Requirements for a SCAT crank?

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules
User avatar

Topic author
Steve Jelf
Posts: 6463
Joined: Fri Jan 04, 2019 9:37 pm
First Name: Steve
Last Name: Jelf
* REQUIRED* Type and Year of Model Ts owned: 1923 touring and a few projects
Location: Parkerfield, Kansas
MTFCA Number: 16175
MTFCI Number: 14758
Board Member Since: 2007
Contact:

Requirements for a SCAT crank?

Post by Steve Jelf » Wed Aug 04, 2021 10:32 pm

IMG_5965 copy.JPG
I was aware that you need to take a little off the rear horseshoe.
But a post in one of the FB Model T groups says:
There's quite a lot more to install a SCAT (A stroke) counterbalanced crank in a T. You need the SCAT specific rods, SCAT specific main caps, and SCAT specific pistons. The pan needs to be beat out to clear the rods. The nutplate ring needs a stud welded in to the one between #3 and #4 if it's a three dip pan.

Is all of that correct?
Wat is the nutplate ring?
The inevitable often happens.
1915 Runabout
1923 Touring


Scott_Conger
Posts: 6431
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
* REQUIRED* Type and Year of Model Ts owned: '13, '15, '19, '23
Location: Clark, WY
Board Member Since: 2005

Re: Requirements for a SCAT crank?

Post by Scott_Conger » Wed Aug 04, 2021 10:46 pm

An "A" crank is quite different than a "T" crank and that's why people go to the trouble and expense to do it. It takes some work, and I'd personally put in a Chevy crank before I screwed around with an "A" crank.

A standard "T" SCAT crank takes very little to fit to a "T" engine.
Scott Conger

Tyranny under the guise of law is still Tyranny

NH Full Flow Float Valves
Obsolete carburetor parts manufactured


Allan
Posts: 5203
Joined: Sun Jan 06, 2019 7:21 pm
First Name: Allan
Last Name: Bennett
* REQUIRED* Type and Year of Model Ts owned: 1912 van, 1917 shooting brake, 1929 roadster buckboard, 1924 tourer, 1925 barn find buckboard, 1925 D &F wide body roadster, 1927LHD Tudor sedan.
Location: Gawler, Australia

Re: Requirements for a SCAT crank?

Post by Allan » Thu Aug 05, 2021 12:43 am

Steve, that is not a standard Scat crank fitment to require so many mods. The standard ones may, require some attention to the rear horseshoe. Some don't even need that. The stroker cranks are a different beast.

Allan from down under.


DHort
Posts: 2461
Joined: Sun Jan 06, 2019 1:30 pm
First Name: Dave
Last Name: Hjortnaes
* REQUIRED* Type and Year of Model Ts owned: 24 Speedster, 20 touring
Location: Men Falls, WI
MTFCA Number: 28762
MTFCI Number: 22402

Re: Requirements for a SCAT crank?

Post by DHort » Thu Aug 05, 2021 2:13 am

If I remember correctly, when Adam installed my Scat Crank he had to modify the babbit on the rods. They did not match the way the journals were ground on the crank. No special parts were used.


Roz
Posts: 79
Joined: Fri Feb 15, 2019 7:53 pm
First Name: Dennis
Last Name: P
* REQUIRED* Type and Year of Model Ts owned: 1925 Coupe, 1925 TT, 1927 Speedster, 1931 Model A
Location: Humboldt TN
MTFCA Number: 31449
MTFCI Number: 24373
Board Member Since: 2012

Re: Requirements for a SCAT crank?

Post by Roz » Thu Aug 05, 2021 7:53 am

I agree with DHort. Every Scat I have put in along with new rods has required the corner radius of the rod big ends to be increased a little. The Scat crank evidently has a larger radius at the rod journals. I haven't measured the difference. It's not a problem, that's just part of fitting the rods.


Norman Kling
Posts: 4071
Joined: Tue Jan 08, 2019 1:39 pm
First Name: Norman
Last Name: Kling
Location: Alpine California

Re: Requirements for a SCAT crank?

Post by Norman Kling » Thu Aug 05, 2021 10:58 am

The one I installed on my T was on a 26. I did not have to modify anything in the crankcase. It was standard T stroke only difference was the counter weights. The crank and block was taken directly to the bearing shop where all the babbit was poured and bored to fit. It was just like working with a standard crank except a little harder to adjust the bearings from below, but if the rods are all the way down when doing the work, no problem. I have not tried to adjust the 4th rod on a 3 dip pan with SKAT. That might be harder than with a Ford crank.
Norm

User avatar

Mark Gregush
Posts: 4956
Joined: Sat Jan 05, 2019 1:57 pm
First Name: Mark
Last Name: Gregush
* REQUIRED* Type and Year of Model Ts owned: 1925 cutdown PU, 1920 Dodge touring, 1948 F2 Ford flat head 6 pickup 3 speed
Location: Portland Or
MTFCA Number: 52564
Board Member Since: 1999

Re: Requirements for a SCAT crank?

