Don Terrill’s Speed-Talk

If the Venturi size is the same on both the 750hp and 950hp, why is the baseline jetting different? I wouldn’t think the signal would be any different with the different throttle body if the Venturi is the same size. The transition or growth in area from 1.375” venturi to 1.75” throttle bore would ...

I settled on the final placement of mine on the inlet side of my X-pipe so that I had a decent amount of collector extension upstream of them. Very happy with the way it runs set up this way. How does it run in the final configuration versus the first location you tried right after the collectors? ...

It depends... Some carbs marketed as 950's are just 750's with an 850 base plate and flow barely over 750... while other 950's have larger throttle bores and are jetted more like an 850. As most of us know, (all else being roughly equal, which it rarely is) the larger the throttle bore, the weaker ...

If the Venturi size is the same on both the 750hp and 950hp, why is the baseline jetting different?

I wouldn’t think the signal would be any different with the different throttle body if the Venturi is the same size.

Mike, did it have any affect on your idle? I'm wondering if they're too far downstream for that :-k It did actually. Idle vacuum went up to 10” from 8”. Also have had to lean to carb out significantly. Especially the idle/transition circuit. Made it way richer per AFR meter, I’m assuming because of...

I settled on the final placement of mine on the inlet side of my X-pipe so that I had a decent amount of collector extension upstream of them. Very happy with the way it runs set up this way.

The AR devices I included in the pics are 3” inlet and outlet, but the internal portion tapers down to 2 1/2” and extends 1/2 to 2/3 of the way into the larger case/chamber. About where the tip of my thumb is in the side profile pic, maybe a bit further.

Has anyone measured flow in both directions to determine the difference in flow? I did this once for an intake manifold device, intuitively it looked like it might be AR, the flow difference was insignificant. I ordered a pair of the 3" in /3". Out. Since they were all Dynatech had in sta...

For those guys who just HAVE TO buy a cam to get that "classic" lumpy idle, small and fast-enough headers and AR mufflers seem like a good idea, so I have to ask: Do these AR devices reduce the lumpy idle sound? (That could be a "downside" for some people.) (Is the sound primary...

The missing disc in one would’ve been grounds for me to just replace all of them while it was apart. But I’m completely guilty of trying to make stuff work when I have my doubts so no judgment from me

Adding to my above comment. The AR devices I included in the pics are 3” inlet and outlet, but the internal portion tapers down to 2 1/2”.

I placed my AR devices at the inlet side of my x pipe so that I still had a good amount of collector extension ahead of it.[/img]

You can raise the manifold up by using a 1266 gasket which is thicker instead of a 1206. Will give you a better seal width up top. Be mindful that you check to see if you’re still sealing at the bottom of the port.

...I think the one above has that plastic extension where the Speedway Motors doesn’t have that, so maybe that’s why its a bit more...but 3x’s more it better come highly polished... That looks like the vent whistle that most HP metering bodies include. Another cap is in the lower right of the pic. ...

I’m currently running a set of copper mr gasket head gaskets on my sbc without o-rings. Stock deck height so I wanted something thin. Copper sprayed them thoroughly and haven’t had any issues.