Head Advice Please?

[Street Ryderz]

Ok so on page 2 of this thread I compared this square head to a round head and the majority opinion said the circular head was preferred. Do you guys still think that holds?

I did recomend this square one from the start lol but they are both very good just depends on what your wanting it to do!If your not going to touch it or the jug the square one should be the best all around the round one works well but really works best on a decked jug and is still mild on comp and the gain is a little better torque with great heat disapation!

 

[KTOKTO]

I'm waiting to hear if KTOKTO is having probs. with piston clearance.

No clearance problems on the gt5, I turned it over with the spark plug out after I installed it just to make sure. I will jet it this afternoon and report back. Can someone explain to me though how changing from one 6cc head to another 6cc head would cause it to run super rich if that is the case?

 

[FurryOnTheInside]

I gota go with my own experience so since I haven't used one of the sq. heads I go with what I know which is the round head. Having said that I have been listening to Ryderz savvy on on performance mods. enough to place one of the sq. heads on my things to try list. I like the idea of not having to deck my jugs to bring the compression up to what a stock slant plug head has. Remember the round head is 8cc's, and the slant plug head is 6cc's. You loose a lot of comp. when you add 2cc's of volume without decking the jug. I'm waiting to hear if KTOKTO is having probs. with piston clearance.

There's a few very very similar looking heads so they're easy to confuse. Gary might be thinking of the/a B.M.W. round head. Or maybe the eBay listings for MZ heads are misleading. Here's what the eBay listings say:

The round MZ "R" head with lots of vertical fins and three horizontal fins, according to the eBay listing is:

MOTORIZED BICYCLE HIGH COMPRESSION 6.0cc HEAD ,YOU GET WHAT YOU SEE IN THE PICTURE ,THANKS B8HS SPARK PLUG RECOMMENDED

Specifications:

• High Compression Head
• Custom Aluminum Design

The MZ "F" head (round when seen from above but with fewer fins and only two horizontal fins, and a flatter top) is also listed as 6.0cc in the description details. It has a narrower squish band (so presumably a shallower combustion chamber) than the MZ "R" head.

The MZ "B" head (the square head) is also listed as 6.0cc in the description details. Has a similar looking combustion chamber shape, similar width squish band to the "R" head but has that into-the-bore design.

 

[gary55]

There's a few very very similar looking heads so they're easy to confuse. Gary might be thinking of the/a B.M.W. round head. Or maybe the eBay listings for MZ heads are misleading. Here's what the eBay listings say:

The round MZ "R" head with lots of vertical fins and three horizontal fins, according to the eBay listing is:

MOTORIZED BICYCLE HIGH COMPRESSION 6.0cc HEAD ,YOU GET WHAT YOU SEE IN THE PICTURE ,THANKS B8HS SPARK PLUG RECOMMENDED

Specifications:

• High Compression Head
• Custom Aluminum Design

The MZ "F" head (round when seen from above but with fewer fins and only two horizontal fins, and a flatter top) is also listed as 6.0cc in the description details. It has a narrower squish band (so presumably a shallower combustion chamber) than the MZ "R" head.

The MZ "B" head (the square head) is also listed as 6.0cc in the description details. Has a similar looking combustion chamber shape, similar width squish band to the "R" head but has that into-the-bore design.

Just remember all that is written is not always true. While they may have changed the chamber design on their R head (which I doubt) the 10 that I have purchased from them are 8cc heads. You put a plug in, place the cd on top, fill with a syringe till you see the little bubble disappear, then measure what's in there.View media item 60721

 

[Carl Walichnowski]

I did recomend this square one from the start lol but they are both very good just depends on what your wanting it to do!If your not going to touch it or the jug the square one should be the best all around the round one works well but really works best on a decked jug and is still mild on comp and the gain is a little better torque with great heat disapation!

Ok so I'm going with the square one because I do not plan to do anything to the head, simply because I have no clue how to do anything. I'm dragging my feet a bit cause I want to improve my braking first & then after that I will get either the square head or an expansion chamber, don't know which one is more important to get.

 

[FurryOnTheInside]

Just remember all that is written is not always true. While they may have changed the chamber design on their R head (which I doubt) the 10 that I have purchased from them are 8cc heads. You put a plug in, place the cd on top, fill with a syringe till you see the little bubble disappear, then measure what's in there.View media item 60721

I quite agree, the listing may give incorrect details so I tried to choose my words carefully. I have not seen any of the three MZ heads in person.
Have you measured the "B" (square) or "F" (flat) head?
Does the piston dome measure 2cc and maybe they're subtracting that from the measurement? I can't imagine there's that much volume in a piston dome but I'm clutching at straws for a possible explanation lol.

 

[FurryOnTheInside]

Ok so I'm going with the square one because I do not plan to do anything to the head, simply because I have no clue how to do anything. I'm dragging my feet a bit cause I want to improve my braking first & then after that I will get either the square head or an expansion chamber, don't know which one is more important to get.

I think they only had one pipe left in stock last time I looked if I remember correctly. You might already be too late and have to wait for more stock anyway.
I don't know if the criteria you're using for choosing which head makes sense. The way im reading the thread, you choose the B square head if your piston crown (edge) doesn't quite reach the top of the cylinder bore, and choose the R (round) head if it does ((or if you already decked (lowered) the top of the cylinder to make the crown come up level with it at the TDC (top dead centre) of the stroke.))

Of course the question of side-by-side measuring of the volume of the heads is still there. I am going to message the vendor on eBay now to try to get an official response to the issue as I am interested in these heads too.

 

[gary55]

Ok so I'm going with the square one because I do not plan to do anything to the head, simply because I have no clue how to do anything. I'm dragging my feet a bit cause I want to improve my braking first & then after that I will get either the square head or an expansion chamber, don't know which one is more important to get.

Importance is relative to the builders desires. Head provides slight increase in performance when properly fitted while prolonging engine life through better cooling and resistance to warpage. Pipe provides noticeably more giddyup. Like your current priorities.

 

[gary55]

I think they only had one pipe left in stock last time I looked if I remember correctly. You might already be too late and have to wait for more stock anyway.
I don't know if the criteria you're using for choosing which head makes sense. The way im reading the thread, you choose the B square head if your piston crown (edge) doesn't quite reach the top of the cylinder bore, and choose the R (round) head if it does ((or if you already decked (lowered) the top of the cylinder to make the crown come up level with it at the TDC (top dead centre) of the stroke.))

Of course the question of side-by-side measuring of the volume of the heads is still there. I am going to message the vendor on eBay now to try to get an official response to the issue as I am interested in these heads too.

Sounds right to me.

 

[gary55]

I quite agree, the listing may give incorrect details so I tried to choose my words carefully. I have not seen any of the three MZ heads in person.
Have you measured the "B" (square) or "F" (flat) head?
Does the piston dome measure 2cc and maybe they're subtracting that from the measurement? I can't imagine there's that much volume in a piston dome but I'm clutching at straws for a possible explanation lol.

I haven't measured the B or F yet, so don't know on those. I also haven't measured the burn chamber by it's self. Hard to get accurate, and doesn't really pertain to head volume without including the squish area. If I were guessing the B head looks to to have a shallower burn chamber than the R. If so, this along with it's encroachment downward into the cyl. could have a guy looking for a 2nd base gasket or a ready supply of wrist pins and bearings.