[grandville455]

Was this originally a 750 cfm Q jet and you ground the rings off, changed the booster design and milled out the ring in the venturi and it still wasn’t as good as the stock 71? So was the WOT better than the 71? What do you use to get inside there to grind that ridge out? Do you think taking the ridge out it lost velocity? Thanks!

[shaker455]

Originally Posted by grandville455

Was this originally a 750 cfm Q jet and you ground the rings off, changed the booster design and milled out the ring in the venturi and it still wasn’t as good as the stock 71? So was the WOT better than the 71? What do you use to get inside there to grind that ridge out? Do you think taking the ridge out it lost velocity? Thanks!

You can read earlier post for your questions:
Post #1 outlines parts used
Post #35 milling machine
Post #76 base plate throttle bore resizing, milling machine
No mods to venturi shape
When outer ring is removed drastic signal loss
Area was much larger than a 455HO casting so signal loss maybe greater
Definite increase in area WOT, others who have done this mod street & strip can confirm
Goal was to regain some signal strength to match the 455HO while gain primary airflow and low speed drivability
This lead to three other approaches that I started to experiment.
If you take a try post up your results
Thanks

[grandville455]

Originally Posted by shaker455

You can read earlier post for your questions:
Post #1 outlines parts used
Post #35 milling machine
Post #76 base plate throttle bore resizing, milling machine
No mods to venturi shape
When outer ring is removed drastic signal loss
Area was much larger than a 455HO casting so signal loss maybe greater
Definite increase in area WOT, others who have done this mod street & strip can confirm
Goal was to regain some signal strength to match the 455HO while gain primary airflow and low speed drivability
This lead to three other approaches that I started to experiment.
If you take a try post up your results
Thanks

Thanks! So looking at this pic, did u remove this ring also? It kind looks like it in the pic?

[shaker455]

Originally Posted by grandville455

Thanks! So looking at this pic, did u remove this ring also? It kind looks like it in the pic?

Yes

Later experiment I had machined a 750 venturi to an 800 leaving outer ring in place like an SD-455 casting.

[grandville455]

Originally Posted by shaker455

Yes

Later experiment I had machined a 750 venturi to an 800 leaving outer ring in place like an SD-455 casting.

How did that work,That’ s funny I’ve been thinking of doing the same but to a 800! I don’t have a mill tho �� so it will be by hand