Fixing hole in side of block

[GreensvilleJay]

For the actual 'patch',find similar thickness steel plate,though 3/16 would be fine. Make a cardboard template and note where the bends are and bend in a vice 'as required'.Make the patch piece about 2mm (1/16" smaller). Now put block on the other side and use whatever steel you have to support the patch from the inside WITH a sheet of aluminum between the patch and the support. Bronze won't stick to aluminum, so if any 'filler' bronze drips onto it, NOT a problem.
Pretty sure even 1/8" sheet steel would be fine and a lot easier to fabricate into a patch. You could maybe use 2 pieces to 'fill' the thickness of the block. Just be sure to clean the 'patch' really,really well....you want it shiny and NO oil on it. For the actual bonding, you'll probably want to 'tack braze' corners then 1/2 the distance, then 1/2 again not a continuous flow of bronze to minimize warping of the patch.

 

[PoTreeBoy]

Don't forget the flux.

 

[lugbolt]

Holy mackerel King Fish THAT'S nothing short of genius !
Some of these guys never cease to amaze me with their knowledge and willingness in sharing with folks they never met but this window thingy is on a different level. Granted RW scissors' endeavors could be said to be for the ,,,,,aheem,,,,shall we say "adventurous" or some might say self destructive but non the less valuable contributions for those into such.

Plexiglass window in crankcase. Stop for a minute and consider had GM included that idea on Corvairs and Vegas, just to name a couple. Take the 6.0L Ford diesel,once root problems were realized the fixes were inexpensive and permanent. In retrospect had engineers been able to look inside 6.0L the problems would be obvious right away and saved FMC billions $$$$$$. If John Force's pit was able to peer inside motors,think of the game changing decisions the pit could make.

Oleracer you best get in line at patent office before some scallywag steals this idea.

I did kawasaki dealer work for a long time too (they had Kubota yamaha kawasucky bad boy hustler and outboards).

The KAF620 "Mule" had a little pushrod 620cc V-twin. Good little engine but they aren't stupidproof. Had one show up, guy says it makes a weird noise. Ok cool I've seen a million + of them and I can probably figure it out. WOuldn't you know, it was a noise I aint never heard before. I did a lot of digging and couldn't find it, not in the clutch (removed it), not rocker arm related, not pushrods, just an odd noise. I was down to removing the engine for teardown and I already knew that the rear cylinder's head gasket leaked a little bit, so I pulled that head off, put the intake manifold back on and taped up the rear cylinder's intake runner (stops the vacuum leak), then fired it up with the head off. Using my trusty smartphone with the slow-pro app, I was able to isolate it to a piston issue. At that point it was a matter of calling customer with estimated cost. The interesting part was seeing the engine run without a cylinder head, especially in slow motion. Wish I still had the video.

There is a youtube channel I think called warped perception or something like that where he puts a plexiglass cylinder head on a briggs & scrapiron head and runs it on gas, then on nitromethane. Watch his channel. Lots of cool stuff there, right down to a see-through rotary (wankel) engine. Until I saw that one I was not 100% sure how the wankel's work, but with that video, now I am 100% positive and 100% positive that they are a flawed design that just happens to be light weight and have an interesting following. Guy pitted next to me at the races once, had a blown (not turbocharged....) methanol injected 13B, no muffler, two tubes about 6" long each, out of the case and that was it.. I hated that thing. If he ever parks next to me again I am moving my stuff somewhere else.

 

[joesmith123]

Make a cardboard template and note where the bends are and bend in a vice 'as required'.Make the patch piece about 2mm (1/16" smaller).

Yes I am listening, make the patch a bit smaller then the hole, bronze will fill the gap between the patch and the engine block

For the actual bonding, you'll probably want to 'tack braze' corners then 1/2 the distance, then 1/2 again not a continuous flow of bronze to minimize warping of the patch.

Yes I am fixing to do like the guy did in the video, he had a blanket to not let the engine block cool down too fast in the area he was brazing

The only other item I can practice on is an actual cast iron skillet that I will put a hole in, and practice patching that properly, get familiar with the nature of the situation, then do the actual brazing on the engine block

Don't forget the flux.

Yes I have not yet gone out to get these materials, I am guessing that a place that is gonna fill up the welding tanks should have bronze rods and the proper flux