Engine internals

Numbers matching engine block.

I don't have exact plans what to do with the engine. Being the original block I'd like to keep it, but instead of restoring the whole engine back to factory specs I am tempted to use some more modern performance parts.

Ford Australia stamped the blocks with the same ID number than the chassis. In 'JG66NM' J is for Australia, G is for Broadmeadows plant, 66 is for model Falcon GT Coupe, N is for 1973 and M is for March. The rest of the VIN is unique serial number.

The last engine rebuild had been done by some previous owner. I was not sure what to expect. For reason unknown to me, the previous engine removal had required cutting the frame crossmember off. After it was welded back in place, the seams were left to rust.

Dismantling the engine was interesting. The block casting number is D2AE-CA, a cast that could accept 4-bolt main bearing caps. It is a good cast from Cleveland Foundry and strong enough for most applications with standard 2-bolt caps.

Now there is something strange with those main bearing caps on this engine. There appears to be two bolts and two machine screws per each cap. As said before, this cast can be machined to accept 4-bolt caps. Like this one here I found from the Internet:

Example of factory made 4-bolt main bearing caps. Source https://www.picclickimg.com/d/w1600/pict/322253979621_/Ford-351-Cleveland-4-Bolt-Engine-Block-Fully.jpg.

It appears that my block came from the factory with standard 2-bolt main caps. Then someone working with the engine possibly thought that more bolts is simply better and instead of acquiring proper 4-bolt caps, ended up machining standard caps to accept additional screws.

I am a bit worried what this kind of modification does to the cap strength. I would be happy to go with standard caps with two bolts keeping them to the block, but now the ridges on the caps have been machined and drilled. In addition, in a real 4-bolt cap the outer bolts would be 3/8", these are more like 1/4".

As you can see from the image below, on 2-bolt caps there should be support ridges on each cap and no holes in them.

Example of standard 2-bolt main bearing caps. Source http://www.mustangtek.com/block/images/D2AE-CA_05_001.jpg.

 

I might just try to get a set of real 4-bolt main caps and have a professional machine shop to fit them over the existing bungle.

No other surprises popped up yet. Some main bearings showed worn grooves but nothing major.

The block was drilled to .030" oversize. The pistons used were Keith Black Silv-O-Lite Cast Pistons 1159. These are dished pistons, producing a bit less compression than the stock engine. Out of curiosity I calculated that the engine have had static compression at the ballpoint of 9.8:1.


 

News at last.

Last time I wrote I was putting the car in storage for a while. That turned out to be over three and half years. During this time I lived over two and half years in New Zealand and collected some bits and pieces. While at that side of the world, I also visited Ford Broadmeadows Assembly Plant site at Victoria, Australia where my Falcon was built.

Visiting Broadmeadows Assembly Plant site in Feb 2019. Car rentals there don't list Falcon GTs, that's the reason for a ponyride.

Back home in Finland the Falcon was kept in a ventilated storage and was exactly as I left it. I thought it would a good time to take the engine out for a full rebuild. There is still a lot of rust repair waiting but I'll return to that later.

The engine bay looks like any old car with all the extra wiring, aftermarket stuff and quick fixes in a mess. I had the heads removed about 20 years ago, replaced the camshaft and timing chain etc. and just put it back to running order. The radiator got a new core at the same time but mainly I just kept the engine as it was.

The original cast iron intake manifold had been replaced by Edelbrock Performer LB 351-4V manifold.

I noticed the original cast iron intake manifold had been replaced by Edelbrock Performer LB 351-4V manifold. Quite common and understandable modification, except this manifold #2665 is intended to be used with "Ford 351-C and Boss 351 engines originally equipped with a 4-barrel carburetor and 4-V cylinder heads" (https://www.edelbrock.com/performer-351-intake-manifold-for-ford-351-4v-cleveland-2665.html). The heads on this engine are Australian ones with 2V head intake port size (1.375" x 2.05"). The manifold did fit mechanically but there was noticeable port size mismatch. It's worth to mention that Edelbrock Performer manifolds #2665 and #2750 for 351C came with smaller port exit dimensions than the ports on the heads; for 4V #2665 - 1.37" x 2.15" and for 2V #2750 - 1.30" x 1.86". This intentional mismatch have been addressed in the product special instructions section:

NOTE: After just purchasing the Edelbrock Performer for my 351C 2V, there is a SPECIAL INSTRUCTIONS section that is nice to know: The port size of the Performer 351-2V and the Performer 351-4V manifold was thoroughly researched and was designed smaller than the head port for several reasons. Although appearing small in size, the legs of this manifold not only flow more than the port in the head, but they also increase the flow in the head. The design of this manifold allows us to use great runner speed which prevents fuel dropout and gives us better fuel and air suspension. This combination is excellent for throttle response, total performance, and provides very favorable emission qualities. As a final note, please do not attempt to match the manifold to the ports. This will not only hurt performance, but it will upset many of the fine features that took months of research and development. (http://web.archive.org/web/20050317051408/http://stangstable.com/manifold.htm)

 Whoever replaced the original manifold should have used #2750 manifold for 351-2V instead.

351C Australian head (2v ports with closed wedge chamber)

The heads came off without issues. I had them checked 20 years ago and to be honest haven't driven much since.

 Remaining engine detached from the transmission easily and was lifted off.

It would be interesting to see the internals..