High Compression Head

[psprat496]

I've got a Starfire 66cc GT-4 engine. Has anyone put MM High Compression head onto this engine? I've heard the head is only for GT-5 engines but why is that? Would it not fit onto my engine?

 

[Creative Engineering]

I've got a Starfire 66cc GT-4 engine. Has anyone put MM High Compression head onto this engine? I've heard the head is only for GT-5 engines but why is that? Would it not fit onto my engine?

psprat496:

I saw your post in the other thread...I'm working on a graphic and a description that will give everyone the info needed to determine whether or not it will work...and better yet, whether or not it will be of any benefit for a given engine.

Jim

 

[psprat496]

psprat496:

I saw your post in the other thread...I'm working on a graphic and a description that will give everyone the info needed to determine whether or not it will work...and better yet, whether or not it will be of any benefit for a given engine.

Jim

Wow that would be great. Really clear up some confusion that people might be having. Have you ever tried to put the head onto a GT-4 or heard of anyone doing so?

 

[Creative Engineering]

Wow that would be great. Really clear up some confusion that people might be having. Have you ever tried to put the head onto a GT-4 or heard of anyone doing so?

I have no idea what the differences are between the GT-5 and the GT-4.

The current cylinder head offering was designed for engines that are as shown in the graphics below. All three graphics are the same...It's just a progressive zoom for reference.

The PK-80 and the Grubee GT-5 have nearly identical deck heights and piston crowns.

The deck height should be nearly zero, and the piston must be crowned. If your piston is flat...forget it...you will get zero performance benefit from this part!

As a final check, simply lay something pliable on top of the piston and bolt the head on. Rock the engine by hand to TDC and back again. Remove the head and check the thickness of the material. .015"-.020" is good.

Yes...something pliable. Light a candle and drip the wax around the perimeter of the piston, building inward to about 1/4" from the edge.

Jim

 

[Drewd]

Where does one get the MM head?

 

[psprat496]

Where does one get the MM head?

Pirate Cycles has them

Grubee Skyhawk Gas engine kit

 

[CarpsCustoms]

wow this thread is old...Anyone here?????? I was wondering if anyones used this head before, was thinking about getting it

http://www.gasbike.net/Racing-CNC-Cylinder-Head.html plz respond guys...ik youre there..i see you

 

[Goat Herder]

I tried Fred's Head. He made that head. Then gas bike bought some. Shipped one to China and with no shame at all stole his design. Get a Fred Head or take from Fred too....

It is his head he deserves the money IMO. http://www.dailymotion.com/video/x132wqv_counterfeit-culture-counterfeit-culture_shortfilms