Max head flow for 25 psi race motor

[05stroker]

Started on one head today. It turned out very nice, the ports are HUGE now! I still have to polish the exhaust ports and un shroud the valves but, I need to get a valve spring removal tool first. Here are a few pics, although they don't really do them justice. They look better in person.

 

[BruceH]

You have been busy today. Are you going to have them tested on a flow bench?

 

[05stroker]

You have been busy today. Are you going to have them tested on a flow bench?

I hope so, if I can get access to one.

 

[05stroker]

I went a lot deeper in the ports the I had planned to smooth it all out.

 

[RocketcarX]

How much time do you have in them at this point?

 

[05stroker]

How much time do you have in them at this point?

About 4 hrs in this one head so far. That is marking it and all.

 

[Department Of Boost]

Here are a few pics, although they don't really do them justice. They look better in person.

I'd say that they do them justice. Those are HUGE!

 

[Department Of Boost]

About 4 hrs in this one head so far. That is marking it and all.

That's not too bad.

 

[Dubstep Shep]

Looks good!

 

[RED09GT]

You'll stay busy for a while in the bowl area once you see what the valves are hiding.
Good work so far.

awesome autocorrect malfunctions brought to you by tapatalk

 

[Department Of Boost]

You'll stay busy for a while in the bowl area once you see what the valves are hiding.
Good work so far.

awesome autocorrect malfunctions brought to you by tapatalk

This^^^^^^

I just did some quick and dirty math.

Intake:

Intake seats above the valve seat 27.94 diameter = 613sq mm x2 = 1226sq mm area

Your new intake opening 2345sq mm

So your intake runner opening to effective valve diameter ratio is about 50%

Even if you could port the area above the valve seat out to the valve size (which you obviously can't) you are still only looking at 1815sq mm of area at the valve end of the runner. Which would still leave you about 23% smaller. In a perfect world the valve end of the runner would be slightly bigger.

So it looks like you are going to want to get every bit you can out of the runners right above the valve seats. You can't make them too big.

Exhaust:

Exhaust ports above the valve seat 27.94mm = 613sq mm

Your new exhaust opening 1892 sq mm

So your exhaust runner opening to effective valve diameter ratio is about 30%

Even if you could port the area above the valve seat out to the valve size (which you obviously can't) you are still only looking at 1104sq mm of area at the valve end of the runner. Which would still leave you about 42% smaller. In a perfect world the valve end of the runner would be slightly smaller than the header end..

So it looks like you are going to want to get every bit you can out of the runners right above the valve seats. Like every bit you can get. You can't make them too big.

On a plus note your intake runner opening vs exhaust runner exit ratio is right at 80/20, which is great. Just gotta get the valve side of the runners a LOT bigger than they are now.

Hope that helps some.

 

[rcm90]

Are you going to check to see what cc the intake and exhaust runners are?

 

[05stroker]

You'll stay busy for a while in the bowl area once you see what the valves are hiding.
Good work so far.

awesome autocorrect malfunctions brought to you by tapatalk

This^^^^^^

I just did some quick and dirty math.

Intake:

Intake seats above the valve seat 27.94 diameter = 613sq mm x2 = 1226sq mm area

Your new intake opening 2345sq mm

So your intake runner opening to effective valve diameter ratio is about 50%

Even if you could port the area above the valve seat out to the valve size (which you obviously can't) you are still only looking at 1815sq mm of area at the valve end of the runner. Which would still leave you about 23% smaller. In a perfect world the valve end of the runner would be slightly bigger.

So it looks like you are going to want to get every bit you can out of the runners right above the valve seats. You can't make them too big.

Exhaust:

Exhaust ports above the valve seat 27.94mm = 613sq mm

Your new exhaust opening 1892 sq mm

So your exhaust runner opening to effective valve diameter ratio is about 30%

Even if you could port the area above the valve seat out to the valve size (which you obviously can't) you are still only looking at 1104sq mm of area at the valve end of the runner. Which would still leave you about 42% smaller. In a perfect world the valve end of the runner would be slightly smaller than the header end..

So it looks like you are going to want to get every bit you can out of the runners right above the valve seats. Like every bit you can get. You can't make them too big.

On a plus note your intake runner opening vs exhaust runner exit ratio is right at 80/20, which is great. Just gotta get the valve side of the runners a LOT bigger than they are now.

Hope that helps some.

These heads are already ported by Kuntz Racing. I would be afraid to take more out of the bowl area because I don't know what they have already removed. My goal here is to open up the runners like I have and unshroud the intake valves. Then get them on a flow bench if possible.

Are you going to check to see what cc the intake and exhaust runners are?

Yes and the combustion chambers Also. That way I will know if I need to mill the hard to keep the CR up.

 

[Department Of Boost]

These heads are already ported by Kuntz Racing. I would be afraid to take more out of the bowl area because I don't know what they have already removed. My goal here is to open up the runners like I have and unshroud the intake valves. Then get them on a flow bench if possible.

You could compare them to the measurements/cut-aways that RED09GT posted. It looked to me that there was a lot of room to grow in there.

When you get the valves out can you measure the ports just above the valve seat(s) and post them up? I'm curious. Thanks.

 

[05stroker]

You could compare them to the measurements/cut-aways that RED09GT posted. It looked to me that there was a lot of room to grow in there.

When you get the valves out can you measure the ports just above the valve seat(s) and post them up? I'm curious. Thanks.

I will measure them after the valves are out.

 

[Department Of Boost]

I will measure them after the valves are out.

Sweet, thanks.

 

[05stroker]

Sweet, thanks.

Intake 29.70mm

Exhaust 33.25mm

 

[05stroker]

Made a valve spring removal too today with a 8" C clamp and got the heads apart. There is a good bit of material on all three ports towards the spark plug that needs to come out. I will have to press the guides out to do what I want there. Best I can tell looking in the water jackets they are thicker there. I opened up one combustion chamber this evening. I think for the rest of them I will set up a guide and use a router with my die grinder bit so I can control the depth better and keep the line strait easier at the top of the intake valves. Here are a few pics. After I am done I will take a min. of .005 off the bottom of the head to clean it back up regardless off what all the cc numbers come to.

 

[JPO8GT]

Dang! your braver than i am. However some swear by hand porting.. We have a local shop that hand ports small and bb ford heads and his stuff is the fastest pushrods in our area. :thumbup: :thumbup:

 

[skwerl]

Why is this thread not moved to Tech yet?