crank evac system

[checkersorwreckers]

Has anyone tried using a crankcase evac system on a circle track car? If so, pros cons

[MM90]

Moroso makes a simple kit, lots of people are running them. I have been running one for two years now. Not really much of a con to it unless your valve covers don't have any baffling in them to keep it from sucking some oil out of the valve cover. But another way I have seen people do it is they run a catch can between the valve cover and the exhaust.

[Egoracing]

Many super engines run vacuum on the crankcase using the oil pump which is more efficient and reliable. The valve cover units work better at sustained high rpm more than many of the small tracks that are run by local racers.

[stockcar5]

pros= more hp, less chance of external oil leaks, plugs seem to last longer. no cons really. the kits are cheap. i have mine hooked to an oil/air separator which works well. it keeps any condensation in the tank and not in the oil.

assuming your not allowed a vacuum pump this is the way to go. vacuum pumps will make much more power but the motor will need special seals and pressurized oiling to things that were normally splash lubed. a friend of mine picked up 60hp on his 565bbc drag motor by adding a vacuum pump.

[dirty white boy]

the idea is for you to run thin weak low friction rings an vacuum is meant to seat them to the cylinder bore,...an will gain 15 to 30 hp on motor with them rings,..if you got stiff rings your not gaining nothing sept for less likely to leak oil witch is in its self a big plus on drag motors as any sign of oil leaking or dripping will end your day on the track...don't think id want one on a dirt motor cause if you loose a gasket or a seal it'll be sucking in dirt an contaminating your oil system...that's a big con to most us...

[stockcar5]

My chassis dyno hooked up a electric vac pump on a drag car and found it gained nothing...

The vac thing started up in Mn by stockcar5 and has been slowly trickling south just due to monkey see monkey do from what I can tell. I haven't ever heard of anyone who has chassis dynoed with one connected then disconnected.

I do also know moroso said theirs wasn't going to produce enough vacumn in the exhaust in 1994 when I installed it to do anything performance wise.

i didnt start it. stoa got it going up here. we dynoed with and without it. pulled 4 inches of vacuum and made 5hp.

[Confused?]

A friend of mine used a belt driven vacume pump about ten years ago on his Mod. He swore that it made a noticeable difference. The motor has to be sealed up completly for a vacume system to work correctly. Also needs very good gaskets.

[stockcar5]

I DIDNT say you started it. I said it started up by you. As in your area.

My bad. Iowa english gets me every time..LOL

[JETAM]

My bad. Iowa english gets me every time..LOL

In today's world of Super-Late Model dirt racing, especially the professional series (WOO,Lucas, others) , most if not all the open engines built by the major engine builders for these cars are running sealed engines with 4-6 stage dry sump pumps that develop lots of vaccuum in the crankcase which allows the use of light low tension ring packages which makes more hp.

[CRDracing]

Certain automobile mfgs have been running increased vacuum on their motorsports crankcases and have found they can yield as much as 10hp. The theory I have heard is the pressure differential is greater on the top of the piston which will cause the piston to drop faster due to a "negative pressure" on the bottom side of the piston. Coupled with different seals and lower tension rings the engine leaks less and wears less extending time in between rebuilds, yet another PRO.