Ford Blitz Restoration/Rebuild

[Mike K]

Originally Posted by Private_collector

I have never been so indecisive with anything as I am with whether or not to assemble the engine myself. There are a couple of areas that I have real doubts about my skills and abilities, and only experience will overcome that. So, after losing considerable sleep last night on that very train of thought, I decided to make a token effort today to attempt one small task that had concerned me. Found my can of valve lapping paste. Grabbed a couple of valves. Read up on the topic in my Flathead V8 rebuilding book, then had a little play.

With both the block and valves being fresh, I only used fine valve lap paste. Sounded a little crunchy initially, but within a little while I was quite amazed how the sound changed to an almost silent, and very smooth rotation of the valve against the seat. I assume when this occurs, you are pretty much done. When I removed each valve I could see that the paste had certainly ground a complete circle where the two surfaces had met. Pushing the valve back in then made a very satisfying 'clink'.

One thing concerns me, and this is something that no rebuild book seems to address. I find that the higher part of each valve (closest to intake manifold) sits ever so slightly proud of the surrounding valve seat. Possibly 1/32" (or less) from flush with block. The lower part is not far from flush. I hope this is correct, and have noted that the valve does sit properly in the seat. Looking at the old engine, I see some valves sit lower against the block, and some are like described above. I am thinking that some of the valves on the old engine may be ground or worn lower than others??? Any way, my great hope is that this is normal.

Having now done a whole TWO valves, it doesn't look to be hard. Asuming that the circumstances I have writren are OK, I will put in an effort to continue and complete all the lapping on Wednesday. Yes, I am numbering each valve, and they are returned to their individual plastic bags once done. I know that 2 valves is bugger all, but I didn't have time for any more today.

The other job that causes some anxiety is the gapping of the piston rings. It sounds to be a wonderful opportunity to piddle away many hours, if you have to gap each one individually. Not going to get too caught up in that until I finish doing the valve work. One stressful event at a time. Have been looking at a number of options with ring grinders. Well, the hand ones anyway. The electric ones look great, but FAR too expensive, considering I don't plan to be using such a tool again. Guess I was a bit green, but it came as a surprise that the rings would even require doing this. I won't be buying any tool until I check to confirm that the rings really do need gapping. Might get to supacheap tomorrow afternoon. They have a 560kg (2000lb) engine stand for $129 at the moment. It looks to be suitable for my needs, and I will need one if I am to make a go of this myself. I had to read back through a number of pages on this thread, to find where Sidevalve engine weight was discussed, so I would know the stand was up to the job. Hadn't realised how boring I am, until I had to read my own posts. Nearly fell asleep!
Attachment 66115
This is the Flathead rebuilding book I am studying. I have found it to be extremely useful, and very easy to read. Lots of detail, and really good illustrations. I have several others, not including the Ford maintenence manual, but this seems to be by far the most detailed. I could highly recommend this book. Especially so for novices like me!

hi Tony

Some time ago I had the hard exhaust valve seat inserts on a series 1 Land Rover ( the seats are in the block ) ground to the correct angles by a engine rebuilder in Warragul. He showed me the gadget he used for checking the valve seat sealing. He used a vacuum hose with a leather or similar pad on the end . With the valves located in their seats , he placed the vacuum pad onto each exhaust port face , where the manifold bolts to. He had a gauge measuring the vacuum , on the vacuum side from memory . Anyway . you could see how effectively the seat was sealing by the amount of air leaking past the seat , this was duly seen on the vacuum gauge

Mike

[Bob McNeill]

TONY I know that you will read the instructions that come with your hone, we normally use kero when honing the bores, only oiled when cleaned and happy with result.

[Private_collector]

That's pretty cool, Mike. Wish I had thought of it.
I admire his quest for perfection.

Regarding Honing
Just ordered a 320 grit Flex Hone of 3.25" size. That is, it can hone up to 3.3" bore, while still having sufficient compression of the hone surfaces to do the job. What really sold me on these is that they indicate their hones are suitable for finishing of a bore where you do not want to go oversize as a consequence of the honing. That, plus the self centering ability of the hone. Also discovered you can use a range of oils with the grit I have chosen, including standard engine oils. Yay! Although grits of 600 (and over if special order) are available, 320 grit is recommended for my application.

Bob, i'm downloading and reading several PDFs relating to use of Flex Hone, right now :-)

[Lynn Eades]

Just as important as any other aspect of the task is the cross hatch pattern. A 60 degree cross hatch is required. This is achieved by the combination of the speed of the drill (hone driver) and your up and down movement of the hone.
Did your new block come with pistons (I forget what you did) or are you sizing the bores to suit the pistons? I would recommend you have it done proffessionally. The piston to bore clearance is very important to a long (engine) life, as is cleanliness. A thorough wash out with hot soapy water after the hone, so that white rags show no marks,then dried and liberally oiled straight away. Along with absolute cleanliness, there is a lot to get right. Much money invested so far. Consider carefully.
If you have to size the bores, the "sheep dag" hone is not the hone to use. It is however good to finish the surface of the bore

[Tony Wheeler]

I'm not quite following here. Why does the block need honing? It's a brand new block, it should already be hone finished to 3.1875 inch. That's what the pistons are designed for, they should fit straight in. Clearance should only be about 1 thou, they'll be sloppy if the bores are honed out further.

If the bores need resizing for some reason, then it should definitely be done professionally as Lynn says. However I don't see why it would be necessary.

[Private_collector]

Block does not need resizing. I am simply doing a final finish to apply the cross hatching better than it is right now. I dont consider it sufficient at present. With the grade of the hone and time spent in each cylinder, nothing will be made 'sloppy'. This is confirmed by the manufacturers information, and advice from 2x mechanics who have inspected the block is that the final hatching has not been done on the cylinders. I believe this was left for the person doing the assembly, rather that at time of manufacture or machining.

The link I posted yesterday will show the specific info on the hone grade I have purchased. Also, a number of youtube videos on its use confirm my use is appropriate. I will give no more than 10 seconds total in each cylinder.

[Tony Wheeler]

Very interesting Tony. I wonder if it has anything to do with being a military block, which would be going through Army workshops. Or is this standard practice for all new blocks purchased bare? I've only ever fitted rebored blocks, and they've always been finished to spec. The only time I've used a hone is for ring jobs, to deglaze the bores and remove the lip. Afterwards I check the piston clearance to make sure it's still acceptable.

It's quite good fun I think you'll find, although if you have an old block it would be worth practicing on, to get the 60 degree pattern Lynn mentioned. Look forward to more pics as the job proceeds.

[Lynn Eades]

Yes, Tony.W., I would recommend a practice. (sheep dag hones are great! They make any bore look good)
Pistons in a set, are not always the same size. In a factory assembly situation the standard pistons used to be graded for size (and or weight) so that an engine might end up with a set about the same. Hopefully the pistons in your set, have been graded (I would expect them to be these days) I would though, measure them.
Tony you will no doubt be setting up a financial relationship with an engine reconditioner for at least the sizing of your gudgeon (con rod) bushes, I am sure you can pick up some expert guidance from him/her (you never know) at the same time.