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jmax857
12-16-2010, 07:51 AM
okay so heres the scoop.
im getting to the point in my build where i am going to start building my engine soon, i plan on using the 6 speed 86 tranny and carb. but i have a few questions before i embark on my journey. i have a furry of questions i couldnt find answers for so forgive me but,
theres a few things i would like to know, so i have a good game plan on how to go about it.
1. are all tri z bottom end cases the same?
2. what do you guys use that i see as your clear coolant hose?
3. is it okay to do the 2mm exhaust port modification, and the added boost port as outlined in the yamaha wrench report, without milling the head?
4. i wont be using the stock fuel tank assembly so the vaccuum lines are no longer neccessary for the fuel pump, what shall i do with these outlets? plug them? or put a breather on them?
5. whats the best paint in your opinion to paint my cases?
6. has anyone done case porting on their tri z?

thats all i can think of for now, but trust me there will be more as i go along.
thanks in advance.

Bryan Raffa
12-16-2010, 08:50 AM
1. 85/86 were the same,, 86 had the lower chain saver hole threded
2. some of these guys were using reinforced clear coolant line to install there in line coolers..probley so the do hack up the oem ones? theres only one spot you can use it.. the rest of the hoses NEED the bends in them,,
3.when you Raise the exhaust port , you lower your compression,, milling the head Just brings it back up.
4.remove the pump, hoses, plug the cylinder fitting off,, use only the small petcock for your on/off,, I use a motion pro fuel shutoff.
5.PJ1 epoxy paint!!!!!!!!! read the Directions! must be above 70*
6.for what you will gain by doing this,, I would find other ways to gain HP.

jmax857
12-16-2010, 01:36 PM
1. 85/86 were the same,, 86 had the lower chain saver hole threded
2. some of these guys were using reinforced clear coolant line to install there in line coolers..probley so the do hack up the oem ones? theres only one spot you can use it.. the rest of the hoses NEED the bends in them,,
3.when you Raise the exhaust port , you lower your compression,, milling the head Just brings it back up.
4.remove the pump, hoses, plug the cylinder fitting off,, use only the small petcock for your on/off,, I use a motion pro fuel shutoff.
5.PJ1 epoxy paint!!!!!!!!! read the Directions! must be above 70*
6.for what you will gain by doing this,, I would find other ways to gain HP.

thankyou very much, and how does raising the exhaust port lower the compression?

Bryan Raffa
12-16-2010, 08:42 PM
When raising the exhaust port the static compression of the motor is lowered. Since there is less volume to compress - it will be somewhat lower. This can be determined by doing a compression test on the motor before and after the exhaust port height has been cut. You can also calculate this figure using some simple math - though real world results vary because of the variables involved.



To get back the compression which was lost during porting it is necessary to reduce the volume of the head. Without doing this step you can not fully realize the effects of the new port timing. Consider it a necessary step. It is most important to get the squish band clearance right. Do it first. Depending of the motor it is usually between .030" and .040". When that is right, work on the dome to make the volume correct.

you should Read..http://www.macdizzy.com/porting103.htm

jmax857
12-17-2010, 07:50 AM
wow thankyou, i thought i had already been through the macdizzy site but never ran across this before.