Looking for the idler pulley driver's side that attaches to the water pump. Here is a photo of the base plate thanks to "Mangusta" Steve. It has a 2.5 inch pulley. Any help?
Terry, curious if you have the aluminum 'base plate' (a custom detomaso part) and the steel boss that goes with it? If you need the latter I've heard that the same may be used on the mid 70s 308GT4 Dino...i.e., making new is probably best - see photo. If needed, height of the boss is 42.5mm, diameter is 23.2 mm, flange dia = 36.2mm. The stock Mangusta has two identical bosses. As for the pulley, my notes show "66 x 20mm", no idea where this part originates, unfortunately.
Nate...Maybe my note was not very clear. I did not have any of it, particularly the base plate which is the most difficult part. I understand the "boss" that the pulley attaches to is the same as the one used on the jack shaft idler pulley and the pulley itself is the same as the one used with the Pantera air conditioner as an idler I believe. With several Mangustas having turned into parts cars, you wonder where these assemblies might have gone. I'm afraid maybe with the engines to someone for use other than for a Mangusta who had no use for that idler pulley and threw it into a parts box of "oddities". I can copy the boss from my idler pulley on the Jack shaft pulley if need be. Was hoping to not have to attempt to manufacture the base plate which would never be like the original. Unfortunately it is not readily accessible for anyone to unbolt and recast for the "needy". Thanks.....
Does anyone know if there is something "special" about cast aluminum parts made for the auto manufacturers such that they are stronger than just a replacement part copied from an original in sand cast method? I question that a sandcast copy (photo above of original) would be strong enough to use in this application of tensioning the belt. Someone sent me a photo of one of these parts but he does not want to sell it....
Hi Terry, I would have zero worries with a sand cast duplicate of the original DeTomaso part. The boss will definitely create a bending stress on the part but the pedestal flange is generous and the casting itself is fairly husky. I can't imagine the original part is anything exotic in terms of casting or the alloy used. If you have somebody who can do the work you should be in good shape. Best, Nate
Seems to me the bracket (or plate) that holds the idler could be easily fabricated from a piece of 6061T6 plate aluminum of the proper thickness.
George, problem is the length of the bosses on the water pump side to position the plate so the pulley will line up correctly. Be a lot easier if able to cast one and have a more original item. Otherwise a piece of stock that I would just add spacers to to get the proper position maybe what I will have to do, if I can't get a casting.
I'd stack some washers as spacers and call it a day... But your result will look nice and original which is a worthy goal. Can't imagine there's much in the way of belt tension. I have some experience with supercharged cars and the belt tension on those is INSANE.