Dual Piston Blow Off Valve - Dump Valve

[John Sims]

I enclose the following as I think it is a really clever piece of kit. So simple yet so effective.

One or two have noted their concerns with regard to vent to atmosphere dump valves sucking in unfiltered air when open at idle. I don't necessarily believe this to be the case as I have tested my previous Bailey dump valve with tiny shreds of tissue and it would seem the the turbo is still producing a positive pressure in front of the closed throttle.

One assumes there may be times when the inlet track between the turbo and the throttle might be at negative pressure but I can't see when that would be.

None the less - I have now replaced my Bailey with a Forge Dual Piston dump valve and it is a damn cunning piece of kit. It has a secondary piston on a weak spring which forces a plug piston into the hole under the main piston. Granted this dose cause a minor restriction to dumping air which has to overcome the spring tension but I would think this is minimal considering the pressures involved.

Additionally, when venting, I assume because the plug piston is moving around in the air flow, you don't get a gawooossshh sound as much as a gawogggleoggleoggle sound. []

Obviously the above is schematic and ignores the intercooler for clarity.

 

[Fen]

I'm more impressed with the drawing than the device, but at least I understand it now. I take it 2TA is winding down for the holiday? []

 

[John Sims]

ORIGINAL: Fen

......... I take it 2TA is winding down for the holiday? []

I wish! I really shouldn't be mucking about doing drawings on the forum when I have Clients I should be doing drawings for. No doubt there will be power points in Scotland though.

Isn't it strange how, these days, one of the most important items on your packing list is the Lap Top.

 

[John Sims]

ORIGINAL: Fen

I'm more impressed with the drawing .......

It is rather good isn't it []

I could do a full 3D rendered animation with semi transparent tubes so you can see exactly what is happening inside, but can you imagine how much that would cost. [8D]