Our Customer Decided On A Fix For The 172 Ford Block!

last week's video ended with a bit of discussion on different options for this block given the parent bores of the block being out of round and the provided finished sleeves having a pretty poor surface finish in this week's video we're going to discuss the fix for that that our customer opted for but to start out our other machine is free so we're going to install a few key locking thread inserts in the head bolt holes that we weren't able to do last week the threads in three head bolt holes are stripped so with the blocks set up on the table of our Peterson tcm25 we're going to level up to do some Machining a machinist level is used and the table can be tilted to get the deck perfectly perpendicular to the spindle of the machine I went ahead and grabbed the right drill bit to fit in our 7 16 inch head bolt holes and with it chucked in the machine we can use the airflow table to Center up on the head bolt hole as the bottom of the hole is still intact after getting the block positioned on the center we'll switch over to a larger drill bit to drill the hole to be tapped with 9 16-12 threads to match the outer threads of the key locking insert with the threads tapped we can use the provided tool to screw in the insert at which point we use another tool to hammer the Locking pins into place in the past I've had questions about different thread inserts but I think different inserts have their place while I do believe a helicoil would be acceptable in this instance if installed properly a solid style key locking insert like this just provides that extra peace of mind the process was repeated on the other two stripped holes before we went ahead and moved over to installing the sleeves although we would prefer to have gone with an oversized OD sleeve the price difference didn't seem to make it worth it but the customer did opt to provide us with a set of twenty thousandths oversized Pistons which will at least allow us to finish the sleeves to the proper clearance and have them come out round and straight after having cleaned the block a little bit better we can see that the bores aren't perfect but they aren't in bad enough condition to justify any further work before installing the sleeves after measuring the sleeves and the bores we should have on average around 1000th press fit but again I say average because the bores are a little bit egg-shaped and not straight just to be safe we're installing the sleeves with a small band of Loctite retaining Compound on the bores for the new viewers yes we know you can use liquid nitrogen to shrink the sleeves and install them as we've done in different videos in the past but there's also nothing wrong with just pressing them into place in the shop press like we're doing here both methods work and both have advantages and disadvantages but at the end of the day the end result is the same as you may recall in the last video we did deck the block and recut the counter bores and the specification for sleeve protrusion on this engine is from flush to three thousands above and on most of these sleeves we came in just about one thousandth protrusion which we're happy with sometimes we do aim for that higher side of spec but with the way that the head gasket barely overlaps one section of the sleeve on these we didn't want a huge step to be trying to seal over as we stated in the previous video when you press a round sleeve into an egg-shaped bore you also end up with the ID of that sleeve turning into an egg shape which is why we prefer semi-finished sleeves when doing this type of work over the finished sleeves like we have here they pretty much always need to be touched up after being pressed into place our fix in this case is rather than running the standard size Pistons that were provided in the sleeve assemblies the customer is sending us 20 000 oversized Pistons allowing us to re-board the ID of the sleeves and achieve a finished cylinder that is round straight and on size as such we've set up a cutter and we'll Center up to bore each cylinder leaving a few thousands to finish it out to the nominal size in the cylinder home originally when we started on this job for the customer it was supposed to be just a rebuild the head but he brought the head in and we realized that the head was cracked so he since replaced the head with another one but I'm assuming this is probably the cylinder where it was cracked and it probably had gotten a little bit of water into the cylinder and then when they tried to start the engine everybody knows that liquids won't compress so when it tried to compress that and it couldn't uh it put a kink in the connecting rod here about the time we think we've got figured out what we need here why we move on a little bit further and then you find just one more thing that's wrong you move on a little farther and you find one more thing that's wrong and it just seems like it'll never end as you can see our cutter is leaving us just around three thousands to finish in the hone which is a good spot to be so we went ahead and got all four cylinders board before moving the block over into the Sun and cv616 cylinder home we'll set up the stones in the hone head adjust the stroke length of the machine adjust the block height for the proper over stroke and make sure that the belts are in the correct position for the spindle speed and stroking speed the new Pistons are hopefully going to arrive on Monday so today we're basically roughing out the bores to get them close to our nominal bore size and once the Pistons arrive we'll be able to double check the measurements and quickly finish out the cylinders for the proper piston to wall clearance as we hone the cylinders we take our time and stop once in a while to measure with the bore gauge and ensure that we're keeping the cylinders straight from top to bottom if we see a tight spot in the cylinder we can pull the dwell lever to dwell the hone head at that position in the bore which takes out more material and therefore straightens out the tight spot it's not a perfect indicator but when the needle on the load meter of the machine isn't bouncing heavily back and forth it's an indication of a straight cylinder this isn't the fully finished product but I guarantee that the surface finish here would run better and longer than what was in the supposedly finished sleeves that came in the kit we can also run a bore gauge from top to bottom at different points in the cylinder and we can see that we are much straighter and definitely much more round than the sleeves were just after being pressed into place at this point we'll wait for our Pistons to arrive to fully finish it out you all killed it on the last video and we had tons of comments asking for a quick part two so hopefully this quick little video satisfied your Curiosity on the fix thanks for watching and we'll see you in the next one

Channel: Jim's Automotive Machine Shop, Inc.

Views: 156,599

Keywords: Engines, Engine Machine Shop, Machine Shop, Engine Shop, Machining, Automotive Machine Shop, Automotive, Cars, Trucks, Tractors, Gas, Diesel, Performance, rebuild, high performance, internal combustion engine, pistons, cylinder heads, jim’s, jim's automotive, jamsi, jamsi online, Blueprinting, rebuilding, engine building, connecting rods, engine block, boring, valve job, engine rebuilding, jim's automotive machine shop, sleeve puller, engine repair, engine mistake, ford, 172 ford

Id: aZ_dMGuuxt4

Length: 5min 48sec (348 seconds)

Published: Sun Apr 02 2023