all the high comp heads ... witch one do you like best ?

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rogergendron1

New Member
Sep 18, 2013
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woburn ma
we have a lot of high comp heads to choose from here . witch one do you use or would you use and why ? let me know what you think is best !

stock head decked down.

dax high comp head

puch 50 hi hi

puch 70 hi hi

rse head

pc head

manic mechanic head

fred head .. 5cc 6cc 7cc comp release dual plug ? witch one ?

ddr head

and what do you prefer ??? squish band or no squish band ?
single chamber or dual stage chamber ?
slant plug or strait plug ?

my perfect head would be a single chamber, no squish band, polished, and milled from a billet block of aluminum with large fins. about 150lbs compression.

pics of all the high end billet heads.
 

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rogergendron1

New Member
Sep 18, 2013
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woburn ma
my choise in heads is going to be the puch 70cc hi hi head, this is because the 70 hihi with the o ring lets me not have to use a head gasket ! verry convieniant and it brings the compression up right where i want it to be around 150 - 160 lbs. plus its not that expencive only 30$ plus shipping. the combustion chamber and squish band look well crafted and it has massive heat fins to keep the motor cool.

but if i had unlimited funds i would buy the ddr head just to say i have it lol !
 

Geezer

Member
May 2, 2011
94
1
8
Illinois
Just put the 1rst Gen Fred head on a new engine that only has around 80 miles on it ...seems to be doing great so far. I'll probly get the RSE head at some point, mostly because i like the looks of it :)
That DDR looks interesting, never seen it before... don't get why it's so expensive, seems like it would be the cheapest one to machine, unless i'm missing something
 

RGZWS6

New Member
May 26, 2011
9
0
1
Illinois
I bought and installed both the Puch 50 and 70 hi hi heads for my 80cc engine. I started with the 50 thinking more compression = more power. I used the stock head gasket, regular 87 fuel at 40:1, and a "6" NGK iridium plug. Initial test run had lots ping...increasing and decreasing with throttle position versus engine speed so I parked and disassembled it. Added octane booster and a "9" NGK plug, and couldn't get it to fire. It just spun and spun and wouldn't start again. Replaced with stock head and it fired right off.

Installed the 70 head with 93 octane, "9" plug, stock head gasket and it started up, though somehow not as powerful as I was anticipating. Turned out I made a small mistake in opening up the mounting holes (6mm versus 8mm) and was losing compression through one of them. Made a nice oily mess on the top of the head and ruined the gasket. $40 down the drain! Spent $5 for correct 8.2mm drill bit.

Put the 50 back on with new head gasket and it wouldn't even turn over. Too much compression to spin. Added TWO new jug gaskets (and matched them to the opening) and it fired right off....similar to the 70 though on performance. With stock head, I had a ported intake with boost bottle, but had to replace it with a non-ported intake since the fins on the Puchs are way bigger than stock.

I'm not that convinced these Puch heads give anything more than a stock head w/boost bottle intake. Still working to prove myself wrong though since that's where the fun is! FWIW I have a 68 jet on NT carb with SBP expansion exhaust, 40 tooth sprocket. Upgraded plug, wire, & boot.
 

rogergendron1

New Member
Sep 18, 2013
882
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woburn ma
I bought and installed both the Puch 50 and 70 hi hi heads for my 80cc engine. I started with the 50 thinking more compression = more power. I used the stock head gasket, regular 87 fuel at 40:1, and a "6" NGK iridium plug. Initial test run had lots ping...increasing and decreasing with throttle position versus engine speed so I parked and disassembled it. Added octane booster and a "9" NGK plug, and couldn't get it to fire. It just spun and spun and wouldn't start again. Replaced with stock head and it fired right off.

Installed the 70 head with 93 octane, "9" plug, stock head gasket and it started up, though somehow not as powerful as I was anticipating. Turned out I made a small mistake in opening up the mounting holes (6mm versus 8mm) and was losing compression through one of them. Made a nice oily mess on the top of the head and ruined the gasket. $40 down the drain! Spent $5 for correct 8.2mm drill bit.

Put the 50 back on with new head gasket and it wouldn't even turn over. Too much compression to spin. Added TWO new jug gaskets (and matched them to the opening) and it fired right off....similar to the 70 though on performance. With stock head, I had a ported intake with boost bottle, but had to replace it with a non-ported intake since the fins on the Puchs are way bigger than stock.

I'm not that convinced these Puch heads give anything more than a stock head w/boost bottle intake. Still working to prove myself wrong though since that's where the fun is! FWIW I have a 68 jet on NT carb with SBP expansion exhaust, 40 tooth sprocket. Upgraded plug, wire, & boot.

dude i dont know what your doing wrong but i am running trhe puch 70 hi hi on a dax 70cc motor with a lightly decked down cylinder and a thin .4 mm heasd gasket.

thats a puch head 70cc hi hi and a .4 head gasket as opsed to the stock 1mm and a decked jug and my compresion is off the charts ! its close to 13:1 and the dynamic cvomp is even higher lol i run 93 oct 40:1 mix full synthetic with a lil upper cylinder lube added (lucas oil upper cylinder lube) and i get no ping what so ever, i also run true fuel pre mix 40 to 1 ethanol free as my main fuel (i only use pump gas when i have to) and that pre mix is awsome ! no ping what so ever and burns geat ! 40 to 1 mix and no ethanol.

