New car surprises . . .

[Archie Cheda]

A list of good ideas . . .

Bob,

I want to thank you for taking the time to type out such a comprehensive list. I also hope neither you nor anyone else will be offended by my choices, which are tailored to my personal compromise between an absolutely 100% original Model A and a highly modified version. In other times in my life, some of these selections would have been different. Even before I purchased this coupe, I decided that I did not want to depart very much from stock, but that I would make improvements that would enhance my enjoyment of the Model A experience.

For me this experience includes things like:

o Shifting a non-sycro trans (I enjoy double-clutching -- learned how to shift gears my Dad's '51 F1 which had a "Brownie").

o Being able to adjust the spark advance and mixture at will while driving.

o Being able to start the engine with a crank -- did that for a whole year on my Grandfather's '37 Dodge pickup while I procrastinated buying a new starter switch.

o Having mechanical brakes that need me to adjust them. (It is nice to be needed . . .)

With the above mind-set, and keyed to the original list, here is what I am currently thinking:

a) Modern straight shaft valves, one-piece press-fit guides and press-fit valve seats;

I need to do more research and am still on "input mode". My personal inclinations and many posts I have read promote the general idea of "if it isn't broke, don't fix it". Applied to the Model A valve train that would mean sticking with the original split guides and valve/keeper design but I see poorer exhaust valve cooling and valve location with the old system, so I am likely to come down on the side of modern guides, keepers, & valves. Regarding seats, I already seem to have inserts, probably on the exhaust only, so I will be installing at least one oversized seat, probably for all four exhausts. If I still have integral seats on the intakes, I will probably leave it this way. I have done valve jobs on two Ford FE engines that each had three exhaust valves sunk over 1/8" into the heads, but have not seen a problem with intakes, and these were hard-working (towing) engines.

b) Modern pistons and rings from small block Chevy & Ford V8s;

This is still open in my mind. I have decided to use modern (narrow) rings, but may stick with original-style pistons (but with narrow ring grooves). I view the engine I am building as the mildest of non-stock engines. The mild cam and compression ratio are the equivalent of where stock engines were later on in the thirties.

c) Modern insert type main and connecting rod bearings;

I am keeping an open mind until I can determine what the quality of the babbitt job on my engine is.

d) Pressurization of the oil to the main bearings;

I will be going for a low-rpm engine, so will probably stay with the traditional oil system design, which seems to be pretty elegant to me.

e) Press-fit camshaft bearings;

I will probably stick with a standard cam bearing size or go oversize if I find wear in the block. I am fine with running the cam in the block as I will not be neglecting maintenance.

f) Lightened flywheel and V8 clutch;

Again, I will be sticking with traditional. I weighed my flywheel and it is original weight. I had a 312 Y-block 45 years ago with a Scheifer aluminum clutch and flywheel, so I have enjoyed the thrill of a light flywheel. At my age, the heavy flywheel is more appropriate.

g) Aluminum timing gear;

Already purchased, along with a new steel crank gear. I will editorialize my preference for replacing both gears together. Old crank gears can be worn undersize by abrasive material lodged in the cam gear, or may be rough enough from rust to "eat" a new aluminum gear. In the world outside model A's every gearset I have ever purchased was in one box as a matched set. I will be checking the crank to cam bore distance and will correct by align boring & using an oversize cam if necessary.

h) Conversion to 12-volt electrical system & ignition primary;

Here I am "old-school" and believe that an original 6-volt system will work fine if it is 100% in proper order. (I have owned two 6-volt autos and two six volt tractors.) I will be adding a bonding strap between the engine & frame. (Note: I will not be driving at night and will have absolutely no electrical accessories.)

i) Pertonrix 40611 hi-voltage ignition coil;

Here I will also be sticking with the traditional system. My distributor has been converted to "new-style" points, but I will probably eventually convert back to traditional.

j) 5.5:1 or 6:1 compression cylinder head;

My plans include a Snyder 5.5:1 head.

k) 160 or 180 degree stainless steel thermostats;

I think I will be OK without a thermostat in my local climate, but this is an easy thing to add at any time.

