Engine Build
Thread Starter
Instructor
Joined: Apr 2006
Posts: 201
Likes: 3
You guys made me nervous about the CR, so I guess I made my builder nervous too. He came back to me and suggested that we can buy the same Iron Eagle 180 head with a 72cc chamber. So I said go for it. I hope this combination makes a difference. So now I still have to make a decision about angled plugs or straight plugs. I would like to go with angled plugs if possible because I have read that the burn propegation is better with them. But, I've talked to a couple of header companys and it seems that there is less choices available with angled plugs. I want to use long tube headers. Any opinions and products that you know of. Thanks.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
You guys made me nervous about the CR, so I guess I made my builder nervous too. He came back to me and suggested that we can buy the same Iron Eagle 180 head with a 72cc chamber. So I said go for it. I hope this combination makes a difference. So now I still have to make a decision about angled plugs or straight plugs. I would like to go with angled plugs if possible because I have read that the burn propegation is better with them. But, I've talked to a couple of header companys and it seems that there is less choices available with angled plugs. I want to use long tube headers. Any opinions and products that you know of. Thanks.
Burning Brakes
Joined: Nov 2014
Posts: 951
Likes: 215
From: Foothills of the Adirondacks.
One last FYI, I weighed the stock assembled factory iron heads, intake manifold, water pump, and exhaust manifold. In comparison the new alum heads, intake, water pump, and long tube headers weighed in 100 lbs less. I thought that was pretty cool in an engine that makes 240 more HP.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I ran your numbers here;
http://www.jeepstrokers.com/calculator/
With the 64 cc heads and 5cc pistons, 4.030 bore, .040 squish, 5.7" rods and the CS XR276HR-10 cam you get.
11.12 CR and 8.96 DCR. That DCR is too high for pump gas.
Now change to a 72 cc head and you get.
10.17 CR and 8.22 DCR. That DCR is just right for aluminum, not for cast iron.
increase the pistons to 7cc and you get.
9.96 CR and 8.05 DCR. Still just a skoosh high for cast iron to be comfortable.
increase to 12cc pistons
9.48 CR and 7.67 DCR. Comfortable for cast iron heads.
You could try for a 9cc piston if you can find one and that would put you at 7.9 DCR.
If you do get dish pistons get the D-dish or also called the reverse dome piston like this one shown here.
http://www.summitracing.com/parts/ue...-030/overview/
Note that they have a flat area for quench when approaching the head. This is important for turbulance for the fuel air mixture and good flame propagation to prevent detonation.
Let us know how it goes.
One more option is to take that cam you chose and have it ground on a 112 LSA. That would drop your DCR to 7.93.
Or choosing a cam with a slightly later intake closing. The one you chose is at 64*. So if it were moved to say 66* then you could drop the DCR to 7.93 as well.
Many different ways to get it in a good operating range. DCR isn't the end all of cam a choice, but it is a good indication of if it will run well on pump fuel without problems from detonation.
http://www.jeepstrokers.com/calculator/
With the 64 cc heads and 5cc pistons, 4.030 bore, .040 squish, 5.7" rods and the CS XR276HR-10 cam you get.
11.12 CR and 8.96 DCR. That DCR is too high for pump gas.
Now change to a 72 cc head and you get.
10.17 CR and 8.22 DCR. That DCR is just right for aluminum, not for cast iron.
increase the pistons to 7cc and you get.
9.96 CR and 8.05 DCR. Still just a skoosh high for cast iron to be comfortable.
increase to 12cc pistons
9.48 CR and 7.67 DCR. Comfortable for cast iron heads.
You could try for a 9cc piston if you can find one and that would put you at 7.9 DCR.
If you do get dish pistons get the D-dish or also called the reverse dome piston like this one shown here.
http://www.summitracing.com/parts/ue...-030/overview/
Note that they have a flat area for quench when approaching the head. This is important for turbulance for the fuel air mixture and good flame propagation to prevent detonation.
Let us know how it goes.
