390 camshaft

[Bill Playfoot]

Why would the camshaft that I removed from my 390 be stamped like it is?

[Bill Playfoot]

Because it has the Fomoco stamp I know it is a factory camshaft. What I would like to know is the info regarding the other stampings.

[frnkeore]

What was the 390 out of?

SK # are experimental numbers, some went on to became production items.

[Bill Playfoot]

The 390 was in a 1966 Thunderbird. I don't know if it was original to the car or not. The numbers on the block mean nothing to me as this is the first engine I am rebuilding

[KULTULZ]

Originally Posted by Bill Playfoot

The 390 was in a 1966 Thunderbird. I don't know if it was original to the car or not. The numbers on the block mean nothing to me as this is the first engine I am rebuilding

... uh ...

Can you verify the CASTING ID (C6AE A) as I can't quite see it clearly?

[scicala]

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When I worked at Ford Powertrain engineering in the 80's and 90's, Eonic was a supplier for camshafts during development. Not sure about actual production.

Sal

[rotorwrench]

It may have started with one grind and then was reprofiled to another. This may explain the change in the numbers.

It's certainly good for a 1966 but could have been used in other applications. The C6AE-A is a 428 number. The C5AE-A would be a 390 number and likely carried over to 1966 but I don't know for certain.

[frnkeore]

Those casting numbers are very hard to make out!

The casting date is either 1965 or 1966 but, the month and day are Jan 16th. It looks more like '66 to me.

Same with the casting number, it could be either C5 or C6 but, I would probably go with C6 on that one too.

You will need to measure the bore, if it's C6, like rotorwrench says, it should be a 428 and will be 4.13 or larger.

We will need a picture of the back of the block and the bottom, showing the main caps too.

A friend of mine has many of the XE, SK & ASK files from Ford and this is what he said, when I asked him:

"Frank ,
It is earlier than my SK part information. Things I can tell you are it is the 28146 number is from mid '66 . The earlier number is from '64. It was ground by Eonic cams in the Detroit area . They did prototype cams for Ford and GM. The "steel stamp" was incorporated in '66 as before that the numbers and name EONIC were done with an "electric pencil" style engraver."

[Bill Playfoot]

I will get better pictures Wednesday night.
Thanks for all of the information.

[KULTULZ]

I think someone (not mentioning any names) lucked out and got a 428.

As for the cam, someone has to have that info. Are the rockers adjustable or non-adjustable?

[Bill Playfoot]

I don't think the rockers are adjustable. I will look at them Wednesday night.
I am a auto body repairer not a mechanic. I thought this might be a fun project to do because I have never rebuilt an engine before. I am not a good photographer either.

[Bill Playfoot]

The valve springs are painted yellow wherever I wiped them when I removed them from the heads

[rotorwrench]

A lot of the high performance type FE blocks had solid lifters so they required the adjustable rockers.

The Q-code 1966 T-Bird with the 428 would have had hydraulic lifters for quiet operation. The "Q" will be in the VIN of the donor car if that is what it is.

The 360/390 FE blocks were all close to 4 1/16 bore at 4.05". The big 406/428 blocks were 4 1/8" bore.

[Bill Playfoot]

The engine is a C5 not a C6. It is hard to read the casting number in the picture.
I measured the cylinders tonight also.

[frnkeore]

With the better picture, it looks like it must be a C5AE-A. No other number has that sharp corner like that.

The C5AE-A block was used for 352, 390 and 427. It is, of course, not a 427, as all 427's had cross bolts and the 2 side holes, above the cam, on the back of the block, wouldn't be drilled and tapped..

Try remeasuring, removing any carbon and carefully move the calipers around, to make sure they are centered. It could be a .040 over 352 or you might get it to measure 4.050. I suspect it's a 4.050 390 though.

Can you tell us what the marking are on the right side, on the back of the block?

Last, pull all 6 of the Welch plugs and see if a 1/4" allen wrench will fit, between the cylinder walls, tight, if not, what size will.

A picture of the main bearing webbing would be useful too.

[Bill Playfoot]

I forgot to include the picture after I scraped the carbon off. There is still a little ridge of carbon but most is removed.

[rotorwrench]

That's it and it's pretty close to standard bore which is a good thing as long as it doesn't have too much wear below the ridge. 360 and 390 blocks were the only ones to have the 4.05" bore with exception to the Mercury 410 but it likely has the M in the casting number for 1966 & 67.

The 352 was a 4" bore and the 427 was a 4.23" bore. A person has to be careful when boring these blocks since they all had about the same thickness of wall but had different bores so this makes them different castings. Boring them oversize can make a 352 into a 390 but at .050" there will be less cylinder wall thickness left over. To bore one to 427 would be removing too much cylinder wall so I wouldn't recommend it. Ford recommended a maximum overbore of .060" but a lot of folks have gone out to .080". This would be the last bore size on a non sleeved block and it would be getting kind of thin.

Most Ford cams were ground for best torque at moderate rpms. To gain more horse power is always a trade off. The higher power comes in at the higher rpm so performance cams start to diminish torque at lower rpms. It always depends on what a person want to do with it. The great thing about the mid range FE blocks like the 390 and 406 is that they can have the best of both worlds as long as a person doesn't go to far with cams, ports, & valves. They become high rpm racing engines after a point. A drag racer will want more torque at the launch but still have pretty good top end performance. This is what made the 428 a better street performer than a 427. The 427 was not easy to beat at the track but wasn't well suited for a lot of street use. The SOHC 427 was a beast but way overkill on the street. Long gone are the days of low price and good quality pump gas. It sure was a lot of fun back then.

[craig]

Looking at the pictures, it's most likely a 390. Since it's got both motor mount castings and appears to have the heavier con rods, it would be newer than a '64. The flycut, dished pistons were common on a 2V 390, 410 and 428. While a flycut, flat top piston was a 390 4V and 360 piston. 352's in that time period were flat top and not fly cut. Now that the heads are off, measure the stroke, maybe you'll get lucky and have a 410.
Show us a picture of the intake ports and casting number between the center spark plugs of the heads

[frnkeore]

Can you tell us what the marking are on the right side, on the back of the block?

I meant to say the left side (drivers side).

410's are usually C6ME blocks, so it's doubtful it would have a 410 crank.

Blocks, in general, through out the FE years, can have quite a mix of sand cores, after 1960. The C5AE, kind of proves that. There is really no relationship between your block and a C5AE-A 427, especially since they had C5AE -D, -E & -H, 427 blocks. Before '60, they had a minimum cyl wall thickness of .170 for 239-292 (312 was .145), MEL & FE. Somewhere between '61 and '63, they changed that and from then on, they can be all over the place but, there are some closer standards for the 428 & 427. The 428's are ~.15, the 427's are ~.13 but, have a kind of clover leaf shape for rigidity. I have a 1970 dated 361 industrial engine (4.050 bore) that has (sonic test) cyl thickness, between cylinders of .259 & .184, the inboard and outboard walls are even thicker.

There are some patterns to wall thickness vs casting# though, your C5 block, may be a little thicker than some other 390's, that's why I ask for the space between the cyl walls but, even if it is a little thicker, if you want to bore over .040, you'll need a sonic test.

[Bill Playfoot]

I think I have pictures of what you want to see.

The cylinder ridge is minimal. My finger nail barely grabs it.
The head pictured is the left side.
I don't have the measuring tool this weekend so I can't get accurate measurements that were asked.