Anyone know if the HD adapter with thermostat routes oil through the filter before it passes the thermostat and then gets directed to the heat exchanger; the same way the JAGG adapter functions. I don't want to start another "to cool or not to cool" argument, just looking for this specific info, thanks.

 

yes....how do I know?.....the oil filter warms up in advance of the oil cooler. once the oil is hot, the valve kicks in and directs the flow to the cooler. So by the time the valve kicks in, the oil filter is hot, and the oil cooler is still cold. after the valve opens, the cooler catches up to the temp of the filter,

 

Make sense. You wouldn't want unfiltered oil going to your engine.

 

In a thermostat type sytem the filter will always get hot before the heat exchanger does, regardless of the location of the thermostat, so that observation is not a proof positive indicator that the oil passes through the filter before it contacts the thermostat and goes to the cooler. The thermostat could be located upstream of the filter, oil would be directed to the filter first, making it hot first, until the thermostat opens, then the cooler would get hot second. With the thermostat upstream of the filter, oil would be directed through the cooler and then back to the filter before going on to the motor. Eventually the oil is going to pass through the filter weather the thermostat is open or closed. I guess I could simplify the question by asking does the oil get filtered befor or after the cooler when using the HD adapter with thermostat.

 

it sounds like you have a good explanation for the answer you were hoping for.

 

No, I don't have the answer I'm looking for. I do fully understand the the oil flow path in the Twin Cam, and I know how the JAGG adapter works because I have one, so I was able to trace the flow of oil through it. I don't physically possess one of the HD adapters, or I could figure it out also. I didn't think it would be a far stretch to get this answer out of the forum.

 

This is an interesting question in regards to how the adapter works, but does it really matter? The oil will go through the filter all the time regardless of the sequence and the oil will flow through the cooler once the thermostat opens.

I'm just trying to understand why it would make any difference to us as riders. The only thing I can think of would be the possibility of the cooler being plugged with contamination if the oil went through there before the filter.

 

I finally got the answer today from Marv at JAGG, heluva nice guy. The HD adapter routes oil to the cooler before it is filtered. Actually the JAGG adapter was purpose designed to filter oil before it is routed to the cooler, in order to overcome the pressure drop associated with the HD adapter. To most people it doesn't matter, I'm conducting experiments and need the info.