Tillotson and Rebuild Help

mitch_wilson

New member
I am currently rebuilding my Briggs Raptor 3 Flathead and I'm planning on installing a 94ss camshaft, billet rod, and a billet flywheel. I'm now trying to decide which Tillotson carburetor I want to put on the engine and I'm deciding between the HL-304WXG and HL-360D, which one would work well with my engine. I'm also wondering if with the new camshaft and billet rod if I need to replace the stock piston. The piston is in good shape so I would like to reuse it but can the stock piston withstand the increase in RPM's once the new cam is installed?
 

1fasttiller

Active member
If you're putting the billet parts in it and the cam you plan to run much higher RPM than the stock, cast piston was ever designed for. That will certainly be your weak point! IMO you're wasting your time and money if you don't put a forged piston in it as well.
 

mitch_wilson

New member
If you're putting the billet parts in it and the cam you plan to run much higher RPM than the stock, cast piston was ever designed for. That will certainly be your weak point! IMO you're wasting your time and money if you don't put a forged piston in it as well.
Do you know where to get a forged piston for a stock bore size?
 

Bob Evans

Grumpy Old Admin
Staff member
The 94ss cam should only get into the 8000 rpm range, the raptor 3 piston should be fine.
I've used them with the stock length ARC rod up into the low 9000 range in baby limited mods without any problems. Of course I could have been lucky. :) Of course for rebuilds you'll need to look at a Wiseco or Burris for replacement.

IMO, the 360 has an awfully big venturi for the combo you mention, it might work but I'd call EC Carbs to see what they recommend.
Personally, I'd be looking at something like a 314 or a 347, but I don't know if you can get them anymore.
Edit- make that a HL 348E
 

CarlsonMotorsports

Premium User
314 or 339 if you are staying with stock valves and lift.

If you have the parts and are just trying to shoestring budget the build, I understand your choice of parts...
Otherwise, why not start with better parts (ie long rod and Wiseco piston.) The cost to go with these parts is within a few dollars of stock compression height stuff. Same with the cam -- instead of going to the cheater hot-stock cam, consider the 112-alt, or the 107ss cam. Way more bang for you buck. Have some big valves and seats installed and you can carry that 360 all day long.


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