Casting 655 cylinder head

[Dez]

What type of head would this be?

Would this be considered a Bathtube head used from 1983-1994?



Thank you.

[GLHNSLHT2]

It's a bathtub head but it's a bit better than the 455 or 287. It flows pretty good right off the bench. There's flow sheets posted around here somewhere on it.

[Dez]

Sweet, is this a drop in to any 2.2/2.5 engine?

Supposedly(sp?) it is 6cc bigger than the 782, correct?

[The Pope]

turbododge has many threads on these heads. Flow sheets and so on.

[BadAssPerformance]

Sweet, is this a drop in to any 2.2/2.5 engine?

Supposedly(sp?) it is 6cc bigger than the 782, correct?

Yes, larger CC, lower compression... I prefer the "G" head (or bathtub) on my 2.2L's Stock to stock other than compression they are very similar. The "G" heads allow for more porting options for maximum flow port jobs.

[mock_glh]

It seems to me that the lower port floor would reduce flow to that side of the valve opening. I've seen many articles on porting that essentially stated that the "line of sight" opening may look bigger but the flow can't negotiate the sharp turn that this creates. I have flowbench experience to verify this.

[4 l-bodies]

It seems to me that the lower port floor would reduce flow to that side of the valve opening. I've seen many articles on porting that essentially stated that the "line of sight" opening may look bigger but the flow can't negotiate the sharp turn that this creates. I have flowbench experience to verify this.

Yep I would concur 100%. The short turn radius is ultra flow sentitive.
Todd

[GLHNSLHT2]

http://www.turbododge.com/forums/f4/...ck-655-8v.html Flow sheet's posted.

[Directconnection]

It seems to me that the lower port floor would reduce flow to that side of the valve opening. I've seen many articles on porting that essentially stated that the "line of sight" opening may look bigger but the flow can't negotiate the sharp turn that this creates. I have flowbench experience to verify this.

Exactly!

[mock_glh]

You really can't compare a 782 head to a bathtub chamber head as far as flow is concerned. The 782 head has about 1/3 of the valve opening blocked off to achieve the swirl effect. They need to be unshrouded before they flow any good.

[The Pope]

the floor at the seat is higher than a 782 head in the 655. The 782 has a dip in it. The fact that the floor is lower at gasket makes the port have higher volume. Unless you guys don't think that the short turn radius has anything to do with flow? So that would mean you guys are for a raised floor port with less volume and less than zero short turn radius at the seat. Doesn't matter though, the 655 beats all the other 8v heads on the flow bench out of the box. At all lifts....

[Turbodave]

Rob, have you got any back to back testing on a 655 casting vs a 445 or 287 bathtub head? I've got one of each around, but I had always thought the 655 casting from the 81/82 cars wasn't worth using based on the old MP 2.2 book, but as you know that's not always the best source. This is interesting info.

[WickedShelby88]

Sounds like with a good port job the 655 is the way to go.. Didn't know what cars they came on. I think I will be looking for one of those for my SC project.

[mock_glh]

The engines that had the 655 head ('81-'82) were 84 hp. The ones with the other heads were 96 hp. Either something else was different or there is more to horsepower than flowbench numbers.

[MiniMopar]

Either something else was different or there is more to horsepower than flowbench numbers.

That is the craziest thing I have ever heard.

[turbovanman²]

I thought Steve aka DC said the 655 was the worst G-head for flow?

[John B]

[mock_glh]

Doesn't matter though, the 655 beats all the other 8v heads on the flow bench out of the box. At all lifts....

The engines that had the 655 head ('81-'82) were 84 hp. The ones with the other heads were 96 hp. Either something else was different or there is more to horsepower than flowbench numbers.

I'm supporting The Pope here. Then I'm giving some facts.

[4 l-bodies]

Okay 655 lovers, this is a cross-sectional cut away illistration of the 655 and 445/287 head. If we are all in agreement that the short turn radius is important, tell us believers in the later heads how the 655 short turn is better? Why wasn't there ANY HP +1 and BV heads offered by Direct Connection or MP in the 655 design?

A picture speaks a thousand words.
Todd

[Turbodave]

Thanks for the pics Todd, that does illustrate things well. I was looking for those last night, thought they were in the MP 2.2 book, but they weren't.