Tri Z Engine Build

[onformula1]

All info is good info even if its bad info its good info.

I used to read Gordon Jennings book in American Lit. in high school. (I never got caught)..LOL

[El Camexican]

No if you did you would need a Holley carb.

That's along the lines of what I was thinking.

Also wondering about the piston windows and the third window some are adding above the stockers. Any idea what the theory is behind these? Seems a lot of engines don't use any windows. Also, if using windows is there a ratio or formula to their area or location?

[MTS]

As far as i know the ports in the piston are more for keeping the piston crown cooler, i would not add anymore to one on a tri z piston like that wiseco for the fact that they need as much piston/ wall support as you can get to keep them quiet and long lasting. i will have some info on the HR head as soon as i can form my thoughts into a comprehedable post lol.

[fabiodriven]

Was thinking of Tecati Dan while messing with this

So funny you say that. I was thinking the same thing when I saw your pics and I hadn't even read the post yet. I can't remember if it was the 500 or his 250 he was doing that with. Either way, that 500 engine he assembled mostly by himself ran super smooth top to bottom, it was like a 4 stroke. A lot of that is due to displacement though, but I feel as though that's the kind of power you're looking for Mexinadian.

[El Camexican]

So funny you say that. I was thinking the same thing when I saw your pics and I hadn't even read the post yet. I can't remember if it was the 500 or his 250 he was doing that with. Either way, that 500 engine he assembled mostly by himself ran super smooth top to bottom, it was like a 4 stroke. A lot of that is due to displacement though, but I feel as though that's the kind of power you're looking for Mexinadian.

It was the 500 build. First time I'd ever seen anyone do something like that. When it comes to 2 strokes I've always been a "clean the ports up the way the designer intended, cut the head .030", put a set of Boyesen reeds in it, jet it and ride" guy.

As far as the power I seek at this point it's a mid to top rush that will try to "tear my tits off". Small bore drag engine. I don't care if it won't idle under 4,000 as long as it hauls the mail from 6,000 to 8,000

3 Wheel Drive: I will be reading them for sure, thanks.

[ATC-Eric]

Great info in this thread. My .02 cents on the flywheel. The vibration was off the chart when I ran a lightened flywheel by Ronnie. Had to put a stocker back in it. My lower body would be completely number after an hours ride.

[El Camexican]

Great info in this thread. My .02 cents on the flywheel. The vibration was off the chart when I ran a lightened flywheel by Ronnie. Had to put a stocker back in it. My lower body would be completely number after an hours ride.

Not sure how yours was lightened, or by how much, do you recall? I have yet to weigh mine against the stocker, should be about 5oz lighter, but in theory my balance should not have changed due to the way it was cut. I believe that the YZ version of the Tri-Z engine used an internal rotor which would have been a lot lighter still. Not sure how they were for vibration.

[aramid]

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As far as the power I seek at this point it's a mid to top rush that will try to "tear my tits off". Small bore drag engine. I don't care if it won't idle under 4,000 as long as it hauls the mail from 6,000 to 8,000

ok, if top end is what you want, this guy might be able to help if you need a pipe . . he made a few pipes for the tri z a while back and if he still has the jig, he might make more . . he is familiar with the dg pipe so he can tell you the difference between that and his . . he might have some tuning tips too or even the mysterious stage III report you wanted to find . . as you know, even though the stock pipe can be modified to boost power a bit, it will always be limited in top end power simply because t was not designed for that.

http://www.dynoport.com/

[MTS]

so, here is a HR head, what i have found is a steep sqush band agle 19° roughly by 12mm wide.now after reading a bit i have found out alot, pretty much that sprock dome with a lesser 14° or so angle and wide squish would be more suited to low rpm\midrange power, the tight squish wide band and high cmpression all fit togther to keep detonation down and increase the heat transfer aspect. the stock head is also very close to 14° but with a much thiner width of the squish around 7mm, so the trade off being a more top end power biased to the stock head with more risk to detonation under a heavy load. the reason being is more surface of the piston crown is exposed to the flame front just before and just after TDC. now the trick thing ronnie did was esentially try and get the best of both designs i think, by running the wide band and steep angle he was able to expose more of the piston crown to make more power and was able to keep detonation to a minimum via the speed the flame could carry across the piston to the edge of the band..thus burning the fuel before it could be super hot and start detonating , this is of course just my opinion...i could be off my rocker...

