Manic Mechanic Get II Head vs Pirate Cylce's Aftermarket Head

hartungej

New Member
May 31, 2011
23
0
0
Madison, WI
I would like to consider upgrading my head on my Grubee GT-5 and was wondering if anyone has tried either of these heads and what their experience has been? I'm looking for a little extra power and speed, and wondering if it would be worth it over the regular china slant head on the Grubee?

Any opinions regarding which one might be better?

What differences in performance have you noticed, if installed correctly? Is it a substantial increase in compression and noticeable performance/speed increase?

Has anyone measured compression after installing one of these heads? I was getting 180-190 out of my stock engine (with a scratched piston, secondary to a bad and now fixed air leak, I think).

Opinions on how easy either one is to install?

Was it worth your $$$?

Thanks in advance!
 

Cruzen 619

New Member
Sep 24, 2011
10
0
0
San Diego
I'm runnin the Pirate High compression head. I installed it the same time I installed their port match billet intake manifold and Delorto carb. I need install just the intake and carb on another bike and the bike has has the head on it can come down really low in RPM while riding and it is very smooth through out the RPM range, I don't know if it made it any faster but it had made it easier and more enjoyable to ride, And I think it looks very cool. After I get my disk brake and 12 guage spoke rims and Sportsman hub and sprocket I going to build another bike and yes i will put on another Pirate Head
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,786
4
36
Indianapolis
I would go to the Manic Mechanic web site and read up on the Gen II head. I understand significant improvements have been made. Jim's good at what he does, and he wouldn't offer it if he hadn't worked the bugs out. And it looks great too. You may want to compare them, before you buy.
 

dmb

Active Member
Dec 4, 2010
1,358
3
36
lakewood ca
180-190 psi? thats alot maybe too much on 91 you could melt a piston or kill your wristpin but i dont know the china girl limits but bairdco seems to get their alot. good luck dennis
 

decoherence

New Member
Aug 23, 2010
476
2
0
sebring,fl
PWAAAHHHH , I love that guage , were'd ja get it . Thats awsome .
i know it isn't the answer you are looking for but,
i forgot what search terms i used in google.
then i changed the settings to "images"
then i use this firefox plug in called "rehost image"
i can right click over any pic on the net. then it automatically has the pic rehosted & puts the URL in the computer's clipboard.
so next time i paste it post's the images new URL.

i do wish i could own a gauge for retarted.
i would want @ least 3 of them.
when one is measured it may be to late.
 

crawler

New Member
Aug 5, 2011
63
0
0
Wichita, KS
manic mechanic.

I bought a pirate one for mine...I removed it before ever using it. I put two compression seals on the spark plug...still mashed the electrodes together. I got an indexing kit, used the two seals, AND indexed it so the electrode was up for more clearance...still mashed it. I still had to back it out several more turns before it quit hitting, and that was just turning the pedals over by hand.

When I say mashed them together, I mean stopped the engine dead, couldn't cycle through.

I went back to one seal, put the manic head on...no mashing. Lesson learned.

Maybe with a different heat range plug, yadda, yadda, yadda, but that wouldn't have left any adjustability, either. Also, it was a mid range plug, so it could have been even worse.

I can't say I'm a fan of the angle plug setup.

pirate:



manic:

 

Goat Herder

Gutter Rider
Apr 28, 2008
6,248
12
38
N.M.
manic mechanic.

I bought a pirate one for mine...I removed it before ever using it. I put two compression seals on the spark plug...still mashed the electrodes together. I got an indexing kit, used the two seals, AND indexed it so the electrode was up for more clearance...still mashed it. I still had to back it out several more turns before it quit hitting, and that was just turning the pedals over by hand.

When I say mashed them together, I mean stopped the engine dead, couldn't cycle through.

I went back to one seal, put the manic head on...no mashing. Lesson learned.

Maybe with a different heat range plug, yadda, yadda, yadda, but that wouldn't have left any adjustability, either. Also, it was a mid range plug, so it could have been even worse.

You have to put the correct type spark plug in these heads. That is all there is to it.... pretty darn simple really...

Heat range don't mean a darn thing if you have not followed the manufacturer directions and use what they say to use. Just throwing any ol spark plug in any engine is plain silly..

So in a nut shell there are only so many variables here. Both heads were made for a dome type piston. What this means? All the other piston variations are flat top pistons.. Follow the directions its very easy to set ether of these heads up right. I like the original Pirate's design looks better and perhaps way more authentic on a classic board tracker looking build my self but that's just me.
 
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crawler

New Member
Aug 5, 2011
63
0
0
Wichita, KS
hey Crawler howabout a full pic of that beast you made there ? it looks pretty fine, i like your style
It's in the cruiser section.

You have to put the correct type spark plug in these heads. That is all there is to it.... pretty darn simple really...

Heat range don't mean a darn thing if you have not followed the manufacturer directions and use what they say to use. Just throwing any ol spark plug in any engine is plain silly..

So in a nut shell there are only so many variables here. Both heads were made for a dome type piston. What this means? All the other piston variations are flat top pistons.. Follow the directions its very easy to set ether of these heads up right. I like the original Pirate's design looks better and perhaps way more authentic on a classic board tracker looking build my self but that's just me.
Yeah, plain silly using the plug THEY SENT WITH THE HEAD!! What directions? there were NO directions. I got a head...with a sparkplug...that doesn't work. the other 4 sparkplugs I have listed for these engines...don't work. All the sparkplugs work in the manic head just fine.

