CG 230 cylinder head

[vtwinaddicted]

Would a cg125 cylinder head work on my brozz 250?

[franque]

The spacing for the cylinder studs should be different, I don't think it'll work. Where are you located?

[NzBrakelathes]

No

[JerryHawk250]

Why a CG125 head? Why not buy the Brozz250 head?
https://shop.brozz250.com/eshopprod_cat_5820373-5934482_product_8486237.Cylinder_Assembly.htm

[vtwinaddicted]

Pennsylvania

[vtwinaddicted]

Combustion chamber size

[franque]

That's what welding is for! If you had a 200, it would work, they changed the stud spacing for the 230.

[JerryHawk250]

Just mill the stock head down to increase the Compression Ratio.

[Baskt_Case]

Just mill the stock head down to increase the Compression Ratio.

2 local shops quoted me less than $50 just to mill one down. And the Brozz (and TT250) head appears to have the best factory ports compared to all the others.

[Megadan]

Ultra budget compression increase, remove the cylinder base gasket and seal with a semi-hardening gasket maker. Just make sure to not block the oil passage to the head. Then replace the head gasket with a TT250 single layer steel unit.

[Rocket tests]

I took measurements with a straight edge and feeler guages then used a $25 handheld belt sander from harbor freight to deck my head. Just gotta keep rotating it with very light pressure to avoid removing metal from the wrong areas.

[CaesarVis]

Ultra budget compression increase, remove the cylinder base gasket and seal with a semi-hardening gasket maker. Just make sure to not block the oil passage to the head. Then replace the head gasket with a TT250 single layer steel unit.

Does that give the same results as shaving?

[CaesarVis]

I took measurements with a straight edge and feeler guages then used a $25 handheld belt sander from harbor freight to deck my head. Just gotta keep rotating it with very light pressure to avoid removing metal from the wrong areas.

How much did you take off?

[JerryHawk250]

How much did you take off?

Removing 1mm or 040" will bump you to 10:1 CR. You can easily remove that with sand paper on a flat piece of steel or glass. Lots of elbow grease and rotating the head every so often to make sure you are removing it evenly. I've done a few. A bench top belt sander will make quick work of it. That's what i used back in the day to shave down outboard heads for racing. ;)

[CaesarVis]

Removing 1mm or 040" will bump you to 10:1 CR. You can easily remove that with sand paper on a flat piece of steel or glass. Lots of elbow grease and rotating the head every so often to make sure you are removing it evenly. I've done a few. A bench top belt sander will make quick work of it. That's what i used back in the day to shave down outboard heads for racing. ;)

How do you keep track of how much material needs to be removed and how much has been removed? That seems like it would be the trickiest part.

[CaesarVis]

I'm going to try the gasket thing Dan mentioned before I go all crazy on my head. Is the below J-B Weld 31314 Red Silicone Gasket Maker the right stuff to use for that?

https://www.amazon.com/gp/product/B00ID8IUJY

And the below gasket from CSC?
https://store.cscmotorcycles.com/TT250-OEM-GASKET-CYLINDER-BLOCK-p/zt41-100.htm

[JerryHawk250]

How do you keep track of how much material needs to be removed and how much has been removed? That seems like it would be the trickiest part.

Lay a strait end across the head and pick a point to take a measurement. Keep checking the measurement as you sand it down until you removed the amount you want. I have a wright up some where on here.

[Megadan]

I'm going to try the gasket thing Dan mentioned before I go all crazy on my head. Is the below J-B Weld 31314 Red Silicone Gasket Maker the right stuff to use for that?

https://www.amazon.com/gp/product/B00ID8IUJY

And the below gasket from CSC?
https://store.cscmotorcycles.com/TT250-OEM-GASKET-CYLINDER-BLOCK-p/zt41-100.htm

Honestly, I don't recommend it. The headgasket is going to be good for a small bump and a little extra power, but leave the base gasket alone. If you must do it, don't use red RTV. Use something like Hondabond HT or Permatex Ultra Grey https://www.amazon.com/Permatex-82194-High-Torque-Silicone-Gasket/dp/B000HBGI8K

[CaesarVis]

Honestly, I don't recommend it. The headgasket is going to be good for a small bump and a little extra power, but leave the base gasket alone. If you must do it, don't use red RTV. Use something like Hondabond HT or Permatex Ultra Grey https://www.amazon.com/Permatex-82194-High-Torque-Silicone-Gasket/dp/B000HBGI8K

Is the red stuff too "permanent" or something? I was thinking about trying to replace both bottom and top gaskets with this stuff. I even saw some people on other posts claiming they don't use gaskets AT ALL!

[franque]

Nope, don't use the red stuff, it's not designed to constrain that sort of pressure. Also, it tends to fragment and clog up oil passages/pumps. If you don't use gaskets, you'll either need perfectly (re)machined surfaces on a Chinese motor, or you'll leak oil. You definitely need a head gasket, too. You'll potentially need shorter pushrods to. Just listen to Dan.