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what can the experts tell me about the history of the Mercury 10XS racing engine. I have a couple and each powerhead has something different done to it. I know one was ran in Pro and has bigger ports (intake and exhaust) and higher compression, thin ring pistons (did Merc make these?), along with some modifications to the combustion chambers, cooling system, etc............
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Daren
DSH/750ccmh/850ccmh
Team Darneille
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Daren, I'm definitely no expert, but from what I understand, the blocks and pistons/rings were standard service motor parts from that time. The 86ish 9.9's and 15's were a smaller bore than the current motors, and they used those really skinny rings on the Pistons. Really cool little motor (always wanted one)
JesseTeam Red
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My daughter raced one when she was a teenager back in the mid 80's. As I remember the motor was offered to the Stock Division by Mercury as a J Stock motor. The Stock Commission rejected it and it was then offered to the Pro Division (converted to Methanol by Mercury) and the Pro Commission accepted it as Pro J. Mercury didn't sell a lot of them and I heard the remaining inventory was scrapped. As far as what fishing motor it came from, I have no idea.
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This (Mercury converting them to run on methanol) makes sense to me by looking at the innards of one of my 10XS motors, as it look like work would have to have been done bh the factory, judging by the parts and the quality of work. They are definitely 13.2 cube motors compared to todays 15 cube 15's. I wil post some pictures of mine....the alky conversion vs the untouched one later
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John Meyers for whatever reason had a bunch of 10xs towers in his basement.....they were the same basic tower used for the 25 and 44xs if memory serves me correct. Jw might know more about motor..........Comment
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Maybe Fast Freddie will chime in with some more details. By the way, if anyone does have a 10xs for sale, I'll take it.Team Red
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Here's what I remember about the 10xs. Beth Hearn racing to JH/JR titles in 1987 and I believe being on the cover of sports illustrated. She had the most points out of anyone in the history of racing for one season all classes combined with around 32000. She dominated J racing when she raced. The motor itself was definitely an improvement on the J60, but Scott Lancaster was the first kid over 38 mph and that was with a J60.Comment
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I also remember Beth Hearn racing that motor in 1987 as both she and i were inducted into the HOC that season. Back in those days JSH/JSR was a Stock Outboard class and hence the kids were competing for the HOC with all the other classes..................also i believe Garrett Armstrong also won JSH with that version Mercury engine at some point. FYI, Beth was the first Hearn to make it into the Hall Of Champions........i always like to remind Ed of that little fun fact!
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Correct me if I'm wrong, but I believe Beth was running the 7.5J, not the 10xs. Two different engines. I had my a$$ handed to me by a few of the 7.5J's that were running out here in the middle 80's. I remember Jenny Peterson and Chris Gregg had them and I know Mike Jones had a couple that were run by his boys along with Matt Yarno and I believe Nathan Adams. I finally got a complete powerhead from the Peterson family that I am looking for a tower housing for to add to my collection.
Doc Collins had a FLEET of these 10xs's of which Susan Rautenberg and I had the opportunity to race for Doc a couple of times in about '87 or so. These engines were running on methanol. My dad indirectly ended up buying these engines that Doc had and I still have two, a really clean Gasser and a Fueler that is currently "Caster Locked". I do remember there were several in Region 11 and I believe Sheryl (Rautenberg) Rucker had one up here in Region 10.
For about 20 minutes in the early 2000's the SORC allowed the Merc 15 to run in A Stock with any Mercury combination that would "Bolt together without modification" on a probationary basis. So my dad took a (Now current) Merc 15 powerhead and put it on the 10xs (Short) tower. It was a GREAT handling setup on my 10' (ROLL-UP!) Austin. However the combination wasn't terribly competitive with the short amount of work and testing we did.
Looking back, I feel we may have missed a great opportunity that Mercury had offered at the time. But each commission did was they thought was right at the time. Nobody that I know has a Delorean to go back and forth in time to know for sure.
J-DubComment
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I think it was '89 I was at Hearn's, we tested a 10SX with a larger power head that was closer to 15 cu.in. that Fred H supplied ( we called it a 15SX) We ran it on my 25 runabout (the same boat that Ed won several 25SSR nationals with) since it was the only boat available with a low transom. We went through at least 15 props with Ed driving & the best it would do was 42 mph. That was the end of the 15SX project.
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J-Dub you may be correct. I just remember Stan Armstrong at Wakefield in the 80's telling me how he had over $5000 into Garrett's JSH rig given the cost of that Merc engine back then! I remember it had a cowl much like the current Merc 15.
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Piston differences.....and some other cool stuffDaren
DSH/750ccmh/850ccmh
Team Darneille
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That was a really cool engine.
Beth and Garrett and many others raced the 7.5 J, not the 10XS. The 10 XS was supposed to be the "new J" for the SO group, but they chose the OMC A with a restrictor. So it was never legal in SO or MO. The PROs allowed it and Doc Collins had a fleet of them, mostly run on the West Coast. I don't remember the alky versions being done at Mercury - Doc did that stuff.
I remember the 10XS mainly for the number that were scrapped when the SO commission would not accept them. The old rules required a minimum manufacturing run before an engine could be accepted and Mercury complied. Mercury sold off some of them at bargain basement price (cheap gear case, mid, and parts for your 25XS), but at the end, 63 brand new 10XS motors were scrapped!
Oh Well........
Fred HauensteinComment
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Fred: is the 10xs tower the same as the 44xs and 25xs tower?Comment
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Some more interesting parts of the Alky 10xs i have and the stock 10xs and them some different things between the 10xs and current 15 Merc partsDaren
DSH/750ccmh/850ccmh
Team Darneille
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Wow memory has failed me badly on this one! Went into the photo album yesterday expecting to see a 7.5 on Beth's boat and low and behold it's an evinrude. Does anyone remember when the evinrude was introduced in J/A classes? Photos I was looking at were in Saganaw Michigan last Merc Challenge race of the year, maybe last merc challenge race period, can't remember the year though? Have to look into my GrassLake archives now.Comment
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Digging deep here, I could be wrong with some of the trivia...
- OMC 15A was introduced in '86 (ASR and ASH).
- Garrett Armstrong won JH with a 7.5 in '85 and '86.
(brown stripe Merc cowl)
- "“I think”" Richard Hearn won JR '‘86 with a 7.5.
-Beth won with a 7.5 in Hinton '87
(red, orange and yellow stripe Merc cowl)
-Sean Rosado won with lots of speed and arguably the ugliest (competitive) kneel-down craft of all time, powered by a restricted Evinrude in '88 (first year of the restrictor).
-Formula A / 200mod was introduced in '‘88 as well.
Hopefully just reporting and not accidentally rewriting history.
BrianPComment
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I remember my son Aaron racing Jack Terrell's OMC ASH at Yelm on probation in JH with restricter plates supplied by Fred Miller, each heat Fred would put a different one in.
Aaron has a picture on him running beside another boat with a 7.5 Mercury on it..
At that time our J class in Region 11 was J Runabout with 60Js. We had 11 of them. Wilde's took Aaron to the nationls at Wakefield. After the test session Aaron called as said the had the fastest boat. What he didn't realize was the 7.5 was also in his class. He did finish 4th with the 60J.
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