After reviewing Beetle’s [You must be registered and logged in to see this link.] post I have decided to take a crack at it. The photo collage shows the beginning of my efforts. With the goal of trying to simplify the mounting and plumbing a bit, I think I have it figured out as to what AN fittings will be needed at the thermostat and at the cooler.
Basically, the thermostat will be mounted on the frame tube in between the right exhaust pipe and the alternator belt housing. Port 1 - fed from the oil pump will need a 90 degree ORB to -6AN and will connect to a hose with a 90 degree upper end and banjo lower end. (Banjo to -6AN at the port also possible. Pro and con insights are welcome as I have no familiarity with banjo fittings. Any flow issues?) Port 2 - output to cylinder heads, will also need a 90 degree ORB to -6AN, but the hose will use a 45 (or 60) degree end to angle up into the space between the cylinder heads. I am planning on changing out the alternator tensioner bolt to a hex head to allow adjustment without having to remove parts. Port 3 - to the oil cooler, can use the straight -6AN nipple but will need a 30 or 45 degree swivel hose end to allow the hose to clear the right engine mount. Port 4 - from the oil cooler, looks to be a straight shot from below so it will likely be -6AN straight nipple to straight hose fitting. At the cooler I am planning on changing out the reducer bushings to 16mm by -6AN and connecting via straight hose fittings.
Now for the things that I’d like some input on. First, I am thinking of using prefabricated Fragola crimped PTFE hoses for the connections at Ports 1, 3, and 4 because they are compact and reasonably inexpensive, with a short lead time here in the U.S.. The clearance between the thermostat and the cylinder fins is fairly tight and I’m not sure the bulk of a field-assembled connector will do for the fitting for Port 1. Port 2 has a bit more clearance but I might still stick with the Fragola prefabbed PTFE hoses.
Question 1: What size are the banjo fittings at the oil pump outlet and the cylinder head inlets? I haven’t pulled things apart to be able to measure.
Question 2 - for Beetle: How did you route the hoses down at the cooler? It’s looking to me like the hoses from Ports 3 and 4 may need to wrap around in front and under the lower right engine mount and go in at the front of the oil cooler housing.
Question 3 - Any thoughts about fabricating the hose assembly up at the cylinder head? It looks like Guzzi uses a custom welded hardline T section that would be hard to duplicate with AN fittings. A double ended or stacked banjo at the right cylinder head might be a workaround. Clearance issues? Taking the old assembly to a hydraulic shop and having them cut the hose and install a crimped 45 degree connector to get to Port 2 might also be an option, or will the -6AN fittings work with the original hose? (Beetle, how did you do this?) I would prefer to remove and store the original parts so that the bike can be returned to the stack configuration if desired.
Question 4 - Are there any issues with using steel banjo fittings at aluminum connection points, such as at the head or the thermostat? There are some ones with angled tubing and barbs that could be fabricated with crimped sleeves that would make for a much more compact installation. Most of these are listed as fuel or nitrous fittings. Would they have sufficient flow for oil too?
Question 1: What size are the banjo fittings at the oil pump outlet and the cylinder head inlets? I haven’t pulled things apart to be able to measure.
16mm.
Quote :
Question 2 - for Beetle: How did you route the hoses down at the cooler? It’s looking to me like the hoses from Ports 3 and 4 may need to wrap around in front and under the lower right engine mount and go in at the front of the oil cooler housing.
Question 3 - Any thoughts about fabricating the hose assembly up at the cylinder head? It looks like Guzzi uses a custom welded hardline T section that would be hard to duplicate with AN fittings. A double ended or stacked banjo at the right cylinder head might be a workaround. Clearance issues? Taking the old assembly to a hydraulic shop and having them cut the hose and install a crimped 45 degree connector to get to Port 2 might also be an option, or will the -6AN fittings work with the original hose? (Beetle, how did you do this?) I would prefer to remove and store the original parts so that the bike can be returned to the stack configuration if desired.
I used a -6AN swivel t-piece of the right cylinder, with a short section of hose to the left. I used a 180 degree coupler on the left cylinder for strain relief. A 90 degree or straight banjo would work. Not 100% visible in this pic.
