Mercury Mark 58, Why The Preferences?

[John (Taylor) Gabrowski]

Lately there have been real good preferences expressed about Mercs Mark 58 outboards that were some of Mercs earliest 44s as were the Mark 55A and Mark 55A(E) engines. What makes them so special to some people? I have at least one Mark 58 block sitting as an empty spare. Any enlightenment?:)

[crankbearing]

Hey John,

It was my understanding that the 58 block has less of a water jacket than the newer 44 blocks. As well I think they cc better then the newer style engine. I have always hunted for 58 blocks and not 58A They just always seemed to be faster when assembled.. 58 blocks were Super Thunderbolt and 58A were Full Jewelled Super thunderbolt along with the 400, 450, etc...

Regards..

[mercguy]

Hey John,

It was my understanding that the 58 block has less of a water jacket than the newer 44 blocks. As well I think they cc better then the newer style engine. I have always hunted for 58 blocks and not 58A They just always seemed to be faster when assembled.. 58 blocks were Super Thunderbolt and 58A were Full Jewelled Super thunderbolt along with the 400, 450, etc...

Regards..

easy Dave, don't reveal all "our" secrets........;)

[crankbearing]

BOOOOOOO YAHHHHHHHHHHHH????

OOPS!!!! :confused:

Regards,

[Ron Hill]

When Merc went to the three screw port covers, the in take side was much larger, but you lost crankcase pressure....

Actually, I thought the early blocks had more water in the jacket and thinner sleeves....they have more holes, too, as a restule they didn't idle as well as the hotter running motors, but they ran faster....I', pretty sure the early 58 E's had very high compression head...I KNOW the 55 E's did...The black blocks with the 89 serial number as the first two numbers...

Add: I thought all 44 blocks said "SUPER THUNDERBOLT" on the them.

30's said TURBO FOUR
40's said Thunderbolt
44's said Super Thunderbolt.....Only from memory, so, like often, I could be wrong...

[crankbearing]

Hey Ron,

Nope the 58 from what I recall was the only super thunderbolt, the 35A got full Jewelled Thunderbolt and the 58A and into todays 44 got Full Jewelled Super Thunderbolt designation...

Regards,

[Ron Hill]

So, the four port cover blocks were Super Thunderbolt? And the Three screw port covers were Full Jeweled Thunderbolts??? Got any pictures of these different blocks? I only raced one 44 in my life and it was a gas burner with Hubbell Horns and Merc 1000 carbs...Scared hell out of me and Erine dawe as wqe raced F Runabout ONCE!!!! (We decided after that, to let the EXPERTS race F Runabout)...1962...

The old four port cover blocks aren't legal for anything are they???

Off subject: Which don't you list all the 44 XS stuff you have for sale.....???? I sure get a lot of traffic on E-Bay when I list a 44 XS prop..

[crankbearing]

OK!!!

Mark 30 - 4 port - "Turbo Four"
Mark 30 - 2 port - "Turbo Four"
Mark 55 - 4 port - "Thunderbolt"
Mark 55 - 2 port - "Thunderbolt"
Mark 35A - 2 port - Full Jewelled thunderbolt"
Mark 58 - 2 port - "SUPER THUNDERBOLT"
Mark 58a,s,e, 2 port - "Full Jewelled super thunderbolt
Mark 400,450,500 - 2 port - Full Jewelled Super Thunderbolt
500 Silver/Black - 2 port - No label just the small H in the corner with bolt on tuner and no exhaust splitter plate.


This is the list that I can remember, I am sure Sam maybe able to clarify any mistakes I may have made.. but this is from memory..

As for the 44XS. stuff. The reason I am not listing anything right now is I have enough stuff to do with motors, gearcases and mod motors until spring.. Not too mention boat building. I will have a new ad by the end of the month which will list all the new stuff and what i have availalbe I am right now working on complete rebuild kits a, b, c levels which will be basically a reseal kit a bearing kit and a full rebuild kit with pistons, plates etc.. in all sizes as well as a lower unit rebuild kit, at reseal level, seals and bearings level and then a complete with shaft, gears, seals, shims and w/p.

