Planet Minis

TankTheory · 03-07-2009, 02:46 PM

Is it true that the CT70hK0 heads are the same as the Kitaco Ultra Heads? Does that make them worth more than a plain old CT70 head if so?

RySem · 03-07-2009, 04:02 PM

I'm gonna go ahead and say that is false. I'm sure others will back that up as well.

dirtbkr188 · 03-07-2009, 04:05 PM

Certain years of the C70, CT70, CT70H, and ATC70 all used the same head, the only thing that makes them rare is that they are no longer available from Honda.
Appearance and price-wise, the CT70H head looks like a stock XR/CRF50 or 70 head, whereas the Kitaco head resembles a TrailBikes race head or an E-22 style head. Combustion chamber-wise, I've never seen a Kitaco one.

50rider340 · 03-07-2009, 04:33 PM

Quote:

Originally Posted by dirtbkr188

Certain years of the C70, CT70, CT70H, and ATC70 all used the same head, the only thing that makes them rare is that they are no longer available from Honda.
Appearance and price-wise, the CT70H head looks like a stock XR/CRF50 or 70 head, whereas the Kitaco head resembles a TrailBikes race head or an E-22 style head. Combustion chamber-wise, I've never seen a Kitaco one.

not completely 69 to 77 i belieave CT70s and other makes had a completely different head than after that year. These heads have a 25IV, and 22 EV in them (like the kitaco ultra head). I have actually all 3 types of heads. The older style has a much larger combustion chamber (like the kitaco head) A 81 passport has a smaller combustion chamber closer to a e22.

Z · 03-07-2009, 05:12 PM

Adam z50+R · 03-08-2009, 09:32 AM

The early c70 atc70, cf70 large combustion dome (chaly heads we call them) are regularly used over the pond
cheap as chips & most of the time free

are matched perfectly to takegawa's R-stage piston design
as 50rider said 25/22 valves

kitaco cams are interchangable but the tak ones are bearing'd so dont fit

someone replicates these heads but with bearing cam, they sell here in the uk

Monkey Bike UK C70 6V Cylinder Head -Roller Bearing Camshaft Type
new head , 25/22 valve, bearing camshaft ,c70 style large dome
uses takegawa's cams ,piston is very close to r-stage kit !! for cheap

one example is.
i did a nice port job on my 70 chaly head
fitted kitaco (non bearing) cam
kitaco valve springs
lightened the rockers
skimmed .25mm

and used a tak 95cc r-stage piston (which i believe chp are selling dirt cheap!)
lightened ,balanced, knifedge the honda 12v 50 crank
and a mikuni 24 flatslider carb

she was a screamer

50rider340 · 03-10-2009, 11:42 AM

Quote:

Originally Posted by RySem

I'm gonna go ahead and say that is false. I'm sure others will back that up as well.

lol i think "others" disagreed with your assumption.

RySem · 03-10-2009, 11:50 AM

Quote:

Originally Posted by 50rider340

lol i think "others" disagreed with your assumption.

Well how bout that. Nobody said that they were the "same" though...and if they were, Kitaco would never make them. Similar perhaps, but not the same. It's also not a matter of CT70H to CT70 as well. The "early" CT70 heads, H or not, had the large chamber...same with SLs CLs XLs etc. I believe this is what TankTheory was trying to get at.

50rider340 · 03-18-2009, 10:07 PM

Does anyone know what year the chamber went smaller? Like was it 81 and older had bigger chamber etc???

dirtbkr188 · 03-19-2009, 07:04 AM

I did a little digging, and found out that the '69-'81 all share the same part number for the head - #12200-087-305
The '82 itself has a different part number - #12200-GB1-305
The '91 through '94 all are part #12200-GB5-931, which is the same head that is on the '97-'09 XR/CRF70 today.

Based on that, you're correct, the '81 and older all had the bigger chamber.

fatcaaat · 03-19-2009, 07:23 AM

TIme for me to chime in as I have been building all sorts of things with various heads.

I personally like the Old GB0 heads (69-81). When ported right, it will flow like any kitaco or taky head with the same size valves. However, it is outdated in that it runs a bearing journal style camshaft. It is also outdated by the fact that the largest lift you can get out of it is 6mm due to the fact that head design doesn't allow a lobe larger than that to clear the bearing journal.

The heads are cheap, easy to rebuild, and are proven by the fact that people are still running original motors 40 years later that have never been rebuilt.

