Water hose quick disconnect for Rossi motors

[Al Peffley]

I purchased a GRM 125cc powerhead from Brennan a few years ago (a prior Team Thompson motor?) with a quick disconnect fitting on the cylinder head that has the same metric threads as those in the GRM water cooling inlet hole (I think the threads are 10mmx1.00, or close to that pitch.) Even though the threads look similar, I know that this special fitting's threaded hole is slightly smaller than a US SAE 1/8" pipe threads male fitting.

The quick disconnect fitting has "PRESTOLOK" and "5/15" stamped on the black quick disconnect collar (it fits 5/16 plastic air line.)

I would like to buy two more of these fittings for my GRM 250cc powerhead to replace the OEM collar-tightened fittings for flared plastic lines. Does anyone know where I can buy these aftermarket quick disconnect air fittings. None of the Parker air/hydraulic line hardware shops around my area have metric elbows like this fitting.

The fitting is a 90-degree elbow with what looks like "C8" stamped on one side and made out of what looks like a stainless steel alloy. I can send someone a digital picture of the specialty fitting if they know something about these fittings and a source for them. Thanks, in advance, for your help in this matter.

Al Peffley
Cell: (206) 406-4996
Email: team_excalibur@hotmail.com

[pops67g]

These fittings are available from GRAINGER. We use them on our 250 & 350 VRP with no troubles.

[Tom Cronk]

Parts #

Pop
can you send me the manufactor and part # for
the water fittings. tcronk@tampabay,rr,com.
Thanks
Tom

[Rex Hall]

Water fitting

The threaded part on the water fitting is 1/8 taper pipe, and you can get the fittings from MSC in metric for the GRM water tube that comes on the GRM motors. They also have them in american sizes, but if you want to keep everything as it came from Rossi, the 1/8 pipe to 8mm tube is what you want.

[Merc1]

http://www.grainger.com/Grainger/gla...071&sst=subset


There are a bunch of options and there are cheaper ones besides these. This is for a package of 10

http://www.mcmaster.com/#push-to-con...ttings/=ml9hq8

[raceright]

MSC Fastenal, have them for about 6 bucks

[Al Peffley]

Fitting Description

Thank you for your responses. I went to the Granger website (thanks for the hotlink). I must have an older GRM cylinder head, because the elbow tapered mounting threads are not pipe threads on the fitting and in the 125cc cylinder. I think the threads on the fitting are tapered M10 threads. A standard 1/8 pipe thread elbow will not fit into the mounting hole (the hole is a slightly smaller bore size, even though the threads are similar in size and pitch to SAE pipe threads.) I am mating the two GRM powerheads I have up to a Lee Tietze PRO tower instead of the Rossi OEM stork. I would like to stick with the 5/16 Parker Hannifin air brake line for powerhead cooling feed line because I can buy the tubing at my local Parker store and it is very cut-resistant. The SS fitting has the Parker "P" cast on it and it makes a good tight fit with their PFT-5A 5/16 OD air brake line. The pneumatic tubing has a reasonably thin wall so the ID is almost a true 1/4 inch diameter.

Al

[Rex Hall]

Water fitting

Al
You keep saying the water fitting is for the cylinder head? Rossi did not put any water fittings in the head, only the cylinder. One in the front is the inlet and one just above the exhaust port is the exit. If yu have one in the head, it has been put there by someone else.

[Al Peffley]

Cylinder Connection Description

I should have said cylinder barrel or just cylinder I guess. The head plates are still intact with no mods to them (maybe a little shaving - heh,heh). I have Parker Hannifin's engineering staff in Michigan working on finding the part number for the fitting I have here and tell me if they still make the disconnect part. They manufacture a new Prestolok brass connector line with a bright green collar disconnect, but it does not seem to fit the 5/16 tubing as snugly nor anchor the tubing as well as the Euro fitting I have. If they come up empty without a part number, then I may try their competitions' quick disconnect fittings that Grainger sells.

[blueskyracer]

I should have said cylinder barrel or just cylinder I guess. The head plates are still intact with no mods to them (maybe a little shaving - heh,heh). I have Parker Hannifin's engineering staff in Michigan working on finding the part number for the fitting I have here and tell me if they still make the disconnect part. They manufacture a new Prestolok brass connector line with a bright green collar disconnect, but it does not seem to fit the 5/16 tubing as snugly nor anchor the tubing as well as the Euro fitting I have. If they come up empty without a part number, then I may try their competitions' quick disconnect fittings that Grainger sells.

Al I bet it would help if you posted a picture or two

[Al Peffley]

Mystery Threads Identified on Cylinder Water Inlet Fitting

I got rid of my English metric thread tap and die set when I sold my 350cc Konig (maybe I should have kept a few - LOL). A machinist friend of mine who used to work on British motorcycles discovered today that the threads on the PH elbow fitting I have on the 125cc motor are English metric pipe threads, not M10x1.00 as I had thought. [Mental note to self - buy another metric thread gauge to replace the one I can't find in the shop...] The GRM cylinder's threads I have are close to US 1/8" pipe threads, but a slightly different pitch (leave it to the "Brits" - just joking, Corin).

Mike Schmidt and Steve told me to apply an 1/8" pipe thread tap about 2/3 the way down the tap into the cylinder inlet hole and call it good on all of my GRM powerheads -- mystery solved for now.

I'll call off the Parker Hannifin engineers back in Michigan that were researching part numbers for this application. It's a good thing the threads aren't M10, I found out M-10/8F8OHGS (M10x1.00 to 1/8" pipe thread) adapters for use with a $5 elbow are $12.01 each [yikes!]

Thanks to all of you for your ideas and posting your sources for these fittings. I am going to stick with Parker Hannifin because I like their tough, 5/16 OD thin-wall air brake line (1/4" ID) that fits very snugly within their PRESTOLOK fittings and Parker Stores are prevalent throughout the US. I prefer the black collar fitting over the green collar fitting style, but I will settle for what I can buy around here. The 90-degree 5/16" elbow fittings (non-swiveling) are only about $5 each.

Al