Briggs 208cc 950 series opened back up...round two

[BigWes]

Ok, so I've been talking about it.

And I did. Some of you remember the first thread I did on this thing. I think it's a few pages deep now and it's closed due to age. I was going to put it on a mini chopper frame but the more I fiddled with that frame the less I trust it. So I put it on an old Ken-Bar Streaker.



I noticed right off it was a runner so I put 18# springs in it. And got some good speed from it considering it's a big heavy yard kart with my big fat self on it. So it's moving a 30 series t/c 10t over 60t out to 18 inch golf cart wheels. 47mph on the GPS. My phone gave the same info.



I decided to have a little fun and throw a little money at it. I made mention of it in other threads.

So right now it's really late and I'm about to make for the bed as I gotta get up and go to work shortly but I had to pull myself away...I didn't want to stop messing with that thing.

Here is where I am with the thing right now. I'm slowly going back together with it. As I was comparing my new cam with my old cam I noticed that there was only .020 difference in lift between the two so...that raises a question. Did someone change the stock cam? From what I've read the stock cam had a plastic gear...mine didn't. So... .020 lift may not even be noticeable in reality. I guess I'll know when I get it back together. I can't visually see a duration difference but that doesn't mean it's not there.

I'll get some more pics up tomorrow as I get it back together.

Here are the cams. The pic came out upside down...old cam closer to the engine



Where I am now.

 

[BigWes]

I was putting it back together this afternoon until this happened.

I don't like it. I don't know what the minimum rod to crankcase clearance is but this seems a little close. Means I gotta take it back apart and start over again. After I do something to clearance the rod...I don't have much metal there on mine

 

[BigWes]

So what happened to my pics?

 

[RobertD]

working on it

 

[landuse]

Is this due to the manufacturing process?

 

[BigWes]

Is this due to the manufacturing process?

No, I don't think it is. The billet rod is bigger around the crankpin and clearance checks advised. I don't have an outer cover installed so my deflection is not exact. I did move it to both extremes and it was very close on the farthest away and touching as I moved it towards to cylinder wall.

I questioned a group of racers about this and from what I gather it's fairly common to open that area up for clearance. It looks worse than it is. The radius of the bottom of the cylinder wall area makes it look worse. I think I can clearance it without even touching the sleeve actually.

Thanks for making that photo magically reappear!

I'll try and put up a pic of my clearance area when I get to that if it works...the file manager I mean.

 

[landuse]

Thanks for making that photo magically reappear!

I'll try and put up a pic of my clearance area when I get to that if it works...the file manager I mean.

Robert got all the bugs ironed out, so everything works like it should

 

[BigWes]

Well, it's not pretty. I'm limited on what I have at home to work on this stuff. I don't really have any tools small enough to get in there and do it quite like I wanted...no not particularly pretty but the rod is clear and it'll work and it's hot out and I'm tired of messing with it. Onto the next parts...

Ok...so I had so pics to upload...but it wouldn't work...maybe later then

 

[BigWes]

Holy smokes!!! My pics just magically reappeared!!! I don't know which one of you guys fixed it but many thanks to you!!!

That kinda makes me feel bad because I plodded along with this project today and continued putting this thing back together with taking many pictures.

---------- Post added at 10:44 PM ---------- Previous post was at 10:39 PM ----------

ok...just tried to upload again...didn't work...it's late I'll figure it out tomorrow...I'm doing something wrong.


I will say this...it runs and I like the way it sounds so far! Just needs some tuning on that Mikuni...but that is a story for another day!!!

 

[landuse]

Holy smokes!!! My pics just magically reappeared!!! I don't know which one of you guys fixed it but many thanks to you!!!

That kinda makes me feel bad because I plodded along with this project today and continued putting this thing back together with taking many pictures.

---------- Post added at 10:44 PM ---------- Previous post was at 10:39 PM ----------

ok...just tried to upload again...didn't work...it's late I'll figure it out tomorrow...I'm doing something wrong.


I will say this...it runs and I like the way it sounds so far! Just needs some tuning on that Mikuni...but that is a story for another day!!!

And you are trying to upload like you always do? I haven't had any issues uploading myself

If you have hassles, please PM RobertD and he will look into it for you

 

[RobertD]

test

 

[Brianator]

All good Robert, nice picture!

