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Mercruiser 485?

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B-racer Avatar
B-racer Jeff Schlemmer
Shakopee, MN, USA   USA
1950 Willys Jeep Pickup "Ratrod"
1971 MG MGB ~ For Sale ! ~
2014 Dodge Charger
Has anyone here heard about this engine? One has been dropped into my lap to play with, or at least it will be in the next few days. Its a 3.7L 4 cylinder, based on half of a Ford 460. The bellhousing is Chevy, so it'll be simple to bolt a T5 to it. Stock was 185 hp 200+ tq. Seems like a pretty easy way to make a decent amount of power, but it'll need a custom water pump setup (electric or a custom mounting plate) and remove the alternator from the timing cover to mount a real one. Rumor is that they blew a lot of head gaskets, likely because of a poor squish area and really terrible (retarded) distributor timing which made them run hot and detonation prone. By adding an aftermarket aluminum head which can be had for around $500 and decking the block it can run 9:1 compression with no detonation. Anyone?



jeff@advanceddistributors.com

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260mgb Jim Nichols
Sequim,WA, USA   USA
There was a few threads on this motor a while back. If not on this forum maybe BritishV8 and HAMB. Jim Blackwood was discussing it.

geezer Avatar
geezer Silver Member charles durning
Magee, MS, USA   USA
1958 MG Magnette ZB "Chick Magnette (sold)"
1967 Morris Minor 1000 Saloon (2-door) "Marvin"
1974 MG MGB GT "Foghorn Leghorn"
A friend of mine had 2 of those in his 40' house boat. Never had any issues. I believe it has an aluminum block and the iron Ford head. Mercruiser marketed the engine as having V-8 power with 4 cylinder economy. The engine bay had lots of room.



"Whether you think you can do something, or you think you can't, you're correct"- Henry Ford

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V8MGBV8 Avatar
V8MGBV8 Carl Floyd
Kingsport, TN, USA   USA
Boat motor? Here is some info from HAMB

"The back of the engine is CHEVY ! bellhousing ....
well...not exactly Chevrolet. It is very close to the Chevy pattern I've heard compared to a barn shape. A dowel pin or two doesn't line up according to my research on this same topic. Also the Chevy starter will not work. You need either the original starter (may or may not work) or I have read that an International Harvester V8 (70's era) starter will work."


"I'm a Merc tech too and these motors have thier quirks but are easy to fix. Problem #1 is that they had too much compresion from the factory. The 'fix' from Mercury was to pull back the timing. Between the bad gas, pulled back timing, over proping and relatively heavy boats these were put into and you've got a perfect recipe for detonation and overheating. Which takes out the voltage regulator (water cooled) and the head gasket. The REAL fix is to install a set of dished 460 pistons which lowers the compression to run on todays swill. NOW you can put the timing where it belongs and the motor has more power and runs cool which keeps everything happy. Problem #2, weak charging system, is somewhat eleviated by fixing problem #1 but they still suck. For the automotive application one would definitely want to axe the OEM charging system and build brackets for a conventional alternator. Problem #3 is the water pump is cam driven and when the seal surface on the camshaft fails it allows water and oil to mix. Not good. Again, new cams and speedi-sleeves are readily available to solve the problem.

We do several of these motors every year. Once they are "fixed" they just keep running and making stupid torque.

-Bigchief."


https://www.jalopyjournal.com/forum/threads/big-inch-four-mercruiser-470-485.289260/



Edited 1 time(s). Last edit at 2019-01-17 11:48 AM by V8MGBV8.

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Pretty much the ultimate 4 cylinder in terms of displacement and reliable if built right. Popular in light weight HotRods. It's a big engine with a long stroke so vertical clearance is a clear challenge. Will require crossmember surgery and other creative solutions. Might be possible to angle it to get hood clearance.

Jim

Stevenp3762 Avatar
Stevenp3762 Steven Pignataro
OAKLAND PARK, FL, USA   USA
Best check the engine rotation direction on it if its from a boat.



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Every saint has a past..... every sinner a future.

B-racer Avatar
B-racer Jeff Schlemmer
Shakopee, MN, USA   USA
1950 Willys Jeep Pickup "Ratrod"
1971 MG MGB ~ For Sale ! ~
2014 Dodge Charger
Engine rotation, even on boats, is usually standard, like this engine.

