Planet Minis

taz69 · 01-13-2009, 06:00 PM

Hey guys im building a Takegawa superhead 124 the older head not the +r but anyways.. I saw on DR-atv they have a 69mm cylinder cheap but I think the cylinder from Kitaco or takegawa is shorter than 69mm... My buds 115 takegawa cylinder is around 62.7 tall and thats with a 50mm crank.. Im using a 54mm crank wouldnt the cylinder be around 67mm tall or so Im only strokeing it 4 more mm than the 50mm crank? IF anyone could check with some calipers or chime in here that has a takegawa or kitaco cylinder I would soooo appreciate it.

AHPminis · 01-13-2009, 06:07 PM

Quote:

Originally Posted by taz69

Hey guys im building a Takegawa superhead 124 the older head not the +r but anyways.. I saw on DR-atv they have a 69mm cylinder cheap but I think the cylinder from Kitaco or takegawa is shorter than 69mm... My buds 115 takegawa cylinder is around 62.7 tall and thats with a 50mm crank.. Im using a 54mm crank wouldnt the cylinder be around 67mm tall or so Im only strokeing it 4 more mm than the 50mm crank? IF anyone could check with some calipers or chime in here that has a takegawa or kitaco cylinder I would soooo appreciate it.

The CRF 124's with the 54mm cranks use the 69mm height cylinders, thats why they come with the longer studs in the stroker kits too. FYI a stock height CRF is 63mm so thats why your friends measured that.

taz69 · 01-13-2009, 06:55 PM

01 02 4433 piston super head 54mm 115124cc Ok here is the second part... stroke crank shaftassy 12v monkey gorilla 124cc takegawa Ok here is the deal when this piston was on a 50mm crank the decking was almost flush with the top of the cylinder I mean real close.. Without the 10mm thin metal gasket it would hit the head so it was close... I got the DR-ATV cylinder longer studds and all.. But now the piston is a little ways down instide this cylinder.. The decking is like 2mm away from the top of the cylinder.. So I figured no way the compression would be really low with it like that.. No I didnt put it together and test it or nothing and maybe if the longer stroke increases compression ok then i could see where it works.. But you use the SAME piston for the 2 different cranks. So you stroke it 4mm and if you use a 6mm taller cylinder than before didnt I just add 2 extra mm.. I know that piston with the same head can come up all the way to the top of the cylinder and not hit the head. With the extra travel of the 54mm crank does it increase compression, and you have to run it lower in the cylinder to keep the compression from being to high?? Kinda lost here lol..

taz69 · 01-14-2009, 06:24 AM

Bump!!!

Kurlon · 01-14-2009, 06:36 AM

You increased the stroke 4mm, but you didn't take into account that he rod length may have changed also. You need a longer rod as you increase the stroke to keep the rod angles in check. As the rod to stroke angle gets lower, the rod has to be at more and more extreme angles when the crank is around half way through a rotation, that in turn tries to drive the piston into the side of the cylinder, resulting in faster wear and more drag.

So, as long as both cranks are setup for the same pin height piston, in this case usually they expect 'short rod' pistons with 19.5mm pin heights, a 50mm crank will have the rod setup so the piston is near the deck with a 63mm tall cylinder, while a 54mm crank will have a longer rod to put the piston at the deck on a 69mm tall cylinder and help keep the rod ratio in check. That's why the import motors went to 78mm tall cylinders when they were only going to 55mm and 57.5mm strokes, they gained rod length to get some longevity. Lifan bumped to an 80-something mm tall cylinder for their first 59mm stroke motors for the same reason.

taz69 · 01-14-2009, 07:15 AM

Ok kurlon so what you are saying is the link to the crank I got has a long rod on it.. Cause for whatever reason this piston is sitting down in the cylinder and I ordered the crank from classic honda... Now im real confused lol.. The 2 parts listed above should work together but that piston on that crank its not comeing close to the top of the cylinder about exactly 2mm down in.. Is it possible the crank I got has a short rod on it??? The above crank is the part# on the Takegawa box I got lol .. How long is a long rod suppose to be???

50WHIP · 01-14-2009, 07:31 AM

That is how some of the takegawa setups work out unfortunately.I used a +r piston and had it machined to fit the old style head and got the deck height correct to 0 in the cylinder.Your crank has the right rod on it that is how they make them.

taz69 · 01-14-2009, 07:52 AM

Hey 50whip ok if thats the correct rod then you think the piston is the problem.. Or should I just deck the cylinder down 2mm.. So if what you guys are saying is true when you go from a 50mm crank to a 54mm crank EITHER the rod has to get longer 2mm or you use a different piston to maintain the same deck height. I think the rod length is the same on the 50mm takegawa crank I have and the new 54mm I just got.. SHOULD the rods be different on the 2 cranks???

