|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
12-09-2022, 06:03 PM | #1 |
Senior Member
Join Date: Oct 2022
Location: Denver metro
Posts: 343
|
Do I have a mercury crank?
Shortly after buying my car with a frozen FlatheadI found a Flathead on Craigslist for $100 so I bought it as a back up. When I showed up to pick it up, he also gave me some other parts. Notably 3 cranks. One has 3.75” written on it, one hd 4.0” and the last has nothing. Obviously I can’t trust what someone wrote on it but I’m hopi g the one that says 4” is a mercury crank. The shop I dropped my block off this week at said the only way to tell is the merc crank will have larger oil holes. Is this true? Here’s some photos. If it is a mercury crank and I decide to machine/use it, what else do I need to change to make it work? Is it worth using? As always, thanks for all your help!
https://www.fordbarn.com/forum/attac...4&d=1670626891 Last edited by busmania; 12-13-2022 at 10:39 AM. |
12-09-2022, 06:09 PM | #2 |
Senior Member
Join Date: May 2010
Location: NJ
Posts: 6,181
|
Re: Do I have a mercury crank?
Oil clean outs are certainly a great indicator. The sure fire way to tell is to measure the width of the large bob weights on the crank Merc. is just over 6" and Ford (3.75" stroke) is either 5.5" or 5.75" (I forget at the moment). Aside from actually measuring the stroke, this is the way to tell.
Last edited by Tim Ayers; 12-09-2022 at 06:17 PM. |
Sponsored Links (Register now to hide all advertisements) |
|
12-09-2022, 06:17 PM | #3 |
Senior Member
Join Date: Jan 2011
Location: sw minnesota
Posts: 4,578
|
Re: Do I have a mercury crank?
Yes ^^^, and I think the merc oil cleanout plug is 5/8, ford much smaller, like 3/8 maybe
|
12-09-2022, 06:20 PM | #4 |
Senior Member
Join Date: Oct 2022
Location: Denver metro
Posts: 343
|
Re: Do I have a mercury crank?
Just to confirm, we are talking the hole in photo 2, yes? On this crank the holes are definitely much bigger than on the other crank. The third has non holes.
|
12-09-2022, 08:54 PM | #5 |
Senior Member
Join Date: May 2010
Location: Canada Where it snows
Posts: 2,058
|
Re: Do I have a mercury crank?
|
12-10-2022, 04:51 PM | #6 |
Senior Member
Join Date: Jan 2011
Location: Central Ohio
Posts: 5,070
|
Re: Do I have a mercury crank?
Sponsored Links (Register now to hide all advertisements)
|
12-10-2022, 05:22 PM | #7 |
Senior Member
Join Date: May 2010
Location: NJ
Posts: 6,181
|
Re: Do I have a mercury crank?
This is correct. These cranks typically have the "kidney bean" dimple in the front throw. They tend to have the smaller clean out holes.
|
12-10-2022, 05:45 PM | #8 |
Senior Member
Join Date: May 2010
Location: Southern Maine
Posts: 1,499
|
Re: Do I have a mercury crank?
Is there a casting mark ICM on it? CM is Mercury, it looks like a cast iron Merc crank and those usually have a casting mark.
|
12-10-2022, 05:55 PM | #9 |
Senior Member
Join Date: May 2010
Location: so cal, placerville, vegas
Posts: 1,394
|
Re: Do I have a mercury crank?
Sometimes I'm puzzled... If crank is loose, what's so difficult about measuring the stroke as Ronnie posted in #5? Takes at least a couple minutes. Couple of 2x6's or 1x6's to support the mains, on a bench or on the floor or where ever, and measure. Done. None of the other characteristics are needed.
|
12-10-2022, 08:12 PM | #10 |
Senior Member
Join Date: May 2010
Location: CLAYTON DE
Posts: 1,283
|
Re: Do I have a mercury crank?
The difference would be is it virgin, or was it stroked to get to four.
__________________
Enjoy yer day. Tom Hate can't fix what it started. |
12-10-2022, 08:26 PM | #11 |
Senior Member
Join Date: Jan 2014
Location: Orcas Island Washington
Posts: 4,944
|
Re: Do I have a mercury crank?
