What's the difference?

[luv2pla]

I am running a limited late model dirt car with the old style Dart 215 Iron Eagle straight plug 64cc heads cut down to 55cc, 2.05/ 1.60 valves on a 360 c.i. SBC with a flat tappet cam (.590/.570, 259/266@0.050 I/E). I generally turn about 7,500 RPM. The engine has small dome pistons and a CR of about 15:1. I probably have around 500 hp.

My question is this: Everything else being the same, what HP and torque difference would I expect going from the old style Iron Eagles to the same thing in a new Iron Eagle angle plug platinum head? Just a percent change or some WAG at this is fine, but I'm sure someone has done an A/B comparison.

New to forum just thinking about some changes for 2009, and looking for advice.

Thanks.

[luv2pla]

OK, let me ask this another way. Will I get more usable power if I spend $750 to port my old Iron Eagles, or spend about that same money on a new set of Iron Eagle Platinum's, and just swap over the parts?

[luv2pla]

How about a guess?

[want-a-be]

Myself...I'd go with the porting. If you get a new set you'll end up wanting to port them also. Who are you thinking of using to do the porting?

It's my understanding that the new heads are a pretty good improvement over the older versions. Especially in the wet flow part of the equation. I've used a few of them on builds and really like how they preform. I'm sure if you make the decision to update, you'll be more then happy. I had a set of the old Dart2s the first year they came out. The new heads kick thier but.

How about the rest of your combination. I'd like to hear about intake to oil pan. What are some of the engine rules you have to play by? If I can help out any feel free to PM me or e-mail. Asking here will give you a pretty good variety of input also.

Dart Vader will be able to fill in any gaps you may have. I'm sure Bill will be chipping in also when they get back on line. Sorry you had to wait for a response. I've been pretty busy in the shop the last few weeks.

Don

[luv2pla]

010 SBC 4 bolt main block.
43 # Eagle forged crank
Carillo rods, 6in
JE pistons 0.070 over 13 cc domes
Comp Cams 12-515-5 flat tappet cam 1.6 intake, 1.52 exhaust rockers
Dart Iron Eagle 215 heads, 2.05 intake, 1.625 exhaust, flat milled to ~55cc, straight plug
Edelbrock Super Victor intake
Holley 750
MSD Ignition

One thing that bothers me - the "flame slot" in the pistons appears to be aligned for a angle plug head, not straight plug. I know there are lots of inefficiencies with domes, and I'm sure this little feature doesn't help!

[want-a-be]

Think you can post a picture of the dome of your pistons? More then likely you can free up some hidden HP by smoothing the sharp edges of your domes. It's pretty easy to do. I'd be glad to walk you through it, or I could do it for you. If your concerned about the fire slot. You could open it up some also.

Don

[luv2pla]

When I pull the motor apart, I'll post some photos.

As far as porter goes, I really don't know who to go with. I've seen HVH and Brzenski list already CNC-ported heads bare for about $1500, and I could buy them and swap my parts out.

[Trmnatr]

I am running a limited late model dirt car with the old style Dart 215 Iron Eagle straight plug 64cc heads cut down to 55cc, 2.05/ 1.60 valves on a 360 c.i. SBC with a flat tappet cam (.590/.570, 259/266@0.050 I/E). I generally turn about 7,500 RPM. The engine has small dome pistons and a CR of about 15:1. I probably have around 500 hp.

My question is this: Everything else being the same, what HP and torque difference would I expect going from the old style Iron Eagles to the same thing in a new Iron Eagle angle plug platinum head? Just a percent change or some WAG at this is fine, but I'm sure someone has done an A/B comparison.

New to forum just thinking about some changes for 2009, and looking for advice.

Thanks.

I cant give an accurate hp/tq or even ET difference, I can tell you known working combos we use alot, take an engine with the Platinums and it will perform better and make more TQ/HP

The first platinum i ever used was the 200cc, you could feel a difference in throttle response over previous 200cc heads

Also, The spark plug on the old heads will hide behind the dome thus needing a fire slot if the piston is thick enough, The platinum heads sit the sprak plug over the dome on most domed pistons - The spark plug is much higher in the chamber with the platinums (usually with platinums the plug doesnt hide behind the dome)

[luv2pla]

I found a comparison between the Dart Pro 1 and Dart Pro 1 Platinum 23 degree, 215's that showed about 25 HP/TQ difference for a ~500HP motor. I wonder if it's about the same for the Iron Eagles?

Has anyone seen any dyno comparison data on any of the porter sites?

[want-a-be]

When I pull the motor apart, I'll post some photos.

As far as porter goes, I really don't know who to go with. I've seen HVH and Brzenski list already CNC-ported heads bare for about $1500, and I could buy them and swap my parts out.

I'd consider Ron's Porting out of St. Louis, Mo. He does a great job.

Don

[luv2pla]

I wonder where Dart Vader and Awesome Bill went? They seemed to have a lot of insight into these Dart questions.

[Dart Vader]

I wonder where Dart Vader and Awesome Bill went? They seemed to have a lot of insight into these Dart questions.

Very sorry for the long wait on any response here, I was gone all last week!

When we were switching engines from old iron eagles to platinum iron eagles around here we saw average gains of 25hp or so.

Hope that helps!

[luv2pla]

That helps a lot.

I guess the next general question is now much difference can you expect going from an "out-of-the-box" head to a good CNC-ported one. Not an all out, get the most out of everything, but a good standard port job. Again for Iron Eagle/Platinum. Is there another 25HP to be found? 50?

Where I work, this is called "value-engineering". LOL

[Dart Vader]

A really good head porter might be able to get an extra 10hp out of some platinum heads, most port jobs will break even and a few will probably even lose power.
The exception, of course, being high end racing engines, where opening up the ports could do some good.