l) Pressurized cooling system;

I did a quick flow-test and my radiator seems to flow well, so I will see how well the engine cools with an open system.

m) Water pump with press-fit front bearing & double sealed rear bushing;

I will probably stick with the pump I have as it can easily be upgraded when the need arises.

n) Modern connecting rod cap nuts without cotter pins;

I will probably stick with tradition on my low-rpm engine.

o) Oil filter installation. There are several to choose from;

I have been "cogitating" on this for a while. I may machine my own adaptor and may stick with a by-pass type filter as I will not be driving on unpaved roads.

p) Modern rear main bearing oil seal, but this requires machining the crankshaft;

After reading a lot of opinions, I am inclined to stick with the traditional system, but will be very careful with details about the oil return pipe and keeping a free crankcase breather cap (more below). I am considering (very carefully) doing a positive crankcase ventilation (PCV) system, but it will be very carefully designed and integrated, not just a modern valve slapped onto the engine.

q) Modern cooling fans. DO NOT USE AN Original!

I am not clear on this. I do plan on not using my OLD original, but was planning on sticking with a two-bladed fan. All my experience and education is that when driving over 25 mph, the road speed moves enough air to make any fan redundant. I do not expect to be caught in traffic jams, or be towing, or be climbing many steep grades. (I have a still-living cousin that is 95 years old and still has a 1931 Coupe -- the last of his four Model A's. He tells me that the Cuesta Grade is not a problem for a good-running Model A.)

Be sure to solder and or braze the oil drain plug thread insert into the oil pan so it does not spin or weep oil.

Thanks -- I will do this, even though it will require me to do some re-painting of my pan. I had not yet run across this advice and appreciate it.

Make sure the oil return pipe in the rear main bearing is not screwed in so deep it impedes the flow of oil.

This is part of the attention I will be paying to making certain my traditional rear "seal" is working properly. I also feel that a very mild PCV system will help. Anyone have opinions about the one-piece FRONT seals vs. traditional two-piece rope seals?

FINALLY, I am open to logical discussion of these sorts of things and would welcome more tips as this project progresses.

Archie

 

[Russ/40]

Archie, clearly you are a very knowledgable mechanic, and I say, a very articulate one. It is a pleasure to have someone with those qualities join us here on the forum. I look forward to your participation and the opportunity to follow along with your project.
I share your love for old machine tooling. I have a prewar Logan that I recently went through.

 

[Archie Cheda]

Can you say "cracked block" ? ? ?

Well, time to remind us all to avoid confusing symptoms with causes . . .

It turns out that there is a crack between the exhaust valve seat and the cylinder in both #2 and #3 cylinders. Yes, the cause of the "clack" symptom was the crack in #2 cylinder, but the reason for the seat coming loose was the crack. If I had just put in an oversized insert, the same failure would have come along sooner or later. (By the way, the bottom of the loose insert was all shiny, indicating that it had been rattling for quite a while.)

The engine rebuilder must have decided that if there is a crack between the cylinder wall and the exhaust valve seat, then all that was needed to repair it was to sleeve the cylinder and install a seat insert. The salesman could then brag to the customer that the engine is sleeved back to its original bore and has hardened inserts. The engine would even run well long enough to make it through the warrantee period. (I worked for an engine rebuilder for over a year and let me firmly state that there are quality rebuilders and those who are not so high quality. No automotive machinist I ever trusted would have let a job like this out of his shop.)

In the first pic below, you can see the two exhaust valve seats. On the right side, it is pretty easy to see the crack running across the top of the block to the counterbore for the#2 exhaust seat insert -- you can also see the white deposit that the engine coolant left on the inside of the valve pocket. On the left, you can barely make out the same features indicating that both of the middle exhaust valve seats were similarly affected. It could be that the overheating occurred since the rebuild, but I my instincts are for the first story.

The second pic is a close-up of the #3 seat and you can see that the crack actually goes right through the seat itself.

