Big bore kit

[mseifert]

I am thinking of putting a big bore kit in my 04 bulldog to the 124cc. I wanted to know what price I am looking at and where is the best place to buy one

 

[JohnBoy]

If you haven't call S&S with your engine number and see what they offer. That will get you a parts price. Labor and any welding and machining and assembly will add to that. Cheaper if you pull the motor and can tune it yourself after reinstall.

 

[mleach72]

I am thinking of putting a big bore kit in my 04 bulldog to the 124cc. I wanted to know what price I am looking at and where is the best place to buy one

I don't think that will work. I believe the S&S cylinders are already stretched to the max to fit the engine block. The 107 is a 4" bore engine. The 124 is 4 1/8" bore engine. Completely different engine blocks. I think your only option would be to stroke the 107 to 113. That requires a lot of work. It would probably be cheaper to just buy a different engine. A buddy of mine just bought a used S&S 113 with 8k miles for $4k.

 

[john sachs]

Bite the bullett, and buy a complete 124" S&S engine. Everything about the 107" engine, re: MODS, is a hassle. The combustion chambers are awful as well. If I recall, the chambers stock are 93 + cc, and the heads flow awful. If it were me, and you are going to stay with the 107", I would bore the cylinders + .020", clean up the heads, but don't get carried away, use the S&S .600" cam, and bore the carb. On another note, if the engine was manufactured before 2004, the 107 heads had a habit of breaking. Check dates with S&S, to find out about your heads.

 

[knothead]

C

Bite the bullett, and buy a complete 124" S&S engine. Everything about the 107" engine, re: MODS, is a hassle. The combustion chambers are awful as well. If I recall, the chambers stock are 93 + cc, and the heads flow awful. If it were me, and you are going to stay with the 107", I would bore the cylinders + .020", clean up the heads, but don't get carried away, use the S&S .600" cam, and bore the carb.

Could not agree more

 

[john sachs]

Today, my lunch time thoughts, and info on the 107" engines I've worked on.
That engine comes in 2 configurations.
1-93 cc heads. 2- (S+S MILLS the 93 cc heads to 84 cc when you order the 84 cc package.)
2 different cams. 93 cc engines get the 585V cams. The 84 cc engines get the 600" cams.
.585V cams are .585" lift. .600 cams are .600" lift
The 93 cc heads have EF 5288 & ER 5288 STAMPED by the exhaust stud side of the head. Stamped, NOT CAST IN NUMBERS. I don't have the stamped numbers for the 84 cc heads.
DON'T MILL the 84 cc heads any further, as that's how S&S came up with 84 cc by milling the 93 cc heads. If you try, you will most likely have intake manifold fitment problems.
Best of my recolection.

 

[Mickmorris]

Bite the bullett, and buy a complete 124" S&S engine. Everything about the 107" engine, re: MODS, is a hassle. The combustion chambers are awful as well. If I recall, the chambers stock are 93 + cc, and the heads flow awful. If it were me, and you are going to stay with the 107", I would bore the cylinders + .020", clean up the heads, but don't get carried away, use the S&S .600" cam, and bore the carb. On another note, if the engine was manufactured before 2004, the 107 heads had a habit of breaking. Check dates with S&S, to find out about your heads.

That’s crazy John. I’ve never seen that ever before except maybe at the drag strip! What failed to make that come apart like that?

 

[john sachs]

Well you can get updated 107" castings, and do this work to them. Port work, chamber work and O/S valves.

 

[john sachs]

That’s crazy John. I’ve never seen that ever before except maybe at the drag strip! What failed to make that come apart like that? Not enough support in the THIN area. IIRC, it was ALL corrected in 04 .