Mark 30H help with a block serial number...

[DeanFHobart]

Can some of the old timers out there confirm the following..... I had always heard that there were ‘some’ Mark 30 H’s out there that had ‘padding’ or ‘rickies’ in the combustion chamber similar to what was in a KG4.

This would obviously give more compression.

Is this true or just a rumor?

[rjparksjr]

Certainly interesting. Hard to believe that after all these years the old Mercs have such a knowledgeable group of devoted followers that truly love them. All the best to you all.

Thank you for all the input on figuring this out!

Kindest Regards,

Bob

[25xs]

Can some of the old timers out there confirm the following..... I had always heard that there were ‘some’ Mark 30 H’s out there that had ‘padding’ or ‘rickies’ in the combustion chamber similar to what was in a KG4. Is this true or just a rumor?

Likely rumor... Although, Cooper Jess may chime in here as I believe he owned a padded 30ci block. Would be nice to have a forensic observation of that block to determine if it was an original casting or a fabrication outside the factory.

Here is a message from Ron Hill a few years ago regarding padded 30ci blocks and 30ci blocks for racing in general.

"Gene,

As far as I know, the Wizard blocks all measured the exact same as the Mark 30 and the Mark 30-H was the exact same as the MARK 30. There were rumors that some Wizards had some blocks that had "padded" heads. My dad spent a lot of time in Iowa, Nebraska, N and south Dakota looking for 30 blocks as finding fresh water block in California were few and far between.

We ended up with three good Mark 30's. One was a Mercury block from Nebraska, we called that the Nebraska motor, one was a Wizard......The Wizard had no markings on the block where usually the four cylinder motors said, "Turbo Four"....just a smooth blank block. My third good 30-H was a black block from an original Mark 30-H....

My fears about the "PADDED" Wizard block came as a way to keep people like my dad from saying "BULL ****". At one time we had maybe 22 Mark 30 blocks. I had my dad measure the intake and exhaust posts on everyone, I wrote the numbers down and sometime switched block on him to double check his numbers. The **** blocks were so close you could say they were the same.

About this time, there were a couple of young races from NorCal that started running very fast in C Stock Hydro. I did their props, so I knew hat pitch they could turn and they won several Nationals, so I liked them....They claimed to run Wizard blocks. My dad decided to find some Wizards for us.....We found several, no "PADDED" ones......

About 12 years ago, I was talking to Lon Stevens and he was telling me how he welded heads in Mark 30 blocks, and mill Turbo Four off the side...He said, "His 30's CC's 14.2....." Most 30's as I recall were closer to 21 CC's..."