I am also offering the tailcone/gearcase thread repair. I am awaiting a new tap for the "d" lower unit threads that should be in from haskins anytime and a new welding cost from the machine shop..

Anyhow this will all be on the updated web-site come January 1... I am in the middle of updating right now.

any more info on this molds for the cases - I am interested I have several foundries that could look after the pour my mahine shop can hadle the finishing work...

Regards,

[Ron Hill]

You don't list a FOUR PORT 44... Was there never a four port 44??? Seems this was what I thought the discussion was about...Old 44 blocks...

I just thought I'd seen a four port 44 block or two...Kenny Schmidt, had a Bull Nosed DeSilva with a Quincy 44...I thought it was a four port block...Newport Beach kid who hung with Ed Brady....Kenny was shot and killed in Mexico by a security gurad at his trailer park....

His Quincy may have been a "D"....The early 44 's were bored 40's....thin cyclinder walls that cooled fast???

I've got to get ORGANIZED...I'll get the 25 XS gearcase on my "TO DO LIST".......but I've lost my list...

[crankbearing]

Hey Ron,

NO I may be wrong, but I do not think that there were any 4 port 44 blocks. That is why the 30 and 40 ci motors in 59 were 2 ports with the same designation but I could be wrong. here are some pics...

[Mark75H]

I think Dave is correct, Merc didn't make 4 port 44's, but racers did ... 44's and 46's I have been told


Add the Merc 300 and 350 as the 40 ci successors to the Mark35A

[Ron Hill]

Replacing a sleeve was so unheard of in the OLD DAYS, that the MOD 44 I saw, four ports, never occured to me that icould have been a bored 40....

Someone help me, but from 40 to a 44 is what??? .060 a side??? Maybe...

We had heard rumors of QUINCY sleeving blocks, but never really saw one...
AN FYI: When my dad read tha the 350 block with 5/8 ports was legal for "D" Stock, he decided we should find one of those blocks....No one would believe how driven we were in those days, but I spends days, weeks...looking for a 350....I finally found one, salted up like hell..We bored it .030, new pistons the whole nine yards....Biggest DOG we ever built...

20:20 hind sight, I think it was water jacketed too hot, we could have gone back in and drilled a few holew, which would have been legal, more or less, and maybe she would have run.....But I also suspect, she didn't have any compression...Like the Black 55 E blocks had...Those 89 serial number motors had some compression...if you don't believe me, ask Clark Malooff...as hes said, "Them black blocks are pissers..."

Clark was one of those guys you didn't mind lose to!!!

LAST ADD:

At Mickey's (Schwarzenbach) Apple Valley Marine, I thought I saw a four port SUPER THUNDERBOLT block......this was 1977..so, maybe, I forgot!!!! I was looking for BLCK 55 E blocks at the time....I just kind of remember thinking, hell, this would make a great D Stock block!!!!

[crankbearing]

Hey Ron,

Yes I always wondered about doing that.. the finished hole in a 40 is 2.442 and in a 44 is 2.565 but I have measured some that were 2.562 as well. It would leave a real thin wall and I think you would be doing rings on a regular basis with the extra heat. On another note, this is one way I thought of getting 40 pistons was to get some unfinished 44 pistons from wiseco have them turned down to 40 CI .030 level and then have the pin hole machined where it needs to be.. or as well you could do this for the early 44CI small wrist pin pistons as well.

Yes the 35A would never rev but if you punch them .030 port them out of site I think we were doing more wide then high but cannot remember then install a set of 4 pipes, they would really howl and hang on coming out of the corner they had all kinds of balls there. I really think these were the beginning of the 650 4 banger as that is a motor that is a real stump puller as well.

