What does vacuum failure mean?

Has anybody seen any of these blocks ?

I have a friend that has one and was wondering what it meant and if he should be concerned.


Thanks
Rob

Merlin blocks are ALL blems,I bought mine 4 years ago and I spent almost as much on machine work to make it useable as the original cost!!!! The lifter bores are short too,I had issue where morel lifters were bleeding off all the oil at idle thru the chamfer at top of the lifter bore and had to get cam base circle reduced .080 to maintain oil pressure below 1000rpm's. As far as "vacuum" failure,I'm not sure but I would avoid it,Smitty

Not to mention they are thrifty with thier nickel content @ the foundry. Dart is far superior IMO.

doesn't that sound like some sort of internal porosity or crack ? ... the inability to pull a vacuum in the water or oil galleries ?

not something i would want to start my build with....

Rob, have your friend check the serial numbers. It it is a vacuum failure block I've been told it will have the letters "VF" in the serial number.

I bought a set of heads from them. The valve guides weren't machined properly which lead to VT failure. They wouldn't refund or pay repairs. I figure I've cost them at least twice what I paid for those heads by bad publicity. I told them I would and this is how I do it! F*ck merlin and the horse they rode in on!

I am guessing oil galleys??? Trying to find someone that had experience or knowledge of them?

I made the costly mistake of buying two Merlin blocks on ebay from a guy. One was ok, the other appeared to be a blem. Had to have the mains and cam journals finished. Nobody near me would touch it. Had to take it to Bill Mitchells Hardcore Performance on Long Island. There must of been something fishy about it as they asked alot of questions about how I got it and were real interested in the serial number. I got it back in about 2 weeks, but they had to finish the mains slightly offset, as that was how I got it. It looked real good until I assembled everything and installed it in the boat. Starter grinding. The mains were so far off, the starter is too far away from the flywheel to engage. I had to pull the engine, disassemble the starter, and have the mounting surface of the starter machined so it would be closer to the flywheel to engage. I didn't even think of this problem, even though it took an oddball timing chain to work. I had just thought the distance between the cam and mains was different, not offset.

Mine had the cyl bores off slightly,decks were not parralell to crank,cam tunnel was wrong,mains were screwed up,ended up with a .010 under timing chain,lifter bores are short and exsposed my morel lifters at .600 peak lift enough to bleed off oil press at idle,had to reduce base circle of cam to get idle oil pressure-NEVER AGAIN. I bought a dart big M this year,just got it back from getting re-machined,wasn't nearly as bad,Smitty

I'm not suprised. I went with Dart. They care about quality. BBB