Hello, I have a 1967 Ford Thunderbird that according to the vin numbers is supposed to have a 390 4 bbl 10.5 Compression Ratio

I am wondering if anybody out there can help out to fully identify it and see if it is all original. I'm sorry if I posted in the wrong section.

Here are the casting numbers

VIN 7Y81Z179379
7=1967
z=390 4bbl 10.5 CR

Head C8AE-H H4?
Connecting Rod C7TE -A B143T V
Crankshaft 2T
Piston .040" over C3AE-6116 A floating with clips 4 valve w/dish slipper skirt measured about 1.77 ? comp height


No block casting numbers block bore measured 4.090"

From what I've looked up the numbers for the engine say 360

I thought that somebody just put in a different engine, but when I tore it down, I found that the crank is ground 10/10, and main and rod bearings are original Ford castings. The pistons, camshaft, and timing gear have FoMoCo stamped on them as well.

I have heard that Ford got used to just throwing parts together just to get rid of the extra parts laying around as they phased the FE engines out, so maybe that is a possibility?

I want to put together a numbers matching 390 for restorations sake, but if this engine is the original I would rather put it back together.

Any help is much appreciated.

 

Mufsa, Welcome to FTE.

The FE 360 truck engine didn't come til 68, was never installed in a car, and sure as the sun is gonna rise in the east didn't have 10.5 CR.

AFAIK, numbers matching is a chebby thing & does not apply to Fords at all. Ford did not match the vehicles, so it's your call on that.

There should be 352 stamped on the drivers side front of the block if it is a FE.



John

 

You've got a .040 360 there. You can convert it into a 390, just by swapping the crank and rods for 390 parts.(keeping the .040 pistons) Then if I'm not mistaken, you'll have a 10.5 to 1 390. If it's got Fomoco bearings,it may have been a reman by Fred Jones, Ford's old "official" parts remanufacturer in Oklahoma City, it should have had a metal tag affixed to the block saying so though.

 

thanks for the replies

yes it does have 352 on the front of the block, I know it's an FE

I know the engines don't do good on numbers matching, what I was meaning is getting engine parts that date match the car so it seems all original

I didn't find any metal tags on it with rebuilders info.

From what I've read the pistons supposed to be in it are flat tops with 4 valve reliefs, but mine has the extra dish ground into it. From Steve Christs book he said that those pistons usually give around 9.5 CR, unless since my pistons have a higher comp height 1.77 vs 1.66, that it bumps it up.
I'm gonna plug the numbers in a compression calculator before I go putting parts in.

Does anybody know if there is a website somewhere with all the pistons info? like compression height?

 

Summit racing and Keith Black Pistons sites have data and compression calculators .

United Engine & Machine Co. Incorporated (calculators)

Keith Black/KB Pistons 1131H-030 - Silv-O-Lite Hypereutectic Pistons - Overview - SummitRacing.com

Silv-O-Lite - Better Pistons Since 1922

KB Pistons for Automotive Applications



The FE wrist pin is .9752 so take half of that .4876 and subtract that from the distance from the top of the piston to the top of the wrist pin hole to see what the compression height is on your pistons .

1.173 = 1.66 compression height
1.273 = 1.77 compression height

1.1875 = 1 3/16"
1.2500 = 1 1/4"

So it will be less than 1 3/16" or over 1 1/4"

 

The dished pistons you have are from the "Regular Fuel" 2bbl 390s issued in the '66 and up model years. They were also used in 360s, where the shorter stroke and longer rod left them down the hole for the low compression used in those engines.

Others here have found flat top pistons in their 360s also. Parts bin motors.... Not sure if anyone has found BOTH dished and flat in the same motor.

As for restoring it to OEM, the 10.5 CR is going to be a pita. FWIW, if using your money, I'd build it to 9.5 and get a better cam in there, such as the 390GT cam or similar. Sure, a Tbird is supposed to be all smooth and quiet and all that, but what the hell, strip the interior and put aluminum panels in there, beef up the suspension, lower it, put a stroker in that thing, adapt in a 4 speed and a cage and pretend you're a privateer running a Tbird in NASCAR in 1967. Serving suggestion, ymmv.

 

You can start by decoding your door tag on the car. Hopefully it's original. As cars were damaged or rotted out and body parts replaced the door tags were often overlooked. This would tell you the plant and month your Bird was made among other things. Compare this to the date code on your engine block. Engine block date code is below the oil filter adapter pad on the small angled part of the block. This followed by the assy date stamp on the left (driver side) "ear" of the block. C8-H heads wouldn't be original to your car. So as others mentioned it could be a rebuilt 360 that was transplanted at some point. Or best case the original block was retained and a 360 built out of it. After 45 years a lot of things can change. But a little detective work will tell the story.

 

Being that this is a rebuilt shortblock, the pistons could yeild any compression ratio. The block could be original to the car, a check of the date code, found behind the oil filter adapter will be the key here. I don;t recall where the car's build date is located, but the block casting would have to be dated a few weeks or a month maybe before that date. The heads almost certainly aren't original to the car, unless it's a late 67 car and the heads are early 68's. Again the date code on the heads will give you a picture here.
You can build a 10 to 1 390 and run it on pump gas, the cam selection is the key. I overhauled one like it that came with a 68 Merc Monterey a few years ago, although it was a 2 bbl motor, it was the Merc version with the Z code build, but with a 2 bbl intake. I reringed it, new bearings, new oil pump, gaskets, etc. I went with a Crane 272* Energizer for the cam, topped it with a 428PI intake and 750 Holley. Before the rebuild it was a premium fuel only motor(93 octane) after the overhaul and cam swap, it was fine with 89 octane. The only other change was .040 Felpro Permatorque blue head gaskets in place of the .020 steel shim stockers.

 

Thanks for all the help guys!

the block date code was a bit hard to read, but it looks like 8k21, so 1968.
Will have to take the wire wheel to it to clean it up enough to tell for sure
the car's date code says June 28th 1967
sucks, I was hoping the car was all original, I will probably look around in junkyards and see if I can find an engine from 67 or older.

if the original engine did have 10.5 cr, then somebody got pedal happy and blew it up probably with 87 octane, I see people do it all the time with snowmobiles

from what i've read online the GT cam is close to Comps 262H?
I don't want to throw in too much of a cam, because I don't have the money to get new valve springs, rockers, pushrods, and higher stall torque converter.
If I measured right the cam that came out of the block has .240 lift, it even has the FoMoCo on it.

If it is a pain to run the 10.5cr, then I might not go that route.
I found the flat top w/4 valve pistons on ebay for $100 hopefully those don't bump it too high.

Back when I first got the car I tried starting it and it fired for a little bit and would just die and occasionally backfire. After tearing down the engine I found the timing chain horribly loose.

I was hoping I would of been able to just get a re-ring kit for $100 and get the engine running.
Didn't think all the parts would have been the wrong ones.

 

I wouldn't worry about it's originality, it's really not an issue unless you're going for a concours restoration. Swap the crank and rods to 390 parts, keep the pistons as is. The 272* Energizer is fine with the stock springs and retainers (pushrods and rockers too) and as I pointed out allows the higher comp ratio to run 89. It's got a pretty smooth idle with the barest hint of a lope when cold.

 

Yeah, a bit of a hassle getting numbers matching parts. I just thought it would be worth more if I did.

I just uploaded pics of it to my garage.

Thanks for all the help and suggestions