viewtopic.php?f=86&t=4967&p=13792&hilit=intercooler#p13792

viewtopic.php?f=86&t=1329&p=8354&hilit=intercooler#p8354

viewtopic.php?f=86&t=1551&p=3584&hilit=intercooler#p3584

viewtopic.php?f=87&t=2141&p=25201#p25201

viewtopic.php?f=55&t=613&p=1379&hilit=octane+booster#p1379
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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