Open flathead
- Thread starter Colt sr
- Start date
MO Predator Racer
Member
I dont know anything about what you would built it with but I know a guy who has a open flathead for sale. It is a blossom racing engine that would be ran on a jr dragster.
Colt sr
Member
Pm me details
Colt sr
Member
Thats what i am wondering as well... i am in no hurry to build it just maybe acquire parts for now
meracer9
Site Supporter
The options are endless when it comes to an open build.
Standard Raptor style block, all billet block?
Stock stroke, .500 stroker?
.060 bore, .160 bore?
380 lift cam, 460 lift cam?
Tillotson, Mikuni?
At the end of the day it all boils down to how deep your pockets are and how BIG you really want to go.
Just saw an Open Flathead posted the other day for $5000.
Pick your poison.
Standard Raptor style block, all billet block?
Stock stroke, .500 stroker?
.060 bore, .160 bore?
380 lift cam, 460 lift cam?
Tillotson, Mikuni?
At the end of the day it all boils down to how deep your pockets are and how BIG you really want to go.
Just saw an Open Flathead posted the other day for $5000.
Pick your poison.
MO Predator Racer
Member
I have a predator 212 that I was told it would be a beast in the small block open class and we had it built for about 900. It has different ratio rockrs that are adjustable and roller rockers and dual valve spring and a billet rod and a aftermarket cam and billet flyhweel and a alcohol carb that is for a predator 420. I know of some people that race that have 2500 in a motor and some with 5000 dollar motors and they both stay towards the front.
Colt sr
Member
So basically i should just let the flatheads sit and buy a kt100 or something more affordable... i know where there is a kt100 for a reasonable price
CarlsonMotorsports
Site Supporter
YUK! Why would any sensible American racer do such a thing? LOL
Open flatheads can be a blast, but they are not faint on the wallet.
It was Steve Vaughn who had his open for sale for $5000, and it has sold. It was a proven piece at one of the biggest open races of the year.
Building an open flathead is very expensive. Maintaining one can be just as expensive.
But nothing, and I mean NOTHING, comes close to that sound.
If you are running UAS or run-whatcha-brung, don't chase HP with a flathead.
If you're really into old school flathead opens, spend away and have a blast with it.
FWIW, we've got most everything you would need to build a solid open.
And to answer someone else's question -- about the only thing used from a stock engine is the blower housing and block itself.
-----
Thanks and God bless,Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
sundog
Member
They have billet blocks too right? Speaking from nostalgia, by the time you get all the mod parts it's not the 5hp briggs go-kart engine we all know and love anymore. Looks like the terminator from the future. From a HP to dollar ratio, you're throwing allot of money at an outdated (flathead) design. Honestly don't see the attraction to a full open. Limited mod maybe, stock appearing definitely. To each his own I guess.
Sundog
Sundog
Colt sr
Member
I was gonna build an open to run rwyb or maybe uas... but if it costs that much i might as well find a wrecked 4 wheeler
Skidude
Member
Maybe, maybe not. For instance, say you build a nice WKA spec limited flathead, then you put a carb on that the venturi is o/max, it’s now an open. Will it best the fastest open to compete with others in the open class, probably not, but it will be fast. You can use a billet block, head and side cover, stroker crank, big valves and so on and nothing in the engine will be OEM Briggs. You can also build something like what I have. I consider it a small open. Briggs block, head and side cover, .200 stroker crank, Wiseco .015 over piston, Horstman H-beam rod, Dyno 112ALT cam, stock size valves, limited spec Tillotson carb.
One Fast Kat
Member
Not many at all. mostly if you build an open flathead some will use the case, side cover, sheet metal, side cover gasket, and seals. And sometimes the stock head , relieved to clear valves.
It all depends on your definition of Open flathead.
Some use absolutely nothing manufactured by Briggs.
But some start out with some type of Briggs flathead.
I'm doing an open 14.5 ci flathead for a friend of mine for the Big O from some stuff he has from a stock appearing and other flathead pieces, we're sleeveing a raptor III block down to 2.548", a Lunati .400 on a ARC 4.250" rod, 34.5 mm intake valve on a reverse port ground .437L cam. ARC billet head and 1.8 # flywheel, it will be fed by a 380 dom. EC tilly, haven't decided on a dykes ring or wiesco piston as of yet, plan to turn it around 8800 to 9000 anyone got an idea what it'll dyno?
MCGEERACING
Member
You’ll mostly see blockzilla and terminator blocks running in the 14.5 open modified class. They can be pretty exotic little engines. The only oem Briggs stuff would be the bearing and seals. The pictured engine, has a welded on fully cnc ported “tunnel port” and matched billet manifold, billet cylinder head with relocated pattern, custom cut titanium small stem valves with custom lightweight aluminum retainers, mikuni tm33 carb with bypass valve, and one of my camshafts. You race them at 10,200-10,500 but we have turned them up to 11,000.
Attachments
MO Predator Racer
Member
I am no expert and I dont know much about open motors but how much power does that motor in the picture make?
MCGEERACING
Member
On both my inertia and water break a good one makes 24hp. In retrospect most people’s 14-16 hp clones make 9.5-10.3 hp on my dyno. So these flatheads on the current kart industries exaggerated dynos would be in the 30’s. A good 14.5 ci ohv with a billet head makes 33-34 hp on my dynos. Which would be in the 2.3 hp per cubic inch range, which is a believable good number for a pushrod racing engine.
MO Predator Racer
Member
Man thats a lot more power than the predator class i am gonna run to start out which each kart makes only like 9hp.