Atom 3.5R oil cooler and catch can questions

[Toilet Duck]

Hello all,

Can anyone confirm what size oil cooler is used on the 3.5R, and does anyone know what sort of drop in oil temp it achieves?

Also, am I correct in thinking that part of the 3.5R upgrade is an oil catch can? If so, what's the reason for this and why isn't one necessary on lower power models? Does the extra power cause increase blow by on the cylinders and pressurise the crank case etc? How is it plumbed in? If any owners could take pics I would be very grateful.

Cheers

[John Scherrer]

I have pics of the Atom Cup cars which were the first to have these installed - it was a requirement,I believe, to meet the race regulations .. I can't get access to those right now, will post later ..

The 3.5R upgrade includes an oil catch tank.

In terms of why it's needed, without one, oil vapour from the sump and positive crankcase pressure is diverted back into the inlet to be burnt. This can cause oil to gum up the inlet valves causing pre-detonation etc.

On normal road spec engines, the average user wouldn't ever remember to empty the tank ..

[Toilet Duck]

Thanks John, look forward to seeing your pics

I get why race cars need them for regs etc, just curious why they are standard fitment on the 3.5R but not "lesser" models? If a 3.5R can have the valves gum up due to vapour etc, I would have thought a 300/310 Atom would suffer similarly. If this is an issue I'd be interested in fitting a catch can to my 310 as they are not massively expensive and would prevent "oily" air going into the inlet manifold.

Cheers

[John Scherrer]

The 3.5R with its additional boost is more liable to give predetonation issues (pinking) ..

[autobackup]

John

Your post stating that the 3.5R upgrade includes an Oil Catch Can/Tank gave me serious pause for thought followed by a hasty trip outside to my Atom to see where it was fitted - however, no matter how hard I searched, I simply couldn't find one fitted to my 3.5R

So having signally failed to find anything I then decided to contact Steve Rooke to ask where it was fitted?

........."Steve - Am I correct in that as part of the 3.5R upgrade an oil ‘catch can’ was installed in my Atom?

If so where is it mounted and how do I empty it as I can’t see it anywhere?..........."

---------------------------------------------------------

FYI - his very prompt reply is appended below :

".............No ‘oil catch can/tank’ has ever been fitted to an Atom 3.5R.
Only to the Cup Cars, which were for track use mainly and the tank is to stop oil contamination of the track surface.

Hope that clears that up?

Regards
Steve
Service Department..........."

I was relieved to get his email as search as I might I couldn't find one fitted to my Atom!!

[Toilet Duck]

Autobackup,

Check this recent thread here

Henry from the factory clearly states you get a catch can with the 3.5R

I've been reading around honda forums and it seems that oil catch cans come recommended on forced induction set ups. I want to fabricate one for my own car but I'm struggling to get a definitive answer as to how it should be plumbed in on the K20 engine

[autobackup]

TD

Wanting to get final clarification I emailed Henry at the factory this morning to ask the question and received the reply from him appended below :

"............My mistake! It’s a V8 that has a catch tank for the oil.

I think I just listed the catch tank for the coolant twice… that’s all

Thanks for the link to Ben @ danbutlers. Will keep it in mind!

All the best

Regards

Henry
Henry Siebert-Saunders

........."

So it is finally definitive that the 3.5R does NOT have an Oil Catch Tank fitted however it DOES have a coolant Catch Tank fitted!!

[John Scherrer]

Sorry if i caused confusion, i was just quoting Henry's post

I will post the pics I have tonight ..

[John Scherrer]

Here's some photos of the Oil Catch Tank installed for the Atom Cup cars (taken at Silverstone Atom Cup - 2013)
Some were taken at the Atom Cup 'shakedown' in April, the rest at the actual Silverstone Race Meeting in September.

It looks like the crancase filter is removed from the 'rocker cover' and relocated on the tank and a single tube connecting the 'rocker cover' outlet to the tank.

[John Scherrer]

and

[John Scherrer]

An example of a more conventional installation where the filtered clean air is redirected to the inlet to be burnt ..

[cvjoint]

Interesting. My Spec Race Ariel, which should be the equivalent of the Cup Car for the US, does not have this tank. The ITG filter is stuck where the tube connects to the valve cover. I suppose it vents into the atmosphere.

[smokin]

I fitted a small (1/2ltr) can to my Atom 2 S/C some time ago. Still nothing in it but then I've not tracked my car since and don't go mental on public roads.

[Toilet Duck]

Interesting.

I think you need to to take a feed off of the PCV valve which is just above the alternator. This is where the crankcase vents off pressure from combustion blow by. Ordinarily the valve/rocker cover port (where the Atom has the small filter) is actually an INTAKE on the OE Honda set up. See below for generic PCV diagram:



On supercharged Atoms (haven't looked at N/A ones) you'll find the PCV valve connected to the supercharger inlet via a hose so as to presumably create a vacuum. All the sh1t coming out the crankcase therefore gets sucked back into the engine which isn't great.

I don't think just connecting the rocker cover vent to a catch can will collect much. The PCV feed is the one to catch. Searching online on Honda forums etc I see a lot of people recommend punching/drilling out the centre of the PCV valve on turbo/supercharged K20's so that the valve is always open and can vent freely.