Author Topic: Engine breathers  (Read 164 times)

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Sharks

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Engine breathers
« on: May 24, 2020, 07:55:43 PM »
Hi!

On Dad's old 1275, he had two breathers. When we put together the new one, we were told that one is sufficient. We were wondering if this was true or if it would be better to have two? What is the general consensus? Additionally, is it a good idea to plumb breathers into the intake?

Thanks, Sharks

Sharks

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Re: Engine breathers
« Reply #1 on: May 31, 2020, 09:07:48 PM »
Decided one wasn't enough and put together another out of some spare parts. Went on and off a few times as we worked out how to shape it.



After getting the angles right it was painted up and bolted on :)

Drakman

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Re: Engine breathers
« Reply #2 on: June 01, 2020, 05:29:06 AM »
Hi Sharks,  This is from MED in the UK re breathers.

https://www.youtube.com/watch?v=U4Flmn9fIhI

Sharks

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Re: Engine breathers
« Reply #3 on: June 01, 2020, 08:03:13 AM »
Thanks Drakman. Good to see that they too use the old fuel pump hole for a breather, and that if we decide to we can go down the route of plumbing it into the intake. Don't think we will worry about trying to jam a catch can into our engine bay though :D

ozmini

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Re: Engine breathers
« Reply #4 on: June 01, 2020, 10:35:30 AM »
Is there room for the bottom radiator hose to connect to the water pump?

Sharks

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Re: Engine breathers
« Reply #5 on: June 01, 2020, 01:20:09 PM »
Good catch, ozmini. I'd totally forgotten about that.
When I get home I'll have a proper look, but judging by the photos I've got with me now it looks like we should be able to make it work.



Thanks for the heads up.

Edit: I think it will fit. Thanks again :D
« Last Edit: June 01, 2020, 04:15:40 PM by Sharks »

Steam

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Re: Engine breathers
« Reply #6 on: June 01, 2020, 04:53:01 PM »
A bit late into this but I have always found 1 to be adequate but an extra one would not go astray.
The trick with plumbing to the inlet manifold is to use a suitable one way valve but I have never had any success as it always seems to screw around with the mixture.
 I have had better results plumbing to the carb, some SU have a spigot for this but not all.
You do have to give it some negative pressure though, or the A series tends to blow oil out of the dipstick
Cheers, Dave

Sharks

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Re: Engine breathers
« Reply #7 on: June 01, 2020, 05:01:04 PM »
Thanks, Steam.

That was the idea - the more negative pressure, the better. We figured plumbing into the carb would increase negative pressure but also didn't want to mess up the mixtures. Our intake manifold does have a spigot on it, but we haven't yet decided if we should use it or not.

Steam

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Re: Engine breathers
« Reply #8 on: June 01, 2020, 06:22:02 PM »
You may have misunderstood my last post, I have found that I have problems putting into the manifold, whereas into the carb allows the mixture to be set with the combustion gases incorporated.
I have wondered if it simulates a manifold leak.
Hope this helps.
Cheers, Dave

Sharks

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Re: Engine breathers
« Reply #9 on: June 01, 2020, 06:32:17 PM »
Hey Steam.

Sorry - I got what you meant. Our manifold has a little hose attachment on it but that would likely mess with mixtures. Dad reckons it's a better idea to plumb the breather into the filter side of the carb, rather than the manifold side. That way the mixtures shouldn't be affected.

Thanks for your insights,
Sharks

Steam

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Re: Engine breathers
« Reply #10 on: June 01, 2020, 06:48:29 PM »
Yep, Dad is spot on. Thats how I do it.
Cheers, Dave