Please explain Cylinder Head differences to me...

[Roo]

I have a Stock/Aftermarket Yamaha head that you can change to different domes... What is the correct term for this?

Also, when someone refers to a Girdled Head, what does that mean? (pics/example would be great)

I should know this, I have been in the Standup community for YEARS!!! :brap:

I am looking to build a motor pretty quick here, but I need to understand the Cylinder Head differences first that are available.

Thanks,
Andrew

 

[SuperJETT]

Normally, the cylinder bolts onto the crankcase, and the head bolts onto the cylinder. The force inside the combustion chamber is acting against the head so the cylinder has to hold it on.

A girdled head has studs that go from it to the crankcase, so the cylinder doesn't have to withstand those forces and is less likely to crack.
Here's a shot of a girdled head.
http://www.x-h2o.com/attachment.php?attachmentid=24050&d=1175023683

 

[oxnard111]

Normally, the cylinder bolts onto the crankcase, and the head bolts onto the cylinder. The force inside the combustion chamber is acting against the head so the cylinder has to hold it on.

A girdled head has studs that go from it to the crankcase, so the cylinder doesn't have to withstand those forces and is less likely to crack.
Here's a shot of a girdled head.
http://www.x-h2o.com/attachment.php?attachmentid=24050&d=1175023683

Well put.

 

[yamaslut]

Normally, the cylinder bolts onto the crankcase, and the head bolts onto the cylinder. The force inside the combustion chamber is acting against the head so the cylinder has to hold it on.

A girdled head has studs that go from it to the crankcase, so the cylinder doesn't have to withstand those forces and is less likely to crack.
Here's a shot of a girdled head.
http://www.x-h2o.com/attachment.php?attachmentid=24050&d=1175023683

IMO ADA heads offer a better sandwiching of the cyls than the ones that bolt into the case nuts... ie. RIVA head. ADA have nice beefy hardware too.

Seem a little stonger than the others... The domes don't lock in place either... This is good, so you don't get uneven wear...

 

[Roo]

Say no more, I now understand 100%!

Thanks!
Andrew

 

[Roo]

IMO ADA heads offer a better sandwiching of the cyls than the ones that bolt into the case nuts... ie. RIVA head. ADA have nice beefy hardware too.

Seem a little stonger than the others... The domes don't lock in place either... This is good, so you don't get uneven wear...

Thanks for the advice, I have been looking at heads and needed this direction. :Banane01:

Thanks,
Andrew

 

[Mark44]

I also like ADA heads I have never had a problem with them.

Mark44

 

[Frosty]

been running ADA on everything i own for the past 5 years... still using the original rubber gaskets they came with... and i've removed the heads several times since... I love ADA.

 

[yamaslut]

just so you know... ADA is the most used and seem to have the best design of all the girdle type heads

 

[yamaboy2000]

Simply purchase an ADA girdle head, install it and forget it, just like a B-pipe..They just work super well and are bullet-proof..............

 

[Roo]

should one be concerned about domes dropping into the cylinder if doing a big bore and running 85mm pistons?

or is it just a matter of ordering the appropriate domes?

tanks,
Andrew

 

[Speedfreak]

The domes have to be cut for each specific motor if you are doing something special like a big bore or stroker.