• 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
D0AE-N CC Head Unshrouding
#1
Guys my question is how many CC's can be gained by unshrouding the valves, 2.19 & 1.71? I know the D0AE-N is supposed to be around 63 CC combustion chamber. I would like to be around 68-70CC's after unshrouding and polishing combustion chambers. Can this be accomplished?
  Reply
#2
Can I ask why you want to lower the compression? I am running CC 2V heads from Australia with around 62cc combustion chamber and run 91 octane pump gas no problem.

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
  Reply
#3
73pony Wrote:Can I ask why you want to lower the compression? I am running CC 2V heads from Australia with around 62cc combustion chamber and run 91 octane pump gas no problem.
My preference is to be around 9.7-9.8:1 compression. Higher altitudes you can get away with more compression. We are on the coast almost at sea level not as forgiving.
  Reply
#4
Ah got you. If you know your cam specs you can also calculate the dynamic compression ratio. There is a calculator on here somewhere for that. IMHO that is more important than static when it comes to performance and detonation. As for how much you can gain by unshrouding the valves, I am not sure. When mine were done it added about 3cc. The Aussie heads are around 59 CC stock.

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
  Reply
#5
73pony Wrote:Ah got you. If you know your cam specs you can also calculate the dynamic compression ratio. There is a calculator on here somewhere for that. IMHO that is more important than static when it comes to performance and detonation. As for how much you can gain by unshrouding the valves, I am not sure. When mine were done it added about 3cc. The Aussie heads are around 59 CC stock.
Our camshaft is a Comp hydraulic roller with LSA 110, 275/281 advertised duration, 224/230 @ .050 duration, and 569/578 lift with 1.73 rockers. I do not know the opening and closing rates though. I called Comp Cams and they no longer can pull that data for special grinds. I probably should try to spec it out with a degree wheel.
  Reply
#6
It should be on the cam sheet that cam with the cam if you still have it.

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
  Reply
#7
73pony Wrote:It should be on the cam sheet that cam with the cam if you still have it.
I do not have a cam card. All the specs I have came off of the Comp Cam box. I have watched videos on how to use a degree wheel to find the opening and closing rates. Cannot find or calculate dynamic compression without those figures.
  Reply
#8
The spreadsheet in this thread will get you close. It uses degrees intake valve opens ABDC and has a calculator to calculate it based on information you should have from the box.

https://www.7173mustangs.com/thread-engi...sion+ratio

2 tabs in sheet, one is static and the other is dynamic.

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
  Reply
#9
On my 71 4v with the deck skimmed and heads shaved, i.e. trued up, I went with +.030" Keith Black hypo KB 148 13cc dished piston. That gives me pretty much what you're looking for, just below 10:1. These KB pistons have a compression height .020" higher than stock Ford pistons, so in my case zero deck. With 64cc GA heads and .039" compressed head gaskets, with a Melling MTF 2 flat tappet cam, the motor runs strong on 91 Shell. 
You will very likely need to rebuild and recurve your distributor especially if you have a stock Autolite or Mastercraft distributor. Clevelands seem to like about 14 - 16 degrees of initial timing with a MAX of 34 -36 total mechanical timing, vacuum plugged off then add about 4 -6 deg of vacuum advance. If you do not run a factory style dizzy, please do not use a cheapo HEI pos. Best bet would be a custom DuraSpark ,I think its from Performance Distributors or something like that.
If you want or need more info on what I did on the distributor, search for my thread or pm me
Good luck,
Geoff.

I learn something new every day!
  Reply
#10
Unshroud the valves for better air flow, but don't remove any more material from the heads otherwise-you'll change their quench characteristics and end up with an unknown and unpredictable outcome. Buy Cometic head gaskets in the necessary thickness to get to your desired compression ratio. Heavily modified heads have reduced value if that matters to you

[Image: 1_01_07_15_8_53_18.png]

"I love my Hookers!" and "Get some Strange" probably have a different connotation to non automotive enthusiasts!
  Reply
Share Thread:  


Possibly Related Threads…
Thread Author Replies Views Last Post
  Head light flashing when using turn signal Robert sneed 1 142 06-21-2019, 07:03 PM
Last Post: Don C
  Cylinder head repair - Opinion's? 7173Vert 2 283 03-31-2019, 01:35 PM
Last Post: 7173Vert
  Are these the right gaskets for head and intake? scgamecock 4 321 02-20-2019, 11:34 AM
Last Post: Carolina_Mountain_Mustangs
  How fafr should I take my 4v head rebuild? scgamecock 5 365 01-05-2019, 07:18 PM
Last Post: Hemikiller
  Amazing how cheap this head combo is!!! scgamecock 19 1,045 11-20-2018, 07:44 PM
Last Post: EvilPuppetMaster
  Should you use head studs? scgamecock 7 467 11-20-2018, 08:53 AM
Last Post: Ron Tanzi
  Where is the water coming from, head?? scgamecock 4 394 11-10-2018, 10:19 AM
Last Post: jowens1126
  Head and Exhaust Confusion digithead 14 1,176 04-20-2018, 07:47 AM
Last Post: Hemikiller



Users browsing this thread: 1 Guest(s)