Mercruiser 120 convert to automotive.

matt167

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I’ve been thinking about starting work on my long abandoned scratch built rat rod in my nice insulated and partially heated garage ( has 8’ of baseboard heat for washer/ drier. Never gets ‘cold’ )… and I happen to come across a model A frame that is perfect for it as I’ve never liked the frame I had for it. Now I get to inventory the ‘stuff’ i have in storage for it. And was thinking that the 120 in the StarCraft Offshore would be cool. It’s a spare engine as I’m dropping the 140 in that boat.

What does it take to switch it to automotive? Can I buy the intake and exhaust manifold for a Chevy II 153? It’s a 1970 engine
 

matt167

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This is more or less how it sits now on a back halved Ranger frame
 

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Scott Danforth

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yes, the 120 is simply the 153 from the chevy 2 with a marine cam

get a different distributor for automotive use. reach out to Tom http://www.langdonsstovebolt.com/ you can get a custom HEI distributor for the motor for street use.

just clean off the rust off the flywheel and bolt a clutch on it after you install a pilot bearing.

other engines to consider are the 3.7 liter mercruiser. it has a cult following on the HAMB https://www.jalopyjournal.com/forum/threads/the-elusive-224-3-7-mercruiser-banger.256713/

may want to check out inliners.org. https://inlinersinternational.org/ at least cruise the classifieds if you are looking for parts.
 

matt167

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Somewhere I read that the Mercruiser 2.5 has a special intake bolt pattern and one needs to be built for it. Is that true or can I grab a Clifford intake? I bought stuff from Steve Langdon years ago for a Chevy 235
 

Scott Danforth

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Somewhere I read that the Mercruiser 2.5 has a special intake bolt pattern and one needs to be built for it. Is that true or can I grab a Clifford intake? I bought stuff from Steve Langdon years ago for a Chevy 235
no, there is no special bolt pattern. the merc 2.5 is the same as a Hyster fork lift 2.5 which is the same as a 1962 Chevy II 2.5. other than the big gap in lobe angles, small duration on the cam, the non-vacuum advance and the wet exhaust. its basically a small truck motor.
 

matt167

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no, there is no special bolt pattern. the merc 2.5 is the same as a Hyster fork lift 2.5 which is the same as a 1962 Chevy II 2.5. other than the big gap in lobe angles, small duration on the cam, the non-vacuum advance and the wet exhaust. its basically a small truck motor.
Perfect. I thought that was probably the case and the internet was wrong. I’ll either see if I can get a Chevy II manifold or a Clifford.

I’ve wanted a 470 for this use but I don’t want the hassle of finding a good core, when I have a good 2.5 here
 

Scott Danforth

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Perfect. I thought that was probably the case and the internet was wrong. I’ll either see if I can get a Chevy II manifold or a Clifford.

I’ve wanted a 470 for this use but I don’t want the hassle of finding a good core, when I have a good 2.5 here
search facetube marketplace. with everyone yanking motors for LS swaps, the perfectly good old-iron is going for peanuts.
 

matt167

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There is a slant 6 and automatic pretty local but the guy wants wayyy too much for it. I do have an LS 4.8, a 350 and a 460 in storage. But not really sure I want to use any of them. Originally I wanted a 1UZ-Fe Toyota V8 but not with an original frame
 

Scott Danforth

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the slant six just never sounded right. great motor, however I can still hear the lifter tick from my childhood.
 

matt167

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It’s $1,000 has a lifter tick and a misfire. No thanks. Aussies did some pretty crazy things with them including a HEMI head

If I could find one, an MGB 1.8L would be pretty cool with 2 SU carbs. I had a ‘74 and it was a blast. I shouldn’t have sold it. The sound of those carbs was amazing
 

matt167

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This little manifold has me thinking. Along with a Clifford 4bbl intake, as finding an original intake ( or exhaust manifold) is seemingly impossible. Holley throttle body EFI would run with the turbo. Putting 4-5 psi without an intercooler wouldn’t hurt I don’t think. Wake it up a little

 
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