[onformula1]

Also wondering about the piston windows and the third window some are adding above the stockers. Any idea what the theory is behind these? Seems a lot of engines don't use any windows. Also, if using windows is there a ratio or formula to their area or location?[/QUOTE]


Sorry, but I feel this will be a controversial topic, I can provide a Ton of info that has been tested, used & raced with excellent results- to it didn't work better than stock, never worse than stock. (Only time wasted with No improvement, but no loses)

Last time You tried to help, and I loved the energy & info you provided & I tried to add with some info that worked & was tested over a number of years...We have a Blown Out Tread that is now buried.

http://www.3wheelerworld.com/showthr...of-Tuning-Tips

PM me if you want.

[cr480r]

The trouble with heads is it's very difficult to isolate changes for comparison basis because every parameter will have an effect on another. Squish width, angle, clearance, dome volume, etc .... You cannot change any of those without changing another. I subscribe to tight piston to head clearances on all engines. It makes sense to me that fewer end gases contributes to additional power, so I leave that constant and adjust the band width and angle to get target msv. While keeping mind of total volume. It's often said that wide squish is for low-mid, and narrow for top end . I generally agree, but it's hard to isolate those variables and keep the volume the same, assuming you wanted it the same for both applications. I picture a large shallow open dome scavenging more effectively at rpm than a deep tight one, but the results are normally attributed to the reduced end gases of the narrower squish, but that variable can be adjusted with clearance and angle... Can of worms. Keep mind of msv, and CR for the application and fuel type and it will run good.

[El Camexican]

First of all I love theory. Good, bad, right, or wrong, it all equates to the provocation of thought which inevitably equates to learning. That said I again thank EVERYONE who is posting on here.

Now for the reality of this build. I am missing a few things that I do not foresee acquiring in the near future. A dyno, and unlimited time and funds being the three main obstacles standing in the way of achieving the perfect combination.

At this time I continue to gather numerical information that will be needed to answer questions as they come up. CR ratio, max RPM and baseline port information can all change with the addition of a thicker base gasket, or a new piston, so I want to have everything well enough documented in a drawing file that a change can be assessed without pulling out the calipers again.

If I had to predict what will happen in the end it would be that the exhaust port will be raised slightly (and narrowed 1mm if I start a new cylinder) the transfers will be widened and angled with top end in mind and a blank combustion chamber will be cut to suit the piston and other dimensions. After that a pipe will likely be modified, or built to suit.

Sorry if this doesn't sound as romantic as building a 100hp 250, with 60ft pounds of torque and a 6,000rpm power-band but I would refer anyone who is disappointed back to the three missing components of this build.

I get that some prefer to converse about this out of the public eye. I will take that offer up and another others that may prefer not to be questioned in public.

Thanks again to all!

[ATC-Eric]

Not sure how yours was lightened, or by how much, do you recall? I have yet to weigh mine against the stocker, should be about 5oz lighter, but in theory my balance should not have changed due to the way it was cut. I believe that the YZ version of the Tri-Z engine used an internal rotor which would have been a lot lighter still. Not sure how they were for vibration.

I don't recall how much was trimmed. I sold it off a few years back so I can't weigh it. The way it was shaved, should not have messed with the balance. I just think because it was lighter it magnified the vibrations the engine already produces. Here's a picture of it.

[El Camexican]

I don't recall how much was trimmed. I sold it off a few years back so I can't weigh it. The way it was shaved, should not have messed with the balance. I just think because it was lighter it magnified the vibrations the engine already produces. Here's a picture of it.

looks like they are cut the same on the circumference, but mine also has a cut across the outer face as well. I guess the vibration could just be inherent to the engine, but I've confirmed that the YZ had a smaller diameter left cheek as well as a small rotor. If the Tri-Z shakes bad then the YZ engine may have loosened a few fillings!

[3 Wheel Drive]

How's the rebuild coming along, any updates, pics?