Re: [T3] Oil filter question

[Jim Adney <jadney@vwtype3.org>]

On 13 Sep 2006 at 14:54, Dave Sanderson wrote:

> On Matt's newly built 1776 engine we installed an external oil  
> filter. We are using a 10W/30 oil and we have installed a Schadek 30  
> mm pump. We used a Fram filter, one of the best or so I am told by  
> the local VW tuners. After tuning the engine and driving around the  
> block the car seemed fine. The next morning when Matt started the car  
> it seems that there was enough oil pressure to blow the seal out of  
> the filter and of course the oil on the road. 

Accidents like this happen due to a combination of things: extreme 
oversize oil pump, cold (viscous) oil, no pressure relief valve at 
the pump.

When the only pressure relief valve is at the far end of the hose and 
internal oil galleys, there is enough impedance to allow the pressure 
to reach extremely high values. Berg has measured pressures of over 
200 psi at the filter (in california!), so he now has an ideal 
solution to this problem in the form of a special pump cover that 
incorporates a pressure relief valve right in the cover and which 
relieves the output right back to the input, so the oil goes right 
back where it's most needed and there's minimal flow dependent 
pressure drop thru the relief channel.  

I built one of the pressure relief Berg covers into an engine that I 
drove in Wisconsin winters for a number of years. I used Fram PH8A 
filters and never had a problem, even at -20 F. OTOH, I only had a 26 
mm oil pump and I was gentle with the rpms until the engine got 
warmed up.

It's also possible the youthful exuberance contributed to the 
experience in the form of a few extra throttle blips right when high 
rpms were most likely to be damaging and the oil was the coldest. 
(Why do we ALL do that???)

I think Fram filters get a bad rap, but they probably aren't the best 
filters that money can buy. It's probably fair to point out that you 
hear about many more Fram failures than others, just because so many 
more Fram filters are sold.

My recommendation would be to buy an original style 26 mm pump 
(bigger is not necessarily better) and a Berg pressure relief pump 
cover, and to lay off the rpms when the engine is cold.

I know that at least 2 of these 3 suggestions will be hard sells.  

;-)

-- 
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
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