The piston has about .1" clearance to the THREADS of the spark plug hole. Now, considering you don't want the electrode up inside the threads...what does that leave you with?

You're right, it's pretty darn simple...it doesn't work right.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,248
12
38
N.M.
WHAT MOTOR WERE YOU USING? '''WHAT MODEL SPARK PLUGS DO YOU SAY YOU USED?''' Well shoot just know don't know what to tell ya because I have one and it works. Never did I have those problems. I did not have any issues at all what so ever. I had a NICE DOME HEAD AND I RAN ALL TOLERANCES CLOSE FOR THE HIGHEST COMPRESSION. WITH THE STOCK TYPE SPARK PLUG RECOMMENDED TOO. Do yeah need me to post a pict of how my plug clearance really is with the plug installed? There is hella plenty of room there on mine...This is why I don't understand what you are doing?

This has me rather curious as it could help clear up confusion for some one looking for a classic looking head approach on a custom build.. a little frame clearance can be a ''big'' plus too? You should post a picture of your said combustion chamber to help others with your personal conviction so we can get down to the details.. I can do a you tube mebbe if it helps? I have that said head right here in my hands as I type..

''''The spark plug on mine is absolutely perfectly flush with the combustion chamber wall with the recommended plug and comes to the center of the chamber.''''

My after thought on the deal I would never spend a lot of money on a china motor again. I mean if a guy just wants to put a uber kewl head on then get a puch head at least they are cheaper in price... just 30 dollars http://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-hi-comp-head-50cc-maxi.htm



Here is a puch head


http://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-hi-comp-head-50cc-maxi.htm Hi Jim..M&M
 
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crawler

New Member
Aug 5, 2011
63
0
0
Wichita, KS
Grubee gt5, mid range spark plug they sell with the head, stock china plug, iridium plug, and two other NGk plugs. It's all boxed up in the garage to make room for the pickup while I'm on vacation.
 

SdCruizer

New Member
Feb 15, 2012
108
1
0
San Deigo
WHAT MOTOR WERE YOU USING? '''WHAT MODEL SPARK PLUGS DO YOU SAY YOU USED?''' Well shoot just know don't know what to tell ya because I have one and it works. Never did I have those problems. I did not have any issues at all what so ever. I had a NICE DOME HEAD AND I RAN ALL TOLERANCES CLOSE FOR THE HIGHEST COMPRESSION. WITH THE STOCK TYPE SPARK PLUG RECOMMENDED TOO. Do yeah need me to post a pict of how my plug clearance really is with the plug installed? There is hella plenty of room there on mine...This is why I don't understand what you are doing?

This has me rather curious as it could help clear up confusion for some one looking for a classic looking head approach on a custom build.. a little frame clearance can be a ''big'' plus too? You should post a picture of your said combustion chamber to help others with your personal conviction so we can get down to the details.. I can do a you tube mebbe if it helps? I have that said head right here in my hands as I type..

''''The spark plug on mine is absolutely perfectly flush with the combustion chamber wall with the recommended plug and comes to the center of the chamber.''''

My after thought on the deal I would never spend a lot of money on a china motor again. I mean if a guy just wants to put a uber kewl head on then get a puch head at least they are cheaper in price... just 30 dollars http://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-hi-comp-head-50cc-maxi.htm



Here is a puch head


http://www.treatland.tv/Puch-50cc-Hi-compression-head-p/puch-hi-hi-comp-head-50cc-maxi.htm Hi Jim..M&M
is that head 50cc only or works on 66cc?
any pics of it mounted wondering about clearance
 

DaveC

Member
Jul 14, 2010
970
0
16
Boise, ID
is that head 50cc only or works on 66cc?
any pics of it mounted wondering about clearance
That's for hi-compression on a 50 cc n motor. They also have a hi-compression head for a 70 cc motor. This works better on both the 50 and 66 cc motors. ON a 50 it will still give a compression boost but not as much. Try to put a 50 cc head on a 66 cc motor and good luck getting it to turn over, compression goes over 14:1. Thats an awful lot of compression over the stock 6.5:1 or so that they are. The holes are 6 mm but they are slightly off to the inside of a Chinee motor. Drilling the hole out to slightly oversized gives you the clearance you need. I'd suggest the Sick Bike Parts head stud kits for 6mm and 8mm bolts. You'll need the 13mm nuts on the 8mm bolts to hold the head on a 8mm stud anyway. You can not get a 14mm socket down between the fins, the supplied 13mm nuts in the SBP stud kit work.
 

Dontwannawalk

Member
Dec 23, 2009
67
0
6
78
Iowa
Dave C,
Do you use the standard gasket with The Puch head & a PK80??
(You're going to think I real obnoxious but I can't tell If I've been actually sending notes to you or not.)

Norm
 

DaveC

Member
Jul 14, 2010
970
0
16
Boise, ID
Yeah, the standard China Girl gasket. I use Permatex Copper Spray-A-Gasket according to the directions to make sure of a seal.

And about the messages. I got an email but when I tried to answer you direct MSN wouldn't let me. I came here to answer ans there was no message in my mailbox so I was hopeing you'd get back to me :)

Just remember there is a slight difference in the distance that the studs are apart. You have to drill the Puch head holes out a bit to fit them over the studs on the China Girl motor, the Puch motor has them closer together by a tiny amount but not enough to make any real difference.