At this point I am going to think about all this for a bit before charging of in one direction or another. Although I have never done it before, I might develop a new skill and try cast iron tapered threaded repair pins -- it may be that the end of the cracks goes too far down in the valve pocket. I guess the next thing to do is a major cleanup and a full magna-flux inspection to see if there are more cracks beyond these obvious ones.

On the "good news" side, the crank and babbitt job seem to be usable. The crank is .020" under on both main & rod journals, but I can see some signs that it was probably welded. Welding on a steel crank is OK with me, but I never have been comfortable with welding on a cast iron crank -- that offends my metallurgical sensibilities. I probably will polish the crank journals and practice my scraping on the babbitt. I found a few things that do not impress me with the person that fitted the crank: he used .025" shim packs, he did not even remove enough babbitt to get through the line-boring tooling marks, and finally, did a very crude grooving consisting of a single helix on mains and no grooving at all on the rods. (When I get to that stage, I'll ask for some advice as this will be my first experience scraping babbitt, although I am getting pretty good at scraping flat cast iron machine ways.)

Anyone have an idea of how much I should have to pay for an un-cracked block? (Then I have to add the $$$ for a new main bearing babbitt job.)

Archie

P.S.: There are a few nickel arc welding repairs on the corners of the deck surface of the block. This leads me to think that it was handled roughly at some point and is one more indication that it was rebuilt by a low end, volume rebuilder.

 

[Bob C]

Maybe if Tod gets his new blocks done you can get one of them.
http://www.fordbarn.com/forum/showthread.php?t=153372

Bob

 

[George Miller]

cast iron tapered threaded repair pins --

They will work fine. I always over lap them 1/2 of a pin. That way they cannot come out. Make sure they go past the cylinder wall and valve seat. You will need to put in a new over size valve seat.

 

[James Rogers]

cast iron tapered threaded repair pins --

They will work fine. I always over lap them 1/2 of a pin. That way they cannot come out. Make sure they go past the cylinder wall and valve seat. You will need to put in a new over size valve seat.

George, while I agree with you on the tapered screws to fix a crack, I don't think they will work on this seat crack since it runs so far down into the bowl. It would be hard to get to that area to insert a pin.

I have other comments on this thread but, it is early and I don't feel like typing right now. To be continued.

 

[tbirdtbird]

It is beginning to sound like that block may not be worth your time and money. There has been abuse and a history of very shoddy repair that prolly made things worse. IMO you are going in the right direction thinking about a different block.

Why not think about an inserted motor while you are at this stage? Add the oil filter to protect your mains and rods and it will last a long long time.

 

[Archie Cheda]

The jury is still out . . .

Thanks for the thoughts, guys -- I am taking it slow for a while before making any big decisions.

I just measured the longest crack and it extends less than one inch down in the exhaust pocket. I can see that it would not be that tough to drill across the seat opening without departing too much from a ninety degree angle from the surface. Because it is an exhaust port, it is also possible to drill through the exhaust port which is directly opposite the crack. Another consideration is that I would have to remove the sleeve, but once I am removing sleeves on two cylinders, I am half way through the job of replacing the torn up sleeves. I could also re-use the STD pistons with new rings in their wide ring grooves. I also observed that the sleeves do have a flange around their tops. On the down-side, I have potential for another surprise -- what will I find when I pull the sleeves?

I am pursuing acquiring another block in parallel with my cogitations. Any inputs on selecting a block for my 1930 Model A? It seems that the blocks got incrementally better as time went on, so I figure a '28 block would not be a good idea, but what about a '29? I may have a shot at one locally.

I probably could not talk myself into buying a new block -- I do not know what the price would be. Inserted bearings are tempting as all my experience is with them, but part of why I bought a Model A was to do something different than my earlier automotive adventures.

I am in a different position than most folks -- this is one of my retirement hobbies and I have a machine tools to make tooling and such. My labor is free, so machining is free, but buying parts takes $$$. What most folks consider a chore is my reason for undertaking this hobby, so please do not feel too bad about these developments. I expected to be doing this sort of project, but hoped to be able to drive the car for a year or two before doing any major work on it.