again man i run the 70 hi hi with a verry thin .4 mm head gasket and a decked down jug i have nearly 13 to 1 comp 6 cc head and 70 cc cylinder volume = close to aroud 13 to 1, and as long as i run 92octain or better at at least a 32 to 1 mix i get no ping, my bike seems to like 40 to 1 and some cylinder lube added. i had a decked down stock head that was 5.8cc measured with fluid displacement, and the puch head at 6cc offers a lot more power simply because of the chamber design and the size of the squish band ! the squish band is huge .

to make the puch 70 hi hi head work like its suposed to you need to measure the squish band clearance and make it perfect, the stock hight and clearance is too tall you need to deck the jug down and use a thin gasket to bring the squish closer to the dome of the piston. this will also raise the comp some too. the puch head is 6cc camber volume same as the fred head. that gives a 66cc motor 12 to 1 comp corrected. a 70cc motor the comp would be higher especialy after decking the jug and using a thinner gasket !
 

max350

Active Member
Apr 10, 2010
322
55
28
Sweden, Örnsköldsvik
I bought and installed both the Puch 50 and 70 hi hi heads for my 80cc engine. I started with the 50 thinking more compression = more power. I used the stock head gasket, regular 87 fuel at 40:1, and a "6" NGK iridium plug. Initial test run had lots ping...increasing and decreasing with throttle position versus engine speed so I parked and disassembled it. Added octane booster and a "9" NGK plug, and couldn't get it to fire. It just spun and spun and wouldn't start again. Replaced with stock head and it fired right off.

Installed the 70 head with 93 octane, "9" plug, stock head gasket and it started up, though somehow not as powerful as I was anticipating. Turned out I made a small mistake in opening up the mounting holes (6mm versus 8mm) and was losing compression through one of them. Made a nice oily mess on the top of the head and ruined the gasket. $40 down the drain! Spent $5 for correct 8.2mm drill bit.

Put the 50 back on with new head gasket and it wouldn't even turn over. Too much compression to spin. Added TWO new jug gaskets (and matched them to the opening) and it fired right off....similar to the 70 though on performance. With stock head, I had a ported intake with boost bottle, but had to replace it with a non-ported intake since the fins on the Puchs are way bigger than stock.

I'm not that convinced these Puch heads give anything more than a stock head w/boost bottle intake. Still working to prove myself wrong though since that's where the fun is! FWIW I have a 68 jet on NT carb with SBP expansion exhaust, 40 tooth sprocket. Upgraded plug, wire, & boot.
It's not so simple to "just" putting on a lot of different parts of a two-stroke engine and believe that you should get out a lot of power
 

Danschutz

New Member
Aug 19, 2013
392
0
0
Wyoming
I run a Puch 70 head with a coke can gasket, sbp expansion chamber a ported cylinder and notched piston. Impressive low end torque using a 41t. It's faster or as fast as my buddies 4.5 hp Arrow motor.

Next chance I get I'm going to get a compression reading.

Dan.
 

RGZWS6

New Member
May 26, 2011
9
0
1
Illinois
to make the puch 70 hi hi head work like its suposed to you need to measure the squish band clearance and make it perfect, the stock hight and clearance is too tall you need to deck the jug down and use a thin gasket to bring the squish closer to the dome of the piston. this will also raise the comp some too. the puch head is 6cc camber volume same as the fred head. that gives a 66cc motor 12 to 1 comp corrected. a 70cc motor the comp would be higher especialy after decking the jug and using a thinner gasket !
Thanks for those tips. I will definitely try that in the weeks to come. I have another 70 hi hi on order.

Where do you get your thinner head gaskets from?
 

rogergendron1

New Member
Sep 18, 2013
882
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woburn ma
Thanks for those tips. I will definitely try that in the weeks to come. I have another 70 hi hi on order.

Where do you get your thinner head gaskets from?
you can make the gasket from thin sheet copper or gasket paper. the stock dax head gasket for the balanced motor is .44 vs the grubee 1mm

and the other poster hit the nail on the head with a sledge hammer ! you cant just through money and parts at the motor and expect it to go fast lol

you need a plan, you need to first off determain a comp ratio you wish to run at... 12:1 is a good goal. once you meet that goal by getting the propper volume head and squish band you need to port for your target rpm and power band... do you want high reves and high powerfull power band or moderatly high reves and a broader wide power band ? how do you ride ? that will determain your porting and pipe. now that your comp is up and your ported for your riding style you need to make or buy a pipe tunned to the target rpm riding range so your power band is in that range. next you can go even further by lightening the top end and grinding piston ramps and skirt cutting for faster revs and even more power ! if ur a pro you can balance the crank and stuff the case. reed valves are not nessary but help make mid to top end power and aid in fuel atomization prevent blow back, with the reed valve you can add a 3rd transfer for even more flow !


start with a plan

1 how do you drive
2 what is the desired comp ?
3 what is your target rpm range ?
4 where do you want the power in that rpm range ?
5 now build to suit !
 

MotorBicycleRacing

Well-Known Member
Jul 28, 2010
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SoCal Baby!!!
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I'm a fan of the Dax head. It is better than the manic and pirate heads at half the price.
I have used all of them before.
You got to be kidding?
I have that head and it is no better than a standard angle fire head.

The squish band is a joke and has a lip on the inside.
Depending on what mood the Chinese motor assemblers are in that day it comes on my motor kits.
Someone bought one in the other day that was cracked in half off another brand of motor.
I don't know if that was a fluke but those heads are pretty thin.
 
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SlowBalt

Member
Mar 8, 2010
759
6
16
Rhode Island
That's weird. I have them on all my engines. Over 5000 mi in one of them. When I switched to the Manic or Pirate heads the engine lost power. And their is a noticeable difference over the standard angle head. I Haven't run a Fred head yet, but I have one on A Arrow 4.5 I haven't had a chance run yet.