Big block lifter pattern

[Ratu]

I was at a machine shop collecting some parts yesterday and saw a cylinder block in the delivery bay. It was a V-8 and I was told it was an aftermarket big block. The block had just been delivered to them and the owner had asked for it to be decked some amount. What intrigued me was the spacing of the lifter bores in the valley of the block. They were uneven. Some pairs were widely separated while the next pairs were much closer together. Now that was weird to find. I do not know why this should be, although I have suspicions as to the reasons. Perhaps it is something to do with getting the push rods around the ports while maintaining decent geometry and avoiding excessive offsets and the like. If that is the case, that would mean that not all of the ports have the same approach angles/trajectories to the cylinder. Perhaps this was a big block Chev or Buick variant? It would be interesting to see the camshaft, as that would have to be non-standard affair with the lobes unevenly spaced. The men at the shop couldn't tell me much and the owner of the business and the best machinist ("Rottler-Yoda") were not in. The owner was not coming by until next week.

Does anyone know about this engine? What engine is it? Who makes this cylinder block and what are the heads for it like?

[pamotorman]

could it have been a GM pro stock block with 9 cam bearings ???

[shoedoos]

This perhaps?

[Kbails]

cfe4.jpg

[Ratu]

Wow! Now that is an impressive piece, but it isn't the same as what I saw.

In the engine in your picture the distance between the lifter pairs for each cylinder is constant. If we measure the distance between the inlet and exhaust lifters for a particular cylinder, it is always the same. The distance between the inlet and exhaust lifters for the engine I was looking at varied for different cylinders. Some pairs had a larger distance between them than did others. I didn't think to get a photo of it. I wish I had.

Anyway, I had not been familiar with this feature previously and am curious to find out more about it.

[Ratu]

Same situation for the second photograph of an excellent engine- an impressive engine indeed. It is different to what I saw in that its lifters pairs are evenly spaced for each cyinder.

[user-17438]

If it's a dart block it could be a dart x, lifted pattern. It straightens the geometry a bunch. But definitely looks goofy. Like lifters almost overlap on some lobes.