Archie

P.S.: If I go the crack repair route, we will have some fun. The LOCK-N-STITCH process interests me -- it uses a more complex thread geometry to balance out the spreading action of the tapered, threaded pins. I included the link for those who might want to get ahead of me . . .

There is a chance that I'll repair the current engine (it was not the original) using the old head and cam. Then I can put it back in and drive the car while I re-work an un-cracked block and swap it in later on, leaving me with a running spare. I have been "blessed" with four cars that had water jacket cracks during my life and would prefer to avoid doing that one more time.

 

[Tom Wesenberg]

P.S.: If I go the crack repair route, we will have some fun. The LOCK-N-STITCH process interests me -- it uses a more complex thread geometry to balance out the spreading action of the tapered, threaded pins. I included the link for those who might want to get ahead of me . . .

There is a chance that I'll repair the current engine (it was not the original) using the old head and cam. Then I can put it back in and drive the car while I re-work an un-cracked block and swap it in later on, leaving me with a running spare. I have been "blessed" with four cars that had water jacket cracks during my life and would prefer to avoid doing that one more time.

Lock-n-stitch to fix, then a spare good block to rebuild I think is a good plan. Years ago when I first saw that lock-n-stitch thread design, I found it quite interesting how it really pulls the sides of the crack together to lock it. As you say, it's a comples thread design.

 

[Archie Cheda]

Santa Claus is on the job . . .

Today, I spoke with my 95-year-old cousin and brought him up to date on my situation. He has restored four Model A's over the last 50 years and offered me his running spare 1931 engine as a gift! I can put this engine in my coupe without any fuss at all. (I do think I will pull the head and pan to make certain things are OK -- I think that this is understandable to anyone who has read this thread.)

It took me some time and counseling from my wise friends, but I have decided to "let go" of plans to save the engine discussed in this thread. In reality, the only good thing about it is the crank and the babbitt in the rods and block. For example, yesterday I measured the clearance between the cam and the block, getting some .010". It is not the original engine in my coupe. I will save the counterbalanced crank and rods. It is hard to justify putting some $500 into the engine, not to mention my labor, just to save the babbitt in the block. I will keep the block for practice when & if I eventually get to machining on a good core block.

Ideally I'll drive this stock engine for a year or so and then decide to keep on going as it is, or to rebuild it with a new cam and 5.5 head. I believe that there is a very good chance that I will like my coupe just fine with a 40 hp stock engine.

Thanks to all who posted info and good wishes -- this is what I call a HAPPY ENDING!

Merry Christmas to all,

Archie

P.S.: I may try doing some crack stitching just to see how it goes. If so, I will start a new thread on what I learn.

 

[Russ/40]

Thanks Archie for the update and wish you many enjoyable hours in your new lady.

 

[Archie Cheda]

Lightning strikes twice . . .

I fetched home my "new" motor yesterday -- the block was number-stamped on 1DEC30, so I assume it first was installed in a 1931 vehicle -- it came out of a 1931 CCPU. Based on recent experience, I decided to pull the head and pan on my "new" engine before I put it in the coupe. Results were a mixed bag: it is .080" over-bored, with two pistons each from different manufacturers. The cylinder walls show signs of "mechanics" that fix stuck motors by towing them. In this case, the damage is not too bad, but it can be felt as well as observed. The valve stem to guide clearance is not too bad and the valves & guides are usable. Best of all, there are no visible cracks.

The bottom end had nothing unusual, rods & mains were .030" under, and the babbitt grooving and chamfering was much more professional than the other engine. The engine had obviously not many miles on it since its last rebuild. It is strange that these two Model A engines have freshly babbitted bottom ends in good condition, but the rest of the engine not really in as good a shape. I had been expecting to find bearing problems more than cylinder wall problems . . .

The second engine is not nearly as bad as the first with regard to the cylinder wall damage, but it still is not really very good. I am even more concerned that the two sets of pistons are possibly out of balance. I have not yet made a final decision, but I am leaning toward disassembly, honing the cylinder walls (even boring if necessary), and checking out the pistons, making the piston weights match, if necessary. This engine will still be what I would call an overhaul, but it should allow me to put off doing a rebuild until I have some of my current projects back together. If I only need to buy rings & gaskets, the cost will not be much. Even if I have to bore, buying pistons will not break me . . .