50WHIP · 01-14-2009, 08:25 AM

I know for sure they use the same piston for both cranks 50 and 54 and I'm almost 99% positive that the piston sets in the hole like you said it does on the 54 mm crank.We used the +r piston which has a taller deck height and machined it down to to work.

taz69 · 01-14-2009, 08:36 AM

So there is NO difference in rod lengths between the 2 cranks?

50WHIP · 01-14-2009, 09:08 AM

I don't have a 50mm out right now only a 54 at my brothers to measure.But I know we cut the +r piston the same for the 50mm in mine and the 54 in my friends.

firepower354 · 01-14-2009, 09:46 AM

50mm Tak has an 88mm rod, and leaves most pistons 2mm in the hole. At least the 5-6 I've had my hands on. 54mm cranks have had 94mm rod, same as a stock Honda. We've had to cut the base of the jug on all of them.

50mm stroke/25mm throw is 4.25 or so more than stock. A 6mm shorter rod leaves it -1.75ish. When I rebuild them, I've used a 6v Honda or XR80 91mm rod, that leaves the piston at +1.25 or so.

54mm stroke/27mm throw is 6.25 more than stock. Add a stock length rod, and you're needing a 69mm jug and should be at deck or above.

taz69 · 01-14-2009, 10:26 AM

Firepower354 so if I get this what you are saying is maybe the rod length has changed on the NEW 54mm cranks to maybe 92mm.. I do know that the +R piston is taller than the old superhead piston.. And if you use the same crank and rod for both, 1 combination is going to be off.. I will check the rod length maybe its changed to accomadate the +R piston... IF so I need to press a 94mm rod on this new crank and be done with it???? XR70 rod would work then wouldnt it?

50WHIP · 01-14-2009, 10:40 AM

I was waiting for fire to get in on this he knows all the ins and outs on these combos.I have a brand new honda rod in the package if you need one.

taz69 · 01-14-2009, 11:25 AM

OK so I went home for lunch and the piston I have is 17mm from the center of the wrist pin to the top of the deck.. 11.5 from top of the wrist pin to the deck and its a 13mm wrist pin so half of that 6.5mm is 17mm.. Does that seem awfully short or not.. The crank is in the bike so measuring the rod on the 54mm crank I will half to tear it appart. Does anyone have Takegawas piston specs?? Or a link that might list there different piston specs.. THANKS agin but for what ever reason that piston is sittin 2mm low in the cylinder.. Thing is the same piston on a 50mm crank comes almost flush to the deck just on this new crank it is in the whole and I meassured the cylinder its 69mm exactly.. Makes me think the rod is shorter than 94mm then huh???

firepower354 · 01-14-2009, 11:30 AM

Odd. Complete opposite from what I've seen before. Get the piston the head calls for, and make the height work, via spacers or jug cutting, I say.

taz69 · 01-14-2009, 12:01 PM

This is the piston right here..01 02 4433 piston super head 54mm 115124cc Im thinking more and more something is funky.. I got a +r piston comeing and ill bet its around 18.5 or 19.5 from center of the wrist pin to the deck.. If so they had to change the rod then....

dax · 01-14-2009, 01:02 PM

http://www.x386.net/TTR/tech/crank.html

There is some info about cranks and pistons.

taz69 · 01-14-2009, 01:17 PM

That is good info let me ask how do they come up with the crown measurement?? And no decking measurement DANGIT lol.

Kurlon · 01-14-2009, 01:51 PM

Heh, thats my info. : ) Bad choice of terminology on my part, crown height is referring to the outside edge of the piston, not the dome.

01-13-2009, 06:00 PM	#1 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Takegawa 124 cylinder height ???? Hey guys im building a Takegawa superhead 124 the older head not the +r but anyways.. I saw on DR-atv they have a 69mm cylinder cheap but I think the cylinder from Kitaco or takegawa is shorter than 69mm... My buds 115 takegawa cylinder is around 62.7 tall and thats with a 50mm crank.. Im using a 54mm crank wouldnt the cylinder be around 67mm tall or so Im only strokeing it 4 more mm than the 50mm crank? IF anyone could check with some calipers or chime in here that has a takegawa or kitaco cylinder I would soooo appreciate it.

