Max head flow for 25 psi race motor

[s8v4o]

Im going to be doing the same as you. Here are the intake and exhaust runner profiles from a junk head that I cut up. I'm really focused on the exhaust ports since that's where these turd motors seem to be lacking. I'm working on a flow bench and should be able to start testing different port shapes in the next month or two.

Thanks for posting those pics. Is it safe to say that all in the intake runners have the same amount of meat around them before hitting any water jackets? Same with the exhaust?

 

[rcm90]

I'm going to be cutting along the runners as well. I believe the exhaust has that much room everywhere, the intake has a hump where the head bolt goes through..and that's going to be the thin spot.. ill try to cut it tonight and post results.

 

[RED09GT]

rcm90, great pics! Would you be able to give me the measurement of the thickness of the wall between the bowl and the water jacket just above the exhaust valve?
Also, how thick is the material in the intake port where it necks down due to the spark plug boss?
It seems like the CNC'd heads are able to create a consistently round bowl on the intake whereas the stock heads have a big bottleneck right there

 

[rcm90]

Will get measurements, and I will cut the spark plug boss as well.

 

[RED09GT]

Will get measurements, and I will cut the spark plug boss as well.

Perfect!

 

[rcm90]

Exhaust side

I started with the exhaust runner, cutting down the center


Backside of the runner


Cut profile of the runner smallest area I measured was .206"



Then at the top of the runner I measured .167" from the water jacket to the port roof. The least amount of material is from the valve guide to the valve seat area, with it coming to .140" at the smallest.


I tried to clean up all the casting flash before cutting to be able to measure off of a more smooth surface, so there is probably .005-.010" more material than I'm actually showing.

 

[rcm90]

Intake side

Off to the intake side!
Here I am cutting down the centerline of the sparkplug.


Cutting down the centerline of the sparkplug and intake runner.


From the shoulder of the plug to the port was the closest at .212"


In this one the closest spot is roughly .150" up from where the valve seat rests, and at its thinnest its .196"


This little guy is cut where the spark plug sealing surface is or where the threads begin. It's is the closest spot in this photo, at .216"


Then from the valve guide to the seat, the thinnest area is .154"

Again I tried to clean up the casting flash, so .005-.010" can probably be added to these measurements.

 

[JoshK]

Why is this still in chit chat?

 

[Department Of Boost]

I love that there is just a random turbo hanging out in this picture.

I started with the exhaust runner, cutting down the center


Backside of the runner
http://s1291.photobucket.com/user/R... Uploads/20131209_185403_zps01756676.jpg.html

Cut profile of the runner smallest area I measured was .206"



Then at the top of the runner I measured .167" from the water jacket to the port roof. The least amount of material is from the valve guide to the valve seat area, with it coming to .140" at the smallest.
http://s1291.photobucket.com/user/R... Uploads/20131209_185744_zps34065827.jpg.html

I tried to clean up all the casting flash before cutting to be able to measure off of a more smooth surface, so there is probably .005-.010" more material than I'm actually showing.

What is the diameter of the port right above the valve on the intake and exhaust?

What are the intake port dimensions?

How about the exhaust port?

I want to do some figurin.

Thanks

 

[rcm90]

I love that there is just a random turbo hanging out in this picture.



What is the diameter of the port right above the valve on the intake and exhaust?

What are the intake port dimensions?

How about the exhaust port?

I want to do some figurin.

Thanks

Haha, I've got my turbo kit just hanging out in the extra room until I finish fabricating the coldside.

On the exhaust where the valve seat rests it is 1.262", farther up (from where I could measure and its not going to be accurate) is 1.079"

The intake side where the valve seat rests is 1.155",and farther up I measured 1.109"x1.148".

Again I have no way to accurately measure this. I will get some repro rubber and mold both runners and be able to make a few sets so they can be sent to a few guys if wanted.

 

[RED09GT]

Excellent work rcm90!

 

[rcm90]

I love that there is just a random turbo hanging out in this picture.



What is the diameter of the port right above the valve on the intake and exhaust?

What are the intake port dimensions?

How about the exhaust port?

I want to do some figurin.

Thanks

I will measure the I.d of the valve guide as well.. forgot to do that.

 

[05moneypit]

Here are some pictures of my heads. They were hand ported by a local shop. Final numbers are 315 intake and 218 exhaust. He said when he did them that he could probably get a bit more out of the exhaust but was afraid of hitting the water jacket. I dont have a picture of them but he also matched the CMDP's to the intake side.

 

[rcm90]

Here are some pictures of my heads. They were hand ported by a local shop. Final numbers are 315 intake and 218 exhaust. He said when he did them that he could probably get a bit more out of the exhaust but was afraid of hitting the water jacket. I dont have a picture of them but he also matched the CMDP's to the intake side.

Do you know mid lift flow numbers? Also what lift were the ports when they did315/218? Also do you know how big the intake and exhaust runners were in CC's?

 

[05stroker]

Here are some pictures of my heads. They were hand ported by a local shop. Final numbers are 315 intake and 218 exhaust. He said when he did them that he could probably get a bit more out of the exhaust but was afraid of hitting the water jacket. I dont have a picture of them but he also matched the CMDP's to the intake side.

Looks nice! I think my exhaust and combustion chambers will look a lot like that but the intake will me much larger in the opening to match the runners on my JPC intake. The delete plate will be the same from top to bottom, I may open the top some and do some porting on the intake opening also. My machine shop cut the plates down today 5.5mm to make the bottom side smooth like the top. I will play with is some on Sat. and see how far I can go.

 

[05moneypit]

Do you know mid lift flow numbers? Also what lift were the ports when they did315/218? Also do you know how big the intake and exhaust runners were in CC's?

This is the flow sheet he gave me when he did them. He didn't CC the runners as far as I know.

 

[rcm90]

This is the flow sheet he gave me when he did them. He didn't CC the runners as far as I know.

Thanks for posting this! Were your heads ported before he got ahold of them? Those "untouched" numbers seem a bit high, I could be wrong though. I'm going to try to grab all of the data I can then input it to an excel file and hopefully get an organized thread so people can go to one place to get cylinder head info.

 

[RED09GT]

Thanks for posting this! Were your heads ported before he got ahold of them? Those "untouched" numbers seem a bit high, I could be wrong though. I'm going to try to grab all of the data I can then input it to an excel file and hopefully get an organized thread so people can go to one place to get cylinder head info.

The before numbers are very high.
Oh well, there are definite improvements.

awesome autocorrect malfunctions brought to you by tapatalk

 

[05moneypit]

They were stock before the porting. I figure flow numbers are kinda like dyno numbers....

 

[rcm90]

They were stock before the porting. I figure flow numbers are kinda like dyno numbers....

They are, just suprised how high they were. Ill just go with a % increase over total flow.

Also ordered some casting rubber and it should be in on Monday.