bean.101

So assembled the short block to check piston heights. Normally old engines have heaps of piston to head clearance.

I found the pistons are below the deck surface 20 thou or half a mm. My head gasket 52 thou thick. So ideally i won't the piston above the deck 10 thou to get my 40 thou piston to head clearance for good squish. So it was back to the surface grinder to remove 30 thou. While i was there i sat the block in the surface grinder on it's deck surface and run a dti through the main tunnel to check how true the tunnel is to the deck and i was surprised to find it was within 1.5 thou.

I haven't put a pic of it being surfaced as there's already one earlier on. So I gave it a wash. I went through all the galleries with gallery brushes. Then put it in our Bupi wash. This is pretty much just a big dish washer. Made in Germany and it's one of the more handy things in the workshop.

Then we just give them a good going over with soapy water. Normally just dish washing liquid and hot water to brake down any left over honing oil. And really get all the machining swarf out of the oil galleries and other spots in the block.

So I have the crank ground and ready to go.

So I got started on the Align hone. This block didn't necessary need align honing It was within book spec in the mains. I haven't fitted aftermarket studs which is another reason for a tunnel hone, the studs normally tighten the tunnel up due to the extra torque you can apply to the stud giving better clamping load. Another reason is if you have run the main bearings this can also put the tunnel out of round and or put a bend through the tunnel. Here's a picture of the cap dresser. I used this to resize the rods earlier on. This is the main cap in it. It ground about 3 thou off each cap.

First picture is the cap ground and ready to be torque up back onto the block. The next picture is with the block in the Sunnen Align hone. Sunnen is one of the industry leaders in honing. Our block hone is also a Sunnen Cv 616.

So I just refitted the main bearings to check clearance. I've got 2 thou vertical oil clearance in the tunnel. Its nice and straight now. This isn't something we do to every block as some don't need any attention. But most old blocks either weren't that great from the start or have had a hard life.

So i got my hands on some plus 15 back -20 main bearings. Thanks to Ford and their below average machining they mis machined the main tunnel on some of their blocks and had to come up with a solution of +15 back bearing to take up the slack. These can be challenging to get at times. 

So then I mount and measured them so I had a size to machine the crank too.

Got the crank dialed in the crank grinder. Start to bring the wheel in and just touch the journal and you can see the .002 thou wear. The grinder has just started to clean up the left side and a bit in the middle.

Once it's all ground we put it into this modified wood lathe we use for polishing.

So I'm just trying to get the short block completed at this point. There's a fair bit of maching in the cylinder head, fitting valve inserts so I'm just concentrating on the bottom end. 

So I measured up my crank and found that the mains are worn about 1.5 thou. But the big ends are within book size. So I mount and measured the rods. I found that I had 2.5 thou vertical oil clearance. Which isn't a major issue but I'm building it for myself so I'll resize them to tighten them up. We would offer this to any customer but more often that not the budget comes into play. And budgets generally compromise most engine builds. My budget is definitely compromising this build mainly in the parts department. 

So I removed the dowels and grind the rod and cap parting faces. Unfortunately I didn't get a picture of the cap dresser.

Note the rod thats been ground on the left.

Now I reassemble the rods and hone them back to a tighter size than they were. I want them three quarters of a thou tighter.

Now that they are all honed to the same size I will mount and measure with the bearings fitted to double check my clearance. This is just a picture of them apart showing them honed and ready for bearings.

So i fitted the torque plate for the honing process. We only have torque plates for certain engine's. But lucky Ford xflow's are in formula Ford's so the boss saw the need to get one made. The torque plate allows you to simulate the tension of the cylinder being fitted to the block while honing. Some blocks move considerably from the head bolts being torqued up. This can distort the bore, sometimes up to 2 thou on various blocks. So it's like honing them in there assembled running state. I have heard stories of shops honing with hot coolant running through the water jackets to simulate total running conditions. All in the name of perfect ring seal you need a perfectly round and straight cylinder.

