Weberman Posted August 3, 2021 Author Share Posted August 3, 2021 When my intake leaked it made a whistling noise. When i poured some water over the leak the noise would stop and the engine would bog down a bit. When i pulled the i take the gasket was mush. I never did like that edlebrock gasket and much happier i used felpro the second time around. It was a better fit from the start. Yeah I used the nice Fel pros, which is why I'm doubting the intake. But the first two just sound much healthier to me. The vacuum has dropped to like 12 too at warm idle. The plug doesn't have that many miles, less than 1,000. Link to comment Share on other sites More sharing options...
Weberman Posted August 3, 2021 Author Share Posted August 3, 2021 Yeah I used the nice Fel pros, which is why I'm doubting the intake. But the first two just sound much healthier to me. The vacuum has dropped to like 12 too at warm idle. The plug doesn't have that many miles, less than 1,000. Also didn't think of this either, forgot the engine is also only at like 7* of timing. I have it down that far otherwise it idles high. I forgot I had it that low to idle right, checked it to see if timing slipped. Which I would think could be some air getting by still as the carb is still all the way out too. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 3, 2021 Share Posted August 3, 2021 Also didn't think of this either, forgot the engine is also only at like 7* of timing. I have it down that far otherwise it idles high. I forgot I had it that low to idle right, checked it to see if timing slipped. Which I would think could be some air getting by still as the carb is still all the way out too. I'm not sure what you mean by"the carb is still all the way out" The engine literally can't breathe if the throttle plates are closed all the way. So it's pulling air from somewhere... Link to comment Share on other sites More sharing options...
nic55kel Posted August 3, 2021 Share Posted August 3, 2021 I'm not sure what you mean by"the carb is still all the way out" The engine literally can't breathe if the throttle plates are closed all the way. So it's pulling air from somewhere... Just a thought but have you checked your PCV valve? It is a controlled vacuum leak. Link to comment Share on other sites More sharing options...
nic55kel Posted August 3, 2021 Share Posted August 3, 2021 Just a thought but have you checked your PCV valve? It is a controlled vacuum leak. It is possible your cam and PCV system do not play nice together. A little light reading: http://www.engineprofessional.com/articles/EPQ315_34-44.pdf They are obviously selling their valve but it does show how changing things on an engine can have unexpected results. Link to comment Share on other sites More sharing options...
Weberman Posted August 3, 2021 Author Share Posted August 3, 2021 I'm not sure what you mean by"the carb is still all the way out" The engine literally can't breathe if the throttle plates are closed all the way. So it's pulling air from somewhere... The idle screw is all the way out, and timing at 7* to keep it low is what I mean by the carb all the way out. I have a very small amount of adjustment left, wouldn't do much. Link to comment Share on other sites More sharing options...
nic55kel Posted August 3, 2021 Share Posted August 3, 2021 The idle screw is all the way out, and timing at 7* to keep it low is what I mean by the carb all the way out. I have a very small amount of adjustment left, wouldn't do much. Your vacuum at 12" Hg is very low should be closer to 15 or higher. I am not familiar with the cam you have but I do not think it is radical enough to bring your vacuum down that much. It may seem counter intuitive but PCV valves let in more air as the vacuum drops (throttle opens). I imagine that you have a different exhaust system on the truck than was on the car and that could make a difference too. Hopefully you find why the vacuum is so low. Link to comment Share on other sites More sharing options...
Weberman Posted August 4, 2021 Author Share Posted August 4, 2021 Your vacuum at 12" Hg is very low should be closer to 15 or higher. I am not familiar with the cam you have but I do not think it is radical enough to bring your vacuum down that much. It may seem counter intuitive but PCV valves let in more air as the vacuum drops (throttle opens). I imagine that you have a different exhaust system on the truck than was on the car and that could make a difference too. Hopefully you find why the vacuum is so low. Yeah I couldn't find many vacuum readings with this cam but the few I did find were 15-17. Don't have cats, exit before rear tires,, glass packs. May cap the PCV for now and then do the timing to where it should be, adjust the idle screw/arm all the way out and see where it ends up at. I would think the intake would've shown up before as I've let it idle for awhile and done short quick trips. But I'm wondering if the long drive warmed everything up good and then made the leak worse perhaps and that's why it pops now. I would think a valve train problem would be RPM dependent not a pedal position. Link to comment Share on other sites More sharing options...
nic55kel Posted August 4, 2021 Share Posted August 4, 2021 Yeah I couldn't find many vacuum readings with this cam but the few I did find were 15-17. Don't have cats, exit before rear tires,, glass packs. May cap the PCV for now and then do the timing to where it should be, adjust the idle screw/arm all the way out and see where it ends up at. I would think the intake would've shown up before as I've let it idle for awhile and done short quick trips. But I'm wondering if the long drive warmed everything up good and then made the leak worse perhaps and that's why it pops now. I would think a valve train problem would be RPM dependent not a pedal position. Have you tried spraying something flammable (brake clean?) around all the possible places the intake may leak. The rpm will pick up noticeably when spraying near the leak. Just take the obvious precautions although that stuff evaporates so quickly the fan will quickly blow it away. These problems are what make these older vehicles interesting. Link to comment Share on other sites More sharing options...
Weberman Posted August 5, 2021 Author Share Posted August 5, 2021 I'm not sure what you mean by"the carb is still all the way out" The engine literally can't breathe if the throttle plates are closed all the way. So it's pulling air from somewhere... Well there may be a vacuum leak somewhere but there's bigger problems. Looks like the #5 exhaust lobe is wiped. Went to adjust/check them and when I took the valve cover off and went over to spin the engine, I noticed it barely moved and went and touched it and the pushrod isn't even touching the rocker. Link to comment Share on other sites More sharing options...
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