panhead 48

Forum rules
Please do not start new topics here, but here: New Panhead and Flathead topics
Post Reply
pan 48
Posts: 5
Joined: Sun Jul 18, 2010 8:49 am
Bikes: panhead 48
shovelhead 77
Location: france

panhead 48

#1

Post by pan 48 » Sun Jul 18, 2010 10:50 am

good morning, I am French and my translation is poor, I am sorry :oops:
i have a panhead 1948 with piston/cylinder standart +0.6
i don't want to put piston 0.7
i want to put cylinder /piston 74 ci because cylinder standart 61ci are impossibble has find.
is it possible to do this operation ?
my bike come back USA
Last edited by pan 48 on Wed Jul 21, 2010 12:22 pm, edited 1 time in total.



steve_wood
Posts: 947
Joined: Tue Jan 08, 2008 12:32 am
Bikes: 56 FLH, 2007 FLHRCI
Location: Belleville, Ontario, Canada

Re: panhead 48

#2

Post by steve_wood » Sun Jul 18, 2010 11:35 am

Tu veux dire que ton moto est presentement 61 ci et tu veux le changer au 74 ci?

(Do you mean that your motor is currently 61 ci and you want to make it 74 ci)

pan 48
Posts: 5
Joined: Sun Jul 18, 2010 8:49 am
Bikes: panhead 48
shovelhead 77
Location: france

Re: panhead 48

#3

Post by pan 48 » Sun Jul 18, 2010 11:37 am

oui , ton français est meilleur que mon anglais

pan 48
Posts: 5
Joined: Sun Jul 18, 2010 8:49 am
Bikes: panhead 48
shovelhead 77
Location: france

Re: panhead 48

#4

Post by pan 48 » Sun Jul 18, 2010 11:50 am

yes

steve_wood
Posts: 947
Joined: Tue Jan 08, 2008 12:32 am
Bikes: 56 FLH, 2007 FLHRCI
Location: Belleville, Ontario, Canada

Re: panhead 48

#5

Post by steve_wood » Sun Jul 18, 2010 1:49 pm

So does anybody know? Is the crankcase the same for 61 ci and 74 ci in 1948? Are the connecting rods the same?

Of course the pistons, cylinders and heads are different. Anything else? Primary chain gearing perhaps?

RUBONE
Moderator
Posts: 4877
Joined: Sat Nov 15, 2008 4:09 am
Bikes: Multiple H-D, Ducati, BMW, Triumph, BSA,...

Re: panhead 48

#6

Post by RUBONE » Sun Jul 18, 2010 5:01 pm

Crankcases are the same. Only difference above the cases is cylinders and pistons. Heads are the same. However, due to crank difference (Stroke is different) the cylinders are not the same length. So either a 74 crank needs to also be installed (rods are the same), or the cylinders need to be shortened, which ruins them for any other use. The only good part about running the 74 bore is the engine becomes a 68 incher, one of the best running combos ever!
Robbie

panz4ever
Posts: 521
Joined: Fri Aug 12, 2005 5:45 pm

Re: panhead 48

#7

Post by panz4ever » Sun Jul 18, 2010 5:11 pm

Robbie what about running SV wheels and stroker plates? Couldn't you just about get the same results?

pan 48
Posts: 5
Joined: Sun Jul 18, 2010 8:49 am
Bikes: panhead 48
shovelhead 77
Location: france

Re: panhead 48

#8

Post by pan 48 » Sun Jul 18, 2010 5:28 pm

where can i buy cylinder and piston panhead 61 " ci standart???

panz4ever
Posts: 521
Joined: Fri Aug 12, 2005 5:45 pm

Re: panhead 48

#9

Post by panz4ever » Sun Jul 18, 2010 5:32 pm

pan 48 wrote:where can i buy cylinder and piston panhead 61 " ci standart???
Here is a place to start... http://www.billscustomcycles.com" onclick="window.open(this.href);return false;

pan 48
Posts: 5
Joined: Sun Jul 18, 2010 8:49 am
Bikes: panhead 48
shovelhead 77
Location: france

Re: panhead 48

#10

Post by pan 48 » Sun Jul 18, 2010 5:53 pm

thank you :wink:

RUBONE
Moderator
Posts: 4877
Joined: Sat Nov 15, 2008 4:09 am
Bikes: Multiple H-D, Ducati, BMW, Triumph, BSA,...

Re: panhead 48

#11

Post by RUBONE » Sun Jul 18, 2010 6:18 pm

Robbie what about running SV wheels and stroker plates? Couldn't you just about get the same results?
No, not really. Sidevalve big twin flywheels are 4 9/32 stroke, 74 OHV is 3 31/32, 61 OHV is 3 1/2.
SV flywheels create a stroker motor which is big on torque and doesn't rev all that well. They also tend to shake more.
61 OHV with 74 cylinders is close to "square" dimensions, ie; the bore and stroke are the same or nearly so. This creates an engine that revs well and is inherently smooth.
So the end result is a radically different feel to the engine. A stroker has that Kick in the pants feel, but a 68" is all day comfortable.
Robbie

Post Reply

Return to “Motor”