Fuel Pressure gauges and blown carbs

[74Dusted]

Had a thread on here that got lost in the server move, it had some good responses about trusting my gut instinct (not mounting it inside the car, even though summit sells "in dash" fuel pressure gauges). So I'm thinking about mounting it on a plate that will have the gauge sticking up through the hood (almost like a dixco tachometer, only the hood will have a 'cowl' over the gauge, and the gauge won't actually be attached to the hood)

I assume that it doesn't matter how they're installed, when they're outside the passenger compartment, right? just run a line from the tee's at the carbs to the gauge, right?

How's the visibility on a gauge that's mounted to the blower/hood/cowl? Can you guys see the numbers ok? my vision is great, but I'm curious how readable those 2-5/8" gauges are when they're on the hood/blower..

Whoops, forgot the carbs too.

My friend offered me a pair of matching AVS's for my 6-71 340 (I can choose either a pair of matching small block AVS's, or a pair of matching Big Block AVS's). What's the cfm like on the small block vs big block carbs? At $25 for a pair of carbs, I'm going to jump on that deal like a fat kid on a twinkie, just not sure which ones I should get.

 

[Blownfish]

Depending on what drive you're going to be running and how your engine is built, a pair of AVS's won't be enough carb for a blown engine. I'm running a pair of Demon 750 blower carbs on my 416 small block.

I have my fuel pressure gauge along with my other gauges mounted to the back of my blower. They're easy to see and no fluids being run inside the car.

 

[74Dusted]

I was looking to go with a 20% underdrive, about 6psi or so.

Nothing radical, just a street driven car. I don't really even 'need' a blower for the lil 340, it's just one of those "gonna do it, simply because I can" type deals

Next year, I'll tear the engine down (like I do every winter) and upgrade some more stuff, and slowly work my way up the boost ladder :burnout:

At the moment it's (awaiting parts & assembly) a '71 340 / 4.04 bore / 3.31" stroke (a 70 340 is currently in the car, the '71 will be taking its place) with 8.5:1 compression. An all iron motor at this point (the '71, not the '70), but next year, I'll splurge on some nice aftermarket heads, and drop the compression down a little bit more and run the boost a little higher.

Methanol Injection is already accounted for and in the budget with the rest of the blower & engine stuff, along with a boost timing controller. Just gotta start ordering all those goodies, and then check my mail every 5 minutes until they arrive

 

[Blownfish]

20% under drive doesn't sound right for a 671, that's a lot, it should be closer to 3% underdriven on a 340 to get around 6psi. I originally set mine up for a 340 with 3% underdrive, but I went with a 416 so I flipped the pullies which made it overdriven 3% and I got about 6 1/2 psi the way it sits.

 

[74Dusted]

20% under drive doesn't sound right for a 671, that's a lot, it should be closer to 3% underdriven on a 340 to get around 6psi. I originally set mine up for a 340 with 3% underdrive, but I went with a 416 so I flipped the pullies which made it overdriven 3% and I got about 6 1/2 psi the way it sits.

Maybe I wasn't reading the chart right on the dyer's blowers website? This computer monitor sucks, and it doesn't help that those charts are so small in size either.