Intake options for Briggs flathead

[OldStrattonMan]

Ok this is my first post so be easy on me, anyway I have a 130202 that I am building with a few upgrades. I'll be port and polishing shaving the eyebrows, billet rod, 94-ss cam and a billet flywheel. I'm afraid that my stock pulsa jet carb will not handle the few upgrades I'm doing. I have been searching so much on this topic but I'm trying to find someone that sells adapters to install a mikuni or tillotson carb and can not find anything to save my life. Will the stock carb work for me or do I need the upgraded carb? Also I will be starting a thread with my rebuild from start to finish. Thanks.

 

[Hellion]

Heheh, your plain-bearing block may not survive all those upgrades. I bet you didn't consider that

I'd ditch your 130202 'garden tiller' engine and look for either a bare Raptor block (model 133230 8124-01) or an I/C (Industrial/Commercial) engine with the cast iron cylinder and dual ball bearings on the crank.

Here's one of the latter in detail: https://www.smokstak.com/forum/showthread.php?t=120907

---------- Post added at 05:11 PM ---------- Previous post was at 04:40 PM ----------

Aside from that, I'd run with the stock carb for a minute just to see what it does--if it runs out of chooch or falls flat on its face.

I'm no expert but some classes (e.g. Controlled Stock class) of Raptor racing used a regular Pulsa-Jet carb that was bored out to allow maximum intake of air/fuel mix.

KartFab (dang that guy, he's everywhere) shows what you can do to make a carb adapter for basically any carb...

https://www.youtube.com/watch?v=ixIyy4RCagM

 

[OldStrattonMan]

Well I guess that's bad news for me so my block is not going to hold up to what I'm doing. I've seen a few others that built these same blocks with mild mods and did ok. I'm not trying to build a race engine at all. I just wanted a little more umph out of it without going to crazy.

 

[Randy H]

Briggs 691922 (pic) and a China PZ22(eBay) is a inexpensive combo. If your not down on making your own intake.
Studz has a nifty steel intake as well.
Older models have a differing bolt pattern (closer)

If you want to run a Tillotson.
https://www.eccarburetors.com/search.html?k=Briggs+intake

Of course plenty of racing has been done with the stock carb and tank, albeit modified. Methanol?

Good info here.
https://4cycle.com/karting/forums/building-a-flathead-jimmy-glenn.94/
https://4cycle.com/karting/forums/flatheads-forever.10/

 

[OldStrattonMan]

Hellion the engine that lee majors did is basically the same thing I'm going to do with mine and his is the same block is mine with the kool bore cylinder. Do really think this block will not hold up to what I'm doing.

 

[OldStrattonMan]

This is a pic of what I'm working with

 

[Hellion]

Well, if you're just going mild and not going all-out and revving to 7K RPM, it will hold up for a while then.

Wasn't sure where you were going with it.

 

[JTSpeedDemon]

Like Hellion said, you basically need ball bearings if you wanna rev it high without the bearings desintegrating/exploding and destroying another beautiful Briggs! I have one too, with ball bearings, etc. and the flo-jet float carb.

 

[Texan]

Look into Tecumseh flathead intakes, there are different versions, but they should bolt right in.

 

[OldStrattonMan]

Like I said this isn't a race engine the most I'll rev is 5k, and I'm going to roll with the stock carb and see what happens.

 

[itsid]

Heheh, your plain-bearing block may not survive all those upgrades. I bet you didn't consider that

I'd ditch your 130202 'garden tiller' engine and look for either a bare Raptor block (model 133230 8124-01) or an I/C (Industrial/Commercial) engine with the cast iron cylinder and dual ball bearings on the crank.

Hmm
my 130202 has two ball bearings (yes it's 4072)
aluminium cylinder sleeve though
same as the 555170 rieken's racing raptor block BTW!
https://www.out2win.com/catalog/raptorblock.html
so it can't be all that bad, can it ?


here's the B&S partslist for reference:
View attachment briggs130202_01.pdf

'sid

PS funny.. with that:

....and to make blanket statements like that...
Our mighty mighty "expert".

still ringing in my ear

 

[Hellion]

You're picking nits, Sid.

Only OldStrattonMan knows for sure; he might by chance have a 4072. Dual bearing 130XXX series engines are still relatively rare.

Show us your 4072 Sid, would love to see it.

 

[OldStrattonMan]

No mine is just bushings no bearing here. I do have a question about some things I've read to help with not having bearings. I hear that people have drilled a small hole in the crankcase around the bushing area. Do yall know exactly where they are drilling this hole and how big?

 

[Hellion]

Hmm, haven't heard that but I suspect it is to allow splashed oil to migrate to the bearing surfaces better.

EDIT--> on both ends of the plain bearing supported crankshaft there is, I believe, an oil passage that allows oil spray to collect and dribble onto the shaft.

Plus something worth considering, "99% of all overhead cam aluminum cylinder heads in the automotive industry have the iron camshaft running on the machined aluminum journals in the head - no inserts."

Didn't mean to scare you about the plain bearings not holding up. The bearings and the block should be fine with your intentions and stated goal. The key to most issues with the Briggs's, or any small industrial engine is maintenance. People just don't maintain them.
It's mainly a dirty 'sludgy' oil that I see that was never changed (think: consistency of pudding) and air filtration (bad filters, no filters).

 

[anickode]

Hmm, haven't heard that but I suspect it is to allow splashed oil to migrate to the bearing surfaces better.

EDIT--> on both ends of the plain bearing supported crankshaft there is, I believe, an oil passage that allows oil spray to collect and dribble onto the shaft.

Plus something worth considering, "99% of all overhead cam aluminum cylinder heads in the automotive industry have the iron camshaft running on the machined aluminum journals in the head - no inserts."

Didn't mean to scare you about the plain bearings not holding up. The bearings and the block should be fine with your intentions and stated goal. The key to most issues with the Briggs's, or any small industrial engine is maintenance. People just don't maintain them.
It's mainly a dirty 'sludgy' oil that I see that was never changed (think: consistency of pudding) and air filtration (bad filters, no filters).

Another thing that happens to these engines a lot is improper storage. Say you've got a rototiller. You'll probably use that once a year for a few hours... Maybe twice? Then what? Shove it back in the shed till next spring. Sitting there with ethanol gas in the carb, maybe the exhaust valve wide open letting moisture into the cylinder, condensation in the crankcase... It all takes its toll.

 

[OldStrattonMan]

Hellion thank you so much for the help and it did get me worried a little about not having the dual bearings. But this will be a learning curve for me and just something I want to have fun with. I will be starting my build thread soon just to show my way through it and hopefully gain a good bit of knowledge on the way.