will parts such as the head or anything else from the later 6.0-7.25 hp vertical shaft flathead fit the 5 hp horizontal shaft briggs flathead? I was curious what was done to get the extra power and can that stuff be swapped over to the 5 hp flattys? Not a flathead guy at all, but have a few vintage frames I want to keep USA powered.
briggs flathead gurus needed
- Thread starter Kyminibiker
- Start date
There is a LOT that can be done to a Briggs 5HP flathead to increase performance and HP- How deep is your wallet?
If you can find it, get yourself a copy of Jimmy Glenn's book "Building a Race Ready 5HP Briggs".
(Sidebar comment- looks to be out of print so might be hard to find)
11 years ago my son (16 years old at the time) used this book as a guide to add noticeable performance to a Briggs Raptor 3 with very good results.
Michael
If you can find it, get yourself a copy of Jimmy Glenn's book "Building a Race Ready 5HP Briggs".
(Sidebar comment- looks to be out of print so might be hard to find)
11 years ago my son (16 years old at the time) used this book as a guide to add noticeable performance to a Briggs Raptor 3 with very good results.
Michael
yea I know there is a ton of stuff out there for the briggs flatheads but I'm lookin to gain just a little bit more out of a stocker with the factory parts used on the 6.0-7.25 hp vertical shaft engines IF the parts interchange, that is. I noticed the chamber on the 7.25 hp flathead vertical shaft engine looks almost like a heart, with a lot smaller chamber volume and thought, maybe that and slightly larger carb with proper jettin might be how briggs got the extra 2.25 hp out of the smaller briggs flathead platform. I was just curious if anyone into briggs could tell me yay or nay on it. I already have some hot clone motors, one of which is a stroker with about 25 hp. I'm not lookin to go that crazy, but a solid 8 hp or so with improved bottom end punch and snappy throttle response would be nice with a flatty powered cruiser. I have a Ruttman pak mule that I want to have good bottom end torque/power as I plan to ride tandem with my wife and myself on it but I want to keep it American powered instead of just tossin a clone on it. I also have a bird built t bird I want to run a briggs flathead on with the same sort of performance goals. I'll just have to bite the bullet and pick one of these heads up and see if they interchange I guess. I was just curious if anyone had done or tried similar.
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so they aren't the same series flathead engines? well, shoot lol thanks and I guess i'll just have to get the dremel out to smooth out ports, relieve etc I already picked up a tecumseh intake that lets you run a pz19 mm carb on a flathead briggs with a slight modification. Plan to keep the rpms under 5k so not sure if i'll toss a rod and flywheel on it.
Yep and total cost with shippin on intake, carb and extra jets is under $20. I wanted to try and boost my low end power as much as possible, thats why I had hoped the later model vertical shaft flathead stuff would fit. the combustion chamber on the 7.25 hp is very interestin. Nice and small, with almost a heart shape to it.
Any of the flatty speed parts I have seen for sale, guys think is made out of gold. I'm not buildin a jr dragster engine here, just a nice cruiser a pz19 is plenty for a stock cammed 5 hp. I can always port and relieve the stock 5hp and I assume shave the head a bit to get the compression up for that nice fast throttle response and punch in the bottom end power.