1991 150 pre-dress out pressure test

[cowboyup]

i've just begun my rebuild on my 1991 150 hp evinrude. Today i installed the center main bearings, seal rings, lower and upper seals and new lower bearing. Tomorrow i'll install the pistons and seal the block. Is there a way to effectively pressure test the block at this point, or do i have to completely assemble, install it on the midsection and test it the old fashioned way?

 

[Dhadley]

Re: 1991 150 pre-dress out pressure test

Are you wanting to pressure check the cooling system of the cylinder compression?

 

[cowboyup]

Re: 1991 150 pre-dress out pressure test

Actually, i'm really wanting to test the seal between the two block halves. Upon getting my block back from the shop (i won't say which one), the mating surface isn't exactly flat. So i'm wondering if i could put extra gel seal in that area and torque that section first, then torque the others? Is there something else i can try?

 

[Dhadley]

Re: 1991 150 pre-dress out pressure test

Gel seal hardens only in the absence of air. If the surfaces arent flat, theres a good chance the sealer wont work.<br /><br />Theres a lot of bolts on a 60 degree motor, so thats a help. How bad is it?

 

[cowboyup]

Re: 1991 150 pre-dress out pressure test

If i lay a straitedge across where #5 and #6 rods connect to the crank, i can see daylight on #5 towards the intake manifold surface. it's really limited toward that section. How much? Well it's enough to have me really concerned. I suspect when the shop heated the upper rubber mount assembly bolt to remove it, it warped that end of the block. Could i remove the crank, put both halves of the block in the oven, then bolt the two halves together in hopes of flattening it out? Then, after its' cooled, i could split it again and begin the reassembly?

 

[R.Johnson]

Re: 1991 150 pre-dress out pressure test

You might give this a try. In machine rebuilding, or repair they use a marking dye to locate high, or low spots on mating surfaces. The dye is put on one surface only, and the parts are mated together. When taken apart the dye will show the fit of these parts. If you use this die, torgue the parts to spec., remove, and see how they fit. The dye is called prussian blue, and sold at machine supply outlets. You could make your own with linseed oil, and any color pigment that will show up well. What are you using for a straight edge?

 

[R.Johnson]

Re: 1991 150 pre-dress out pressure test

You might give this a try. In machine rebuilding, or repair they use a marking dye to locate high, or low spots on mating surfaces. The dye is put on one surface only, and the parts are mated together. When taken apart the dye will show the fit of these parts. If you use this die, torgue the parts to spec., remove, and see how they fit. The dye is called prussian blue, and sold at machine supply outlets. You could make your own with linseed oil, and any color pigment that will show up well. What are you using for a straight edge?

 

[ronuncw]

Re: 1991 150 pre-dress out pressure test

As good fortune would have it, my straitedge was slightly bent. I set the crankcase cover on and it was right on. Okay, now how do i check pressure check the cooling system of the cylinder compression? secondly, is there a difference between gel seal and gel seal II?