Don Terrill’s Speed-Talk

Interesting question. I asked Superflow about this 3 or 4 years ago and they told me at that time they didn't offer one. Hmmmmm, do they now?

to simply change back to a non boost referenced mode, plug the external boost fittings and open a vacuum port from the power valve cavity through the baseplate so it sees full manifold vacuum.

That's a sh/tbox vac secondary electric choke doorstop. From your description of the motor - put a double pump carb on it. that's always a debate. That said, I've run a bunch of these on the dyno, and they've always run well (100 times better than a Holley). I've never heard back from the customer'...

I've run dozens of Dean Nickerson's carbs on dyno jobs and have never been disappointed. http://www.nickersonperformance.com

that's the way the Brawler and QFT shiny carbs get when exposed to the elements. It's more cosmetic than anything else. Like the other guy said, try to low ball him if you can live with what the carb looks like. remember though, it will never get any prettier, it will only continue to oxidize. FWIW,...

the last time I bought one (15+ years ago?) from Superflow it came in a Grainger box. I just looked on grainger.com and couldn't find it though

Brambles wrote: ↑Wed Feb 10, 2021 10:20 pm I just ordered a Quick Fuel SS 780 VS...hopefully not the same issues with that carb...

The QFT (and now Brawler) VS carbs do NOT have the same problem. The secondary opening action is tunable with the needle screw on the side of the vacuum can.

get rid of the unlite distributor and put in a MSD Pro Billet with a black bushing, a light silver and a heavy silver spring and tune the timing curve from there. Also, I don't care what the O2's are saying, a 69 jet in that 850 is too lean IMHO. Likely a tad to lean in the secondary as well. The no...

my years of dyno experience have told me that the centrifugal superchargers are softer on the bottom, regardless of the drive ratio. I've run a bunch of marine stuff that the customer's like because the lack of bottom end torque won't blow the drives up

just be aware that Superflow no longer supports the 901's. Replacement electronics are getting really hard to find. I bought a new 901 in 1988 and it served me well for a long time. When I had a major electronic failure in 2017, I bought the "902" upgrade kit that eliminated all of the old...

the 933 head is used on gen 5/6 engines that are built for generators that run on propane/natural gas. They have real small combustion chambers that will bring the compression up a couple of points and small valves as well. I've run tons of these on 454 engines that are set up for 375- 400 HP street...

Total and complete pain in the ass. A multi step process that drags on over multiple days. None of the engine builders that I dyno engines for do them anymore...

what kind of water pressure are you seeing in the engine? Also, what is the thermostat/thermostat housing set up you are using?

I don't know how you can make any decisions without knowing how much boost you are making now. Without that info, you're shooting blind...

I know I'm going to get beat up for this, but it's Monday morning and I haven't been bashed yet on the inter webs. That engine needs to go on a dyno to see what the problem is. You can throw parts at it all day long, and waste your time and money chasing the problem. There. Bash away...