Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties UL cylinder sleeving

UL cylinder sleeving

Moderators: Curt!, Pa

Post Thu Aug 17, 2006 11:37 pm

Posts: 42
Location: Finland
I am now rebuilding engine in my UL project. Now when cylinders are out
I noticed that they are sleeved to STD size (no new sleeving but driven
with that setup).
Bore is shiny with small vertical marks from piston travel.

But the sleeve size bothers me. It is about 3.5" (89mm) OD and there
can't be lot original casting around it. Is this normal dimensioned setup
or is this too big risk-taking...sleeve has flange in upper edge.

Cylinders are original 11 fin 1200cc UL.

-B-

Post Fri Aug 18, 2006 6:17 am

Posts: 2684
Location: Los Angeles, CA
It is not uncommon for sleeved cylinder to develop a crack between the fins. A friend took his cylinders to LA Sleeve. A year later he pulled them off the shelf for installation and one had cracked while sitting on the shelf.

Post Sat Aug 19, 2006 11:35 am

Posts: 148
Location: Dorothy, NJ. USA

I'm thinking of sleeving 13 fins to 74 stock size to match fronts. problem? :?

Post Sun Aug 20, 2006 6:03 am

Posts: 42
Location: Finland
i will check those cylinders for cracks but I would like to
know what outside diameter sleeve is normal ( recommended) size
for UL 74" cyliders?

-B-

Post Sun Aug 20, 2006 10:17 am

Posts: 148
Location: Dorothy, NJ. USA

3.5" they're at 3.494 and a cracked lower, below the bolt base,area on the other with a similar overbore. I have two fronts at .030 and .040 74 overbore. going on a 37 and a 38 U's with 4.5 strocker wheels, wanted to match them up. going to use iron heads to look right. Might go to modern carbs tho. 37 going into a 35 V frame, 38 going into aftermarket straightleg rigid. Getting near retirement so this project is aproachin quickly. The 46U keeps puttin along just fine after 35 years with 74 inches and the 51 linkert w 3sp. But I want to leave somptin to each of my 3boys...

Post Wed Aug 23, 2006 8:16 am
don User avatar

Posts: 573
Location: Spokane WA USA
"I would like to
know what outside diameter sleeve is normal ( recommended) size
for UL 74" cyliders?"

Based on;
Los Angeles sleeve, Centrifugal cast iron for harley-davidson,
3.422 bore, X 1/16" wall, 8" long is/was Catalog No. T-701H.
3.547"
Would be extreme maximum for your 3.5" (89mm) cylinder.
-yes, 80 sleeves,
Email Info@lasleeve.com to see if they can supply 3/32" wall 3.312 bore
Sleeves for Your 11 fin cylinders. O.D. would be just at 3.500"
I would have them do the work.
don
Last edited by don on Thu Aug 24, 2006 6:38 am, edited 1 time in total.

Post Wed Aug 23, 2006 11:47 pm

Posts: 42
Location: Finland
>>3.547" Would be extreme maximum...>>

So my sleeves (installed by previous owner) are under that.

I was not sure if that LA sleeve, Don is refering to, is for 74" or 80"
flathead cylinders...

In 74" cylinders those are sure extreme.

Maybe I dare to use them..but no drag racing.

-B-

Post Thu Aug 24, 2006 6:40 am
don User avatar

Posts: 573
Location: Spokane WA USA
reply in last message!
don

Post Sun Aug 27, 2006 10:39 am

Posts: 2684
Location: Los Angeles, CA


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