Its ALIVE!!!! (the video)
11-19-2007, 07:45 PM
#11
6th Gear Member
Thread Starter
Join Date: Dec 2006
Location: Citrus County, FL
Posts: 8,007
RE: Its ALIVE!!!! (the video)
i have driven it around the block a few times, its not really wanting to idle in gear. what you heard was about 850 RPM or so and thats about as low as I can get it so far. I briefly messed with the air/fuel screws today, my vacuum gauge is telling me I have about 10 inches of vacuum @ 800 or so, which is damn low and is going to make for a hard tune. I need to check and verify the secondaries are closed all the way.
for exhaust i have hedman longtubes into 2 1/2 pipes (or are they 2 1/4??), a pair of flowmaster 40 series, and no crossover. i've heard alot of sound bites of people with built 302's and flowmasters and they always sound more mellow. I always thought a large portion of my rumble came from the 12:1 302 that was in there, but even this 10:1 289 sounds virtually the same. its kinda a double edged sword, because my long duration cam that surely has alot of overlap is whats making it sound hot - but also killing my vacuum. i have to say though, the exhaust sounds better than most i have heard around here from a small block...... then again i may be biased
and yeah, sleeeeeeper (except for the fact that it rumbles like the dickens)
for exhaust i have hedman longtubes into 2 1/2 pipes (or are they 2 1/4??), a pair of flowmaster 40 series, and no crossover. i've heard alot of sound bites of people with built 302's and flowmasters and they always sound more mellow. I always thought a large portion of my rumble came from the 12:1 302 that was in there, but even this 10:1 289 sounds virtually the same. its kinda a double edged sword, because my long duration cam that surely has alot of overlap is whats making it sound hot - but also killing my vacuum. i have to say though, the exhaust sounds better than most i have heard around here from a small block...... then again i may be biased
and yeah, sleeeeeeper (except for the fact that it rumbles like the dickens)
11-19-2007, 10:12 PM
#16
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: Its ALIVE!!!! (the video)
Doesn't this forum have a Pinto section? [8D]
What are the specs on your cam? Cuz yeah, 10in does sound kinda low. But you also cut the divider down on that intake quite a bit, didn't you? It's half way to being a single plane. It does sound real good though, aside from that it would be a nice sleeper.
What are the specs on your cam? Cuz yeah, 10in does sound kinda low. But you also cut the divider down on that intake quite a bit, didn't you? It's half way to being a single plane. It does sound real good though, aside from that it would be a nice sleeper.
11-19-2007, 10:39 PM
#17
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Join Date: Dec 2006
Location: Citrus County, FL
Posts: 8,007
RE: Its ALIVE!!!! (the video)
the cam is a 300/300 .500/.500 and i dunno any other specs on it. its a crane grind from the late 70's that sat unused for about 20 years.
i wonder if i welded that divider back up if i'd gain some vacuum? i wouldnt think it would matter much would it?
i wonder if i welded that divider back up if i'd gain some vacuum? i wouldnt think it would matter much would it?
11-20-2007, 12:21 AM
#18
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Join Date: Apr 2007
Location: California
Posts: 10,468
RE: Its ALIVE!!!! (the video)
Well, if any one cylinder is trying to pull air through more barrels on the carb(4 instead of just 2)it could lower vacuum cuz there's less resistance. But the carb is small too, so that should help. 300/300 total on a flat tappet cam from the late 70's though, prolly got some decent overlap, so I doubt welding the divider back in would make much, if any difference. I'm sure part of it is the cam, I'm running a mild Crane Hyd roller and with that Weiand intake and the same carb, my idle vacuum at like 800rpm is only around 12.5". Might not hurt to make sure the secondaries are all the way closed though, the linkage on mine was a bit sticky on the driver's side for the thing that limits how far the secondaries can open in relation to the primaries. I put some antisieze on it and it helped it along just fine. Keep in mindtoo that the 570 comes with an 8.5 power valve out of the box, so if your vacuum fluxates, or drops down enough when you're in gear, it could be opening the power valve at idle. What's your idle vacuum at?
