Puch Head?

[Wild Bill]

Who is running a Puch head and do you have a link to which one fits a 66CC?
How are they performance wise and do you run 2 head gaskets like I have read some people do?

 

[bulljo]

I run the 70cc puch hi hi head but im pretty sure there all the same bolt pattern and the double gaskets is a preference because some pistons are higher at topdead center so you better check it befor you decide to run it and you probably gonna need leaneer jets too...... and performance wise the engine definately runs different up hills speed and torque wise. Also detonation may be a problem with this head so colder plug and higher octane

 

[k.mah]

Running the 70cc hi hi head and wont turn back. I dont run any head gaskets and havent had any clearance issues. Better torque for sure! And like stated above, be prepared to run a cooler plug and higher octane gas. Or getting a cdi that can retard timing is even better. You do need to drill out the bolt holes if you have 8mm studs, which is easy to do. search on www.treatland.tv for them. should be ~$30+shipping

 

[fx-2]

I have Jet motor with the 70 cc high compression head with one head gasket . It's a good idea to put a better upper rod bearing in it . You can find them a Bearing Direct http://bearingsdirect.com/ , you want a 10x14x15 . I also use the Jaguar CDI kit works great . Hope this helps . Dan

 

[bulljo]

Nice bike and header size. Your frame is like a laguna seca Bmw huh did you paint it yourself?

 

[fx-2]

The bikes a new build , the paint is nasty real bad . After I get some miles on it I'll do a nice paint job . Here the build http://motorbicycling.com/showthread.php?t=43040 . Dan

 

[max350]

I do use 2pc cylinder base gaskets to raise the cylinder a bit to get the right compression ratio. becomes possitiv effect raises the ports a little

 

[lambofgod121980]

I too run a puch hi hi head with 2 head gaskets. Combined with ngk b7hs plug. Treatland has them for 30 bucks. Mine is modded for an over the top exhaust so the head is about 1/2 as tall as stock puch head. Doesn't affect cooling at all in my opinion. Even Modded its wayyyyyyyyyy cooler than the stock slant head or the strait plug head that comes in the kits factory.

Edit- almost forgot, I'm useing 2 head gaskets because with only 1 bike was stoooooopid hard to get started and didn't want to wind out. The second I added the second head gasket, fired right up and has no porblems winding out. Wasn't a clearance issue as piston never hit. I think I had too Much compression if there is such a thing.

 

[Wild Bill]

Well such good reports on the thing that I just ordered the 70cc hi hi head. Thanks everyone!

BTW did you guys notice an increase in MPH?

 

[Wild Bill]

I have Jet motor with the 70 cc high compression head with one head gasket . It's a good idea to put a better upper rod bearing in it . You can find them a Bearing Direct http://bearingsdirect.com/ , you want a 10x14x15 . I also use the Jaguar CDI kit works great . Hope this helps . Dan

I love that bike FX-2!!!!

 

[lambofgod121980]

I didn't notice any real increase in MPH. But what I did notice is smoother running altogether. Kinda tightend it up if you can get what im trying to say. I got a little tourque out of it for sure. And coMbined with My voodoo expansion chamber it ran great. A SMAller sprocket and high 3rpms will give you speed.
Beware china girls are not designed for high rpms constantly and while fast is cool, a china girl is not for speed. I have been through 3 engines trying to "go fast" and with this 4th one it will all be about cruising at mid rpMS. Will be swapping out My 40t sprocket for the 36t to get the speed I want at cruise rpMS \M/

 

[Wild Bill]

I have Jet motor with the 70 cc high compression head with one head gasket . It's a good idea to put a better upper rod bearing in it . You can find them a Bearing Direct http://bearingsdirect.com/ , you want a 10x14x15 . I also use the Jaguar CDI kit works great . Hope this helps . Dan

I researched the Jaguar CDI and Ordered one, I am a tuning and tweeking fool and this just sounds like whats needed to use with that head!

 

[Moto]

Its the best upgrade in my book, besides exhaust. Ive run these heads on about 3 engines and the acceleration difference is shocking. That being said there is potential to murder top ends if you dont do a few things:
Make sure your piston wont hit the head by determining proper head gasket spacing.
Make sure your bore is setup right: the 66cc engines have a 47mm bore, some of the puch heads have a 45mm bore. When running thin head gaskets you have to dremel out your bore to make sure the piston doesn't hit the head. I will attach a pic later. If you have a pretty thick stock head gasket it shouldn't be a problem. Great build btw.

 

[Wild Bill]

Thanks Moto, I am gonna use a depth gauge and dial indicator to measure piston/head clearance but regardless I will use the double gasket trick others are doing at least to begin with and if compression seems lower than a hi-compression head should have then I will go to one gasket if theres clearance for it.

Since theres more torque with higher compression, I am hoping to be able to pull 8th gear since its a little too high of a gear for the torque I now have, I may gain both acceleration and top end speed.