Hamish Posted October 31, 2016 Report Share Posted October 31, 2016 Can you tell me what you guys do with the crank breather. Mine is approx 1" dia. and is only points up about 6 to 8" looks like PO mod. I believe this is a kas kastner take on things ? I also have the TR 4 vented rocker cover and sealed cap. Q1. How is the crank breather fitted is it a push fit ? Q2 for Motorsport does this need venting to a catch tank as per the rocker vent or can you add a vent air filter ? Q3. Is it needed with the rocker cover vent. Or can the rocker cover vent be enlarged to compensate ? I don't know what the bottom crank seals are ? As I understand crank pressure can blow via here. If it all should go via the catch tank. How do you vent the tank? That's different to venting the rocker etc to atmosphere ? Ta H Quote Link to post Share on other sites
Motorsport Mickey Posted October 31, 2016 Report Share Posted October 31, 2016 As per Q2, for M/sport the crank as and rocker cover normally vent to catch tank, often placed in void between passengers front wing and bulkhead. Make the pipe Dias as big as you can. The rear crank oil seal is a scroll cut into the crank mandrill which propels the excess oil along the crank rear mains and drops it back into the sump. It relies on the rear alloy oil seal plate which bolts up with the rear mains (which has it's own scroll in the alloy to skim meer thous away from the crank mandrill and "haircut" excess surface oil off again into the sump. Whilst the dimensions of clearance between alloy oil scroll and crank surface are maintained it works tolerably well as long as the engines running. When stood with engine off the oil will find it's way along the crank with it's labyrinth seal and drop on your drive. Fit the additional rear scroll lip seal from Christian Marx which works wellaccording to reports. Mick Richards Quote Link to post Share on other sites
Motorsport Mickey Posted October 31, 2016 Report Share Posted October 31, 2016 Sorry missed a bit, the catch tank vents to atmosphere via a selection of holes in the top sometimes the cap. No different to having pipes pointing out of engine into atmosphere except in engine blowup with oil beng pumped out the catch tank is meant to limit oil spillage on track. Mick Richards Quote Link to post Share on other sites
roy53 Posted October 31, 2016 Report Share Posted October 31, 2016 Both pipes can be push fit but best to add a clip to secure and go into a 2ltr minimum catch tank. best if this is then vented by a filter but can be just into their by a series of holes.TR2/3 TR4 OR TR6 ?? can send you photos if required although i would think they are on the forum somewhere. ROY Quote Link to post Share on other sites
Hamish Posted October 31, 2016 Author Report Share Posted October 31, 2016 Sorry it's a tr3(a) with tr4 additions. I was wondering as to the pipe to crank case method of fitting. So I wouldn't be a million miles out if each the crank and rocker breathers shared a tank with ambiant venting. Thanks all. H Quote Link to post Share on other sites
alan57 Posted October 31, 2016 Report Share Posted October 31, 2016 If engine size is more than 2000cc then the blue book says a 3 litre catch tank is required. Quote Link to post Share on other sites
Hamish Posted October 31, 2016 Author Report Share Posted October 31, 2016 3litres !!! Good job I don't want to go as far as fia track events then. It would have to be on the passenger seat. ! Quote Link to post Share on other sites
Stanpartmanpartwolf Posted November 1, 2016 Report Share Posted November 1, 2016 Do not fit a fanboy-style breather filter- it will clog quickly with oil & cause back-pressure and leaks. Ensure that your "catch tank" has vents to atmosphere of an identical area to your breather hose/pipes, which all too often will be made from heater hose. Use ONLY oil-resistant hose. Anyone recommending a "vented cap" is a charlatan IMO. Then, for amusement's sake, take a metre of 12mm ID hose and breathe through it yourself. Now you will understand the importance of free breathing for any engine. Elimination of even the slightest back pressure is vital. This is why plenty of 4A engines leak buckets (when the PCVV gives up) & earlier 2/3/4 engines don't, until they're complete toast. Pip Pip! SPMPW Quote Link to post Share on other sites
Tom Fremont Posted November 1, 2016 Report Share Posted November 1, 2016 Not to hijack this thread which is obviously about racing use... I've done 115K miles on a TR250 engine with Webers seeing to PCV with the original SMITHS valve - street use only. Never seen another so fitted, and really wonder why. The SMITHS takes care of the job very well and reliably ( never needed to replace the diaphragm in 22 years ), eliminating the dreaded stench which was the prime motivation for me. Cheers, Tom Quote Link to post Share on other sites
Hamish Posted November 1, 2016 Author Report Share Posted November 1, 2016 Thanks to all. I free breathing catch tank (or multiple thereof) of some sort will be the order of the day. Quote Link to post Share on other sites
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