Archie

P.S.: I checked the rod bearing clearances using a magnetic base test indicator today only to read that it was suggested by Tom W. years ago in this post:

Another method I've used is to mount a dial indicator to the block using a magnetic base, then put the point of the indicator on the crank web next to the bearing being checked. Now, you'll have to carefully pry the crank up and pull down as close to the web as possible without rotating the crank. This can be a bit tricky, but will save having to R & R the bearing caps a bunch of times to check and shim.

I did not do the mains, but it works well on the rods: Just turn the crank slightly past BDC so that the crank has started to push the rod back upward -- then use a rod and a light hammer to tap the piston upward while watching the change in the indicator reading. You could also get some indication regarding rod journal roundness, buy repeating the test at mid-stroke, but it is necessary to restrict the crank from turning. This is not necessary at BDC because the mechanical advantage does not allow enough force to move the crank when the piston is lightly tapped. I found these reading to repeat very well.

 

[tbirdtbird]

congrats on the 'new' block!
ya tow starting! really! like it is gonna fix whatever was wrong.

anyway, if you are considering new pistons , consider the 283 style short skirt narrow ring pistons that are available. with your background i don't have to sell you on the benefits. I say 283 style because they are not pure grafts from a chevy. You can get a set of 283 style with narrow rings and short skirts from John Cosper at Pete's Auto Machine in Albuquerque in NM for about 250.00. He has them made up so that you can use the original rods (thus saving 500.00 on new rods). You may have to re-bush or hone the small end of the rods obviously. If the block deck has been cut much, you may have to shave some off the top of the pistons (no big deal, you still end up with a far superior piston). By some accounts the original A pistons were proud of the deck by about .030. A racer today would tell you not to intrude on the quench area at all. Hone your cyls obviously. John knows what he is doing.

Based on the many engines we have worked on in this shop that were set to modern piston clearancing (.0025) we set our clearances to .0035. The rule of thumb has always been .001/ inch anyway. There are several builders around me that use the modern spec of .0025 (wrong for an A) and we have overhauled a lot of these motors when they score and seize. John's pistons have done the trick each time. If you search under my name you will find numerous postings to this effect, and I have posted pix of what happens when you do not observe the .0035 rule. I have been viciously attacked by 'armchair mechanics' to which clearancing is just a number on a piece of paper, ppl who have never taken a wrench to a motor and have never done disassembly and failure analysis the way you have done. Cyls 3 and 4 run hotter by at least 20* than cyls 1&2. An infrared gun on the drivers's side cyl walls will confirm this in a heartbeat. The water enters the block between cyls 2&3 and then is immediately sucked forward by the pump allowing way less cooling for 3&4. Careful observation by even a third grader can figure this out. When we get a seized motor it is always either cyl 3 or 4 or both. When there are threads about seized pistons it is always 3 or 4 or both. This is why the modern spec of .0025 is invalid for this motor.

You need to know this before you proceed. Proceed as you will but know the peculiarities of the motor. I am sure I will now get the usual barrage of criticism from the armchair mechanics out there who like to bash me. But, look at it another way: if you clearance at .0035, the rotation of the earth is surely not gonna change....not because of a lousy thousandth of an inch. Search my name you will find some interesting and hilarious reading...haha
good luck with your project!

 

[Archie Cheda]

Hope to hone . . .

tbb,

Thanks for the info -- I have read many of your posts and when I do my thorough rebuild, I plan on definitely using narrow rings and likely the "Pete's" pistons. I will do a final review of what is available when I get around to doing the major rebuild.

The purpose of this engine is to get the car back on the road for a year so I can drive it and get some personal knowledge about how exactly how I want to do the more serious rebuild. (I also have a mill and lathe all apart for restoration. This is in the same 800 sq.ft. shop where I am also working on the coupe.) I am hoping to hone and not have to bore this engine, but if I do, I would prefer to keep my investment down and spend the $$$ on my rebuild.

