07 vs 08 flow chart

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The flow numbers are very close to the same between the 07 and 08 cylinder heads .The real performance from the 08 is the decreased port volume and extended divider which raises the velocities consideably adding much more power in thev low to mid range .stock for stock the 08 head out performs the 07 head .on a modified engine that is going to have porting performed to it the 07 head is a better starting point for a pro level head .I have already seen several 08 heads in here that were ported and actually made wores than stock flow numbers.Increasing flow numbers with out changing port cross section raises velocitys .The 08 head can be ported with some increases in flow but not to the level of a welded and ported 07 casting.I still prefer to start with the 07 head for all of my porting .if any body is looking for an improvment in power and is not plaqnning on port work the 08 head is a very good choice.

good post Mr Hamp, that was well said and many questions were answered.

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The flow numbers are very close to the same between the 07 and 08 cylinder heads .The real performance from the 08 is the decreased port volume and extended divider which raises the velocities consideably adding much more power in thev low to mid range .stock for stock the 08 head out performs the 07 head .on a modified engine that is going to have porting performed to it the 07 head is a better starting point for a pro level head .I have already seen several 08 heads in here that were ported and actually made wores than stock flow numbers.Increasing flow numbers with out changing port cross section raises velocitys .The 08 head can be ported with some increases in flow but not to the level of a welded and ported 07 casting.I still prefer to start with the 07 head for all of my porting .if any body is looking for an improvment in power and is not plaqnning on port work the 08 head is a very good choice.

yes , i really like the 07 head for my all out national motors also .

but i still use alot of 08 heads for the better velocity in the bottom and mid to make it easy to ride for the up and comming riders.

and you are so correct Ron, when porting on the 08 head you can surly hurt yourself more than help ! :thumbsup:

I have also came up with a method of increasing measured velocitys in the port with out decreasing the volume by more than 1 cc but i really dont want to divulge that much here Honda wont get to see this one ether this is alsi with the 07 head.

I have also came up with a method of increasing measured velocitys in the port with out decreasing the volume by more than 1 cc but i really dont want to divulge that much here Honda wont get to see this one ether this is also with the 07 head.

your secret is safe with me Ron -----and yes -----it does work very well !! :ride:

it is a shame that when a guy really figures out how to make something really work , ----it is not long before one of the major companys gets a hold of it and starts putting it into production and or using it on the race team, .

which does make the bikes way better for all the customers -------but we never get paid even close to what they should pay us for it before using it .

like what Honda did on the 08 cam ------there is a reason on why that 08 cam is so good --------it was not honda that figured that grind out ----

:thumbsup:

How about a big bore? Which stock head would work best with a 280cc ?

I already have a 08 cam, but the head is stock 06.

how better do the 07 and 08 heads flow aginst the 06 head

How about a big bore? Which stock head would work best with a 280cc ?

I already have a 08 cam, but the head is stock 06.

I'm running a ported 07 head with 08 cam. I am also using all stock oem 07 valves and springs and it is running great

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