8HP flathead briggs performance parts

#1
Hello,

I have looked around the web for performance parts for an 8HP briggs, it's a 190400 model. I am mostly interested in a stonger connecting rod and flywheel but it seems Billet only makes those for the 5HP briggs. Am I incorrect with that assumption? Could anyone here point me to a place that sells what I am looking for?

Thanks in advance!
 
#2
I asked this question once. I was told the Briggs 6-8 HP engines wouldn't take the higher revs. I suppose the lack of R&D and parts has more to do with them not being used in competition than anything else- and why the 5 "does" have the aftermarket parts.

There isn't really anything available for them except for original parts.

Hello,

I have looked around the web for performance parts for an 8HP briggs, it's a 190400 model. I am mostly interested in a stonger connecting rod and flywheel but it seems Billet only makes those for the 5HP briggs. Am I incorrect with that assumption? Could anyone here point me to a place that sells what I am looking for?

Thanks in advance!
 
#3
I asked this question once. I was told the Briggs 6-8 HP engines wouldn't take the higher revs. I suppose the lack of R&D and parts has more to do with them not being used in competition than anything else- and why the 5 "does" have the aftermarket parts.

There isn't really anything available for them except for original parts.
I was afraid of that, I guess next time I will have to buy a vanguard v-twin. They make some stellar performance parts for those engines, you can even get a supercharger on those things! Thanks for the confirmation though.
 
#4
I was afraid of that, I guess next time I will have to buy a vanguard v-twin. They make some stellar performance parts for those engines, you can even get a supercharger on those things! Thanks for the confirmation though.
Well yeah, they are after all industrial engines. I run the six (same basic engine) on my Tote Gote. Good torque, but no where near the RPM of my highly modified flathead five.

I have the five on a Taco with a jackshaft running about the same gears you are thinking about. It might go 40. It's sluggish on take off. From your other thread, I see what you're trying to accomplish, but trust me, you do not want to spin that Briggs at 4K, because you WILL be buying another motor.

At some point, I mini bike stops becoming a mini bike, and a Yamaha 125 becomes the logical choice.
 
#5
Well yeah, they are after all industrial engines. I run the six (same basic engine) on my Tote Gote. Good torque, but no where near the RPM of my highly modified flathead five.

I have the five on a Taco with a jackshaft running about the same gears you are thinking about. It might go 40. It's sluggish on take off. From your other thread, I see what you're trying to accomplish, but trust me, you do not want to spin that Briggs at 4K, because you WILL be buying another motor.

At some point, I mini bike stops becoming a mini bike, and a Yamaha 125 becomes the logical choice.
Haha thanks for the advice, I decided to keep it under 4k and go with a sprocket that will give me more low end torque so high revs are pretty much out of the situation now.
 

joshua. c.

Well-Known Member
#6
the briggs 8 hp flathead is a 305cc engine and theres a briggs ohv 10 hp 305cc engine that iv heard has lots of aftermarket parts. both engines they are the same cc's and horespower range so dose anyone know if the parts are interchangable?
 
#7
ARC makes a rod and flywheel for the model #19. These are for vertical 8hp engines. You would have to do something for a dipper though. Performance 3 in. pistons are available through jr. dragster part places. Dyno cams will take care of a cam for you.
 
#8
the briggs 8 hp flathead is a 305cc engine and theres a briggs ohv 10 hp 305cc engine that iv heard has lots of aftermarket parts. both engines they are the same cc's and horespower range so dose anyone know if the parts are interchangable?
Pretty sure it's because my engine is old and inefficient but it's a 319cc not a 305.
 
#9
ARC makes a rod and flywheel for the model #19. These are for vertical 8hp engines. You would have to do something for a dipper though. Performance 3 in. pistons are available through jr. dragster part places. Dyno cams will take care of a cam for you.
Sorry to be a pain but I couldn't find one, you wouldn't happen to have the link would you?
 
#13
I just bought a new 8hp I/C short block with a 3/4 in. shaft. For $76.00 on ebay I couldn't pass it up. I have a complete used one in the garage to make it complete.
 
#14
Hello,

I have looked around the web for performance parts for an 8HP briggs, it's a 190400 model. I am mostly interested in a stonger connecting rod and flywheel but it seems Billet only makes those for the 5HP briggs. Am I incorrect with that assumption? Could anyone here point me to a place that sells what I am looking for?

Thanks in advance!

If you are wanting your Flathead briggs 8 horsepower to turn up higher RPMs I can tell you how it can be accomplished. I currently have a flathead 8 horse Briggs bored 30 over the head has been shaved 60,000 and the Magneto has been Advanced somewhat. Also I've had the rod shock printed. Put a tachometer on it and it turned 8,000 RPMs with no load and held it. There is one key to achieve high RPMs with such a long stroke. You must use double valve springs. It's difficult to do you can use the stock valve springs however you must find another valve spring that will fit inside and also it has to be wound in the different direction. Even if you have a rotator on the exhaust valve it can be accomplished. That is how you achieve such high RPMs because it prevents the valves from floating. I hope this helps anybody trying to soup up an old school Briggs & Stratton.
 
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