01-13-2009, 06:55 PM	#3 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? 01 02 4433 piston super head 54mm 115124cc Ok here is the second part... stroke crank shaftassy 12v monkey gorilla 124cc takegawa Ok here is the deal when this piston was on a 50mm crank the decking was almost flush with the top of the cylinder I mean real close.. Without the 10mm thin metal gasket it would hit the head so it was close... I got the DR-ATV cylinder longer studds and all.. But now the piston is a little ways down instide this cylinder.. The decking is like 2mm away from the top of the cylinder.. So I figured no way the compression would be really low with it like that.. No I didnt put it together and test it or nothing and maybe if the longer stroke increases compression ok then i could see where it works.. But you use the SAME piston for the 2 different cranks. So you stroke it 4mm and if you use a 6mm taller cylinder than before didnt I just add 2 extra mm.. I know that piston with the same head can come up all the way to the top of the cylinder and not hit the head. With the extra travel of the 54mm crank does it increase compression, and you have to run it lower in the cylinder to keep the compression from being to high?? Kinda lost here lol.. Last edited by taz69; 01-13-2009 at 07:10 PM.

01-14-2009, 06:24 AM	#4 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? Bump!!!

01-14-2009, 06:36 AM	#5 (permalink)
Kurlon Super Moderator Join Date: Feb 2005 Location: Windham, ME Posts: 8,301	Re: Takegawa 124 cylinder height ???? You increased the stroke 4mm, but you didn't take into account that he rod length may have changed also. You need a longer rod as you increase the stroke to keep the rod angles in check. As the rod to stroke angle gets lower, the rod has to be at more and more extreme angles when the crank is around half way through a rotation, that in turn tries to drive the piston into the side of the cylinder, resulting in faster wear and more drag. So, as long as both cranks are setup for the same pin height piston, in this case usually they expect 'short rod' pistons with 19.5mm pin heights, a 50mm crank will have the rod setup so the piston is near the deck with a 63mm tall cylinder, while a 54mm crank will have a longer rod to put the piston at the deck on a 69mm tall cylinder and help keep the rod ratio in check. That's why the import motors went to 78mm tall cylinders when they were only going to 55mm and 57.5mm strokes, they gained rod length to get some longevity. Lifan bumped to an 80-something mm tall cylinder for their first 59mm stroke motors for the same reason.

01-14-2009, 07:15 AM	#6 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? Ok kurlon so what you are saying is the link to the crank I got has a long rod on it.. Cause for whatever reason this piston is sitting down in the cylinder and I ordered the crank from classic honda... Now im real confused lol.. The 2 parts listed above should work together but that piston on that crank its not comeing close to the top of the cylinder about exactly 2mm down in.. Is it possible the crank I got has a short rod on it??? The above crank is the part# on the Takegawa box I got lol .. How long is a long rod suppose to be??? Last edited by taz69; 01-14-2009 at 07:23 AM.

01-14-2009, 07:31 AM	#7 (permalink)
50WHIP 3rd Gear Member Join Date: Apr 2005 Location: INDIANA PA. Posts: 1,991	Re: Takegawa 124 cylinder height ???? That is how some of the takegawa setups work out unfortunately.I used a +r piston and had it machined to fit the old style head and got the deck height correct to 0 in the cylinder.Your crank has the right rod on it that is how they make them.

01-14-2009, 07:52 AM	#8 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? Hey 50whip ok if thats the correct rod then you think the piston is the problem.. Or should I just deck the cylinder down 2mm.. So if what you guys are saying is true when you go from a 50mm crank to a 54mm crank EITHER the rod has to get longer 2mm or you use a different piston to maintain the same deck height. I think the rod length is the same on the 50mm takegawa crank I have and the new 54mm I just got.. SHOULD the rods be different on the 2 cranks???

01-14-2009, 08:25 AM	#9 (permalink)
50WHIP 3rd Gear Member Join Date: Apr 2005 Location: INDIANA PA. Posts: 1,991	Re: Takegawa 124 cylinder height ???? I know for sure they use the same piston for both cranks 50 and 54 and I'm almost 99% positive that the piston sets in the hole like you said it does on the 54 mm crank.We used the +r piston which has a taller deck height and machined it down to to work.

01-14-2009, 08:36 AM	#10 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? So there is NO difference in rod lengths between the 2 cranks?

01-14-2009, 09:08 AM	#11 (permalink)
50WHIP 3rd Gear Member Join Date: Apr 2005 Location: INDIANA PA. Posts: 1,991	Re: Takegawa 124 cylinder height ???? I don't have a 50mm out right now only a 54 at my brothers to measure.But I know we cut the +r piston the same for the 50mm in mine and the 54 in my friends.

