puch head ??
- Thread starter Hoopermotorbikes
- Start date
If the engine has M8 stud s like many or most do you will need to drill the heads M6 holes out for the engines larger 8mm studs, I have a Puch Hi Hi 50cc head on a 66cc and it works fine, the 66cc is a 47mm bore and so I had to use two head gaskets to prevent piston from hitting the head since the combustion chamber on the Puch 50cc head is so small, but there a chance you wouldn't have to worry about that.
Only concern I have is if the bolt pattern on the grube 49cc engine is big enough for the Puch heads, I dont have any 49cc engines and I've never owned a grube engine of any size but I do have an older 66cc engine that has 6mm studs and a smaller bolt pattern than all my other 66cc engines and the Puch headswont work on it because of the bolt pattern being different.
Im sure some of the other guys or gals can ring in here and let you know if the bolt pattern on the . 49cc grube will allow you to use the Puch head.
Im just not sure if it will work on that engine or not.
Map
Only concern I have is if the bolt pattern on the grube 49cc engine is big enough for the Puch heads, I dont have any 49cc engines and I've never owned a grube engine of any size but I do have an older 66cc engine that has 6mm studs and a smaller bolt pattern than all my other 66cc engines and the Puch headswont work on it because of the bolt pattern being different.
Im sure some of the other guys or gals can ring in here and let you know if the bolt pattern on the . 49cc grube will allow you to use the Puch head.
Im just not sure if it will work on that engine or not.
Map
I don't have a 49cc engine to compare, however I have a Jug here from a 60cc (45mm bore), which has 6mm studs. And I'm guessing is the same as a 49cc?
It has 60mm spacing across the diagonal.
The puch head I have here has 63mm across the diagonal.
A 66cc 8mm stud engine has 64mm across the diagonal.
Hope this helps.
It has 60mm spacing across the diagonal.
The puch head I have here has 63mm across the diagonal.
A 66cc 8mm stud engine has 64mm across the diagonal.
Hope this helps.
if you have 6mm head studs you should be fine, i bought a puch hi comp from a 74cc with a 47mm bore sore it worked great for me other than i had to drill out the holes in the head to 8mm from 6mm and also had to use allen head bolts sense there was no room for nuts.
93 octane will probably not be enough you will more than likely need to run 110 to prevent deto. the chambers on those heads are really small
93 octane will probably not be enough you will more than likely need to run 110 to prevent deto. the chambers on those heads are really small
I run regular 87 octane in my engines with Puch heads and I use shouldered acorn nuts that require a 13mm socket, the 1/4" drive deep sockets have thin walls and work great with the Puch heads as long as you use a nut that will work with a 13mm socket.
87 octane and Opti2 mixed @ 100:1 is how I roll with my Puch heads and I just GPS' s 50.3 mph on my fastest bike a couple weeks ago.
Im not saying high octane fuel is a bad idea but I've never needed it with any of my china girl builds personally.
Map
87 octane and Opti2 mixed @ 100:1 is how I roll with my Puch heads and I just GPS' s 50.3 mph on my fastest bike a couple weeks ago.
Im not saying high octane fuel is a bad idea but I've never needed it with any of my china girl builds personally.
Map
A standard Puch head will NOT fit a 49cc engine. The bolt spacing is too small regardless of stud size.
That's what I was trying to say, the holes in the head may be able to be stretched, but not an easy job.
A well shaved and shaped centerfire should adequately cool and give enough compression for a 48cc motor unless your in a really hot climate, or you plan to go extreme on the mods.
A well shaved and shaped centerfire should adequately cool and give enough compression for a 48cc motor unless your in a really hot climate, or you plan to go extreme on the mods.
I guess you MIGHT be able to elongate the holes enough to physically get it on, but it would require serious butchery. I'd just mill or lap the stock head and rework the squish for .030 or so...
I'm sure there are better moped heads for the 49cc bolt pattern with some research.
I'm sure there are better moped heads for the 49cc bolt pattern with some research.
Just to depunk the myth... it is possible - and its easy!!!! I just did it this afternoon, to try and cool down my fuk'n hot 50cc engine. I had already had the stud holes drilled out to 8mm, but there was also easy clearance with the 6mm studs, so you might not need to do so. It is however very easy to do, just drill out the existing stud holes and use washers to keep the 10mm nut from falling in there 
The motor is a standard 40mm bore 50cc chinagirl. this is the head:
https://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-comp-head-50cc.htm
slipped right on. ?!
-Moto
The motor is a standard 40mm bore 50cc chinagirl. this is the head:https://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-comp-head-50cc.htm
slipped right on. ?!
-Moto
Last edited:
Is that the 70cc puch head they are talking about?
I was talking about a standard 70cc head fitting a 49cc motor.
I was talking about a standard 70cc head fitting a 49cc motor.
no im pretty sure they are the same thing. It has the same bolt hole pattern as a 47mm puch gila head, just a different squish. I have run the head which is not on my 50cc on my 66cc engine as well. I guess the extra space given by pairing the 8mm holes with the 6mm studs just creates enough wiggle room for everything to line up...
will post some pics in the morning.
I was talking about the Puch hi hi 50cc head which does have the same bolt spacing but has a smaller combustion chamber, I run one on one of my 66cc china girls, you must run two head haskets or two jug gaskets unless you modify the 50cc puch head or the piston will hit the head.
Map
Map
the 48cc engine's head studs are slightly closer together than the 66cc version, It wouldn't surprise me at all if a puch head slipped right on, no modification required. The puch head is 2mm smaller on the diagonal than the 66cc if memory serves. Now that I've got a 48cc engine to play with, I'll start measuring.
