Squish measurement and setting

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JanBros
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Re: Squish measurement and setting

#31 Post by JanBros » Mon May 21, 2018 4:47 am

Gus the crank guy wrote:I just read that you said why would squish clearance need to be raised the wider the band? Are you serious? Maybe that's why I don't use that math you provided, I have a Dyno and I have 50 sets of domes I know why the seize for no apparent reason and I know what works and what doesn't
everything is working together. just swapping a dome and have a bad effect doesn't mean that dome is wrong, it means you haven't matched other things to get the best out of if.

math is a lot easier and faster than checking stuff in real life. and it costs a whole lot less. but I'm gonna leave you in your ancient wisdom.
if it runs, you can race it !

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Re: Squish measurement and setting

#32 Post by Gus the crank guy » Mon May 21, 2018 9:31 am

This is a true story, back in 1976 a guy came into the shop (Yamaha) in the Detroit area and he was redoing a 125 and it was gonna be the fastest lightest bike period, he was a little different, he worked at the GM tech center in Warren, he finally comes in because he got it done and it won't run! He cannot figure it out everything is done by the book, we tell him bring in the motor, this genius in lightening everything I mean everything drill 300 1/4" holes in the Piston front, back and the top! We're like are you kidding? He was like what? You have no compression! He asked us why? The guy was so book smart he was stupid... now I'm not saying your stupid but when you said a wider band won't raise heat I'm done reading

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T.RexRacing
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Re: Squish measurement and setting

#33 Post by T.RexRacing » Mon May 21, 2018 10:59 am

Gus the crank guy wrote:I just read that you said why would squish clearance need to be raised the wider the band? Are you serious? Maybe that's why I don't use that math you provided, I have a Dyno and I have 50 sets of domes I know why the seize for no apparent reason and I know what works and what doesn't
Well then new guy let's see some of your work. You show up and begin arguing like a woman with a respected established forum member. Put up or shut up.
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
Salvador Dali

Gus the crank guy
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Re: Squish measurement and setting

#34 Post by Gus the crank guy » Mon May 21, 2018 11:27 am

I'm not arguing with him I'm saying most people just want to know what and why it's a 5 minute explanation is all, I don't remember how to post pics but I'm signed up to race my lil bike at Gingerman and Elkhart Lake in open 2 stroke so I'll see how bad it is against TZ 250's and the like. ?

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Re: Squish measurement and setting

#35 Post by Gus the crank guy » Mon May 21, 2018 12:23 pm

https://guschristensen.smugmug.com/Rz395" onclick="window.open(this.href);return false;

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Re: Squish measurement and setting

#36 Post by Gus the crank guy » Mon May 21, 2018 12:28 pm

I spent 2 months building it it has a 4 mil cub cylinder shaved down to fit a stock stroke crank, runs on pump gas 93 octane, weighs 277 with no fuel in it and has 85 rwhp, I am building a 7 mil next week, I will have it on the Dyno and may use that at Road America.

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Re: Squish measurement and setting

#37 Post by Gus the crank guy » Mon May 21, 2018 2:19 pm

I've been on this forum since 2007 I believe, always on the 500 side, now that I'm racing Lil bikes I joined this side

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T.RexRacing
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Re: Squish measurement and setting

#38 Post by T.RexRacing » Mon May 21, 2018 3:46 pm

Nice ride. Good luck. Who built the frame?

We all have different approaches that work for us. Some are just wrong but they're few and far between. Unless a member is telling someone something that's going to do damage why waste bandwidth arguing? Especially when you simply don't understand their way. Why not simply ask for an explanation?