Regards,

Regards,

[crankbearing]

Hey guys,

There is one thing we cannot forget, we can go through the books all we want but we really never know what was coming out of the factory on any given date. I have a black block 55 with the pads and the tits gone off the ports I have not measured the height yet.. but the kicker is it is a matching numbers block and it has AJ carbs openings.. So did they run short of 55 fishing blocks that run and use h blocks that day.. who knows.

but onto stories - I received a bunch of parts in lieu of finishing a boat for one of my customers and in that I got a mod motor which was a 58 block with a 75 stamping and an unmatched crankcase, I as well got a 35A mod from the guy in RI with all the stuff from Fred Auger's estate well one motor came out of Pittsburgh and the other from RI and you guessed it the crankcase cover on the motor from RI has a 75 stamped on it.. The other cool history fact is the 35A mod has CB stamped all over it.. and the only name I can think of is Clyve Bayer. (spelling??)

Regards,

[Mark75H]

I have seen black blocks with AJ fronts too. Strang said the black finish was just a test to see if the finish would make the block stiffer, it denotes nothing else

[David Mason]

Al the Bayer stuff we have is stamped, or has it in the casting, the name Bayer Marine, never seen a CB for Bayer.

[crankbearing]

Hey Dave,

I realize that the flywheel and stack plate have the bayer name on them but then the block has CB stamped all over it as well. I did not know I just wondered if it could be possibly built by bayer..

Regards,

[John (Taylor) Gabrowski]

When a DSH racer here needed a replacement block for a Merc Mk55H, the Merc depot here supplied us with Mk 55E (electric start blocks) that ran better than an original Mark 55H 4 inspection port block. The question came up then as it does now periodically, being, that since a person was buying a heavier electric start motor, they need some compensation horsepower wise for the increased weight so they gave them better/higher ports. Fully half of the dozen 55Hs here became the 55E block and that did not make the Mark 55H-1 guys happy as they could rarey beat the Mark 55E based engines, which were legal too! :)

[Ron Hill]

The 55 Fishing Block weren't made legal in APBA until after 1974.....

And the 55E, black block 89 serial numbers were the hot block for D STOCK, but tI thought this THREAD was about 44......blocks and I'm still wondering if I ever saw a four post FACTORY 44 block...

Thanks for posting, John...and I agree that many a D HYDRO driver didn't like the FISHING BLOCK motors...because they were fast!!!

ADD: I saw an almost new Merc 300 today....I didn't buy it...I'm sticking to two cyclinder 40-50-60 OMC's....Bought a "CHERRY" gearcase today for a Short, 15" shaft, ....I'm going to build a motor for Bill Boyes...

[Ron Hill]

55 E and all "FISHING BLOCKS" has the ports .060 lower than the 55-H...

Had the "H" block not had high in take ports, the high exhaust ports may have helped its performance....But the low ports got around the course much faster.


In 1974, my National Champion Du motor would come off the corner, at Bakersfield at 55 MPH...the first "FISHING BLOCK" I ever ran came off the same corner at 62 MPH and was gaining speed not still losing speed....


Right then and there, I never raced a 55 H block!

[John (Taylor) Gabrowski]

I had to go back and look at the records of the kafufull all over again from the 1970s. My notes from stock years put the electric start Mark 55Es port timing above the Mark 55s and within .005 inches next to the Mark 55H. In inspections the Mark 55Es porting was comparable to Mark 55Hs. Fully half of the Mark 55H blocks here supplied by Merc as replacement blocks for D-Stocks were Mark 55Es. They were all legal and competitive with 55Hs and 55H-1s.

I really must be more precise for some of you, do I? :D

Of course, especially those with very plain agendas. :)

[Mark75H]

There is no separate part number for 55 & 55E blocks

[crankbearing]

I was at Ron's on the weekend pickup some more stuff to liquidate on Ebay for Dort and I picked up what I thought to be a 35A block but when I looked at the ports I wondered, so looked up the serial number on the block and it is in the 59 55H serial # group.. but the label on side says full jewelled thunderbolt not just "THUNDERBOLT" and it has the bolt holes on bottom for the first bolt on tuner which is new to me for that style of block compared to the early 500.. interesting what you discover.. I also found a couple 55H blocks one mod and one stocker both built by Kurtz (spelling)

It is wild the things you discover about this stuff..

but the real neat thing is in reading the list of serial group numbers for

56-57 there were only 1000 55H's made and in 59 only 310.

Regards,