Post by Mark Gregush » Thu Aug 05, 2021 12:22 pm

If they are talking about the SCAT "Stroker" crank, then yes that take different rods and caps, along with inspection plate spacer. Pistons can be stock or high compression T. Langs catalog page 64/65. This one is longer stroke, which I think is same as Model A, hence calling it Model A stroke.
I know the voices aren't real but damn they have some good ideas! :shock:

1925 Cut down pickup
1920 Dodge touring
1948 Ford F2 pickup

User avatar

dr1960
Posts: 122
Joined: Sun Jan 06, 2019 10:45 pm
First Name: David
Last Name: Ruedy
* REQUIRED* Type and Year of Model Ts owned: 1915 Model T Runabout
Location: Yukon, Oklahoma
MTFCA Number: 50076

Re: Requirements for a SCAT crank?

Post by dr1960 » Sat Aug 07, 2021 1:39 pm

Steve - contact Mike Bender. He put a Scat crank in my model t engine. if i remember correctly, Scat makes a 1-1/4 crank for T's.
David - Yukon, OK
1915 Model T Runabout


Dan McEachern
Posts: 1180
Joined: Sun Jan 06, 2019 11:08 am
First Name: DAN
Last Name: MCEACHERN
* REQUIRED* Type and Year of Model Ts owned: too many. '14 touring, 2 depot hacks, 2 speedsters
Location: ALAMEDA,CA,USA

Re: Requirements for a SCAT crank?

Post by Dan McEachern » Sat Aug 07, 2021 2:02 pm

There are two versions of the SCAT crank. One version is 1.25 diameter rod and main journals and stock T 4" stroke. These are pretty much a drop in crankshaft. The other version of the SCAT crank is similar to the dimensions of a Model A crank- 4.25" stroke, larger main journals (1.600") and larger rod journals (1.5" diameter). This crank requires larger main caps, as the main saddles need to be bored to about 1 3/4" to accept the larger main journal. Rod wise, SCAT makes special rods or you can use Model A rods, depending on your choice of pistons. The larger crank stroke requires additional clearancing of the pan in a few places- more so for the stroker crankshaft. Hope this clarifies things a bit.


Kerry
Posts: 1297
Joined: Mon Jan 07, 2019 2:42 pm
First Name: Frank
Last Name: van Ekeren
* REQUIRED* Type and Year of Model Ts owned: 1916 touring, 1916 pick-up, 1924 coupe, 1926 touring, 1927 touring
Location: Rosedale Vic Australia

Re: Requirements for a SCAT crank?

Post by Kerry » Sat Aug 07, 2021 6:07 pm

The early scats were the ones that gave trouble in fitting as they had journal size of 1.250" if you used off the self vendor supplied rods the babbitt size was the same, so no oil clearance, scats are now running Ford factory specs of a 1.248" journal.


speedytinc
Posts: 3840
Joined: Fri Feb 12, 2021 12:24 pm
First Name: john
Last Name: karvaly
* REQUIRED* Type and Year of Model Ts owned: 14/15 wide track roadster. 23 touring, 27 roadster pickup, 20ish rajo touring
Location: orange, ca
MTFCA Number: 14383
Board Member Since: 2020

Re: Requirements for a SCAT crank?

Post by speedytinc » Sat Aug 07, 2021 10:12 pm

Kerry wrote:
Sat Aug 07, 2021 6:07 pm
The early scats were the ones that gave trouble in fitting as they had journal size of 1.250" if you used off the self vendor supplied rods the babbitt size was the same, so no oil clearance, scats are now running Ford factory specs of a 1.248" journal.
I had a really cherry motor with standard mains. Scat provided a 1.250" on request. Worked out best for me. A little time saver & no shim loss.


Original Smith
Posts: 3284
Joined: Tue Jan 08, 2019 10:43 am
First Name: Larry
Last Name: Smith
* REQUIRED* Type and Year of Model Ts owned: 13 Touring, 13 Roadster, 17 Coupelet, 25 Roadster P/U
Location: Lomita, California
MTFCA Number: 121
MTFCA Life Member: YES
MTFCI Number: 16310

Re: Requirements for a SCAT crank?

Post by Original Smith » Sun Aug 08, 2021 10:14 am

I have a Scat in a 13 engine. I had to make the area around the front bolt hole a little thinner, along with the bolt.

Post Reply Previous topicNext topic