How to identify Merc V6 Blocks

[mdc]

Is there an easy way to identify the difference between a Merc 2.5 and 3.0l block without removing the heads and measuring the bore. I looked at a powerhead that had the fuel injection and electrics removed. The seller said it was a 2.5l. The only #s I could make out on the block looked like B-11C4 E 3 075 95 on the starboard edge where it bolts to the front half and 5087 8 on the top edge on the port side. It had 6 petal reed cages. Did any 2.5's come with 6 petal reeds?

[wrechin2]

Head bolt patterns are TOTALLY different.

2.5's were either 5 or 7, 6 pedal are 3.0L.

I will post the different head bolt patterns.

[wrechin2]

Here are the different patterns. The 2.0, 2.4, and 2.5 have "squared" patterns.

The 3L is more "rounded" guess is the best way to state it.

[mdc]

Thanks for posting the head bolt diagrams James. The seller insisted he had a 2.5 but after sending him the diagrams I think he realized he had a 3.0 and has decided to keep it. I was looking for a 2.5 200hp.

[wrechin2]

No problem. Glad to help.

[86vintage]

I recently was told there were stamped marks on the block to identify 150, 200, 225 hp blocks something like HH stamp I looked and could not find a clear stamping on three different blocks - Any advice?

Thanks

Jamie

[silverbullet02]

I recently was told there were stamped marks on the block to identify 150, 200, 225 hp blocks something like HH stamp I looked and could not find a clear stamping on three different blocks - Any advice?

Thanks

Jamie

Good thread on this over in the general section...

http://forums.screamandfly.com/forums/showthread.php?t=205144