One more option is to take that cam you chose and have it ground on a 112 LSA. That would drop your DCR to 7.93.
Or choosing a cam with a slightly later intake closing. The one you chose is at 64*. So if it were moved to say 66* then you could drop the DCR to 7.93 as well.
Many different ways to get it in a good operating range. DCR isn't the end all of cam a choice, but it is a good indication of if it will run well on pump fuel without problems from detonation.
Last edited by REELAV8R; Jan 17, 2015 at 12:53 PM.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
I ran your numbers here;
http://www.jeepstrokers.com/calculator/
With the 64 cc heads and 5cc pistons, 4.030 bore, .040 squish, 5.7" rods and the CS XR276HR-10 cam you get.
11.12 CR and 8.96 DCR. That DCR is too high for pump gas.
Now change to a 72 cc head and you get.
10.17 CR and 8.22 DCR. That DCR is just right for aluminum, not for cast iron.
increase the pistons to 7cc and you get.
9.96 CR and 8.05 DCR. Still just a skoosh high for cast iron to be comfortable.
increase to 12cc pistons
9.48 CR and 7.67 DCR. Comfortable for cast iron heads.
You could try for a 9cc piston if you can find one and that would put you at 7.9 DCR.
If you do get dish pistons get the D-dish or also called the reverse dome piston like this one shown here.
http://www.summitracing.com/parts/ue...-030/overview/
Note that they have a flat area for quench when approaching the head. This is important for turbulance for the fuel air mixture and good flame propagation to prevent detonation.
Let us know how it goes.
One more option is to take that cam you chose and have it ground on a 112 LSA. That would drop your DCR to 7.93.
Or choosing a cam with a slightly later intake closing. The one you chose is at 64*. So if it were moved to say 66* then you could drop the DCR to 7.93 as well.
Many different ways to get it in a good operating range. DCR isn't the end all of cam a choice, but it is a good indication of if it will run well on pump fuel without problems from detonation.
http://www.jeepstrokers.com/calculator/
With the 64 cc heads and 5cc pistons, 4.030 bore, .040 squish, 5.7" rods and the CS XR276HR-10 cam you get.
11.12 CR and 8.96 DCR. That DCR is too high for pump gas.
Now change to a 72 cc head and you get.
10.17 CR and 8.22 DCR. That DCR is just right for aluminum, not for cast iron.
increase the pistons to 7cc and you get.
9.96 CR and 8.05 DCR. Still just a skoosh high for cast iron to be comfortable.
increase to 12cc pistons
9.48 CR and 7.67 DCR. Comfortable for cast iron heads.
You could try for a 9cc piston if you can find one and that would put you at 7.9 DCR.
If you do get dish pistons get the D-dish or also called the reverse dome piston like this one shown here.
http://www.summitracing.com/parts/ue...-030/overview/
Note that they have a flat area for quench when approaching the head. This is important for turbulance for the fuel air mixture and good flame propagation to prevent detonation.
Let us know how it goes.
One more option is to take that cam you chose and have it ground on a 112 LSA. That would drop your DCR to 7.93.
Or choosing a cam with a slightly later intake closing. The one you chose is at 64*. So if it were moved to say 66* then you could drop the DCR to 7.93 as well.
Many different ways to get it in a good operating range. DCR isn't the end all of cam a choice, but it is a good indication of if it will run well on pump fuel without problems from detonation.
Same info I got. Build as designed, 5 CC flat tops, 72 CC iron heads will not run on Premium pump gas. Change to 72 CC Aluminum heads your fine. I would avoid the Keith Black Hypereutectic pistons. SRP, Speedpro are fine. KB has high top ring and broken top ringlands are common. With modern combustion chamber design there is no advantage to angle plugs.
Last edited by 63mako; Jan 17, 2015 at 01:28 PM.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
KB has high top ring and broken top ringlands are common.
I believe that the broken top ring land is due primarily to installation error.
KB requires a much larger ring gap on the top ring than other manufacturers.