I will be using a fully ported atc70 head, coupled with a 13:1 compression 54mm piston and cylinder, cam (with the 6mm lift and tons of duration), heavy springs, and a mikuni VM20 carb on a 1971 Honda CT70 bottom end for a special motor project here this weekend. I guaran-damn-tee that this motor will run circles around a TB88cc race head kit and will have only cost me $200 to put it together, compared to $350 for the TB kit.

50rider340 · 03-19-2009, 11:41 AM

Sickkk I'm stoked I have a 81 c70 head that will work great with the Dratv high comp 114 kit awesomeeeee. I wasnt sure if the 54mm piston dratv sells would clear it but the part numbers match so I'm pumped, my scoot is going to go so fast lol.

We bend the rules for 50cc mopeds in CT a little bit. As far as im concerned i have a "honda ca102 that came with a 50cc push rod motor, lol. Right now it just has a 52.4 high comp AHP piston and e22 with G2 cam, all my buddy got a gpx140 and another one got a lifan 138, so i gotta step it up to a 114 haha.

Fatcattt how well does the 13:1 54mm piston rip???? From the lookds of it that piston squeezes in the head just like a takegawa piston does in there head its gotta perform amazing.

fatcaaat · 03-19-2009, 12:29 PM

I don't know how it performs yet. The squeeze will be good, but what about flame propagation? We'll seee I guess.

TankTheory · 03-23-2009, 12:47 PM

I still can't believe you rigged up a computer fan to your oil cooler..

slimbo · 03-23-2009, 07:30 PM

Quote:

Originally Posted by fatcaaat

TIme for me to chime in as I have been building all sorts of things with various heads.

I personally like the Old GB0 heads (69-81). When ported right, it will flow like any kitaco or taky head with the same size valves. However, it is outdated in that it runs a bearing journal style camshaft. It is also outdated by the fact that the largest lift you can get out of it is 6mm due to the fact that head design doesn't allow a lobe larger than that to clear the bearing journal.

The heads are cheap, easy to rebuild, and are proven by the fact that people are still running original motors 40 years later that have never been rebuilt.

I will be using a fully ported atc70 head, coupled with a 13:1 compression 54mm piston and cylinder, cam (with the 6mm lift and tons of duration), heavy springs, and a mikuni VM20 carb on a 1971 Honda CT70 bottom end for a special motor project here this weekend. I guaran-damn-tee that this motor will run circles around a TB88cc race head kit and will have only cost me $200 to put it together, compared to $350 for the TB kit.

How is this coming along? What 13:1 piston are you using?

03-07-2009, 02:46 PM	#1 (permalink)
TankTheory 2nd Gear Member Join Date: Jun 2007 Location: .860. Posts: 549 My Mood:	CT70Hk0 Head vs. Kitaco Ultra Head Is it true that the CT70hK0 heads are the same as the Kitaco Ultra Heads? Does that make them worth more than a plain old CT70 head if so?

03-07-2009, 04:02 PM	#2 (permalink)
RySem 2nd Gear Member Join Date: May 2008 Location: Oakville, CT Posts: 377	Re: CT70Hk0 Head vs. Kitaco Ultra Head I'm gonna go ahead and say that is false. I'm sure others will back that up as well.

03-07-2009, 04:05 PM	#3 (permalink)
dirtbkr188 3rd Gear Member Join Date: May 2004 Location: New Jersey Posts: 2,970	Re: CT70Hk0 Head vs. Kitaco Ultra Head Certain years of the C70, CT70, CT70H, and ATC70 all used the same head, the only thing that makes them rare is that they are no longer available from Honda. Appearance and price-wise, the CT70H head looks like a stock XR/CRF50 or 70 head, whereas the Kitaco head resembles a TrailBikes race head or an E-22 style head. Combustion chamber-wise, I've never seen a Kitaco one. Last edited by dirtbkr188; 03-07-2009 at 04:11 PM.

