maveRick
05-23-2002, 12:50 AM
After going through four seized crankcase evacuation pumps, I'm going to try yet another.
I have decided to try the GM "Air Injector Reactor Pump", or "AIR" pump (GM p/n 12568241 (www.gmpartsdirect.com)) used on late model GM 5.7L's (Camaro, Firebird, etc).
Background:
The first two I went through were Ford Racing's P/N 9486-A460 ($175+) belt driven pumps. The second two were modified (3 or 4 vein) from a Powerstoker smog pump and also belt driven.
All of these pumps are belt driven. They replace the existing smog pump on the 5.0 block (low position allows hot oil to readily enter pump).
All the pumps were eventually junked because oil got into the system and caused the heated veins to seize the pump (which, in turn, caused other problems while on the road).
Both large diameter hoses (#12 AN) and small diameter (3/8" polymer) hoses were used as vacum lines in the system at differenet stages of development.
The location of the #12 braided line was first connected to a fitting welded to the rear of the lower intake with a fabricated baffle located at the lower outlet.
It was thought the g-force during acceleration was causing oil to contaminate the pump. The #12 line was discarded and replaced by two (2) 3/8" lines located on the top of the valve cover near the front of the engine.
Some form of adjustment (via volume change, valves, various size pulleys, etc.,) was used to regulate vacuum (from 5Hg at idle to 15Hg max at 6000 rpm's) on all the pumps.
Also, a catch can ("jazz" can) was used to accumulate the excessive oil prior to entering the pumps to prevent contamination on all the setups.
After consulting with a well-renowned bow-tie engine builder, I was told that going to the more expensive ($360+) Moroso pump (P/N 710-22640) (http://www.jegs.com/photos/71022640.jpg) would also seize up with “that much oil getting to the pump” (note: Chevy blocks have an 'oil restrictor' location in the rear of the block to limit the amount of oil going to the top of the heads, Jeg's P/N 892-2415 (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=20623&prmenbr=361) are typically used).
Three major problems associated with 5.0 blocks and crankcase evacuation systems (on street/strip usage) are;
1) The pump is located much lower than the highest level of oil in the engine (allowing gravity fed oil to enter into the pump).
2) All the Ford pumps run off the crank (robbing a portion of the h.p. gained by using an evacuation system).
3) I am not aware of any features similar to GM's that would lend itself to using 'off-the-shelf' flow restrictors (I was advised by a few mechanics that I should put pipe-cleaners in the push rods to limit the volume of oil going to the topside of the heads).
The reasons I am going to try the GM "Air Injector Reactor ("AIR")Pump" are:
1) Ford Tech Representatives failed to provide me a solution to the problem.
2) The "AIR" pump runs off 12V and pulls relatively little current vs. robbing horse power from engine.
3) It also runs at a constant speed (as opposed to running at the rpm of the engine) and should be easier to manage once the desired amount of vacuum is achieved.
4) The "AIR" pump can be located ABOVE the valve covers - providing less of a chance to pick up oil droplets (via the benefit of gravity alone).
5) The price of the “AIR” pump is $98.00
6) The inlet diameter of the "AIR" pump is 7/8" (volume sufficient to prevent droplets of oil to rise into the vacuum lines).
My intent is to use the raised oil 'spout' found on a typical set of 5.0 valve covers (located near the front of the engine) as the crankcase evacuator line outlet. I intend to weld another raised spout on the opposite valve cover (nearest to the front of the engine).
I'll try to take good pics of the installation. I’ll also contribute a write-up upon the completion (good or bad) of this attempt at obtaining a reliable and affordable crankcase evacuation system for street/strip SBF’s.
I have decided to try the GM "Air Injector Reactor Pump", or "AIR" pump (GM p/n 12568241 (www.gmpartsdirect.com)) used on late model GM 5.7L's (Camaro, Firebird, etc).
Background:
The first two I went through were Ford Racing's P/N 9486-A460 ($175+) belt driven pumps. The second two were modified (3 or 4 vein) from a Powerstoker smog pump and also belt driven.
All of these pumps are belt driven. They replace the existing smog pump on the 5.0 block (low position allows hot oil to readily enter pump).
All the pumps were eventually junked because oil got into the system and caused the heated veins to seize the pump (which, in turn, caused other problems while on the road).
Both large diameter hoses (#12 AN) and small diameter (3/8" polymer) hoses were used as vacum lines in the system at differenet stages of development.
The location of the #12 braided line was first connected to a fitting welded to the rear of the lower intake with a fabricated baffle located at the lower outlet.
It was thought the g-force during acceleration was causing oil to contaminate the pump. The #12 line was discarded and replaced by two (2) 3/8" lines located on the top of the valve cover near the front of the engine.
Some form of adjustment (via volume change, valves, various size pulleys, etc.,) was used to regulate vacuum (from 5Hg at idle to 15Hg max at 6000 rpm's) on all the pumps.
Also, a catch can ("jazz" can) was used to accumulate the excessive oil prior to entering the pumps to prevent contamination on all the setups.
After consulting with a well-renowned bow-tie engine builder, I was told that going to the more expensive ($360+) Moroso pump (P/N 710-22640) (http://www.jegs.com/photos/71022640.jpg) would also seize up with “that much oil getting to the pump” (note: Chevy blocks have an 'oil restrictor' location in the rear of the block to limit the amount of oil going to the top of the heads, Jeg's P/N 892-2415 (http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=20623&prmenbr=361) are typically used).
Three major problems associated with 5.0 blocks and crankcase evacuation systems (on street/strip usage) are;
1) The pump is located much lower than the highest level of oil in the engine (allowing gravity fed oil to enter into the pump).
2) All the Ford pumps run off the crank (robbing a portion of the h.p. gained by using an evacuation system).
3) I am not aware of any features similar to GM's that would lend itself to using 'off-the-shelf' flow restrictors (I was advised by a few mechanics that I should put pipe-cleaners in the push rods to limit the volume of oil going to the topside of the heads).
The reasons I am going to try the GM "Air Injector Reactor ("AIR")Pump" are:
1) Ford Tech Representatives failed to provide me a solution to the problem.
2) The "AIR" pump runs off 12V and pulls relatively little current vs. robbing horse power from engine.
3) It also runs at a constant speed (as opposed to running at the rpm of the engine) and should be easier to manage once the desired amount of vacuum is achieved.
4) The "AIR" pump can be located ABOVE the valve covers - providing less of a chance to pick up oil droplets (via the benefit of gravity alone).
5) The price of the “AIR” pump is $98.00
6) The inlet diameter of the "AIR" pump is 7/8" (volume sufficient to prevent droplets of oil to rise into the vacuum lines).
My intent is to use the raised oil 'spout' found on a typical set of 5.0 valve covers (located near the front of the engine) as the crankcase evacuator line outlet. I intend to weld another raised spout on the opposite valve cover (nearest to the front of the engine).
I'll try to take good pics of the installation. I’ll also contribute a write-up upon the completion (good or bad) of this attempt at obtaining a reliable and affordable crankcase evacuation system for street/strip SBF’s.