2 port 30H Serial Number confused

[crankbearing]

Hey Sam,

I have a Mark 30 2 - Port block - 1164 are the first few numbers of the serial plate.. It reads Turbo Four on the side. It falls below Grubbs serial number listing for 1958.. It actually falls into the Mark 28 Serial Group.. Would this be one of the mysterious 30H reconverted back to Mark 30 engines. It is a factory sealed motor. fairbanks mag and AJ51A carbs - two pumps..

I also found an ad for 1956 that shows a 55H in the twin blues color, Do you know if they were available in that colour in 57 as well..

What year was the carter to KA switch bulletin (kit) offered.

Regards,

[Ron Hill]

As I recall, the Flat Top Pistons, and KA Carb Kit was offered in 1959...We didn't get our Kit until late July 1959, but we did get it in time for the 1959 Western Divisionals at Long Beach, California. My first DU race, and I won....Pretty sure Bill Boyes and John Soto, NorCal, had the kits then too...So, I'd say they came out in the Spring of 1959, about the time the "B" kit came out...

When the 55-H's hit California, they were all green, until the white, two port 55-H came out in 1958...They came standard with Flat Top pistons and KA7A carbs....Again, I think...

Almost ever 55-H , green, which we called "GO GREEN" because they were the color of stop light green, broke rods because the only way you cold get any spped out of them was to advance the timing...Our 984540 never had the timing advanced and was basically a "DOG", untilw we went to solid rod, Flat Top Pistons and KA7A carbs....Then, we advanced the timing, richened it up and ran HO-3 Champion plugs....

I don't know anything about two port Turbo Four's...I know the two ports were DOGS because they didn't have any crankcase pressure (Intake ports were cast too big, but the sleeves were the same as the four port)...

I ran a two port "D" in Beloit, 1960, my dad thought this block wold be good, I went to the Nationals with John Landon and only had room for one motor for my C and D...So took the new one...I got second, but my four port, I found, after getting home and testing was faster and quicker off the corner.....

My dad found several two port 30's in Nebraska, all we did is keep the cranks and rods, and scraped the blocks...never looked at serial numbers.

[Mark75H]

Mr. Memory is correct agian ... you can pretty well trust Ron's recall

The 55H conversion flat top edge pistons and KA7A carb were allowed in 1959 so that 1956 batch 55H's could be updated and no one could say that the 1959 55H's (that all came with flat tops and KA7A's) had an advantage over the original 1956's that came with Carter N's and less flat pistons.

The same changes were allowed to be made to 20H's, too ... but for a different reason ... 20H's were allowed to update to try to keep up with Hot Rods

I'm not at home this weekend and can't answer the serial number question. There isn't a serial group for 30H's for 1957, 1958 or 1959 ... but I think the only 30H's made after 1956 were made in 1962

[crankbearing]

I am showing a serial group of 1166471 - 1166568 in my list. Also on my sheet it says some of the Mark 30H were converted back to mark 30's and sold in 1958.

Regards,

[Ron Hill]

Now if my memory serves me correctly, all the 4 port, black block, Mark 30-H's came with two pumps....So, I'm a thinking, the two porter you have may have been an "H" at one time..

If my memory would click in, I would remember the number, but Mercury did build a patch of Mark 30-H's...seems the number was 250, Charlie would remember, but no one really wanted to buy them. They pulled the powerheads and put them on fishing motors, the props, Part number 48-something were sold off for $5.00 each as my dad ended up with about 25 of them, later, when R.Allen Smith worked his magic on these Kamics, they became the best CU wells in the world....My mistake was telling Pop Smith how damn good they were, as he made Stan Armstrong, Larrry Castaneto, Tom Barrett from Maryland, Don Pontius, Bill Boyes to name a few....that all had the same Kamics by Smith...

The lower units bounced around for quite awhile, some were remachined and double drilled so they would fit Mark 55-H and Mark 30-H, problem was that by double drilling them, they all broke, even on a "C", mostly "D"....though...

The double pump, two port motors may have been these Mark 30-H's powerheads...

I know that Waldman and Herring had CLEAN NEW Mark 30-H mid sections on their "A" and "B" Quincy loopers....at a time when no one else could get them...The last 50, were rumored to have gone to about the time Quincy got stronger rods from Mercury... (No notch).....

Oh, the stuff Mr. Memory knows...

[crankbearing]

Hey Ron,

Your doing well! At 37 I cannot remember where I put my keys half the time..

I am thinking that it was a 30H block as well in that serial range.. which with all the other motors listed in 1958 are in that 11+ serial range.I just wish there was something different about a 30H to verify it. In the 65 and prior service manual per year motor listing, It lists a 55H and a 30H for 1958 but not in 1959 or later. In 60 it looks like the Mark series naming convention was departed for the 200,300,350 etc.. numbering system..

what did you think about that picture I sent you the other day..

Regards,

[Mark75H]

There are quite a few errors in Merc's literature. You have pointed out one of them.

[crankbearing]

OK! I took that two port Mark 30 apart and it has flat top pistons, heavy rods, 55H reed cages and large taper crank and this was factory sealed motor with a big K stamped in the seal.

Regards,

[Ron Hill]

The Flat Top Pistons were good and so were thee solid rods... But when that crank came out, it was not legal to machine down the big taper flywheel, so the cranks, in those days were close to junk, in fact we junked the ones we had...

Later, my day machined fishing flywheels to "H" weight and the SORC (Stock Commission) made machining the heavy (Fishing) flywheels legal...

At the same time they allowed Mark 55 reed blocks to be machines to "H" carb opening...and if you study the early Mark 55 reed blocks, once opend to "H" carb, you'll know why we never used the SO CALLED BIG reed blocks in our Mark 30_h's or our Mark 55-H's.....

[Mark75H]

OK! I took that two port Mark 30 apart and it has flat top pistons, heavy rods, 55H reed cages and large taper crank and this was factory sealed motor with a big K stamped in the seal. Regards,

Wouldn't be the first motor with a faked seal out there

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