03-07-2009, 05:12 PM	#5 (permalink)
Z 5th Gear Member Join Date: Sep 2003 Location: KANSAS Posts: 8,539	Re: CT70Hk0 Head vs. Kitaco Ultra Head

03-08-2009, 09:32 AM	#6 (permalink)
Adam z50+R 2nd Gear Member Join Date: Sep 2008 Location: England Posts: 298 My Mood:	Re: CT70Hk0 Head vs. Kitaco Ultra Head The early c70 atc70, cf70 large combustion dome (chaly heads we call them) are regularly used over the pond cheap as chips & most of the time free are matched perfectly to takegawa's R-stage piston design as 50rider said 25/22 valves kitaco cams are interchangable but the tak ones are bearing'd so dont fit someone replicates these heads but with bearing cam, they sell here in the uk Monkey Bike UK C70 6V Cylinder Head -Roller Bearing Camshaft Type new head , 25/22 valve, bearing camshaft ,c70 style large dome uses takegawa's cams ,piston is very close to r-stage kit !! for cheap one example is. i did a nice port job on my 70 chaly head fitted kitaco (non bearing) cam kitaco valve springs lightened the rockers skimmed .25mm and used a tak 95cc r-stage piston (which i believe chp are selling dirt cheap!) lightened ,balanced, knifedge the honda 12v 50 crank and a mikuni 24 flatslider carb she was a screamer

03-18-2009, 10:07 PM	#9 (permalink)
50rider340 3rd Gear Member Join Date: Mar 2004 Location: CT Posts: 3,082 My Mood:	Re: CT70Hk0 Head vs. Kitaco Ultra Head Does anyone know what year the chamber went smaller? Like was it 81 and older had bigger chamber etc???

03-19-2009, 07:04 AM	#10 (permalink)
dirtbkr188 3rd Gear Member Join Date: May 2004 Location: New Jersey Posts: 2,970	Re: CT70Hk0 Head vs. Kitaco Ultra Head I did a little digging, and found out that the '69-'81 all share the same part number for the head - #12200-087-305 The '82 itself has a different part number - #12200-GB1-305 The '91 through '94 all are part #12200-GB5-931, which is the same head that is on the '97-'09 XR/CRF70 today. Based on that, you're correct, the '81 and older all had the bigger chamber.

03-19-2009, 07:23 AM	#11 (permalink)
fatcaaat 3rd Gear Member Join Date: Sep 2004 Location: Arlington, VA Posts: 3,778	Re: CT70Hk0 Head vs. Kitaco Ultra Head TIme for me to chime in as I have been building all sorts of things with various heads. I personally like the Old GB0 heads (69-81). When ported right, it will flow like any kitaco or taky head with the same size valves. However, it is outdated in that it runs a bearing journal style camshaft. It is also outdated by the fact that the largest lift you can get out of it is 6mm due to the fact that head design doesn't allow a lobe larger than that to clear the bearing journal. The heads are cheap, easy to rebuild, and are proven by the fact that people are still running original motors 40 years later that have never been rebuilt. I will be using a fully ported atc70 head, coupled with a 13:1 compression 54mm piston and cylinder, cam (with the 6mm lift and tons of duration), heavy springs, and a mikuni VM20 carb on a 1971 Honda CT70 bottom end for a special motor project here this weekend. I guaran-damn-tee that this motor will run circles around a TB88cc race head kit and will have only cost me $200 to put it together, compared to $350 for the TB kit.

03-19-2009, 11:41 AM	#12 (permalink)
50rider340 3rd Gear Member Join Date: Mar 2004 Location: CT Posts: 3,082 My Mood:	Re: CT70Hk0 Head vs. Kitaco Ultra Head Sickkk I'm stoked I have a 81 c70 head that will work great with the Dratv high comp 114 kit awesomeeeee. I wasnt sure if the 54mm piston dratv sells would clear it but the part numbers match so I'm pumped, my scoot is going to go so fast lol. We bend the rules for 50cc mopeds in CT a little bit. As far as im concerned i have a "honda ca102 that came with a 50cc push rod motor, lol. Right now it just has a 52.4 high comp AHP piston and e22 with G2 cam, all my buddy got a gpx140 and another one got a lifan 138, so i gotta step it up to a 114 haha. Fatcattt how well does the 13:1 54mm piston rip???? From the lookds of it that piston squeezes in the head just like a takegawa piston does in there head its gotta perform amazing.

03-19-2009, 12:29 PM	#13 (permalink)
fatcaaat 3rd Gear Member Join Date: Sep 2004 Location: Arlington, VA Posts: 3,778	Re: CT70Hk0 Head vs. Kitaco Ultra Head I don't know how it performs yet. The squeeze will be good, but what about flame propagation? We'll seee I guess.

03-23-2009, 12:47 PM	#14 (permalink)
TankTheory 2nd Gear Member Join Date: Jun 2007 Location: .860. Posts: 549 My Mood:	Re: CT70Hk0 Head vs. Kitaco Ultra Head I still can't believe you rigged up a computer fan to your oil cooler..

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