stock 782 vs the stock 655 8v heads

[The Pope]

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This head I was told by Gary D flows less than a 782 at low lifts and therefore sucks. Clearly I wasted a lot of time on that BS. The 655 starts pulling away from a 782 at .100" lift on the intake and .200" on the exhaust.

On the being fair factor the 655 was machined 10 years ago and has the single angle cut seats and valves. The 782 in question has the muilti angle grinds and seat hone that is standard today.

[The Pope]

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Here we have the stock 655 flow curve and numbers, on the bench I use....

[The Pope]

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Here we have the POS 782 head complete with muilti angle seat and valve grinds rebuilt with no casting marks on my flow bench. Woohoo, no wonder there isn't a power difference most of the time between a 1 and 2 piece stated by people. The head flows worse than the intake. The way it should be though, an intake should always flow a little more. This wasn't even a fair baseline, it had things working in its favor and still dropped the ball.

[87OmniT2]

Thats funny, I was running a ported 655 head on my CSX which I purchased on ebay and everyone over on turbo mopar told me that head was junk and only an idiot would try and port one. I just sold it to pay for a LWP 782 head.

[The Pope]

Quote:

Originally Posted by 87OmniT2 Thats funny, I was running a ported 655 head on my CSX which I purchased on ebay and everyone over on turbo mopar told me that head was junk and only an idiot would try and port one. I just sold it to pay for a LWP 782 head.

The LWP is going to really out flow a stock 655. Extensive shaping and adding of matterial to a 782 vs a simple port job the 655 needs will make an expensive 782 work better. For most people the garage port job will take very little time to do. Then comes intakes. Port and polish a 2 piece and it kills 15 CFM on my head. If a lone wolf head really flows 30 CFM more than my head great, but if you stick a factory modded intake on it it will turn into a that flows no better that mine. The 2 piece can be opened up height wise in the runners to get air past the injector, but only if it is on the 655. I'll see pretty soon the results, But on my flow bench the ported 2 piece dropped flow to 166 per port. If I can get it up to 175 or 180 on a 655 it won't, matter how much CFM the 782 runs over the 655. The 655 would do better because of a better intake, not because it does better by itself. When you buy the LWP head be sure to add the $500-$600 more for the intake or you won't be able to use it.

[87OmniT2]

Quote:

Originally Posted by The Pope The LWP is going to really out flow a stock 655. Extensive shaping and adding of matterial to a 782 vs a simple port job the 655 needs will make an expensive 782 work better. For most people the garage port job will take very little time to do. Then comes intakes. Port and polish a 2 piece and it kills 15 CFM on my head. If a lone wolf head really flows 30 CFM more than my head great, but if you stick a factory modded intake on it it will turn into a that flows no better that mine. The 2 piece can be opened up height wise in the runners to get air past the injector, but only if it is on the 655. I'll see pretty soon the results, But on my flow bench the ported 2 piece dropped flow to 166 per port. If I can get it up to 175 or 180 on a 655 it won't, matter how much CFM the 782 runs over the 655. The 655 would do better because of a better intake, not because it does better by itself. When you buy the LWP head be sure to add the $500-$600 more for the intake or you won't be able to use it.

Im gonna play around with making my own intake. Ive got a one piece cut apart now and I plan on porting the runners not that the top hald of the plenum has been cut off. I will then enlarge the plenum substantially and TIG weld it all back together. We'll see what happens.

My 655 flowed 181/131 @ .500" The LWP head will hopefully be flowing 190's/178 @ .450" So, yea....there wont be any comparison. But it cost a few bucks more than the old ported 655.

[The Pope]

Quote:

Originally Posted by 87OmniT2 Im gonna play around with making my own intake. Ive got a one piece cut apart now and I plan on porting the runners not that the top hald of the plenum has been cut off. I will then enlarge the plenum substantially and TIG weld it all back together. We'll see what happens. My 655 flowed 181/131 @ .500" The LWP head will hopefully be flowing 190's/178 @ .450" So, yea....there wont be any comparison. But it cost a few bucks more than the old ported 655.

I haven't seen anyone sell a completely port big valve 782 for less than $1,500 done right. A guy could port a big valve 655 for $600 out the door and make money. In fact I could do 3-4 655 heads in the time to do one 782 right, and thats just cutting. The guys adding matterial and flow benching during porting have to really be spending time. A few bucks?

[Garret]

What cars are the 655s on? are those the early casting TBI heads?

[87OmniT2]

Quote:

Originally Posted by The Pope I haven't seen anyone sell a completely port big valve 782 for less than $1,500 done right. A guy could port a big valve 655 for $600 out the door and make money. In fact I could do 3-4 655 heads in the time to do one 782 right, and thats just cutting. The guys adding matterial and flow benching during porting have to really be spending time. A few bucks?

Mine is a stock valve 782. My 655 was a big valve head. The LWP stock valve will out flow the large valve 655 though.

What makes the 655 so much easier to port?

[87OmniT2]

Quote:

Originally Posted by Garret What cars are the 655s on? are those the early casting TBI heads?

They are early casting carbureted heads. 81-82. So, they would need turbo valves.

[gkcooper]

Is the 655 cast iron?

[The Pope]

Quote:

Originally Posted by 87OmniT2 Mine is a stock valve 782. My 655 was a big valve head. The LWP stock valve will out flow the large valve 655 though. What makes the 655 so much easier to port?

for starters there is no real combustion chamber work other than to polish a bath tub head. Then comes the massive intake port cutting on the 782. The 782 port gets 3/16" wide from gasket to bowl. Then it is raise 3/32" at the gasket to .300" at the guide, at that point your using straight edges to make sure there is no wave in the walls or the roof. Then there is measuring constantly to keep each runner exactly the same size, which you must do when making a huge cut and change in port shape. I use a caliper to check depth within .01" of each other and the same on the floor. I get the last .05" with 120 grit roles. Then when you get the seats done the machine cuts the combustion chamber and leaves a bump in the angle cut you have to take out.

The 655 needs the gasket matched on the exhaust which is a big cut but easy. Then the intake gets blended, removing the bumps and smoothing of edges. The intake is large enough that you don't make it really any bigger. Both will get very little in the bowls as well. My tool cuts 1/8" deep per second with aluminum so even the exhaust is a "quiky". The head just doesn't need much, less than most any other head needs. In fact porting wise I am going to do about the exact same thing to the 655 that I do to Edelbrock 440 RPM heads.

I would like to get the Powre Lynz tool and cut the intake. Big companys like Indy and others use this to create a boundry layer in huge ports. The air that is on the edge or the port is dead and slows flow, thats why polishing creates CFM. The Powre Lynz tool can create a boundry layer of air. This is like adding grease for the air to slide on that makes the port, from the airs eyes smaller and slicker. Some of there cuts are extreme. I want the CNC lined look which is very mild cuts to a polished runner. Again just on the intake but I think it is a good idea on the 655

[The Pope]

Quote:

Originally Posted by gkcooper Is the 655 cast iron?

no it looks like a 445 aluminum head with full size ports.

[puppet]

Here's a couple shots of a 655.
http://www.turbododge.com/forums/att...8&d=1143741179
http://www.turbododge.com/forums/att...9&d=1143741202

[Brian Putman]

Quote:

Originally Posted by puppet Here's a couple shots of a 655. http://www.turbododge.com/forums/att...8&d=1143741179 http://www.turbododge.com/forums/att...9&d=1143741202

That's the way the ports look on my 445 casting, except probably a little larger still. I know my exhaust ports are larger.