Ported Dart pro 1 pre platinum

[Carnut1]

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First 1206 pull. Close to goals. How do the experts cc a port that has been cut into the common wall bolt? I was using a bit of vaseline to keep it watertight but that isn't holding at this point. Thanks, Charlie

[JoePorting]

Port cc isn't important. Make sure the roof is straight by checking it with a straight edge such as a 6" machinist steel ruler. Also try and make the bowl is as deep as possible by cutting up to the spring seat, then blend it into the straight roof line. SBC heads suffer from a shallow bowl.

[Carnut1]

Port cc isn't important. Make sure the roof is straight by checking it with a straight edge such as a 6" machinist steel ruler. Also try and make the bowl is as deep as possible by cutting up to the spring seat, then blend it into the straight roof line. SBC heads suffer from a shallow bowl.

Been watching the spring seat depth. Inching up on it. Thanks, Charlie

[user-612937456]

I haven't heard anybody suggest epoxy the floor to shrink the volume and move the speed up closer to the roof?

[statsystems]

I haven't heard anybody suggest epoxy the floor to shrink the volume and move the speed up closer to the roof?

I've seen that not work. It depends on the head. Sometimes you need the volume and if you fill the floor it will kill flow above .450-.500

[JoePorting]

The smallest intake cross section on an SBC head is the first one inch. So filling in the floor might raise the lower lift numbers, but will reduce your high lift numbers.

[zums]

You have the info right there in your program, do you not know how to figure average port csa/ fps and how to apply it to a running engine?

[GARY C]

How do the experts cc a port that has been cut into the common wall bolt?

I sleeve mine so they don't leak I use the sleeve from a brass hinge kit made for a toilet seat, you can get them at home depot. It's easyer than making sleeves, just drill and are reem to half inch.
1 kit will do 1 head.
It's a kit like this.
http://www.ebay.co.uk/itm/REPLACEMENT-T ... 0741764389
BTW... Your screen shot looks like part of Vizards new program?

[Carnut1]

How do the experts cc a port that has been cut into the common wall bolt?

I sleeve mine so they don't leak I use the sleeve from a brass hinge kit made for a toilet seat, you can get them at home depot. It's easyer than making sleeves, just drill and are reem to half inch.
1 kit will do 1 head.
It's a kit like this.
http://www.ebay.co.uk/itm/REPLACEMENT-T ... 0741764389
BTW... Your screen shot looks like part of Vizards new program?

That is good info. I like the sleeves because they look better than an open hole but I have not done any myself. I was surprised how many cfm the hole ate up if I sealed the top of the hole. This is D.V.'s program. Thanks, Charlie

[JoePorting]

I've never seen any CFM gains from cutting even close to the head bolt holes. Don't see why people do it. Any given intake port wants to be tall and deep, not wide. Cutting into the head bolt holes just makes the port wide for no reason. An intake port shouldn't be any wider than the throat IMO.

[Carnut1]

You have the info right there in your program, do you not know how to figure average port csa/ fps and how to apply it to a running engine?

Actually, I unlike many on the internet don't know everything! I am working on changing that. If you could explain that I would appreciate it. I do know that matching the airspeed to the engine makes the torque improve in the rpm range you set it for which will improve horsepower in that range. The specs I have been given are as much power as possible and 400+ cubes @7000 + rpm. Maybe E85 maybe alcohol. It makes it harded to design if all the aspects aren't pinned down. Projects are just sometimes like this, and I still need to do the best job I can with what info I have. Thanks, Charlie

[Carnut1]

I've never seen any CFM gains from cutting even close to the head bolt holes. Don't see why people do it. Any given intake port wants to be tall and deep, not wide. Cutting into the head bolt holes just makes the port wide for no reason.

When I did my Afr 220's I came close but did not break through. Breaking through on these Darts was not intensional but just add it to the learning curve. On these I figured I already broke though I might as well make it wider, these bowls are narrow compaired to the AFR 220's so I was hoping for an nice gain but I did not see it. Thanks, Charlie

[GARY C]

That is good info. I like the sleeves because they look better than an open hole but I have not done any myself. I was surprised how many cfm the hole ate up if I sealed the top of the hole. This is D.V.'s program. Thanks, Charlie

I thought I recognized his work, I have the preliminary version of his recent cam and head program and it looks very similar.
I was taught when drilling and reaming for the sleeve to stop about a 1/2 inch above the deck surface, this leaves a lip for the sleeve to sit on so that the sleeve loads the deck surface when bolted down.

[Carnut1]

That is good info. I like the sleeves because they look better than an open hole but I have not done any myself. I was surprised how many cfm the hole ate up if I sealed the top of the hole. This is D.V.'s program. Thanks, Charlie

I thought I recognized his work, I have the preliminary version of his recent cam and head program and it looks very similar.
I was taught when drilling and reaming for the sleeve to stop about a 1/2 inch above the deck surface, this leaves a lip for the sleeve to sit on so that the sleeve loads the deck surface when bolted down.

Does anyone make a self guiding reamer for this? I needed to sell my good drill press before leaving N.Y. Thanks, Charlie

[GARY C]

I've never seen any CFM gains from cutting even close to the head bolt holes. Don't see why people do it. Any given intake port wants to be tall and deep, not wide. Cutting into the head bolt holes just makes the port wide for no reason. An intake port shouldn't be any wider than the throat IMO.

I bet Self Racing Heads, the inventor of the "Port Intruder" would greatly disagree with you. I know his customers would, or at least the two I know that started dominating their classes after switching to his heads.

Tony with AFR told me it is something that has to be factored in to what you are doing with the head and if not then you may not notice any improvement.