Crankcase Evacuation System
Discussion
Hello All......
Has anyone Fitted one of these , If so , how effective is it and was it a noticable performance upgrade .
Built primarily for race applications, this system is designed to reduce pressure build-up in the engine crank-case. The results are better piston ring seal, less intake charge contamination, and reduced oil leaks, while increasing engine performance.
Has anyone Fitted one of these , If so , how effective is it and was it a noticable performance upgrade .
Built primarily for race applications, this system is designed to reduce pressure build-up in the engine crank-case. The results are better piston ring seal, less intake charge contamination, and reduced oil leaks, while increasing engine performance.
Never used one myself on any breed of motor but the comics give them a good write-up with a claimed 15-30 hp increase on a 600 hp v8!.
I would think they are more an advantage in a outright track/race motor, high revs, narrow low tension rings etc etc.
In a street setup you lose 15hp when you turn on the aircon and electrics!
If you just want to drop crankcase pressure then run a hose into a crankcase vent tank. See what difference it makes, if any. Its a lot cheaper experiment than a crank vac pump and doesn't have any drive losses either.
A similar small hp increase is attainable with a short electric water pump for $200 or less.
Also, similar,small power gain's can be had with better quality valve springs/pushrods/rev kit's, all of which will help look after your cam and followers too! (maybe more important than minor crankcase pressure?)
I would think they are more an advantage in a outright track/race motor, high revs, narrow low tension rings etc etc.
In a street setup you lose 15hp when you turn on the aircon and electrics!
If you just want to drop crankcase pressure then run a hose into a crankcase vent tank. See what difference it makes, if any. Its a lot cheaper experiment than a crank vac pump and doesn't have any drive losses either.
A similar small hp increase is attainable with a short electric water pump for $200 or less.
Also, similar,small power gain's can be had with better quality valve springs/pushrods/rev kit's, all of which will help look after your cam and followers too! (maybe more important than minor crankcase pressure?)
Yeh , got 685 hp on this baby , so the no's are right for possible gains.
This set up will pull a vac. using the exhaust just after the collectors +/- 3 " or so after , you place pipe with a one way valve to the breathers on the tappet covers , one on each side (exhaust ) . The more you rev the higher the vac. Its A really cheep and simple add on , with all positive motor gains.
This set up will pull a vac. using the exhaust just after the collectors +/- 3 " or so after , you place pipe with a one way valve to the breathers on the tappet covers , one on each side (exhaust ) . The more you rev the higher the vac. Its A really cheep and simple add on , with all positive motor gains.
Hi Steve D
Question 1 :-
Do you already have a PCV valve fitted?
I would think this will give the same benefit as the connection to the exhaust.
Proper power gains require a larger vacuum to be pulled across the power range which the PCV will not do.
Answer :-
Not on my carb all blanked off. Fits to each exhaust with - 12 AN pipes and one way valve also - 12 AN. Its A Moroso product Crankcase Evacuation System . Acording to Moroso it does pull larger vacuum.
Hi 738 driver
Question 2 :- Make sure your valve-gear really is up to the required rev- range first!!
Answer :- Contacting AMS as we speak.
Question 1 :-
Do you already have a PCV valve fitted?
I would think this will give the same benefit as the connection to the exhaust.
Proper power gains require a larger vacuum to be pulled across the power range which the PCV will not do.
Answer :-
Not on my carb all blanked off. Fits to each exhaust with - 12 AN pipes and one way valve also - 12 AN. Its A Moroso product Crankcase Evacuation System . Acording to Moroso it does pull larger vacuum.
Hi 738 driver
Question 2 :- Make sure your valve-gear really is up to the required rev- range first!!
Answer :- Contacting AMS as we speak.
Strike, just to explain my opinion a little further.
The cheap power system you are looking at is not the vac pump unit I was referring to.
The exhaust vac system you are looking at will only really work fully on a very low back-pressure exhaust system, ie little or no silencing. This is fine in hot-rod or dragstrip circles but if you are using an Ultima road-silencer system there will exist some back pressure during most running (apart from overrun when you really need an extra 15hp of course!!) So assuming you dont initially have excessive crankcase pressure then the exhaust header/collector back pressure will exceed the crank pressure and the one-way valve will be closed ! Hence no evacuation when you need it.
If you really want it to work you need a venturi in the tailpipe (after the silencer), something which in an Ultima is quite an easy fit, not so however on most cars hence why one has not been developed. At the minute I dont have the time but Im sure an exhuast or small engineering CO could knock some up for those interested.
The old PCV induction is the best all rounder as it fits all cars and lubes the valves too. So unless you are searching for every last ounce of power , ie drag racing then the small losses due to contaminated induction, are far offset by the simplicity and relibility the PCV provides!
This is why I asked about your valve gear, if you are drag racing most high output SBC motors are doing well at 200-400passes (100-200 miles) before a valve gear rebuild ! So if you do or plan to take your Ultima to the strip regulary did you advise A/S beforehand?
If you are just looking for an extra 15hp to call it a round 700 then look at the real important stuff in your motor and remember the sales figures are usually corrected.
As with most things in life theres a good chance every single component will have been built by the lowest bidder. So unless you want/like to rebuild every couple of months, then maybe try to read and understand as much about your motor as possible, it will gain the respect it deserves and reward you with reliability and performance you seek!
Have fun !
The cheap power system you are looking at is not the vac pump unit I was referring to.
The exhaust vac system you are looking at will only really work fully on a very low back-pressure exhaust system, ie little or no silencing. This is fine in hot-rod or dragstrip circles but if you are using an Ultima road-silencer system there will exist some back pressure during most running (apart from overrun when you really need an extra 15hp of course!!) So assuming you dont initially have excessive crankcase pressure then the exhaust header/collector back pressure will exceed the crank pressure and the one-way valve will be closed ! Hence no evacuation when you need it.
If you really want it to work you need a venturi in the tailpipe (after the silencer), something which in an Ultima is quite an easy fit, not so however on most cars hence why one has not been developed. At the minute I dont have the time but Im sure an exhuast or small engineering CO could knock some up for those interested.
The old PCV induction is the best all rounder as it fits all cars and lubes the valves too. So unless you are searching for every last ounce of power , ie drag racing then the small losses due to contaminated induction, are far offset by the simplicity and relibility the PCV provides!
This is why I asked about your valve gear, if you are drag racing most high output SBC motors are doing well at 200-400passes (100-200 miles) before a valve gear rebuild ! So if you do or plan to take your Ultima to the strip regulary did you advise A/S beforehand?
If you are just looking for an extra 15hp to call it a round 700 then look at the real important stuff in your motor and remember the sales figures are usually corrected.
As with most things in life theres a good chance every single component will have been built by the lowest bidder. So unless you want/like to rebuild every couple of months, then maybe try to read and understand as much about your motor as possible, it will gain the respect it deserves and reward you with reliability and performance you seek!
Have fun !
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