01-14-2009, 09:46 AM	#12 (permalink)
firepower354 Advertiser Join Date: Oct 2006 Location: Flint MI Posts: 10,976 My Mood:	Re: Takegawa 124 cylinder height ???? 50mm Tak has an 88mm rod, and leaves most pistons 2mm in the hole. At least the 5-6 I've had my hands on. 54mm cranks have had 94mm rod, same as a stock Honda. We've had to cut the base of the jug on all of them. 50mm stroke/25mm throw is 4.25 or so more than stock. A 6mm shorter rod leaves it -1.75ish. When I rebuild them, I've used a 6v Honda or XR80 91mm rod, that leaves the piston at +1.25 or so. 54mm stroke/27mm throw is 6.25 more than stock. Add a stock length rod, and you're needing a 69mm jug and should be at deck or above. __________________ If it has my name on it I did it;) FirepowerMinis.com Custom FPM parts and engines. Parts and service for all makes. Honda Trail Bikes parts and accessories. Pitster/Piranha/Thumpstar bikes, parts, engines and accessories.

01-14-2009, 10:26 AM	#13 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? Firepower354 so if I get this what you are saying is maybe the rod length has changed on the NEW 54mm cranks to maybe 92mm.. I do know that the +R piston is taller than the old superhead piston.. And if you use the same crank and rod for both, 1 combination is going to be off.. I will check the rod length maybe its changed to accomadate the +R piston... IF so I need to press a 94mm rod on this new crank and be done with it???? XR70 rod would work then wouldnt it?

01-14-2009, 10:40 AM	#14 (permalink)
50WHIP 3rd Gear Member Join Date: Apr 2005 Location: INDIANA PA. Posts: 1,991	Re: Takegawa 124 cylinder height ???? I was waiting for fire to get in on this he knows all the ins and outs on these combos.I have a brand new honda rod in the package if you need one.

01-14-2009, 11:25 AM	#15 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? OK so I went home for lunch and the piston I have is 17mm from the center of the wrist pin to the top of the deck.. 11.5 from top of the wrist pin to the deck and its a 13mm wrist pin so half of that 6.5mm is 17mm.. Does that seem awfully short or not.. The crank is in the bike so measuring the rod on the 54mm crank I will half to tear it appart. Does anyone have Takegawas piston specs?? Or a link that might list there different piston specs.. THANKS agin but for what ever reason that piston is sittin 2mm low in the cylinder.. Thing is the same piston on a 50mm crank comes almost flush to the deck just on this new crank it is in the whole and I meassured the cylinder its 69mm exactly.. Makes me think the rod is shorter than 94mm then huh???

01-14-2009, 11:30 AM	#16 (permalink)
firepower354 Advertiser Join Date: Oct 2006 Location: Flint MI Posts: 10,976 My Mood:	Re: Takegawa 124 cylinder height ???? Odd. Complete opposite from what I've seen before. Get the piston the head calls for, and make the height work, via spacers or jug cutting, I say. __________________ If it has my name on it I did it;) FirepowerMinis.com Custom FPM parts and engines. Parts and service for all makes. Honda Trail Bikes parts and accessories. Pitster/Piranha/Thumpstar bikes, parts, engines and accessories.

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01-14-2009, 12:01 PM	#17 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? This is the piston right here..01 02 4433 piston super head 54mm 115124cc Im thinking more and more something is funky.. I got a +r piston comeing and ill bet its around 18.5 or 19.5 from center of the wrist pin to the deck.. If so they had to change the rod then....

01-14-2009, 01:02 PM	#18 (permalink)
dax 1st Gear Member Join Date: Jun 2006 Posts: 156	Re: Takegawa 124 cylinder height ???? http://www.x386.net/TTR/tech/crank.html There is some info about cranks and pistons.

01-14-2009, 01:17 PM	#19 (permalink)
taz69 2nd Gear Member Join Date: Nov 2005 Posts: 476	Re: Takegawa 124 cylinder height ???? That is good info let me ask how do they come up with the crown measurement?? And no decking measurement DANGIT lol.

01-14-2009, 01:51 PM	#20 (permalink)
Kurlon Super Moderator Join Date: Feb 2005 Location: Windham, ME Posts: 8,301	Re: Takegawa 124 cylinder height ???? Heh, thats my info. : ) Bad choice of terminology on my part, crown height is referring to the outside edge of the piston, not the dome.