If you gap the top ring too small the ring ends butt together and seize in the bore breaking off the top ring land.
Gapped properly I have had no issues with my KBs. They are one of the few well priced pistons that have proper compression height and good D-dish design available. In flat tops you have many more options. D-dish, not so many.
Drifting
Joined: Oct 2005
Posts: 1,920
Likes: 51
From: Angier nc
Aluminum allows the best of both worlds,compression and timing.Why would you NOT want to take advantage of that??
The weight loss of the front end is an added bonus.
I don't understand the attraction to iron heads but then again I did fail kindergarten so have at it.
The weight loss of the front end is an added bonus.
I don't understand the attraction to iron heads but then again I did fail kindergarten so have at it.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
You guys made me nervous about the CR, so I guess I made my builder nervous too. He came back to me and suggested that we can buy the same Iron Eagle 180 head with a 72cc chamber. So I said go for it. I hope this combination makes a difference. So now I still have to make a decision about angled plugs or straight plugs. I would like to go with angled plugs if possible because I have read that the burn propegation is better with them. But, I've talked to a couple of header companys and it seems that there is less choices available with angled plugs. I want to use long tube headers. Any opinions and products that you know of. Thanks.
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Thread Starter
Instructor
Joined: Apr 2006
Posts: 201
Likes: 3
My last conversation with the builder, he said with the 72 cc heads that the compression was going to come in around 9. something. A very high 9.xxx to 1.
So my next question is, i don't understand these different piston cc's. If the pistion is a flattop, how do you get a 5cc piston, or a 7cc piston , or 9 or 12cc??? Oldchev.
So my next question is, i don't understand these different piston cc's. If the pistion is a flattop, how do you get a 5cc piston, or a 7cc piston , or 9 or 12cc??? Oldchev.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
My last conversation with the builder, he said with the 72 cc heads that the compression was going to come in around 9. something. A very high 9.xxx to 1.
So my next question is, i don't understand these different piston cc's. If the pistion is a flattop, how do you get a 5cc piston, or a 7cc piston , or 9 or 12cc??? Oldchev.
So my next question is, i don't understand these different piston cc's. If the pistion is a flattop, how do you get a 5cc piston, or a 7cc piston , or 9 or 12cc??? Oldchev.
http://www.summitracing.com/search/p...rder=Ascending
These are all Dish 12 CC. Notice also there are different compression heights (pin centerline to piston top) which give you different piston to deck distances that also effect compression.
http://www.summitracing.com/search/p...rder=Ascending
Safety Car
Joined: Jan 2009
Posts: 4,000
Likes: 299
From: New York
Cheap ........ That is the only real reason any would use an iron head.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
The odd thing is they are not cheap, actually pretty expensive. Iron Eagle 72 CC heads set up with Roller Springs are $1300. You can buy Profiler heads that are aluminum, flow better, made in USA and set up with roller springs for a couple hundred less or the DART SHP for the same price.
Thread Starter
Instructor
Joined: Apr 2006
Posts: 201
Likes: 3
Engine Build
Hi Folks, thought I would give you an update on my new engine. Last Saturday I watched them dyno it. It's going to be delivered tomorrow.
Here's the facts: 415 lb-ft at 2500rpms. ( since I'm running 2550 at 65mph I think we nailed that pretty good) Holds that to around 4100rpms. Then is climbs...at 4323rpms peak torque is 490 lb-ft. At 5400 torque is 446 lb-ft and HP is 459. At 5900rpms torque is 415 again and peak HP hits 467 horsepower. Geez, I hope that's going to be enough.
The engine has the parts in it that we've discussed during this thread. Dart Iron Eagle 180, 72cc heads, Flat Top Pistons, Comps 08-423-8 cam, Edelbrock Performer intake. Dave.
Here's the facts: 415 lb-ft at 2500rpms. ( since I'm running 2550 at 65mph I think we nailed that pretty good) Holds that to around 4100rpms. Then is climbs...at 4323rpms peak torque is 490 lb-ft. At 5400 torque is 446 lb-ft and HP is 459. At 5900rpms torque is 415 again and peak HP hits 467 horsepower. Geez, I hope that's going to be enough.