While I was typing, a friend dropped off his rigid hone which I will use in my 5 hp drill press to clean up the bore. I find your advice regarding piston to bore clearance amusing -- I totally agree, but in my case, I really do not have a choice as I expect to be honing out the bores a thousandth or two to clean up the "stuck engine" damage, so I am more concerned about piston slap than seizing. I can live with some cold piston slap . . .

Archie

 

[Archie Cheda]

No more surprises . . .

I have now disassembled two Model A engines and am getting comfortable with the design. The oldest engine I rebuilt was my Grand-father's 1937 Dodge pickup, but it had inserted bearings. I have also "done" a Ford 8N -- I guess I must not make too many comparisons as there was at least a decade between the designs, plus the little 120 cu.in. tractor engine borrows some V8 parts and design principles, making it familiar to me. It is also nice to be able to buy a piston/ring/sleeve kit and swap it in.

Observations:

The babbitt job on the mains was not as pretty as the rods and even has a small bit of babbitt missing from the edge of the front main cap. The groves were hand-cut. My guess is that the rods were purchased and the mains done locally. The scraping job on the mains does not to appear to be full bearing, so I think I'll do a bit of scraping of my own. I'll get some exercise lifting the blued crank in and out, but I am used to using cast iron straight edges -- I can barely pick up my five-footer, so I got a six-foot aluminum Busch with cast iron faces, which weighs only about a third as much. Question for the experts: can I separate the job into fitting the block babbitt to the crank and then do the caps one at a time?

The two pairs of pistons are very different: three rings on one pair and four on the other. Before I put it together, I will match their weights (with rings). It occurs to me that I may have to buy two sets of rings unless anyone has broken sets in .080" over. I may go ahead and use new pistons whether I bore it or just hone it. First step will to see how the honing goes.

The camshaft regrind was done on a B core, but the intake lobe measurements I made indicate a lift at the cam ranging from .265" to .297" and the base circles vary. I am assuming that this is common with regrinds where each lobe would be ground until it cleans up. I would expect that new cams would usually have the same base circles, but please educate me if I am wrong in my thinking.

None of the above would seem to keep me from getting this engine back together without any major expense.

I am not doing any more work on this project until next year,

Archie

 

[1930artdeco]

Archie, don't forget about the Turlock swap meet at the end of January. You should be able to find several core blocks fairly easily.

Mike

 

[tbirdtbird]

"lift at the cam ranging from .265" to .297"

not sure you are gonna be happy with this lift. Stock A lift was .302 per Brattons. Stock A cam breathes badly enough even at .302. The Stipe IB330 cam has .330 lift on a B profile cam and will really wake up a motor. Sounds like the grinder did not grind the heel, just the lobe

 

[Synchro909]

Tbird, I'm not going to harangue you, quite the opposite. I have worked in a restoration shop doing all sorts of classic and vintage cars and we regarded the one thou per inch rule as a minimum. Your 0.0035 clearance for a Model A is just what I would do.
It's amazing what some shops do. Bearing and cylinder clearances are sooo often just plain wrong. I have a friend with a 1914 Hotchkiss (French) with 3 inch journals. The shop that rebuilt it gave them a clearance of just 0.001. Needless to say it didn't go far and the shop refused to accept that they did anything wrong!!
Stick to your guns and let those armchair mechanics have a seizure!!!

 

[Archie Cheda]

Mike,

Thanks for the reminder -- I will try to attend.

tbb,

I am "on the fence": my other cam has a badly worn center bearing, but perhaps I can turn up a good used one at the swap meet. Before I pull the cam, I will go back and take measurements much more carefully, that one lobe could have been an error on my part. I am pretty set on using a Stipe IB-330 when I do my complete rebuild -- I just want to put that off for a year or so and take my time to enjoy the build.

