Hey guys, currently i'm putting together a flathead for the open/rwyb class at my local dirt track. Starting with a kool-bore block, bearing side cover, cryo crank, angle plug head, .026 head gasket, a stock length rod and piston combo. Last but not least i got a billet tool steel Dyno Cam from marketplace for 50 dollars along with the springs and retainers. The cam did not come with a card but measured out to be .233 lift with high duration and overlap, leading me to believe me this is a 233SS Grind. My question is if this cam is hot enough to even have a chance. So far my competition is some predator motors with cast rods turning 5500 rpm. Forgot to mention i will be using a tillotson HL304 gas carburetor. Will this powerplant give me a chance?
Flathead cam help
- Thread starter Mrgofast
- Start date
Flathead Builder
Member
What rod are you using? Is it an OEM (stock) Briggs rod or is it a higher RPM rated ("Billett") rod? What RPM will you be turning?
Michael
Michael
Last edited:
Since that picture the carb has been installed correctly, i was having problems with running into the header. It is going to use a wiseco super stock piston, and a stock length ARC billet rod. Going with a JR flywheel as well. If the cam is truly a 233ss then i wont be turning anymore than 7200 ish. Maybe a little more if i fiddle with cam timing.
Skidude
Member
That cam is kind of mild but you shouldn’t have any problems outrunning a Predator 212 if the governor is still hooked up. Now once they change the cam and valve springs and delete the governor you’ll probably need more power. You can jump up to a Dyno 110 (not a SS), and you don’t have to weld the block. You’ll need extended lifters and dual valve springs. Definitely will need a billet rod. As for your carb, if you're running gas you can flip it back over if you need to. I’ve always had better luck on gas running the fuel inlet on the bottom, which is how most were installed on the original equipment, ie, chainsaws, tampers, augers, snow machines, etc. Now those were all 2-strokes. If I was going to run a Tilly on gas I’d opt for a 314 in place of the 304.
CarlsonMotorsports
Site Supporter
Where to start...
No, the cam isn't big enough, but then how adept are you at building these engines? Most bigger cams will require clearancing of the crank and welding of the lifter bores or at least putting guides in them and back facing for the increased lift to clear the lobes. Then you'll need to use double springs and backface the spring chamber so you don't kill valve guides from the springs sitting crooked. Then there's the valve guides.
As Chip mentioned - is your Wiseco Superstock piston chromed? If not, you'll kill that cool bore cylinder in a heartbeat.
So much more, but we can cover that when you get to it. Enjoy your build, take your time, and get ready to rebuild soon.
These are fun little engines to build (and I highly encourage folks to get dirty and have fun with them,) but there's a lot more to them than just bolting on parts.
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Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
35 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
No, the cam isn't big enough, but then how adept are you at building these engines? Most bigger cams will require clearancing of the crank and welding of the lifter bores or at least putting guides in them and back facing for the increased lift to clear the lobes. Then you'll need to use double springs and backface the spring chamber so you don't kill valve guides from the springs sitting crooked. Then there's the valve guides.
As Chip mentioned - is your Wiseco Superstock piston chromed? If not, you'll kill that cool bore cylinder in a heartbeat.
So much more, but we can cover that when you get to it. Enjoy your build, take your time, and get ready to rebuild soon.
These are fun little engines to build (and I highly encourage folks to get dirty and have fun with them,) but there's a lot more to them than just bolting on parts.
-----
Thanks and God bless,Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
35 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
OlsonKarter
Member
Most of those carbs needed to be T slotted more than drilled I am sure Mr Carlson can take care of that. If you dont you will starve for fuel. If you are going to run methenol its a must.
Jon Brogden
Member
That's an old 304 gasser there, when you flip it over the gas shaft will be in the way of the header. You need an alky shaft , it will pull up from the right side with the pump stack up and run you about 15 bucks. I've tuned 314g gas carbs on various flat head builds, when they're right you get a puff of black smoke right off the bottom then clears right up. If you tune that out , it won't come off the bottom hard. When you get ready to build the carb PM me if you need some help.
Ted Hamilton
Helmet Painter / Racer
@CarlsonMotorsports -- anyone ever try Nikasil'ing the exterior of a regular (but undersized to match) piston and running it in a Cool Bore? Would be much easier than finding unobtanium...
It is a cheromed piston, that was one of my first challenges. Ive built a couple flatheads and messed around with them but more clome stuff to be honest, im familiar with having to clearance cranks and cams. I figured the cam would be on the small side, i just wondered why they would make such a small grind on am adjustable billet core. The engine rule is 213cc maximum 4 stroke only, no gearboxes. Theres not much for competition in the open class at the moment, as hardly anyone has a true "open" kart ready. The class has been filled with predator motors with basic upgrades running on turf tires so i figured a well-built flathead in limited or super stock trim would outrun a "stage 1" predator no sweat. Brian is your price to sleeve a block $150? I remember reading that somewhere on here.
CarlsonMotorsports
Site Supporter
Much easier to just have the piston coated. Piston coatings are available from several places now and is much easier than finding NOS chrome pistons. Nikasil works better on a surface that doesn't flex or move. We've had it done to cylinder, obviously -- that's another solution to the aluminum on aluminum problem, but can be quite expensive and still require align boring and finish honing to a spec size prior to the Nikasil being applied (all = expense.) Installing a hardened steel sleeve is actually cheaper @ $150 (including the sleeve, align boring and finish honing.) As it is, few want to spend that much on an old aluminum bore flathead -- we've scrapped probably a hundred of them for this reason and I probably still have 40-50 aluminum blocks here. Not likely that I'll be sitting on a gold mine of '69 Camaro parts anytime in the future, but I've got plenty of Briggs flatties around to wait for their stock to rise.
