Lets See Your Porting.

Putter

Active Member
#31
Here's the porting I did myself on my Briggs 7hp block.

I used a 3/16" diameter carbide tree burr in a high speed air grinder to shape the pockets and ports and then polished them up with a 1/4" slotted rod with cloth backed sandpaper rolled around it, powered by an die grinder. I felt the intake port turned out too slick, so a six second shot of aluminum oxide in the blasting cabinet was used to give it a nice satin finish.

As you can see, compared to the before picture, I took quite a bit of meat out of the ports. Hopefully I didn't overdo it on the intake and lose my bottom end velocity. (looking for a big wheel trailbike to put this motor in)

Bob
Briggs-7hp-153.jpg Briggs-7hp-167.jpg
 

Minimichael

Well-Known Member
#32
Nice job. What's up next?

Seriously though, that's some nice porting work @Putter. Not touching the eyebrows? That intake looks like it flows like a storm drain. You worked both those ports a ton.

Here's some of my novice work to a gx200 I built in about 2021. I worried I'd taken too much and made a bowl out of the intake, but it ran great on testing and breaking in. It's been on the shelf since.

Hey, it's great to see engine talk on here and pictures newer than 1975.

How about it, folks? Who's done porting in the last two decades? Let's see em
 

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Putter

Active Member
#34
Thank you, Minimichael! I was a machinist for 47 years and had porting experience for the first 10 working at an automotive machine shop. Last 37, aerospace and production machining. A really FUN and satisfying career.

I did do a bit more work on the block, unshrouded the valves, milled a bit off the deck and head.

Here are a few more pics from 2011 when I built this engine. It still has never been fired, just sitting around looking pretty. It's a 1969 ball bearing 7HP that has NEVER been run outside the factory. Was a display engine at a Briggs dealer for many years, got sold to an old boy, he stored it for 20 years in an old leaky storage shed. Eventually he put it on Craigslist for $25! I had to drive up to high country Colorado to pick it up. As you can see, it started out as a wrap and pull rope start. The out of focus small pic was saved from his Craigslist ad. Brigg-7hp.jpg Briggs-7hp-291.jpg Briggs-7hp-425.jpg Briggs-7hp-429.jpg Briggs-7hp-431.jpg
 

Minimichael

Well-Known Member
#35
That's a great story and a good looking engine. $25 plus a ride up into the Rockies? Sounds like they paid YOU to take it. Hey that's some bold eyebrow work, and your shrouding is just invisible. I'll bet the new deck is just barely hiding the top of that top ring. Nice and clean with no restrictions.
 
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Davis

Well-Known Member
#36
Thank you, Minimichael! I was a machinist for 47 years and had porting experience for the first 10 working at an automotive machine shop. Last 37, aerospace and production machining. A really FUN and satisfying career.

I did do a bit more work on the block, unshrouded the valves, milled a bit off the deck and head.

Here are a few more pics from 2011 when I built this engine. It still has never been fired, just sitting around looking pretty. It's a 1969 ball bearing 7HP that has NEVER been run outside the factory. Was a display engine at a Briggs dealer for many years, got sold to an old boy, he stored it for 20 years in an old leaky storage shed. Eventually he put it on Craigslist for $25! I had to drive up to high country Colorado to pick it up. As you can see, it started out as a wrap and pull rope start. The out of focus small pic was saved from his Craigslist ad. View attachment 320404 View attachment 320405 View attachment 320406 View attachment 320407 View attachment 320408
Perfect tote Gote motor. Let me know when you want to sell it.
 

Putter

Active Member
#38
Perfect tote Gote motor. Let me know when you want to sell it.
Hey Davis, I'd be willing to sell it but one thing you need to to know.

I owned my Grizzly (very similar to the Tote Gote) for several years with a 6 horse Briggs in it. It ran just fine, but I wanted to throw this fresh 7HP in it.

Big problem, though they are both based on the same big block, they were very different in width. The ball bearing motor's mounting holes to the outside of the drive side if quite a bit wider. Makes it near impossible to fit in the frame and line up the clutch.

I believe the difference is all in the output bearing housing. Here is a pic I just took, measuring from the crankcase to the step on the crankshaft. It's right at 2 3/4 (2.75) inches.
004.JPG
 
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