what was done to this crank?

[fbref5269]

hi all,

i purchased on old merc c service section 2 engine this summer and i'm beginning to restore it. i took the crank out and found some interesting machining that had been done on the throws. the ends have been beveled and i've seen that before. by the way the beveling was done very well. now for the big question, what was done to the flat part of the throws???? you can see on the pictures that there was a groove or a trough milled in it. my question is what was the reason for doing it.


i would also like to know who raced the engine. here is what i've been told. jack kugler had it for a while and never ran it. he cannot remember who he bought it from. however he said it won the nationals when they were in california. may have won both the hydro and the runabout c service classes. he was not sure. any help out here? that is all i know. if the owner who raced this engine has any pictures of him/her running it i would like some copies to use in my display. i do intend to run it at a vintage race one day.

i've also included a picture of the exhaust side of the block and a muffler that was on it. i don't know if the muffler was on it when it was raced, but it did have a bunch of castor on it.

any help would be great.


frank
collector of old things that were new when i raced

[Bill Van Steenwyk]

It would surely help if you knew who the orginal owner was. The reason I say that is (to the best of my memory) there were not that many of these around in the time frame they were being built and run (late 60's/early70's). I know that Waldman had one, Larry Latta had one I believe, possibly Pete Hellsten, (although I do not remember a 4 cylinder, he definitely had a 2 cylinder Merc), and "Dirty Ernie" LaRose from the St. Louis area had one that Bill Seebold Sr. built and tuned for him. I drove that motor on his Hydro one year at DePue when he smashed his thumb and could not hold the throttle or wheel, don't remember which. Think I finished 2nd and Butch Leavendusky won with a Speeditwin and Marchetti Hydro. That combination (Leavendusky's) was almost unbeatable for quite a number of years, if nothing broke on the motor.

There was MUCH controversy about these motors being used in C-Service at the time, and I think that was the reason for the Division 1 and @ 2 desinations even though they ran together most of the time they were run, they were scored separately. Again from memory, the main bone of contention (other than a lot of the Speeditwin guys just did not like the Mercs) was that the Merc was allowed to run the same lower unit as the Speeditwin which made it very competitive against the Speeditwin.

Another possible source of info on this modification might be Harry Brinkmans book on Mercs, although I can't imagine the Mod category at that time would allow such drastic cutting/shaping on a crank. Possibly Dudley Malone in Oklahoma City or Kenny Bayer in the Tulsa area might shed some light on what the modification was intended to do.

[Mark75H]

It looks like the intention of the machining is to scoop mixture away from the reeds and force it to the center of the rod area to align and force it to the transfer passage

[fbref5269]

bill,

i left a message for dudly to call me about the modification.

dave augustine seems to think that the nations were in bakersfield in 1984. does anyone have the c service results for the race?

frank

[Danny Thayer]

It looks like this may have come from Harry O'Brien's shop one of his early motors, mid 70's to early 80's. This is crank mod is to keep the fuel in the crank case more active. Try it and see if there is a differance, it will suprise you.

[fbref5269]

sam,

this was from a merc c service block, not a looper. could it be to increcse air volumn and thus increase pressure?

frank

[fbref5269]

danny,

any idea whose engine it might have been? did the mod work?

frank

[Danny Thayer]

It looks like Harry's work. The engine could have been one of Dorn's, Spandou's, Miller's its hard to say. Are there any stampings on the block? If so that might give you a starting point.

[fbref5269]

danny,

i'll take a look tomorrow. i did see the bore size stamped on the top. nothing really jumped out at me, but i'll take a closer look. did any of the guys you mention win the nationals at bakersfield? the ehhaust and the intake ports have had some mojor work done to it. i far cry from my old merc c service i ran in the 70's. it came from the junk room at a johnson dealership. paid $5 for it. it was fun class, ran against henry shakeshaft every race.

frank

[Danny Thayer]

Frank I'm not sure, Dorn or Spandau may have. I was young back then and we got away from baots and started foolin with dirt bikes. We didn't get back to the boats until 82. From what you are discribing it sounds like Harry's work, the first exhaust cover looks like an O'Brien plate, if you could take the intake covers off and take a picture of the ports I could probably tell for sure if it is one of Harry's motors. Another way is pull the exhaust plate and let me see the filler block. This could have even been one of Harry's son Mike O'Brien's motors for a while.