 

[BigWes]

Well, something flakey is going on.

Anyway, I cropped this image and it loaded fine.

None of my images were too large before. Maybe I'm missing something.

This is where I clearanced my rod. I need more appropriate tools for this kind of work if I keep doing it. But it's done.



I'll add more to this as I resize pics.

 

[BigWes]

Is this due to the manufacturing process?

Lol, I'm sorry, I didn't clearly see and understand your question until just now! I feel bad! What you have circled and what looks like a crack in that picture is where the rod cap connects. So yes, it is indeed part of the manufacturing process. The ARC rods are machined, according to them, in a process like a single piece. Each one is serialized and can't be used with a different rod cap. It is a precision fit work of art to be honest and I don't say that about just anything. The seams are stepped so they are in perfect alignment during assymbly assuming the assymbler doesn't botch it.

---------- Post added at 09:40 PM ---------- Previous post was at 09:39 PM ----------

I'll post a pic of a new one tomorrow

 

[Brianator]

You must have done a good job because I can't even tell where you touched it! I'm sure Flyinhillybilly is the guy to answer this but is there any reason that the block can't be clearanced instead of the rod? On a plated bore I wouldn't attempt it but of it's a cast iron bore it would be feasible no? Block clearencing is common on automotive engines....

 

[BigWes]

You must have done a good job because I can't even tell where you touched it! I'm sure Flyinhillybilly is the guy to answer this but is there any reason that the block can't be clearanced instead of the rod? On a plated bore I wouldn't attempt it but of it's a cast iron bore it would be feasible no? Block clearencing is common on automotive engines....

I didn't touch the rod. I opened up the block on both sides. I went in with a die grinder and a small stone and knocked off about .030 or so then came back with a 200 grit buffing wheel and tried to contour off the bottom and blend in my work as to remove any sharp edges the best I could. It's more noticeable on the bottom side because I had to cut away a little more of the sleeve and iron is much harder to blend out than aluminum. Plus the back wall of the casting presents a more square profile which is more difficult to make look nice with limited work space.

 

[BigWes]

Here is the bottom of the cylinder where I clearanced for reference.

 

[BigWes]

Here are the internals ready to go. I use oil as an assembly fluid. The same oil I run. If it was a really tight new engine I might use something different but I don't see a need with this old thing. I just wetted it all down good.



Pic of engine with clone sidecover installed, much nicer BTW.




And the other side. Still need to take care of some plumbing. At some point the stock tank is going away as well.

 

[landuse]

Nice and shiny!

 

[BigWes]

Holy crap this thing is fast. Uh, bottom end pull is extremely unexpected. I can't say what the top end is yet because we didn't get home from the beach until late and I didn't start working on it again until 10pm. I finally took it for a run about 1230am. The Mikuni seems a bit finicky. I had to adjust the needle all the way rich to get it pull a load. Anyway, I cranked it up. Climbed on. Gave it a little gas to go around the back yard and to turn around and it did a complete 180 right out from under me. It spooled up that fast. Caught me completely by surprise. So I thought well I'll just run up to the end of the road and back and park it before someone calls the cops. I pulled out of my driveway from the cement and when I hit the asphalt I stomped it. I think I ran out of torque converter in maybe 20-30 feet. I felt the belt slip ever so slightly when the driver locked up. If the Ken-Bar would had a live axle instead of that differential and big tires it might have been able to lift the front tires. I don't know. I do know I backed off the throttle to maybe 1/2 to 3/4. As dark as it was it was too fast. I got up to the end of the street where it meets the blvd so I decided to make a u-turn. I thought what the heck it's 1230 in the morn and no one is around so I floored it on the black asphalt as I did my u-turn. It pivoted on the front tires while the back ones were spinning. I had to let off or it just would have done a complete 360.

Man, I can't imagine the kind of fun you guys with those light weight racing frames and the sure enough really hotrodded engines are having. I guess maybe your racing tires probably stick a lot better than my golf kart tires though. I know the big golf kart tires slide around a lot. I should have never messed with that engine. I keep finding myself searching for a deal on a used racing frame.

It's gotten late on me again and I got consumed by my projects. I will try and get a few more pics uploaded soon.