Ramair crankcase breather mod

[Gregger]

Rob, so then you agree with me?
Best to not to dump crankcase breather directly into the intake.

Old School.....Love it. You must have worked on a least one 265 Chevy small block in your day. Just take the downdraft tube off the back and install it on the Rocket. The best thing this did was keep the underside of the car from rusting..... Glad when they switched to PCV systems.



I just took the filter supplied with my Ramair and attached a 6 inch piece of tubing before attaching it to the breather fitting. So far no oil venting issues or oil film on the back of the block.

 

[BeastMaster]

If one were to do this, it would involve drilling a hole in the muffler, attaching a metal fitting of some sort, running a line to the crankcase breather and putting a check valve in between? What sort of fitting would go into the muffler (silencer) and what sort of check valve would be used? What sort of hose would be use to attach to the muffler fitting since that would be getting very hot? Thanks for helping me to understand this.

It seems like a ton work for I don't know what. Personally I'll just stick with a catch can.

 

[1olbull]

Old School.....Love it. You must have worked on a least one 265 Chevy small block in your day. Just take the downdraft tube off the back and install it on the Rocket. The best thing this did was keep the underside of the car from rusting..... Glad when they switched to PCV systems.



I just took the filter supplied with my Ramair and attached a 6 inch piece of tubing before attaching it to the breather fitting. So far no oil venting issues or oil film on the back of the block.

Ha! Ha! Ha! Good Call!
I have rebuilt this engine! 25 years I drove my 55 Belair with OEM 265 power pack and dual exhaust.

 

[Claviger]

To make your own evac system you need a fast acting check valve with low cracking pressure, PTFE internals preferred, a piece of steel pipe (I used cold rolled brake line 3/8", and cut a 10" section off), and a hole in the exhaust just past the merge collector (point of highest velocity in the pipes). You cut the steel pipe at ~45 degrees and weld it into the exhaust just after the merge collector at an angle. Then use some oil safe hose from the new steel pipe, to the check valve, to the crank case breather point with the arrow on the check valve pointing from the crank case to the exhaust. Leave 6-8" of steel pipe between the hose and the merge collector. I haven't had any heat issues with it thus far.

I used this check valve, it works great: UPR 10MM Non-Return One Way 3/8 Inch Air Fuel Oil Check Valve Diesel Gas - Black

To test, pull the hose from the crank case connection point, start the bike and put your finger over the hose. If it builds suction, it works. You can connect a gauge if you're really interested in the amount of vacuum built, but in reality, ANY vacuum is a gain over the stock/vented or atmosphere method.

I went this way instead of a catch can for a few reasons, it's nearly free HP, ensures no oil vapor enters the chambers and reduces your fuel octane, it discourages oil leaks since the whole area under the piston is now under vacuum so a seal leak would suck in instead of oil being pushed out. Additional benefits include, better ring seal, less oil frothing, airborne contaminants being draw out immediately instead of mixing with oil and creating an acidic mixture in the oil pan over time.

All in all, its cheap, and it's the best solution with zero compromises except very minor environmental concerns (but you need to not have a catalytic converter for this setup to work so that's kind of hilarious).

PS: OP = original poster

 

[warp9.9]

To make your own evac system you need a fast acting check valve with low cracking pressure, PTFE internals preferred, a piece of steel pipe (I used cold rolled brake line 3/8", and cut a 10" section off), and a hole in the exhaust just past the merge collector (point of highest velocity in the pipes). You cut the steel pipe at ~45 degrees and weld it into the exhaust just after the merge collector at an angle. Then use some oil safe hose from the new steel pipe, to the check valve, to the crank case breather point with the arrow on the check valve pointing from the crank case to the exhaust. Leave 6-8" of steel pipe between the hose and the merge collector. I haven't had any heat issues with it thus far.

I used this check valve, it works great: UPR 10MM Non-Return One Way 3/8 Inch Air Fuel Oil Check Valve Diesel Gas - Black

To test, pull the hose from the crank case connection point, start the bike and put your finger over the hose. If it builds suction, it works. You can connect a gauge if you're really interested in the amount of vacuum built, but in reality, ANY vacuum is a gain over the stock/vented or atmosphere method.