The oil pan is made in a way that it would be easy to tip this engine, similar to the Datsun or Slant-6. I haven't yet looked at actual length or height comparisons, but its sitting in my garage until I have time to play with it. With 67+ pages of info on the HAMB, its a proven setup. I have the equipment to deck the block and ceramic coat piston, valves, and the combustion chamber, so I'm sure detonation won't be an issue even with significantly raised compression. Since the factory cam is designed in a way to help make up for very poor exhaust flow, a new cam will be in order - or at least a regrind. Or a supercharger. winking smiley



jeff@advanceddistributors.com

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Whatever performance mods work on the Ford 460 will also work here of course, I think you could even use the 460 cams possibly, and it could be possible to adapt a 460 intake. Undoubtedly those Hamb guys have done nearly every possible mod. Half a set of 460 headers should work too.

From my perspective it's one of those swaps like the Roadmaster was. If it can be done it should be done. If for no other reason than just to prove it. Anyway should you find it possible and decide to go ahead you have my support if it can be of any benefit to you. I'd love to see this one.

Jim

Stevenp3762 Avatar
Stevenp3762 Steven Pignataro
OAKLAND PARK, FL, USA   USA
Unless it's counter rotating half of a twin screw setup....



AC ACE rebody panels for the MGB



Every saint has a past..... every sinner a future.

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
That'd just be a cam change. Ign and water pump should be upgraded anyway.

Jim

Gerry Avatar
Gerry Gold Member Gerry Masterman
Prairieville, LA, USA   USA
While not specifically the setup you are asking about, while I was working at LSU Petroleum Engineering, I was exposed to another Ford 460 mod. It was a 460 that was set up to run on one bank while the other bank was a natural gas compressor. I was told that the nat gas side was simply a special head and manifold plumbing. Naturally the engine side manifolds were different, too. These were used in the oilfield to pump natural gas from producing well. Was told the make was buying all the Ford 460 engines that they could find and they were getting scarce. Reminds me of the VW 2 cylinder air compressors from days past

B-racer Avatar
B-racer Jeff Schlemmer
Shakopee, MN, USA   USA
1950 Willys Jeep Pickup "Ratrod"
1971 MG MGB ~ For Sale ! ~
2014 Dodge Charger
The fellow who ran one of these in a roadster at Bonneville was pretty adamant that the cam design on a 4 cylinder needs to run an enormous LSA - 114-117 to avoid extreme intake manifold pulsing. We saw this our race Datsun as well, but not to as great an extreme. Even at a balanced runner length we were spitting fuel. We will either run the 470 or 485 cam, which is a pretty wild design, maybe with an adjustable rocker assembly for a little greater lift. Head modifications, increased compression, ceramic coatings to reduce detonation, and an undetermined belt driven water pump at this point should round out the basics. With an aluminum head and water pump it'll weigh significantly less than a stock B motor. I'm still not sure what it'll be mounted in - a B, or our spare Datsun pickup or ??? It would make more power than the Flathead V8 in my Willys pickup. This one has 135 hours on it but needs a re-ring due to minor rust from sitting without running for so long.



jeff@advanceddistributors.com

Rick Fawthrop Avatar
Rick Fawthrop Richard Fawthrop
Langley, WA, USA   USA
Are you going to put a Boss head on it?
The rumor I heard was that Sonny Leonard used parts are fairly reasonable.

B-racer Avatar
B-racer Jeff Schlemmer
Shakopee, MN, USA   USA
1950 Willys Jeep Pickup "Ratrod"
1971 MG MGB ~ For Sale ! ~
2014 Dodge Charger
No I won't be putting a $3-6K cylinder head on it. John Kaase reproduces them. This will be the first time I exercise restraint and do a low budget build. I'll put some effort into porting the head and getting the Intake/Exhaust flow ratio better than 66-69%, and resolving the ignition and quench related problems in the chamber. The porting alone should enhance the power output significantly. I've worked on these heads before.



jeff@advanceddistributors.com

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
The only real challenge I see is getting it to fit under the hood. Have you taken any measurements yet? I know it'll be tight but I'm really curious to know if it even looks possible.

Jim

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