We leave 4 thou of material to hone out as this gives us a good base to start achieving good rk rvk and there's another value aswell but I can't think of it right now. But we start off honing with a course stone which gives us a deep groves and removes material quickly.  Once we've removed 3 thou we change stones to a smoother grit this removes the tops from  the course stones while taking more material out. I'm also happy say I have removed all the bore wear marks after removing 2 thou of material. Now we move to a finer stone again same thing applies. Each different grade of stone removes material in different ways. Some stones will take more out of the bottom middle or top of the bore, so you have to measure the bore to make sure you're keeping it straight. The stones also react to load. Theres a round handle onto of the machine that applies load to the stones in the bore. If you wind to much load up it normally takes more material from the middle of the bore as there's no real strength there. Extra load can also create heat which will give you a false reading of size from the material expanding. 

Once we are at finish size we have what we call plateau stones. These are 800grit they don't really take much material out but smooth the tops off from the previous set of stones. Then we move to our cork stones. Which look nothing like cork. These are really good a removing left over honing material out of the cross hatch. We only give the bore a couple of strokes with these. Once a year we clean the machine out. It normally has about two 20 liter buckets fill of cast iron sludge sitting in the bottom of it. This machine runs 200 liters of honing fluid. Which is great as one of the jobs of the fluid is to keep the block cool as well as wash the honed material away from the honing head while honing. A drum of honing fluid isn't cheap at $2500 Then there's all the stones we burn through. So the honing process has one the highest consumables cost in the workshop per year. From start to finish it can take a hour to two hours to hone a block after a rebore. A deglaze or what we call a rering hone is normally about three quaters to a hour. 

So I got the block into the boring bar. It's pretty straight forward boring a block. Doing a cylinder liner is a bit more involved as far as the boring bar is concerned. This block is at 30thou over or .75mm in metric. I have bought 40thou over or 1.mm pistons. It has a bit of wear. But hopefully it's should clean up once it's honed. This picture is of a test cut. So you dial the boring bar head into the bore. If you have a decent amount of wear it pays to slightly offset the bar towards the wear so you clean all going well at the next oversize.

So in this picture you can see the boring bar hasn't totally cleaned with this size cut. I have only set the bar at 81.90mm. So I have .1mm or 4thou to hone out to get to our finished size of 82mm. We generally like to leave this amount to hone to achieve good rk rvk this is the depth of hone pattern. I'll go into that a bit more once we get to honing it.

Once we've finished honing we normally go to the surface grinder. The top of the block is a little corroded so I'll probably take a few cuts to clean it up. 

So I've done a light cut to see how it looks

You can see it still needs more off it. In this case it's not a issue to take more off the deck. When you are dealing with a late model diesel or performance engines that have been set up with good tight clearances it pays to watch how much your removing as you may have to detop your pistons as they may start getting to close to the head once assembled. Also valve reliefs can also need deepening. But this is more so a issue in extreme cases. This good old xflow should be fine. But i will be checking all this later once i can dumby the engine up

So I forgot to get a picture of the molasses. But here's a couple of pictures of the head once out. The molasses sort of just loosens the rust. Then you have to wire brush to get the rust off. 

I didn't put the block in what we call our hot tank as I haven't removed the cam bearing.. Our hot tank is only for ferrous metal. And the cam bearings would react with the acid. The cam bearings are in reasonable condition and this is build is on a budget. I run the tap through the head bolt threads and main threads. Removed all the gallery bungs and frost plugs. I found a decent build up of rust at the rear of the block that i chipped out with a screw driver through the rear frost plug hole. And also gave the block a good wire brushing. I gave all the machined surfaces a sand up with emery tape on a file.

So I took the engine into work to strip and assess the damage. The cylinder head has been sitting around on the ground for a few years, so its pretty rusty. I have bought some molasses. It's pretty good for breaking down rust. We normally mix two of these 500g jars up with about 40 or so litres of water. The mix isn't that critical. I'll leave the head and rocker cover in the molasses solution for three or so days. The damage is pretty minimal. It's must of been idling when it dropped the valve. There's only a very small nic in the top of the bore and a small dent in the valve seat. 

Project discussion above

This has been in storage but that has come to a end so it was time to dig it out of the shipping container its been sitting in. I've had this for about eight years. I bought off my brother, its dead in the reg so plan is to get some live plates back on it. It has a few spots of rust in the body and the engine dropped a exhaust valve.

So I pulled the short block out as the head had been pulled off years ago. Although it dropped a valve it hasn't done any major damage. Someone has done a sweet red paint job on the engine bay. I won't open up a can of worms by painting it at the moment. Just concentrating on just getting it up and running then focussing on the rust to get it back on the road.