Custom cut aluminum pistons

pmuller9 said:
The 4032 alloy has less thermal expansion than the 7075
I assuming you would temper the 7075 to T6?

You mentioned 4.25" bore.
Will the bore spacing stay at 4.480"?
Will this be a cast iron block?
Will you improve cylinder head sealing by going to a six bolt pattern around the cylinders rather than the present four bolt?
Four bolt or Cross bolted main caps?
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Would be going with a 4.900 bore space with 10.00 deck height,

Aluminum

6 bolts for the head has been entertained as i did have an issue a years back

I entertained the idea of having standard caps with a 6 bolt cradle with windage cover

For oiling have the pump run off the crank rather than the cam

Tiple pattern flange on the rear to accept sbf, bbf, and diesel pattern transmissions

Maybe a slot for a high pressure fuel pump and low pressure carb pump

Leaning towards running a timing chain that is thick or running gears all the way up like the cosworth DFV to drive the cam

Cam drive at the front like the smaller 6s so you have the choice to run a distributor

Dedicated oil cooler lines that exit the motor and could be used in a turbo application

Oil squirters that mount from the block rather than run through the rods

Dont really have anything else that i could think of needing to change but if it comes up will be worked on
 
pmuller9 said:
The 240/300/4.9 head ports are undersize for the 50 cu inch 300 cylinder displacement even with bigger valves and porting.
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Paul, this is incorrect. The stock port size is big enough for a 4,500- 5,000 rpm motor that achieves 100%ve. The problem is the port chokes at a low velocity. That’s where your cfm limit comes from.

A stock head can move 90cfm per square inch. The head I have been working on is moving 113.5cfm per square inch.
 
Wesman07 said:
The problem is the port chokes at a low velocity. That’s where your cfm limit comes from.
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Correct me if I'm wrong.
As the velocity increases, the 80-degree port angle makes it difficult for the airflow to turn around the short turn radius which chokes the port as the airflow is pushed to the other side of the throat.
This decreases the effective area of the throat
 
Wesman07 said:
A stock head can move 90cfm per square inch. The head I have been working on is moving 113.5cfm per square inch.
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I have read a good deal of your porting and testing, at least I believe I got to follow it.

When you achieved this flow number, at what size valve and lift was this possible?
 
pmuller9 said:
Correct me if I'm wrong.
As the velocity increases, the 80-degree port angle makes it difficult for the airflow to turn around the short turn radius which chokes the port as the airflow is pushed to the other side of the throat.
This decreases the effective area of the throat
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Yes. That is correct. There is another challenge that compounds this situation, but what you are saying is correct.
 
sixtseventwo4d said:
I have read a good deal of your porting and testing, at least I believe I got to follow it.

When you achieved this flow number, at what size valve and lift was this possible?
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I have a test port that moves over 220cfm… maybe 230? (It was off my calibration chart) with a 1.78” valve @ 0.600” lift. I did not use this port design though. It was too difficult to achieve repeatable results and the flow at 0.600” lift was not important to me. It was more of an experiment.

As a general rule for valves, a wedge head can flow a maximum of 80cfm/sqin of valve area at 0.5” lift and 90cfm/sqin at 0.8”lift. A really good wedge head might be closer to 90cfm/sqin of valve area at 0.5” and 100cfm/sqin at 0.8” lift.
 
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Wesman07 said:
I have a test port that moves over 220cfm… maybe 230? (It was off my calibration chart) with a 1.78” valve @ 0.600” lift. I did not use this port design though. It was too difficult to achieve repeatable results and the flow at 0.600” lift was not important to me. It was more of an experiment.

As a general rule for valves, a wedge head can flow 80cfm/sqin of valve area at 0.5” lift and 90cfm/sqin at 0.8”lift. A really good wedge head might be closer to 90cfm/sqin of valve area at 0.5” and 100cfm/sqin at 0.8” lift.
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So what would be the ideal angle for each face with the intake and exhaust valve for the wedge? 45 degrees? 50?
 
Tbone3366 said:
So what would be the ideal angle for each face with the intake and exhaust valve for the wedge? 45 degrees? 50?
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That depends on your intentions. 45 degree seat are most common for street applications because they last a long time. 50 and 55 degree seats can yield more high lift flow at the expense of longevity.
 
Wesman07 said:
That depends on your intentions. 45 degree seat are most common for street applications because they last a long time. 50 and 55 degree seats can yield more high lift flow at the expense of longevity.
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Ok, for the cam i was thinking about running a 1.6 ratio rockers above the cam (sohc config) but will be milled and be roller rockers, should there be a crease in the roof, or should it be rounded
 
I’m not sure I follow your question. And I am hesitant to answer anything regarding over head cam designs as my experience is limited to rebuilds. I have only become intimate with these 300 heads.

What I can give you is a link to many online calculators that will be of use. If you scroll down you will find one that will use bore, stroke and MCSA (minimal cross sectional area). This will tell you what rpm your port will be optimal for.

 
Wesman07 said:
I’m not sure I follow your question. And I am hesitant to answer anything regarding over head cam designs as my experience is limited to rebuilds. I have only become intimate with these 300 heads.

What I can give you is a link to many online calculators that will be of use. If you scroll down you will find one that will use bore, stroke and MCSA (minimal cross sectional area). This will tell you what rpm your port will be optimal for.

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Ok thank you and no worries, im the inverse, but with turbo applications in mind, dohc motors specifically
 
A Pent Roof type Combustion Chamber can work very well and likely is much easier to machine or cast in place over the Hemi Style Chambers, I guess depends on the equipment you have to work with.
 
Tbone3366 said:
Ok, for the cam i was thinking about running a 1.6 ratio rockers above the cam (sohc config) but will be milled and be roller rockers, should there be a crease in the roof, or should it be rounded
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A hydraulic SOHC rocker arm arrangement typically has the roller follower under the cam with the valve tip at one end and the hydraulic adjuster at the other end.
A 1.6 ratio follower will have less force on the roller over a higher ratio follower.

Will you use a hydraulic adjuster?
 
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6.2 Raptor/SD has wee hydraulic lash adjusters at their valve end


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pmuller9 said:
Roller cam follower rocker arms typically sit below the cam with the valve tip on one end and the adjuster on the other.
A 1.6 ratio follower will have less force on the roller over a higher ratio follower.

Will you use a hydraulic adjuster?
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Ok, and yes i will be using a hydraulic lash adjustment
 
pmuller9 said:
Thanks Firepower
I stand corrected.
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I ordered the rocker, im going to make a quick foam test rocker shaft and set it ontop of my 240 head and snap pics see how it would sit centered and get the angle of how it rests with the approximate angle of the valves
 
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