Mercury Mark 40-H

[Aeroliner]

Well it all started by buying a whole bunch of engines from Charlie Miller up in Canada. My brother David and I drove up to his place to pick up a truck load of engines. In the lot was a Mark 40-H that really needed to be restored. Well we stopped at Doug Kays in Detroit on the way back and dropped the 4 four bangers off for restoration. All the engines were appart except for the 40-H and Doug asked what do you want done with them. Well I just told him to put them together. About a month later Doug called and said I would like to start on the 40-H also and being he had a all of the 44's in the works for me I told him to go ahead with it also. Well before I knew what happened and a lot of discussion we now have this wild red engine. I think its might be the only 44 cubic inch Mark 40-H with power dome heads. Yes that right its now 44 cubic inches with mercury 500 cylinder heads and a Brinkmen style port job. Hope you like the photos. We ran it last Saturday and hope to be on the water the first warm day in Detroit. Oh through in some others that are compete and some in works.

Alan

[Mark75H]

I think its the only 44 cubic inch mark 40-H. Yes that right its now 44 cubic inches

Probably not the only 44 inch Mark40H ... some alky racers ran 44 and 49 ci Mk40H's in E back in the 1950's. Hu Entrop may have been one of them.

[Silas_53A]

I sat there are stared at those engines for about 20 minutes. They are beautiful, just beautiful. One of these days I need to get my hands on one of these 30h/40h/55h's for my DSR. I plan on restoring it back to its race days, but getting an old merc will be a while. (we all know how plans go...)

I bet they didn't even look that good straight from Mercury. Nice work.


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[Aeroliner]

Thankyou for your kind words. If you would like to view some of our other boats and engines at www.Aeroliner-Boats.com

Alan

[Bill Gohr]

Those engines are beautiful, very nice work, I really like the purple dyno, how much HP will it hold?

[Aeroliner]

Those engines are beautiful, very nice work, I really like the purple dyno, how much HP will it hold?

Right now we have a temperature issue were working out. Hope to have that resolved soon. Also when the loading device is utilized all the water leaves the unit in .2574 seconds as recorded on the data system.

Alan

[Plan-b]

WOW... very nice

[Mark75H]

How on earth could anyone get them to 49 cubic inch there does not seem the space between pairs of cylinders to ever punch one out that far with liners to increase the bore. Please explain further?

I thought the crank throws were on the same centers? Are KG9's and 40H's shorter than 55's?

[John (Taylor) Gabrowski]

As far as I recollect the crankcenters to throw are the same for KG9, Mark 40H, Mark 50, Mark 55, Mark 39H, Mark 55H and Merc 350-400 to 500s too. You can use the same Merc 600-4 series small wrist pin connecting rods in them as well with the newer style flat top pistons for the older 4 bangers and the 44s came with them flat topped already as a newer technology. But how would anyone get them to near 50 cubic inches? The reed block locating pin block side holes would be gone and the liners would have to be on top of each other some how?? But where is the space still, for that?

[Mark75H]

The bore for a 49 would be 2.70 vs 2.56 for a 44 ... 0.070" thinner on each side of the reed cage back location pins ... yes, that would be very close to the pin holes, but they would still be there by a thousandth or 2 if the liners didn't need to touch.

My guess is that they just left the pins out and the liners either just touched or just didn't. I don't know of anyone still alive who would know the details