Thanks for the reply. Its surprising to me that the relatively small pressure (>15 PSI) difference the vacuum would have on the rings would have a noticeable effect given the large pressures from combustion. Not doubting what you say -- just hard to understand why. I'd like to keep the PCV if I can get the hose off that single runner. Might get away with a 1/2" spacer under the carb if one exists with a PCV port. Hood clearanc is tight now with the Air Gap intake. Isn't the PCV valve supposed to close when the throttle is closed like on idle or when slowing down? Shouldn't the PCV valve prevent crank case vapors from getting into the intake when slowing down? I think the PCV valve that's on there is a GM one. Chose it because it had a 90* elbow on it. That wouldn't matter, would it? Thanks for your help.
A vac pump isn't a wise choice on a street car it can suck the oil off the piston pins and cylinder walls for a gain 10-20 h/p in a street car it reduces you longevity and the pumps require frequent rebuilds also that being said Jim your carb should have a pcv port under the rear bowl if it is a double pumper the runner on the intake is better left as a port for the brake booster or trans modulator.
The carb is a Quick Fuel. I checked for a PCV port but didn't find one ... UNTIL I LOOKED AGAIN!! Oh, boy. Don't know how I missed it. Good news is I didn't find a 1/2" ro 3/4" carb spacer with vacuum port or I would have ordered it. Thanks!!! Next question. I have my PCV valve in one valve cover and a vented cap in the other. So, its not putting much vacuum on the crank case and it sucking quite a bit of air thru the crank case. Should I have an un-vented oil fill cap so as to limit the air flowing into the intake and create a vacuum in the crank case?
I don't see the need to eliminate the breather it needs fresh air to vent the crankcase. Does your valve cover have a baffle under the pcv port?
Yes, there's a baffle under the PCV valve but none under the vented filler cap. But, its not putting oil out on either valve cover so I'm not concerned about the missing one.
Maybe at higher rpm the baffle is filling with oil causing the smoke had this problem with a set of stock covers on a 351w .. the pcv only works at idle and cruise situations at wot it is closed and your valvecover breather relieves pressure when the engine returns to a vac situation (closed or light throttle the valve opens) Honestly I wouldn't put a whole lot of worry behind it id move you vac line to the carb, if your worried you can run a catch can inline with the pcv its normal it have some oil and vapor pass through.
347 vs 5.0 Dyno Charts Just went back and compared the 347 dyno chart to the 5.0 chart. 347 provides 78 more RWHP (274 vs 196) and 72 more ft lbs of torque (317 vs 245). Differences: 347 vs 302 CI Edelbrock Performer RPM Air Gap intake vs Edelbrock Performer 289 Quick Fuel 650 CFM carb vs Holley 600 Dart Pro 1 170 CC heads vs lightly ported E7 heads Custom hydraulic roller cam vs (I think) stock HO cam Roller rocker arms vs stock E7 rockers Electric fan vs belt driven AC compressor belt missing vs installed MSD e-Curve distributor and MSD Blaster II coil vs HEI distributor 235/60/15 tires vs 205/70/14s Cragar SS 15" wheels vs factory 14" wheels (Cragars are noticeably heavier) The same: About 9.0:1 compression in both Built C4 and stock converter 3.00 Traction Loc Exhaust system (Doug Thorley shortie headers, 2.5" exhaust pipes, Thrush Turbo muflers, 2.25" tail pipes.
Finally finished up the dyno tune today. Changed the accel pump to 50 cc, more aggressive pump cam, up two numbers on the main jets, and took 2* of timing out (was occasionally getting a little spark knock on start up). Runs good now with just a touch of occasional hesitation. I could go up a little on the nozzles or to another accel cam but I'm going to leave it alone for a while and see how it runs under different weather conditons. I'm ready for Sunday when the Greensboro Dragway opens for the first 2012 T&T.:bananaman
Thanks, Don. I'll post the results. I'd like to see the 13s in 1/4 (when I get to a 1/4 mile strip) and 8s in 1/8th. Hoping it'll hook on 235 60 15 street tires.
I think you will be surprised when you get it to the strip, I would chance to say high 12s are more likely but traction may be an issue, at least getting going once you gone no issue. Good luck
