502HO with a 750 Demon, vacuum secondaries. Runs like a scalded dawg! Went through two Holley 750's before giving up on them. The Demon bolted on, with no adjustment except idle speed.
Charles www.65ss.com ----- Original Message ----- From: "Dan Mascheck" <[EMAIL PROTECTED]> To: "'The Chevelle Mailing List'" <Chevelle-list@chevelles.net> Sent: Saturday, June 25, 2005 9:25 PM Subject: RE: [Chevelle-list] 454 carbs > Fred, > > After much talk with BDS...I have a 454 I have installed an 8-71 blower > on. The owner of BDS told me, if I was going the carb route, to use the > Holley 750 double pumper(4779). He said the Holley was by far a better > platform to tune for my 8-71 blower. I bought two...had them dyno-tuned by > BDS, and the results have been fantastic. The BDS owner doesn't seem to like > BG Carbs. > > I also have a friend that has a 72 GTO. They put a 750 Demon carb on it and > it's run poorly. They just switched it to a Holley and the engine is running > much better!! > > I like the design of the BG carbs...and was serious on getting a pair for my > blower.....Now....I'm glad I went with Holley! > > I wonder if anyone has had good luck with BG's? > > Dan Mascheck > Wharton, TX > > -----Original Message----- > From: Fred Dowaliby [mailto:[EMAIL PROTECTED] > Sent: Saturday, June 25, 2005 8:34 AM > To: The Chevelle Mailing List > Subject: [Chevelle-list] 454 carbs > > Hi Folks, > > I am once again in need of your expertise and advice, this time re: > carburetor selection and tuning. My car is a '68 Chevelle based 32 Ford > street rod, 454/th400 with 3:08 rear. I estimate it weighs about 2800 > lbs. > > Pertinent engine vitals: flat top pistons, Edelbrock Performer RPM > heads, air gap intake, Comp Cams CB 280H-10 cam. The stall converter is > 2200. > > I am currently using a new out of the box Holley 750 dbl pumper carb. I > have tried a Speed Demon 750 vacum secondary. Both have resulted in > lackluster performance. There is no bog, they just don't have any > punch. My comparison is the carb I was using (never should have sold > it!), an older Holley 750 dbl pumper. That thing used to run like a > beast! I replaced it with the Demon because it just looked grungy, I > got sucked into how pretty the demons looked, and I wanted to "clean > up" the engine. I then replaced the Demon with the Holley thinking I > should have stuck with mechanical secondaries like worked well before. > This resulted in the same lackluster performance. I made the mistake of > breaking the rule "If it ain't broke don't fix it!". > > I am at a point where I just don't know what to do. Is a 750 big enough > for this engine? Should I start playing with the main jets? I don't > know what's in there now, but I recall the old one had #72/#70 for > primary/secondary. > > I don't have any experience with carb innards. Should I look for a > trustworthy carb expert/shop? > > Thanks for your help, > > Fred Dowaliby > > > > > > > >
