Blow by system Oil breather hoses sizing

I'd go with "wrong part" -- the hose from MCP (the official old F part supplier) looks more size-wise like your existing part:

https://www.ferrariparts.co.uk/part/ferrari/116783

(and the wall thickness and amount of reinforcement on the DinoParts pieces seem very excessive for that application.)

 

Can't agree with that -- look at the reinforcement in each. The MCP piece has a single layer of fibers (which is appropriate for this near-zero pressure application) while the DinoParts has about 4 layers of fibers (which also increases the wall thickness).

Yes, needs to be compatible with hydrocarbons and have enough temperature resistance for a hot engine but only low pressures (that green heater hose was a terrible choice).

 

Do a google search on cloth braded hoses. You will find many sources.

 

Can agree that that Dinoparts picture looks much more appropriate, and there are plenty of steps for a mistake to happen anywhere from procurement of the bulk hose thru cutting to length and then packaging.

 

That looks much to big to securely seal with a clamp. 19mm (3/4") ID is the typical size of the breather hose. Your bigger size hose is probably for the part 9 in the diagram, probably the 22mm hose ID.

The old hose may have the flourosilicone liner, which makes it fine for a breather hose application. Regular silicone hoses are not ok for oil, even the limited amount in the breathers.

The larger diameter cloth braided breather hose used to be available from Newco products, not sure of they still carry them - their hose was branded Continental. Italian Car Parts also has the correct sizes. http://www.italiancarparts.com/parts/308.html#hoses Or maybe here...https://teaguecustommarine.com/12-fc647-cloth-braid-push-lock-hose-sold-per-ft

These cloth covered hoses are not so common in these larger diameters. Smooth hoses of suitable wall thickness will work as well, if you order from the various F parts suppliers they will not likely be the cloth braided style.

 

22mm I.D for the breather pipes. You can source the braided hose on Amazon.

 

Currently replacing all the breather hoses in my '79 Euro GTB. This is what I'm using (not suitable for the concours crowd): https://www.amazon.com/dp/B0CKRT3HVL?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1
- Dave

 

That will work fine, the cloth braid attracts dust and grime, and does not serve much purpose. Probably increases burst strength and adds some abrasion protection, neither is which is of concern in breather hose applications.

 

I just think the cars past the high school mod stage ….bigger wheels , silicone hoses , exposed trumpets on the carbs etc etc .
It’s all about OEM . I went with braided from Marenello classic ,and even correct Co piglia binding for the air duct rubbers .
The oil breather hoses are new despite appearing aged due to the inevitable braided dirty look .

It’s just this type of detail is NOW important and not difficult to achieve.

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The fuel hoses are not OEM as upgraded to E 5 / E10 ethenol compliant….I don’t think any prospective owner is going to weaponise those in price negotiations, but the rest as far as possible need to show attention to detail and conciseness ownership .

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For those detail obsessed, after cutting the hose and before installing, you can use some superglue on the cut cloth ends to prevent fraying. If frayed when installed, clip with some nail clippers and use some superglue to prevent it further fraying.

 

I can appreciate that for some, but as the owner of Italian cars since 1981, I have never been a fan of the cloth braided hose. It looks old and decrepit five minutes after it's installed, plus the braiding can obscure imminent failures in the inner rubber portion of the hose. No, just give me some perfectly serviceable hose that I can pick-up at O'Reilly's and if the next owner wants a 100 point car, I'm sure the helpful members here can point them towards the appropriate vendors.
- Dave