Now you guys have me wondering. I'm gonna run down to the shop after dinner and see what characteristics my merc crank has. This has been quite informative. Four years ago I was looking at a crank at the Portland swap meet. Guy wanted 100 bucks for it, claimed it was 4" mercury. While I was trying to measure it with a tape, some guy standing there watching me went up to the guy and bought it.
__________________
Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson) |
12-10-2022, 08:59 PM | #12 |
Senior Member
Join Date: Oct 2022
Location: Denver metro
Posts: 343
|
Re: Do I have a mercury crank?
So I’m pretty sure it is mercury. Is it worth using in my build? What else will I have to change to use it?
I was basically thinking of building a mostly stock engine with maybe a slightly better cam (is that a thing with flatheads?) and adjustable lifters and I’d like to run dual carbs. Will this crank be a nice upgrade if it measures out and is serviceable? |
12-10-2022, 09:40 PM | #13 | |
Senior Member
Join Date: Jan 2014
Location: Orcas Island Washington
Posts: 4,944
|
Re: Do I have a mercury crank?
Quote:
__________________
Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson) |
|
12-10-2022, 10:31 PM | #14 | |
Senior Member
Join Date: Oct 2022
Location: Denver metro
Posts: 343
|
Re: Do I have a mercury crank?
Quote:
|
|
12-10-2022, 10:45 PM | #15 |
Senior Member
Join Date: Dec 2015
Posts: 547
|
Re: Do I have a mercury crank?
Use the 4” crank. You will be glad you did.
JB |
12-11-2022, 12:31 AM | #16 |
Senior Member
Join Date: Jan 2014
Location: Orcas Island Washington
Posts: 4,944
|
Re: Do I have a mercury crank?
So you see, merc cranks aren't just for hot rods, us truck guys love them too. BTW, the one I just went and checked on has 3/8" clean out holes, a kidney bean imprint on the front throw and measures 6 1/8" across the thick bob weight. It was recently turned from std to 10/20. And I'm pretty sure you can use your rods and the full floaters from your 59ab. Some prefer them.
__________________
Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson) |
12-11-2022, 12:57 AM | #17 |
Senior Member
Join Date: May 2010
Location: now Kuna, Idaho
Posts: 3,779
|
Re: Do I have a mercury crank?
|
12-11-2022, 05:45 AM | #18 |
Senior Member
Join Date: May 2010
Location: CLAYTON DE
Posts: 1,283
|
Re: Do I have a mercury crank?
Yes I am aware, but if that were done and I wanted to pass it on, I would mark the stroke in it.
__________________
Enjoy yer day. Tom Hate can't fix what it started. |
12-11-2022, 06:11 PM | #19 |
Senior Member
Join Date: Oct 2022
Location: Denver metro
Posts: 343
|
Re: Do I have a mercury crank?
Some photos. The big weight is 6.25ish inches across. There is an etching of 1CM. The oil holes are definitely 5/8”. I’m pretty stoked!
706DFC5E-201C-4054-B4EC-6E3B0DBE1527.jpg 5E5AED4D-A47E-4AD7-881A-0128012BE9D2.jpg 3D5FEFE1-AC58-438C-A6C9-489A27981A46.jpg |
12-11-2022, 08:07 PM | #20 | |
Senior Member
Join Date: Jan 2014
Location: Orcas Island Washington
Posts: 4,944
|
Re: Do I have a mercury crank?
Quote:
__________________
Owner/Operator of 'Jailbar Ranch' on the side of Mt. Pickett. Current stable consists of 1946 1/2 ton pickup turned woodie wagon with FH V8, 1947 Tonner Pickup (red) mostly stock with exception of a cummins 6at turbo diesel, 1946 Tonner Pickup (green) with 226 cu in 6 cyl flathead, 1979 Toyota landcruiser wagon, completely encased in 1947 Ford Jailbar sheet metal. Ok, cornbinder rear fenders..... 'Rusty ol' floorboards, hot on their feet' (Alan Jackson) |
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|