Synchro, tbb, & others,

To date, someone else has always fit my pistons as part of a bore job. The engine rebuilder/automotive machine shop where I worked for a year (I ran the counter and wrote work control software) rejected the once-standard Ford method of fitting pistons with a long feeler gage and a force gage -- he used a micrometer on the piston skirt and bore gage on the cylinder to check the clearance. We occasionally had a comeback, which was usually blamed on something the customer did. I am interested in who takes the old Ford method seriously and how far back it goes. I think it captures & standardized what some old craftsmen did. Assuming that the correct clearance is chosen, it would seem to be much more fool-proof than measuring at a single point on the piston skirt.

I also agree with not being so afraid of piston slap that one risks frying a piston . . .

Archie

P.S.: I am sure that many folks have stories on both sides of the process of deciding who screwed up, the customer or the shop. I saw screw-ups on the part of the shop and got chewed out more than once for "being too honest" with a customer. Several of my commercial customers expressed their thanks for my honesty and I never did get fired, probably because my main role was writing software based on knowing the operation thoroughly. I also saw plenty of customers who forgot something minor, such as coolant or oil . . . The funniest one was the guy that brought back his fried engine, full of oil, demanding a refund or a free engine. The owner cut open the oil filter and it was bone dry, proving that the oil was added after the engine was fried . . .

 

[Archie Cheda]

Are we having fun yet ? ? ?

This engine project is part of my hobby, so while it may seem strange, I am enjoying the process. My plan was to buy this coupe as a driver and not get into it for a year or so while I gained experience and education regarding Model A's. Because of this I was disappointed that I had to get into it sooner than planned, but make no mistake, I had planned on getting into it. Thanks to my generous cousin, I will get it back on the road in a month or so, with minimum expense. Then I will have a stock engine to gain driving experience with and that will help me when I make decisions regarding my "good" engine rebuild.

Since my last post, I have been learning -- about Model A engines in general and about the second of my engines. The last posted measurements were my quick check of a couple of lobes on the cam -- not too much fun while the cam is still installed. This morning I did accurate measurements of valve lift and got the following:

Valve	Lift	Percent less than stock
1-EX	0.248	14%
1-IN	0.248	14%
2-IN	0.284	1%
2-EX	0.283	1%
3-EX	0.277	3%
3-IN	0.256	11%
4-IN	0.255	11%
4-EX	0.261	9%

This cam is even worse than my quick measurements suggested. It appears to be in good condition regarding the lobe surfaces (no pitting or galling), but the numbers tell the story -- it seems to be a "less than quality" regrind. I also am uncomfortable with a break in the early lift (on several lobes) -- I can feel with my fingers. Something does not seem right about this cam. Fortunately I am planning on attending the Turlock Swap Meet and will have my measuring instruments with me . . .

I went out and measured up my first engine's cam. I'll spare you all the (boring) details because the lift at the lobe is very close to the average of .262" some 13% lower than the stock .302", but at least it is even across the cylinders. The front & rear bearing journals are around .005" undersize, but the center is a full .009" low (repeating earlier observations). It seems to me that this is just too much loss in engine oil delivery and stability of valve lash. I would really appreciate opinions regarding using this cam.

I also did a lot of measuring of the pistons & cylinders:

	Cylinder:	Taper	Piston	Clearance:
	Top	Bottom			Maximum	Minimum]
1	3.961	3.958	0.003	3.954	0.007	0.004

2	3.960	3.958	0.002	3.954	0.006	0.004

3	3.961	3.957	0.004	3.950	0.011	0.007

4	3.960	3.959	0.001	3.950	0.010	0.009

It does look as if using my old pistons would work, but I found a new set of .080" Badgers on eBay for $60 and by the time I match the weights of my odd pistons and fudge three-ring sets onto 4-ring pistons, I can justify the $$$. The Badgers are marked "Minimum Bore Size: 3.9550", so I will have no worries about the pistons being too tight. I'll check the balance, just to be sure . . . I'm going with Hastings rings if anyone is interested.

Archie

P.S.: Since I asked about using a long feeler gage to fit pistons, I read through several posts where folks I am learning to respect mention this method. I know a machinist is proud of being able to take precision measurements, but there is something fool-proof about the feeler gage method. (Notice, I did not say that it was "idiot-proof" . . .)