|
Typically, you get a bog, not a surge when the secondaries open too soon. If it surges,as in picks up some acceleration, then it is probably pretty close. The bog is a drop in power, because the engine isn't ready for that much opening. I don't even think it is an issue much with double pumpers if the pumps are adjusted correctly, mostly with vacuum secondaries. Having said that, I was actually wondering if he meant when the primaries on the secondary carb opened? They have a progressive linkage. It is also pretty important to put a balance line between the 2 secondary vacuum tops. There are special tops available, they keep the secondaries on both carbs operating together. Without the balance line it's possible to have the secondaries open on the primary carbs, then drop closed again when the secondary carb primaries open and the vacuum signal drops. Under mild throttle conditions this can create a less than linear acceleration and weird carb actions.
|
I believe the 427 came with 550 bj-bk carbs:confused:
|
1 Attachment(s)
Quote:
|
I believe 550 cfm sounds right for the 2-4 set up. The 715 was used in a single 4 bbl. application, including the early Shelby GT350. If they are the correct carbs they aren't 715s. You can pull the list# off the airhorn to find out for sure. I think (2) 715 carbs are a little much on any street engine...even a Boss 9. I also believe that the 715 only came with the cathedral bowls and won't even fit a 2-4 set up without a bowl change.
|
Quote:
Carbs are: C5af 9510 BD List 3800,and, C5af 9510 BC List 3301 I'll look up the invoice from Carl,but he told me on the phone when I ordered them they were 715's Whatever they are they work well,and the throttle bore's look to big for 550 or 600's. I have a 715 wit center hung float bowls ,I'll check the throttle bores on it for comparision |
According to the NV SAAC site, those were used on some S/C and later 3000 series cars. They are 710 according to their site, so 715 is almost the same. The secondary is a 3300, you may have read the stamping incorrectly, they can be a little crude at times. Learned something new, now I can back to sleep :-)
Just a note regarding the throttle bores, if you are referring to the butterfly openings...they aren't what determines the CFM, it's the body venturi. More than one CFM carb uses the same baseplate, when examining look down the venturis to compare size. |
Quote:
Old eyes maybe don't see those little numbers as well,but since these are the rerelease Holleys they may have gotten it wrong.I'll look again. And,they work very well,does not seem to be overcarbed and throttle response is awesome. I made only 2 jet changes to get them dialed in,and didn't touch the vaccum secondary spring P.S. Carls has more than one dual 4 bbl setup avail for big or small block use |
| All times are GMT -7. The time now is 11:20 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: