96_banshee_96 Posted February 23, 2007 Report Posted February 23, 2007 Couple questions for you guys. How do I tell how many cc domes are in my cool head. I looked all over them and I dont see any numbers that would tell what they are. Also what is the difference between a hot rods truned and welded crank and a regular stock crank.What does the truned and weld mean? Quote
locogato11283 Posted February 23, 2007 Report Posted February 23, 2007 they should be etched into the side somewhere. ive never recieved a done that didnt have a number on it... who did you get the head from or did you buy the bike and wanna check now? Quote
sredish Posted February 23, 2007 Report Posted February 23, 2007 you could take a dome, put a spark plug in it and then use a 30cc syringe, fill it to 30 on the money, then squeeze it into the dome. when it's full, count how much is still in the syringe and deduct it from 30. that's how big your domes are. Quote
96_banshee_96 Posted February 23, 2007 Author Report Posted February 23, 2007 you could take a dome, put a spark plug in it and then use a 30cc syringe, fill it to 30 on the money, then squeeze it into the dome. when it's full, count how much is still in the syringe and deduct it from 30. that's how big your domes are. I bought the motor with the domes on it and I just wanted to know for sure what size they were. Guess I will look harder or do the syringe thing. Quote
FireHead Posted February 23, 2007 Report Posted February 23, 2007 (edited) If they are PD domes they will be ingraved with their size on the coolant side of the domes. I think the Noss domes are the same as well. However, it seems like everyone "custom" makes domes these days and I am sure there are folks out there that don't go to the trouble of engraving the back side of the dome. The syringe idea will work if the domes are fairly normal, but it will not work if they are cut for a long rod or stroke crankshaft. The way we check competitors heads at work is by making a silicone or foam cast of the chamber with the spark plug(s), valves, and what ever else installed on the block with the piston at TDC, then you pull the cast off, put it in a graduated cylinder full of water and see how much water it displaces. That was the longest run-on sentence ever...............I'm out. :thumbsup: Edited February 23, 2007 by FireHead Quote
Bansh-eman Posted February 23, 2007 Report Posted February 23, 2007 long stroke or not you should still be able to messure the volume like sredish said... volume is volume either way it takes the same amount of displacment Quote
96_banshee_96 Posted February 23, 2007 Author Report Posted February 23, 2007 Damn that is a lot of work just to find out the cc's. Think ill try the syringe method first. Any input on the truned and welded crank. Quote
Bansh-eman Posted February 23, 2007 Report Posted February 23, 2007 what about it? how to tell if its done or you just asking is it worth doing? Quote
96_banshee_96 Posted February 23, 2007 Author Report Posted February 23, 2007 what about it? how to tell if its done or you just asking is it worth doing? Just wanted to know what the difference was between a truned and welded crank vs. stock crank. I wanted to know what truned and welded meant. The motor that I bought is supose to have a truned and welded hot rods crank in it. By the way I looked and found 21 on the edge of both domes so im asuming that they are 21cc domes. Thanks for the help guys. Quote
Bansh-eman Posted February 23, 2007 Report Posted February 23, 2007 (edited) trued means that the weight of the crank is equal all the way around same concept as when you balance your tires... there for eliminating viberation and taking stress of moving parts that can be damaged by it not being true... welded is nothing more then a small tack on the web of the crank... the big weight looking thing... there is a pin that can only come out on the outside of the webing... to insure that it dosent seperate you drop a small weld on there to secure it in place.. theres a little more to the trueing then i said but you get the jist of it... Edited February 23, 2007 by Bansh-eman Quote
FireHead Posted February 23, 2007 Report Posted February 23, 2007 long stroke or not you should still be able to messure the volume like sredish said... volume is volume either way it takes the same amount of displacment If you have domes that are cut to have the piston travel into them, than the syringe method as described above would generally measure the dome to be alot larger than it actually is. :thumbsup: Quote
Bansh-eman Posted February 23, 2007 Report Posted February 23, 2007 (edited) If you have domes that are cut to have the piston travel into them, than the syringe method as described above would generally measure the dome to be alot larger than it actually is. :thumbsup: hummm i guess it makes scence.... kinda hard to to fill it to the edge when its been cut into the dome i guess? im sure theres some ez way to messure it ... but when you can buy new domes for 50 bucks fuk guess work juts get new ones and be done with it... and the dispalcement thing isnt 100% casue you cant tell exactly where to stop filling... you need the dome to be level ... just too many thing to effect the proper messurement that way... i know when messureing displacement of our old gokart 2 strokes my dad had a setup for something similar to that... used this long glass tube that held atf or something im not even sure casue i was young enough to not care ... build the motor added the fluid and brought motor to TBC and messured something??? never asked what he was doing just saw him doing it... what ever it was... it worked Edited February 23, 2007 by Bansh-eman Quote
FireHead Posted February 23, 2007 Report Posted February 23, 2007 hummm i guess it makes scence.... kinda hard to to fill it to the edge when its been cut into the dome i guess? im sure theres some ez way to messure it ... but when you can buy new domes for 50 bucks fuk guess work juts get new ones and be done with it...and the dispalcement thing isnt 100% casue you cant tell exactly where to stop filling... you need the dome to be level ... just too many thing to effect the proper messurement that way... i know when messureing displacement of our old gokart 2 strokes my dad had a setup for something similar to that... used this long glass tube that held atf or something im not even sure casue i was young enough to not care ... build the motor added the fluid and brought motor to TBC and messured something??? never asked what he was doing just saw him doing it... what ever it was... it worked I agree about the price of the domes and that measuring what he has probably isn't worth the time involved. You might even be able to find them under $50. As for the method of measurement, I still feel the syringe is a bit dubious. The method I described and the following method are the only ways that I know of that work well enough to talk about. The method you may not have access to involves measuring the dome with a CMM machine, extrapolating the curves that make up the part in a CAD environment, then you have to make a shell of the chamber while still in the CAD program, thus the CAD program can calculate the volume of the chamber. In reference to your go kart method, that will probably work as well. I think what your dad was doing, was assembling the engine, bringing it up to TDC, filling the chamber with fluid until full, then measuring how much fluid he put in. That method is probably good enough for government work, but it has the potetntial to be messy, though that may only be me assuming that other folks are as clumsy as I am. :thumbsup: Quote
Bansh-eman Posted February 23, 2007 Report Posted February 23, 2007 only thing is the way my pops did it wouldnt be right for cc's casue you lose some for plug...so im not sure if thats what its for or if he was doing something else... i guess i could call and ask him but to me im not hat worried about it Quote
FireHead Posted February 23, 2007 Report Posted February 23, 2007 only thing is the way my pops did it wouldnt be right for cc's casue you lose some for plug...so im not sure if thats what its for or if he was doing something else... i guess i could call and ask him but to me im not hat worried about it I am bored out of my gourd sitting here at the track...........................so I'll pretty much make a conversation out of anything at this point. :: Quote
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