I went this way instead of a catch can for a few reasons, it's nearly free HP, ensures no oil vapor enters the chambers and reduces your fuel octane, it discourages oil leaks since the whole area under the piston is now under vacuum so a seal leak would suck in instead of oil being pushed out. Additional benefits include, better ring seal, less oil frothing, airborne contaminants being draw out immediately instead of mixing with oil and creating an acidic mixture in the oil pan over time.

All in all, its cheap, and it's the best solution with zero compromises except very minor environmental concerns (but you need to not have a catalytic converter for this setup to work so that's kind of hilarious).

PS: OP = original poster

I kind of went a combo route first I vent to a baffled catch can then from there thru the one way brake booster valve and to the exhaust. This way I catch any trash before it goes out the exhaust.

 

[PaddyO]

To make your own evac system you need a fast acting check valve with low cracking pressure, PTFE internals preferred, a piece of steel pipe (I used cold rolled brake line 3/8", and cut a 10" section off), and a hole in the exhaust just past the merge collector (point of highest velocity in the pipes). You cut the steel pipe at ~45 degrees and weld it into the exhaust just after the merge collector at an angle. Then use some oil safe hose from the new steel pipe, to the check valve, to the crank case breather point with the arrow on the check valve pointing from the crank case to the exhaust. Leave 6-8" of steel pipe between the hose and the merge collector. I haven't had any heat issues with it thus far.

I used this check valve, it works great: UPR 10MM Non-Return One Way 3/8 Inch Air Fuel Oil Check Valve Diesel Gas - Black

To test, pull the hose from the crank case connection point, start the bike and put your finger over the hose. If it builds suction, it works. You can connect a gauge if you're really interested in the amount of vacuum built, but in reality, ANY vacuum is a gain over the stock/vented or atmosphere method.

I went this way instead of a catch can for a few reasons, it's nearly free HP, ensures no oil vapor enters the chambers and reduces your fuel octane, it discourages oil leaks since the whole area under the piston is now under vacuum so a seal leak would suck in instead of oil being pushed out. Additional benefits include, better ring seal, less oil frothing, airborne contaminants being draw out immediately instead of mixing with oil and creating an acidic mixture in the oil pan over time.

All in all, its cheap, and it's the best solution with zero compromises except very minor environmental concerns (but you need to not have a catalytic converter for this setup to work so that's kind of hilarious).

PS: OP = original poster

Thanks Rob for the detailed explanation. The crossover pipe of the touring is after the collector if I am remembering correctly. Would that be a good place to tie-in to? If I can find someone who can weld, I can give that a try.

 

[Claviger]

I'd suggest not into the crossover, somewhere before the split will draw a lot more Vacuum, the setup is not particularly functional with restrictions like the cat box in place. It's more an open exhaust deal.

 

[PaddyO]

I'd suggest not into the crossover, somewhere before the split will draw a lot more Vacuum, the setup is not particularly functional with restrictions like the cat box in place. It's more an open exhaust deal.

Thanks again Rob.

 

[ChrisACT]

Isn't the Rocket a dry sump engine? Therefore isn't there already vacuum being applied to the crankcase? Presumably applying additional vacuum may potentially interfere with the dry sump system?

I very much doubt it as the amount of vacuum you're talking about would be so tiny as to have no real effect.

Just a thought though. If you're only reintroducing the same sort of level of vacuum as the stock system then of course, no issue. But if you're taking vacuum from an alternative source and that is significantly higher vacuum, then perhaps it'd be worth being certain it's not going to cause issues.

I'm just spitballing here. I don't think it'd be a problem.

 

[Mad Dog]

Moroso 97810: Weld-In Nipple for Header Collector Sold Each | JEGS

Here you go guys. Check valves and nipples ready to go. It’s old school racing stuff, no doubt it will pull a vacuum. How much power it makes for our motors and when is questionable, but at the least it’s a great way to get rid of the crankcase fumes.