****UPDATE POSTED @ POST #18************Well took the bike in to an Indy and was going to have the 107 refreshed with new cams and headwork. Have been running it for 20K miles with stock heads and Woods Tw6-6 cams. Got a call last night from him and the news was not good. He checks the bikes over good before doing something like this and he found the Rod bearings are seizing, pistons have scuff marks on the skirts, some blow by showing on pistons, and the cylinders are out of round and out of spec.

What he found:
Cylinders were mic'ed in a fixture like the should be, they are .0032 in wrist pin direction and .004 perpendicular to the wrist pin. He says he usually shoots for .002 and from what I have read that is standard.
Top ring was gapped correctly ~.016 but the secondary ring was over .024

I had started hearing a knocking noise that sounded like valve train at 2400-3400 rpm's, now I know what that noise was. I drove the 2 hours down to his shop at his request to look at the damage. He wanted to be sure I understood what he found and discuss the options I had.

So the choice is rebuild bottom up with new crank, Lefty and main bearings, new pistons and cylinders, new support plate, oil pump, etc.... OR
S&S 124LC crate motor.

Cost isn't that much more for the S&S when all said and done.

Now I will open this up to opinions on which way you would go and why, but I am leaning right now towards the S&S.

BTW....60K on the bottom end of the motor, runout was .0035 when the 107 was done.

 

Interesting. Who's 107 kit/parts?

My thinking is the same, 124 when the 107 goes, but for example, I just spent $1700 on a busted valve spring, new valves, heads, etc for the front cylinder. If it keeps doing crap like that I might be better off just doing the 124, but in my case, cylinder was fine. You can never predict the future, unfortunately

 

Not sure I want to go there. I will tell you I have been impressed by this Indy shop with his knowledge and eye on detail. He told me he usually does't install kits from any of the vendors because of the tolerances he sees. This may not go over well with many vendors who sell the kits but he said they put the kits together and stay on the high side of the tolerances to ensure clearance of piston/rings with cylinders.

He likes to match the pistons and cylinders together and he does all his own boring of cylinders. Of course he is not the only builder that does this.

This made sense to me and it's not intended to bash any of the "Kits" out there.
Lesson learned on my part that I should have double checked all tolerances and gaps before assembling the 107. Maybe some guys out there can learn from my mistake.

 

can't go wrong with a S&S 124 inch, and then you can still sellyour remaining engine even if it is in pieces.

 

Well that really stinks. Sorry to hear it but I bet you'll be smiling even more with the 124!

Good luck

 

Couple of threads out there on the 124 with impressive numbers and the owners sounded like they are thrilled. Heck. It's not my money. Stop jerking around trying to fix a problem child and let us know how much you like your new 124.....

 

for a few more dollars you can get a crate S&S 124 motor...to me, it's a no-brainer. With the S&S you get a bulletproof lower end and power in reserve. Although I would go with the HC not the LC.

 

S & S does not weld their crank on a 124 crate motor. Would not call the lower end bulletproof. I had them weld the crank in my built 124.

 

I thought S&S put out a video showing that their pressed 3 piece held up to more torque than a welded stock one did.

 

Watch the S&S vids on their crank vs a welded crank. The welds on a pressed crank basically do nothing to strengthen the joint according the torque test done by S&S.