You opened a Smugmug account just for a photo? :smt003
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
Salvador Dali

Gus the crank guy
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Re: Squish measurement and setting

#39 Post by Gus the crank guy » Mon May 21, 2018 5:56 pm

I built the frame myself, I know exactly what he's saying, if someone asks about it he or she is maybe just getting to understand it, to throw that formula at someone was ridiculous, and not even tell him the angle I thought was kinda being like ha ha figure that out, but maybe I'm wrong. I'll say this jet it rich as hell you run that squish to tight you'll seize that thing bigger than shit. Out

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Re: Squish measurement and setting

#40 Post by T.RexRacing » Tue May 22, 2018 11:24 am

So you'll continue to be an arrogant shit. Bye.
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
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Questo vecchio rz
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Re: Squish measurement and setting

#41 Post by Questo vecchio rz » Tue May 22, 2018 12:39 pm

Hey Gus, You pretty much are " the guy" for 500 cranks aren't you. Quite the undertaking $$ to help everyone keep the old 500s going.
If you are willing , post up a (new separate)thread on your track bike. I like what you've done to accommodate the R-6 running gear. Looks like a fun project
Thanks
Banshee (Baja) race bike,+ 2 A Arms,L.E.Ds, Toomey, +4 stroker IMS tank, run flats.
96 GSXR SRAD, Future Yoshimura rep.
85 custom Tri-Z
RZ/YZR bike(project)
86 VFR750 RC24 Merkel replica (project)
Royal Enfield Bullet 500

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Smoker
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Re: Squish measurement and setting

#42 Post by Smoker » Tue May 22, 2018 1:16 pm

I always enjoy reading these threads.

I've been riding RZs most of my life, but have limited experience and knowledge about building a proper high performance two stroke engine. I don't have time to sit down and read books about it, but with threads like this, I'm getting good info a little at a time. (Even though I don't always understand!)

Jan is very knowledgable and his input on this site has been a great help to me.

Hard to believe some of you guys don't know who Gus is. He's definitely an OG on the 500 side of the site. Seems strange that some guys on here don't read the 500 side. I'd also like to see details of your 350 build.

Does this mean you guys don't know about my RZV500 project??? :smt003

Sorry I can't contribute to the squish conversation. Just want you to know, your words aren't wasted.

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Re: Squish measurement and setting

#43 Post by Gus the crank guy » Tue May 22, 2018 2:27 pm

I'm trying to upload pics I took this morning of Dyno runs of our 68 mm bore cylinder's, they can be seen on my pic in the previous post RZ395, in essence the first run was run at .048 squish at 9.5 mm wide band it netted 89.8 rwhp, the next dome was .050 at 9.5mm wide same compression and netted 93.4 rwhp the next was .053 clearance at 9.5mm wide and netted 95.5 rwhp I'm looking for the .040 clearance run but it was down 3 rwhp from the .045. This is how I try things before posting hope you get something out of it!

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Re: Squish measurement and setting

#44 Post by Gus the crank guy » Tue May 22, 2018 2:35 pm

I did mean to ask how are you running a stock head on Athena cylinder's?

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Questo vecchio rz
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Re: Squish measurement and setting

#45 Post by Questo vecchio rz » Tue May 22, 2018 5:07 pm

That's what's so cool about these lil motors. The performance potential is astoundingly good. Love the RZ500, but when you compare a built RZ 500 tuned as far as possible @ 110-120 h.p.and a weight around 470 lbs! then you compare it with a built 350 and a weight with around 300 lbs, its simply no contest. Apples to Orange's though besides the extreme performance. The 500 is iconic & a super cool bike and valued as such ...but the 350 is the Hot Rod built by racers for a fraction of the cost and far quicker.
I'm eager to follow learn about your track bike Gus, I had no idea you had that project hidden in a garage. Also dyin to know how your bike will fare vs a TZ 250.
TZs are laying down a honest 70-90 h.p and 260 lbs. Thinking you'll have a boatload more tourqe. Although I suspect bone stock TZ will still have a substantial top end advantage vs a stock 350 ratio trans?
Keep us posted. Thanks
Banshee (Baja) race bike,+ 2 A Arms,L.E.Ds, Toomey, +4 stroker IMS tank, run flats.
96 GSXR SRAD, Future Yoshimura rep.
85 custom Tri-Z
RZ/YZR bike(project)
86 VFR750 RC24 Merkel replica (project)
Royal Enfield Bullet 500

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