Question 4 - Are there any issues with using steel banjo fittings at aluminum connection points, such as at the head or the thermostat? There are some ones with angled tubing and barbs that could be fabricated with crimped sleeves that would make for a much more compact installation. Most of these are listed as fuel or nitrous fittings. Would they have sufficient flow for oil too?
Beetle, thanks for the photos and the insights. I see that you had some of the same struggles in trying to get everything plumbed in. I am appreciating why Guzzi went with the custom piece of hardline between the cylinder heads. By the way, it looks like you reused the original feed hose that went from the oil pump outlet to the cooler. Correct? If so, what is the size of the threaded metric fitting on the end?
By the way, it looks like you reused the original feed hose that went from the oil pump outlet to the cooler. Correct? If so, what is the size of the threaded metric fitting on the end?
By the way, it looks like you reused the original feed hose that went from the oil pump outlet to the cooler. Correct? If so, what is the size of the threaded metric fitting on the end?
Correct. All the stock fittings are M16.
What type of adapter is needed to get the original oil cooler hoses from 16mm F to -6AN M? I read somewhere that they have an o-ring on the metric male end. I haven’t had mine apart yet to know what I’ll be looking at upon disassembly. The only thing that I’ve found that seems to fit the description are these.
Is the tapered (angled) end on both of those the -6AN M end and the other end just a straight 16x1.5mm thread? What seals the 16mm connection? I’m guessing that it’s an aluminum crush washer as the same “gasket” part number is used for the banjo connections in the parts manual. It seems like a strange method for a hydraulic hose connection. I’m wishing that I had a photo of the disassembled hose to cooler connection to better understand it.
While this is indeed an inspired pursuit, I've moved this thread to the GRiSOLOGY section...
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2012 MOTO GUZZI GRiSO 1200SE
2013 MOTO GUZZI STELVIO 1200NTX - Orange Blossom Special
beetle GRiSO Capo
Posts : 10200 Join date : 2013-09-30
Subject: Re: Oil Thermostat Redux Sat Apr 10, 2021 2:07 am
GuzziLooper wrote:
Is the tapered (angled) end on both of those the -6AN M end and the other end just a straight 16x1.5mm thread?
Yes.
Quote :
What seals the 16mm connection? I’m guessing that it’s an aluminum crush washer as the same “gasket” part number is used for the banjo connections in the parts manual. It seems like a strange method for a hydraulic hose connection. I’m wishing that I had a photo of the disassembled hose to cooler connection to better understand it.
Crush washers and o-rings, where applicable. I wish I'd taken more photos of the whole process.
In getting the parts together for the project I ordered two of these Fragola 491971 16x1.5mm F to -6AN adapters (at right of photo) to be able to connect the -6AN hoses to the oil cooler “reducers”. Of course, they came in with no o-rings and no recommendation for what o-rings to fit into them. I have a couple of extra -6AN to ORB fittings and in fitting one of their o-rings into the bore of one of the adapters it seems to fit and to mate up with a 16mm M fitting. Does anybody see a problem with this? I’m guessing that the o-rings would be compatible with motor oil but question whether having them directly in contact with it is a good practice. Is there some other way to seal up the connection, perhaps with internal or external aluminum crush washers?
I'm making slow progress on the oil thermostat project, having procured an oil cooler assembly off of a crashed bike via Ebay. I wanted to avoid getting my bike all apart and then finding unexpected surprises, of which there have been a couple. Part of the goal of this project is to come up with a standardized parts list to assist those who might want to add a thermostat to their GRiSO. I plan to use the original hoses, unmodified, and pre-made standard length hoses to connect the thermostat to the cooler. I also want to have it so that it is easy to revert to the original configuration.
First set of images: Disassembly - 8mm socket - three bolts - remove air deflector. Note the bonded metal (plated steel) and rubber crush washer between the reducer (adapter), new ones on order from MG Cycle.
The first problem surfaces upon disassembly of the output hose from the cooler. (Apparently swing arm bearings aren't the only thing that lacks lubrication from the factory. The o-ring damage could have likely been prevented with a drop of motor oil.) New Viton o-rings (1x8x10mm) on order from McMaster-Carr. There is no part number listed for these o-rings in the GRiSO parts manual.
