Did the base plate have a idle passage in it..? if so does it need to be divided..? do you have a explanation or reason for the idle passage VS no idle passage found in some aftermarket base plates. From what i understand the passage is for vacuum secondary carbs but when converted to 4 corner idle the passage must be divided.
This Holley carb after market base plate is for double pumper bodies with 4 corner idle circuits. In order to use this method you will have to have this style of Holley or other brand body and plate or convert the body and plate over which is a whole different process itself. This method will effect the idle transition slot's air circuit and idle circuit also. I don't recommend vacuum secondary carbs for this either.
I''m considering the same thing. I have a new 750 main body with annular boosters and an old Quick Fuel 850. From your experience, does this modification have any downsides? Did it affect jetting?
It can effect things like jetting, idle, and responsiveness. This is based on your cam, heads, and cubic inches. Every motor is unique when modified and that is the fun of tuning your build. Good luck with your project!👍
@@claytonstoolbox This has a huge improvement on top end rpm with a fatter idle for a street driven car with a noticeable increase on gas consumption at the same time unfortunately. For high performance race or hot street set ups keeps the power gains inline.
Do you leave the 850 gasket as is or can you lengthen the idle hole on the 850 gasket so the gasket idle hole goes from the 750 idle hole to the 850 idle hole
The 850 gasket hole will match up with 750 body "new" hole that is created by drilling a channel between them. That is why you see I used the 850 base plate gasket to mark and drill the holes into 750 body. Good luck with yours!👍
@@TheBigstratNo effects on gasket. It has air going through the circuit and not gas. You could put small amounts of epoxy or jb weld into old hole if wanted.
Not exactly sure what you meant, but I have seen this swap in a reverse version as 850cfm body onto 750 baseplate doing same modifications. Not sure what the actual cfm would equal too. Thanks for watching! 👍
Great Video 💪👌👍🏻👏
Thank you 👍
Did the base plate have a idle passage in it..? if so does it need to be divided..? do you have a explanation or reason for the idle passage VS no idle passage found in some aftermarket base plates. From what i understand the passage is for vacuum secondary carbs but when converted to 4 corner idle the passage must be divided.
This Holley carb after market base plate is for double pumper bodies with 4 corner idle circuits. In order to use this method you will have to have this style of Holley or other brand body and plate or convert the body and plate over which is a whole different process itself. This method will effect the idle transition slot's air circuit and idle circuit also. I don't recommend vacuum secondary carbs for this either.
I''m considering the same thing. I have a new 750 main body with annular boosters and an old Quick Fuel 850. From your experience, does this modification have any downsides? Did it affect jetting?
It can effect things like jetting, idle, and responsiveness. This is based on your cam, heads, and cubic inches. Every motor is unique when modified and that is the fun of tuning your build. Good luck with your project!👍
@@djrowe10 Have you seen noticeable performance gains in the conversions you put together?
@@claytonstoolbox This has a huge improvement on top end rpm with a fatter idle for a street driven car with a noticeable increase on gas consumption at the same time unfortunately. For high performance race or hot street set ups keeps the power gains inline.
Do you leave the 850 gasket as is or can you lengthen the idle hole on the 850 gasket so the gasket idle hole goes from the 750 idle hole to the 850 idle hole
The 850 gasket hole will match up with 750 body "new" hole that is created by drilling a channel between them. That is why you see I used the 850 base plate gasket to mark and drill the holes into 750 body. Good luck with yours!👍
@@djrowe10 thanks Dj
My main concern is when the fuel hits the gasket on its way to the new home in the main body
Does it soak the gasket
Thanks Bluey
@@TheBigstratNo effects on gasket. It has air going through the circuit and not gas. You could put small amounts of epoxy or jb weld into old hole if wanted.
Buen vide y es posible de 850 cfm hacer que trabaje como de 650 para un motor mas pequeño
Not too sure about that combo since I have never tried it. If you try it please let me know how it works for you. 👍
Would be interesting to stick it on a flow bench see what the final figures come to
Top job tho 👍🏻👍🏻
I have flow benched others in the past at around 820-840cfm. I think I will be able to get it on a flow bench some day hopefully. Thanks for watching!
Yupp...swap subs with....2 for 1
Not exactly sure what you meant, but I have seen this swap in a reverse version as 850cfm body onto 750 baseplate doing same modifications. Not sure what the actual cfm would equal too. Thanks for watching! 👍
How do these flow compared to a 850?
It will flow 820-840cfm. The biggest advantage to this set up is higher venteri velocity for for a crisp throttle response.