A good port job on the old pre-platinum heads will probably net you 20 horsepower or so.

[luv2pla]

So the bottom line is new platinums over old iron will get about 25 HP;
new CNC-ed platinums might get 35 HP over non-ported old;
new ported vs old ported might gain 15HP.

For a non high-end engine, is this a pretty fair summary?

[Dart Vader]

That's pretty accurate I'd say.

[luv2pla]

Thank you very much for the input, and read-between-the-lines advice!

[luv2pla]

Another question: will the Dart Iron Eagle Platinum 49cc heads work with off-the-shelf JE dome pistons in a 350 SBC?

[Dart Vader]

Another question: will the Dart Iron Eagle Platinum 49cc heads work with off-the-shelf JE dome pistons in a 350 SBC?

Not with typical off-the-shelf JE dome pistons, no.

But both JE and Mahle make pistons that are designed to work with our 49cc heads, I know that Mahle 21 degree flat tops work with them, I don't remember what JE pistons do.

Either company can, of course, make a set that will, if you want to wait.

[want-a-be]

I have used some claimer flat top pistons and Kieth Black pistons with very good luck. The Keith Black Piston had a .163" dome on it. Make sure you check piston to valve clearance pretty good when you build anything. If you need help with that PM me and I would be more then happy to help you out.

Don

[luv2pla]

My old style 64cc iron eagles work OK, even cut down to ~55cc. I was looking at upgrading, but I've got quite a few other things that would have to be changed to get it all right.

Another question; when gasket matching the heads and intake, do you just slap the gasket on the port and line up the bolt holes? What about on the intake? My 2925 has slotted holes. Do you try to mark the intake with it sitting on the heads, or how exactly do you get them aligned?

[want-a-be]

LOL...man I hate matching the intake to heads...but I'd like to think I do a good job of it.

Some do the gasket but I don't like that. There is a company that is called Brezinski, (Spelling may be wrong), that makes a pretty good tool for this. Been a while since I have been in contact with them, but they should still be around.

What I do is,...Take a straight edge and line it up with the edges of the runners on the heads and mark them on the outer edges of the intake flange. So when you mock it up you'll be able to see the marks. Make sure to check and recheck all the marks you're making as a wrong mark will create more work later.

Next,...get some old gasket material thats about the same thickness and will crush about the same. The old gasket that you just took off will do nicely even pieces of it will be ok to use as long as they are clean. When mocking eveything up use the old head gaskets and the intake gaskets. This spaces everything to where it should be when assembled. If you're just using the gaskets at the ends of the intake, like I do, you only need the bolts where you have the gaskets. Don't over tighten as this will flex and maybe crack the intake. It only needs to hold things in place.

Mock eveything up. Everything doesn't really need to be torqued but they do need to be snugged. When you put the intake on leave it loose enough to be able to slide the intake forward and backwards for the best fit and for the least amount of work. Look down the intake runners to see how everthing lines up. Look in every runner. When you like what you see snug the intake down.

You should be able to see the marks on the heads that you made before. Transfere those marks to the intake. Take your time and double check everything. From there you can mark the intake flange with a square. This can be a lil' tricky cause you might not have a good square edge to work with.

As your matching things up and you're getting close I like to check my work. Easier to adjust how things are going when the material is still needing to be ground out then add it back.

Right or wrong...I like to leave .010"-.020" all around the intakes runners. When the intake is a lil' smaller then the heads it helps shear off some reversion. Or so thats what I was taught.

There might be a few runners in the head that will have to need to be moved a bit. Could blend it in or weld the intake. If you opt to blend the head I like to use a .060", or the next thicker, tig welding rod for a scribe. Sharpen it up and bend it around so you can get to the edge you're wanting to mark.

Hope this helps more then confuses you. I'm not very good at explaining myself in text form. Sorry for the long post.

Don

[luv2pla]

I think I understand everything but the 3rd paragraph. Do you take all edges to the outer edge, only top and bottom, only the sides?

Also, once the intake is lined up on the heads, how do you transfer the mark to the intake if it's sitting on the heads?

Thanks.

[want-a-be]

Take the tops and bottoms of the runners out to the front and backs of the intake flange. Transfere the marks to the intake with a scribe on the edge of the intake. From there take the intake off and finish transfereing the marks to the flange of the intake.

I sent you a PM with my number if you'd rather talk about it.

Don

[Awesome Bill]

Your head ported will yeild way better results than the new Platinum. But port the platinum and you pretty much have the same thing. Maybe a little more torque but, when we port the steel heads, we have been porting them for years the same way the new platinum port is laid out. We also lay back the intake valve side of the combustion chamber so the head winds up pretty much the same. I have used Ron's and he does very nice work. But, he does not do steel heads. Maybe has more than he can do with aluminum. We can fully port those heads with valve job that makes plenty of power for under $1500.00 Race ready. No better porting on steel heads than what we do along with a killer valve job.

[want-a-be]

Ron's does still do Iron heads.

Here is his web site. http://www.ronsportingservice.com/products-dart.htm

Heere is a post he made on Speed talk. His user name is winterhoff and here is the link to the thread. http://speedtalk.com/forum/viewtopic.php?t=13238&highlight=rons+porting

Ron is only an hour and a half or so from me. I've seen tons of work and been to his shop a few times. Been a while though. He does great work.

Don

[Awesome Bill]

Thats funny, I called him about 2 years ago to do a set of steel heads and he told me he does not do that any longer. Maybe he has changed his tune a little! Either way, a good head porter is only worth what the dyno give him or her.