What the heck kind of connectors are these anyway? I can't seem to find anything online to say that "These are DIN-1782 connectors. Use Adapter BR-549 to get to a -6AN." Anybody?
The second problem is that the Fragola 16mm to -6AN adapters (to be used at the thermostat) have too small a bore to accommodate the original hose fitting. I have another style and will turn (or file) some thread (2mm) off of the 16mm (plated brass) adapter couplers to allow them to mate up to 16mm F to -6AN M adapters with a bonded crush ring seal. (More on this later, a friend of mine who has a lathe will shorten them tomorrow morning.)
By the way, a nod to Fragola for being the only company savvy enough to put out a PDF catalog of all their parts. Trying to figure it out using the Jeg's and Earl's websites was a nightmare. Needless to say if I pull this off the parts list will be Fragola.
Unscrewing the "reductions", as Guzzi calls them yields but one surprise; that the inside end is beveled, probably to reduce flow turbulence. Note the machined surface for the bonded metal/rubber crush "Dowty" washer. If reusing these I would be sure to put them back on the way that they came off. Note the beveled edge on the rubber on the one side where it was inside the threaded hub on the cooler.
Reassembly with -6AN fittings and hoses shows the basic concept. The original feed hose to the heads will be re-routed through the V between the two frame tubes on the right of the bike (hopefully) to connect to the conglomeration of fittings at the top right of the thermostat.
Today's update on the oil thermostat project. I'm waiting on the 1x8x10mm o-rings for the oil line connectors. With any luck I should be able to do the installation later this week.
Upper left - Screwing the Guzzi oil cooler adapter into the Fragola 16mm F to 6AN M fitting brings a problem as the one bottoms out inside the other with a 2.9mm gap at the joint where the bonded crush ring is supposed to go. Solution: Remove 1.5 to 2.0mm from concave tapered end. The material is nickel plated brass and is easy to file or cut on a lathe.
Upper right - I had a friend remove 2mm (.080) from the end with convex taper (IMPORTANT, not the other end!) with his lathe. The original bonded crush rings were 1.5mm thick, the replacements from MG Cycle are 2.0mm thick, as are some others that I obtained from another vendor. Had I known this I would have only removed about 1.5mm of material. The idea here is to make it so that the original bushing can be put back into place if needed. As it is, the removal of 1-1/3 threads should be not be an issue.
Lower left - AN6 fittings at the thermostat. Silver dots indicate lubed (o-ring) and/or tightened fitting. "Two wrench rule" followed, using two pairs of Knipex plier wrenches (world's handiest tool).
Lower right - Another view showing the wrap around arrangement at the output port. With any luck I will be able to reroute the oil feed hose to the heads in the V formed by the frame tubes and couple it up to the thermostat output port.
I installed the oil thermostat today, albeit not quite in the fashion that I had originally anticipated. The basic concept is valid but things are really tight. It fits, it works, but I'm not entirely happy with the result as there are too many joints in the plumbing up behind the exhaust. I had to lose the mounting brackets as there was just no room for them in between the frame and the cylinder fins. At this point I am probably going to revisit this next winter when I get back to Arizona with the goal of reducing the number of fittings and reducing the amount of fill in between the cylinder fins, frame, and exhaust pipe. Fortunately, with the way that I did it things are easy to reverse.
I think that Beetle's concept of mounting the thermostat on a sub-plate above the exhaust pipe has merit. The hose over to the heads is quite long and is able to wrap around the front tube of the frame and come back in to the thermostat. A short jumper hose between the original oil feed hose and the thermostat should work, and a couple of hoses with right angle fittings at the top should couple nicely from the cooler into the thermostat.
Beside of all installation topics, what led you to the 215 °F (102 °C) model ? Isn't a 185 °F (85 °C) model even better, as the engine temperature remains slightly lower without being too low; even at 185 °F moisture contained in the engine oil is evaporating through the oil separator. Just try to heat a pot of water to 185 °F and see how much vapour is generated. We have to deal with an air/oil-cooled engine and the oil temperature is still relevant. With ambient temperatures up to 104 °F (40° C) in the last days keeping the engine temperature in the useful range is the main task.
Subject: Oil Thermostat Redux 
Tue Apr 06, 2021 9:25 pm
