The channels going to the oil filter are jammed. Now the oil flows to the radiator (made of one third of the GAZ-51 oil cooler) through the cut-in fitting, then flows through the fitting to the bypass valve located in the cover of the oil filter, and after the filter - to the engine oil channels. I punched the pressure gauge into the hose rupture in front of the radiator. Tests have shown that after all the modifications, the idling pressure does not drop below 1.5 kG/cm2.
A considerable part of noise is generated by ball bearings - they are completely in the Ural engine. This means that they must be disposed of in favour of plain bearings.
It is rather difficult to separate the connecting rods from the crankshaft: there is no room for oil channels in the standard crankshaft. Therefore, I decided to limit myself to remodeling the main ones. In the first variant, the space occupied by the bearing in the crankcase was filled with bronzographite, in which the main crankshaft necks rotated. This variant turned out to be quite workable, but still decided to use traditional parts - connecting rod inserts from "Volga". He pressed hardened steel bushings on the main necks and polished them to the "Volga" size. In the hole bearing pressed bushings with internal size for the installation of inserts, and for their antennae made grooves. The inserts are inserted at the side. The crankshaft is held from axial movement by a plate attached to the front neck.
For greater wear resistance on the plane with which the crankshaft rubs against this plate when the clutch clutch is released, the bronzografit is welded. On the other, less loaded side, the crankshaft is held by a sprocket. The ball bearing on the front journals of the camshaft has also been replaced by a bushing made of duralumin. To lubricate the inserts, he drilled oil channels, and the bushing had to be lubricated with grease on a separate plastic tube - otherwise it did not work.
In the first variant of the engine the working volume after installation of pistons from 2-liter "Moskvich" D 88 mm increased to 828 cm3. And what if you increase it even more? And I installed a crankshaft from the "Wolf". With its radius of 78 mm crank radius the volume of 948 cm3 was formed. These additional 10 mm piston stroke pulled a chain of rearrangements.
When installing "Muscovite" pistons, which are more than the standard ones by 10 mm, one bore of the cylinder will not do. I cut the sleeves out of "wolf" cylinders (they cannot be pressed out - they are "filled").
The new sleeves with an outer diameter of 95 mm were made of "Muscovite" and pressed with a tension of 0.05 mm. After installing the crankshaft with a "long" stroke under the cylinders had to slip spacers. Their thickness together with the gaskets was about 9.5 mm. In order for the Dnieper rods to reach the faraway rods, each of them was welded with a 15-millimeter piece of Ural rods. Rubber bushings made of Zhigulevskie silent blocks were inserted under the guide covers. As it turned out, they have excellent resistance to oil.
Disorderly: the working volume of the engine has increased, and the volume of the combustion chamber in the head has remained the same. Moreover, a part of this volume was "eaten" by convex heads of "Muscovite" pistons. In order to keep the degree of compression within reasonable limits, I arranged so that the pistons do not reach the top edge of the cylinder by 8 mm. But even now the engine sometimes detonates, even on 95th gasoline. We will have to make the spacers under the cylinders even thicker.
I used the carburetor "Okva", but I had to increase the holes of both nozzles of the accelerator pump up to 0.8 mm. And to the place where the gasoline jets coming out of them, steel tubes were brought up. The second ends of the tubes led to the place of connection of the collector with the cylinders.
Only after that did the bike really go. After installing the "wolf's" crankshaft, the carburetor turned the primary chamber to the collector pipes. Either this turn has influenced, or all has occurred at the expense of the increased working volume, but the engine "sucks out" from the carburetor everything that it has prepared, to a drop, and additional tubes now, leaves, are not necessary.
I forgot about the failures of the engine as a nightmare. But the question is whether to replace the "Okva" carburetor with another - more - because the engine has long outgrown the "Oki" engine in volume. Or to swing at fuel injection?
But I just wanted to repair the old Ural.
The starter from "dozens" is small, but it is still a hindrance. To get around it, the shape of the inlet manifold pipe had to be complicated. Between the cylinders and the crankcase there are spacers and two paranite gaskets with a total thickness of 9.5 mm.