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#1
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Vacuum Pump vs. Header Evac?
I currently run a stock PVC in valley pan and a valve cover breather routed to the open air cleaner base (other valve cover is sealed) While my engine performs well, it does go through a little oil consumption with zero leaks.
My thought was that a vacuum pump may help seal rings a little better, etc. but was not real excited about dropping $800 for a pump kit. Are the header evac systems a decent low buck option on a mostly drag car, or not worth the effort due to lower vacuum ability compared to a pump? Anyone have testing results comparing the two options? Sent from my SM-G965U using Tapatalk
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68 Firebird-- Street/Strip - 400/461 Eagle Forged Bottom End & Ross Flat top pistons. KRE 325 CFM D port, Ultradyne 263/271 @.050, .4267 lift. Crower Solid roller lifters and 1.65 stainless rockers. Quickfuel 1000 on Torker2 intake and 2" open spacer. Hedman 1.75" headers. TH400 w/brake. Ford 9" w/3.80 gears & 28x9 Hoosier pro bracket drag radial. Best ET: 1.35 60ft, 6.29 @ 107.20 mph, 9.99 @132.33 mph. 3,300 race weight |
#2
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A vacuum pump definitely has the potential to make more power.... Also has the potential to be a major PIA! We've always run pcv valve with pan-evacs on our street strip cars and have never had any issues. Unless you're worried about the last ten horsepower my vote is for the pan-evac. Also frees up some money to be spent else where.
If your rings are have sealing issues the vacuum pump will give you fits... The valve seals usually cause more issues than the rings with oil consumption nowadays. Last edited by PAUL K; 11-06-2019 at 08:53 AM. |
The Following User Says Thank You to PAUL K For This Useful Post: | ||
#3
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Thank you for the note. Have you run the evac system with mufflers? I have read that it is not advised, but some have commented it is ok if you have a straight through/low back pressure muffler like the Dynomax ultraflow.
Sent from my SM-G965U using Tapatalk
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68 Firebird-- Street/Strip - 400/461 Eagle Forged Bottom End & Ross Flat top pistons. KRE 325 CFM D port, Ultradyne 263/271 @.050, .4267 lift. Crower Solid roller lifters and 1.65 stainless rockers. Quickfuel 1000 on Torker2 intake and 2" open spacer. Hedman 1.75" headers. TH400 w/brake. Ford 9" w/3.80 gears & 28x9 Hoosier pro bracket drag radial. Best ET: 1.35 60ft, 6.29 @ 107.20 mph, 9.99 @132.33 mph. 3,300 race weight |
#4
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You're welcome! Never had an issue and have only ran them with mufflers...good mufflers and a well thought out exhaust system.
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#5
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I went to header evacs from a PCV system a few years ago. It didn't seem to improve my ET any but it does make me feel better about not introducing any oil into the intake tract through a PCV valve. No issues with running on the street or track through my exhaust. I've ran the evacs with a full Flowmaster system and now my "custom" system with Pypes Race Pros. My car did start smoking from the right bank about 1/2 way through this year's Drag Week. Turns out the left evac check valve quit working and allowed exhaust to flow from the left check valve, through the engine, and out the right check valve pulling oil mist with it. That proves the system can actually move some air and that you should keep a spare check valve on hand!
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'68 Firebird 463/pump gas/SD 325 E-heads/266-272 SR cam/1050 Dominator/3.73/ET Street Radials/1.37 60'/6.30@108.80/9.93@135.14 Hot Rod Drag Week finishing averages: 2014 - 11.12 @ 118.56 2015 - 10.84 @ 124.97 2016 - 10.56 @ 127.88 2017 - 10.29 @ 130.74 2018 - 10.29 @ 130.53 2019 - 10.16 @ 132.34 2021 - 10.09 @ 132.69 2022 - 10.13 @ 133.07 9.93 run - https://youtu.be/hII0_UlYM4U |
The Following User Says Thank You to firechickenman For This Useful Post: | ||
#6
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An interesting read, We race with a guy running an s10 evac pump
http://grannys.tripod.com/evac.html
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69 Firebird, 462 turbo 400 3000 stall, 8.5 323 rear |
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