The engine has the parts in it that we've discussed during this thread. Dart Iron Eagle 180, 72cc heads, Flat Top Pistons, Comps 08-423-8 cam, Edelbrock Performer intake. Dave.
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
Hi Folks, thought I would give you an update on my new engine. Last Saturday I watched them dyno it. It's going to be delivered tomorrow.
Here's the facts: 415 lb-ft at 2500rpms. ( since I'm running 2550 at 65mph I think we nailed that pretty good) Holds that to around 4100rpms. Then is climbs...at 4323rpms peak torque is 490 lb-ft. At 5400 torque is 446 lb-ft and HP is 459. At 5900rpms torque is 415 again and peak HP hits 467 horsepower. Geez, I hope that's going to be enough. The engine has the parts in it that we've discussed during this thread. Dart Iron Eagle 180, 72cc heads, Flat Top Pistons, Comps 08-423-8 cam, Edelbrock Performer intake. Dave.
Here's the facts: 415 lb-ft at 2500rpms. ( since I'm running 2550 at 65mph I think we nailed that pretty good) Holds that to around 4100rpms. Then is climbs...at 4323rpms peak torque is 490 lb-ft. At 5400 torque is 446 lb-ft and HP is 459. At 5900rpms torque is 415 again and peak HP hits 467 horsepower. Geez, I hope that's going to be enough.
The engine has the parts in it that we've discussed during this thread. Dart Iron Eagle 180, 72cc heads, Flat Top Pistons, Comps 08-423-8 cam, Edelbrock Performer intake. Dave.
Le Mans Master
Joined: Oct 2007
Posts: 7,455
Likes: 977
From: RI, Now Franklin/Nashville TN
Le Mans Master
Joined: Oct 2007
Posts: 7,455
Likes: 977
From: RI, Now Franklin/Nashville TN
Hi Folks, thought I would give you an update on my new engine. Last Saturday I watched them dyno it. It's going to be delivered tomorrow.
Here's the facts: 415 lb-ft at 2500rpms. ( since I'm running 2550 at 65mph I think we nailed that pretty good) Holds that to around 4100rpms. Then is climbs...at 4323rpms peak torque is 490 lb-ft. At 5400 torque is 446 lb-ft and HP is 459. At 5900rpms torque is 415 again and peak HP hits 467 horsepower. Geez, I hope that's going to be enough. The engine has the parts in it that we've discussed during this thread. Dart Iron Eagle 180, 72cc heads, Flat Top Pistons, Comps 08-423-8 cam, Edelbrock Performer intake. Dave.
Here's the facts: 415 lb-ft at 2500rpms. ( since I'm running 2550 at 65mph I think we nailed that pretty good) Holds that to around 4100rpms. Then is climbs...at 4323rpms peak torque is 490 lb-ft. At 5400 torque is 446 lb-ft and HP is 459. At 5900rpms torque is 415 again and peak HP hits 467 horsepower. Geez, I hope that's going to be enough.
The engine has the parts in it that we've discussed during this thread. Dart Iron Eagle 180, 72cc heads, Flat Top Pistons, Comps 08-423-8 cam, Edelbrock Performer intake. Dave.
Thread Starter
Instructor
Joined: Apr 2006
Posts: 201
Likes: 3
Thanks All. And a very special thanks to everyone for all the help. It won't be running in the car for awhile because I have alot of detail work to bring the car up to how I want it now. But I'll be around and wanting to discuss some of the other work. Thanks again. Dave.
Burning Brakes
Joined: Nov 2012
Posts: 788
Likes: 100
From: Indianapolis IN
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
Mine looks identical to this with the exception of the stud on ps rear runner.
http://www.summitracing.com/parts/wnd-7546
Last edited by Kacyc3; Feb 28, 2015 at 02:10 PM.
