Speed Demon 575
Thread Starter
Heel & Toe
Joined: Jun 2009
Posts: 22
Likes: 0
From: Kent, U.K.
Speed Demon 575
I've got a 75 with a mildly rebuilt engine in the UK. Forged pistons, roller rockers, Edlebrock Performer manifold and cam, and want to change my old Holley 600. I've had recommendations for Barry Grant Demon carbs. Is anyone running a similar engine to mine with a BG carb? If so, which one?
I'd wondered about the Speed Demon 575 as I want off-idle response rather than top end, but I obviously don't want to strangle the engine at speed. Their techies are reccomending a 750, which seems huge to me, but it apparently has annular jets which can help make a big carb work on a smaller engine.
Any thoughts anyone?
I'd wondered about the Speed Demon 575 as I want off-idle response rather than top end, but I obviously don't want to strangle the engine at speed. Their techies are reccomending a 750, which seems huge to me, but it apparently has annular jets which can help make a big carb work on a smaller engine.
Any thoughts anyone?
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I can't think of a reason to change out the Holley 600 if it's a vacuum-secondary carb.
Unless the engine is >= 383 CID and/or making > 1.2 HP/CID, a 600-650 CFM vacuum-secondary carb is the perfect size and configuration for a mild street engine. Take that money and invest it in a good tune, and an overhaul if the carb has been around for a while.
Unless the engine is >= 383 CID and/or making > 1.2 HP/CID, a 600-650 CFM vacuum-secondary carb is the perfect size and configuration for a mild street engine. Take that money and invest it in a good tune, and an overhaul if the carb has been around for a while.
Thread Starter
Heel & Toe
Joined: Jun 2009
Posts: 22
Likes: 0
From: Kent, U.K.
Still love to hear from anyone running a Speed Demon 575 vac secs on an auto trans 350 C3, or indeed a 750 with annular boosters.
Any thoughts on which is best for my mild 350 (forged pistons, roller rockers and Edelbrock Performer manifold and cam). BG tech says 750, but a well known speed-shop says the 575.
Thanks, Rob.
Any thoughts on which is best for my mild 350 (forged pistons, roller rockers and Edelbrock Performer manifold and cam). BG tech says 750, but a well known speed-shop says the 575.
Thanks, Rob.
