8hp ohv briggs suggestions for mild mod build

conehead

New member
I have a 2003/2004 briggs ohv that I want to do a mild mod build , kinda best bang for the buck motor. I need the help of all you experts, fyi I do have full machine shop access just low on bucks lol. I will be racing this engine on clay ovals. would really like to run on gas but will use methanol if I have to. thanks for any help , jack l
 

PD Power

New member
Does it say 305 on it......or 206??

An Animal was never called an 8 hp engine.
The 8 hp Intek is a 305 cc engine.
Figure out....FOR SURE....what it is, then certainly
Jimbo, myself, or several others on here can help you.
 

Chipg56

Member
You need to determine what model you are starting with for any of us to give you accurate info. Find the model number, often on the PTO side of the valve cover. It will probably start with 12, 15, or 20. Potent motors can certainly made out of any of them but need to know what you are starting with to give the best advice. Some provide better starting platforms then others.
 

alvin l nunley

Premium User
Makes no difference what engine it is, start with a higher compression ratio. Quick and easy. Compression is the Holy Grail. And remember; a high compression ratio means you may need higher octane gas.
A racing cam would be next on my list. Again, quick and easy.
Follow that up with the right carburation. Not so quick and easy, or cheap. Getting the right mixture, a mixture to match up with the compression, the cam and the carb is a daunting task.
Comments, compliments, criticisms and questions always welcome.
 

Jimbo

You can fool some of the people some of the time
AL
Since you don't know what you are talking about (AGAIN)
Let me try to give you some important information.
If it is a Generation 1 or 2 Animal engine or an industrial engine it may blow the cylinder completely off the crankcase if you modify it. If it is an industrial engine it will also not have a ball bearing for the clutch side. It may just have and aluminum crank bearing surface. How do you think that will hold up in a modified motor?
However, a Generation 4 or 5 Animal will accept a reasonable amount of modification and last for a very long time.
 

Jimbo

You can fool some of the people some of the time
You will spend more making an intek into a race motor than if you just bought an Animal engine.
Also be aware that the flywheel on an intek is not safe at racing rpm's.
However, if you want to go ahead with it i have every part you would need.
Make a list and check it twice.
 

alvin l nunley

Premium User
So what “I think” you’re saying is; I wasn’t wrong, just that my suggestions might make too much HP, (which was the question) for some engines that nobody races. Or very few race, at least from what I read here.
Comments, compliments, criticisms and questions always welcome.
 

PD Power

New member
So what “I think” you’re saying is; I wasn’t wrong, just that my suggestions might make too much HP, (which was the question) for some engines that nobody races. Or very few race, at least from what I read here.
Comments, compliments, criticisms and questions always welcome.
Agree, that you weren't wrong philosophically, but wrong on the application.

"Understand that a "cobbler should stick to his last".
 

conehead

New member
ok here is the info I found on the valve cover...........so help me out experts is it woth doin anything to or not? thanx


briggs 8.0 hp Intek I/C

model- 202412
type- 0145E1
code- 050816YE
 

spud majic

New member
what you have is a 305/model 20 briggs. the i/c suggest it probably has a iron sleeve and maybe even a ball bearing on the pto side. this is a good base for an open. first things that come to mind for upgrades is rod, cam, flywheel, pushrods and valvesprings. get a decent 1" or larger dia carb(an hl380 are a good fit if you can find one) and you have a nice engine that can put up well over 20hp very reliably.
 

conehead

New member
what you have is a 305/model 20 briggs. the i/c suggest it probably has a iron sleeve and maybe even a ball bearing on the pto side. this is a good base for an open. first things that come to mind for upgrades is rod, cam, flywheel, pushrods and valvesprings. get a decent 1" or larger dia carb(an hl380 are a good fit if you can find one) and you have a nice engine that can put up well over 20hp very reliably.
I knew I would be replacing cam, rod, valve springs and pushrods...... I was hoping to get info on which cam, carb, and springs to use ...thanks
 

ABR #69

Member
Call Jimbo, and have fun.
 

Jimbo

You can fool some of the people some of the time
I have a .365" lift cam that works great for that motor if you add roller rockers you can get anywhere from .400 to over .500" lift at the valve.
I have roller rockers starting from 1.2 ratio and going up from there.
Unlike other roller rockers, they do not require longer push rods or other machine work to the head and fit under the stock valve cover.
 
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