anybody much about with the Etec heads?

Seem to have a good exhaust port, and I believe the taller vortec port has more potential than the old style port.

Seem to flow decent out of the box, not killer, but pretty good. Especially when you compare them to other heads with the 2.02 valve.

Anybody port these things?

 

i have these heads on my 383. took engine down couple weeks ago and sent my heads to the flow bench to see whats up. needless to say anything out of the box needs attention-everything. the flow bench doesnt lie but advertising does. needed a valve job bad and some blending, picked up 20 cfm per cyl. just by doing that. save your money get iron vortec, cant flow any better than that.

 

Iron is out of the question.

 

GM fast burns ?

 

Valves are too small.

 

I am either going to get Dart pro 1 200s or Edelbrock Etec 200.

I like the tall ports with the raised runners. They should in theory have a higher velocity.

 

Tall ports, raised runners have their own issues. For the $ I would look at the AFR 195 eliminators. Good port velocity and great flow numbers, Probably as good or better than the others. Standard configuration = more options for intake and exhaust. Can get them race ported out of the box and they will outflow anything else 200 cc or under.

 

http://www.worldcastings.com/Motown23degHead.htm

I ran three types of heads on my 383. The smallest being AFR 210's

You are smarter to big the first time. So you don't have to buy a second set. The Motown 215 might really be good if you can wait till March.

 

If I build another motor, I intend to go a completely different route. Most likely a big inch Gen 3 motor.

I like what you have done, but I am looking at something that operates about 1000 rpm less. I will keep an eye on those motown heads. I probably wont be buying anything top end like soon

I am thinking Etec200s with a bowl blend and valve job, and the new edelbrock pro-flo XT system.

Depending on what the motowns do, I will keep an eye on those.

The edelbrock signature series motor made 460hp with 9.5:1 compression way to low for the motor. A better cam and more compression will put it at the 500hp mark. Right where I want it.

Anything more than that, and I need to not be looking at a 383.

 

With so much TQ down low I hardly ever run my 434 motor much over 6500 rpm.

 

Gkull,

Based on displacement

Your 227cc heads would have the same displacement to cc ratio as my 383 with Etec 200s.

Pretty sure that your 227cc heads also have 2.08 which also translates to a good 2.02 valve for a 383. when you compare valve area to bore area. I honestly think that your valve diameter should be determined by your bore, and your rocker ratio should be determined by your stroke. A longer stroke will want valves that open at a faster rate, as your piston speed is faster.

If your control is 1.5 = 3.48" stroke, a 3.75" stroke will require a 1.62 and a 4" stroke will require about a 1.72 rocker ratio.

But I am an odd one. But I really think that 200cc heads and 1.65 rocker ratio will be more than adequate for my needs.

 

I have recently installed a 383 from EngineFactory.com.

The 475hp unit.
http://www.enginefactory.com/475hp.htm

It has almost the same configuration as the Edelbrock Signature motor.... same heads, cam,manifold and carb... although compression is a little healthier at 10.3:1

I am still sorting out some tuning issues, but motor is showing some good potential. It pulls well from down low, and really starts to get exciting above 3000 rpm. I haven't pulled more than 5000 rpm yet.
Can't find a decent stretch of safe road to wind it up.
Builder recommends about 5800 max rpm.

My biggest concern at moment is motor does not like cruising along at less than 2000 rpm. I'm hoping its just carb jetting and ignition timing.
It's running well enough to get a few miles on for running in, but it's not running crisp and clean. Proper dyno tune should sort it out.... hopefully.

Timing has been set at about 34* total (vac adv disconnected), with about 12* at idle.
Funny thing is, the surging I experience with cruising at around 1800 rpm is indicative of a lean condition, yet the plugs are fouling up making me consider the jetting is still too rich?

Once the tune is sorted out I'll pull a few WOT runs on the chassis dyno to see how honest those power claims from supplier are.

Booked in for the 17th Jan.
Hoping for at least 350 rwhp.

 

Of course here is a dark horse

http://www.brodix.com/heads/tonydyno.html

 

Here is a comparison chart of available heads. It is a little outdated. The AFR eliminators are not on there just the older AFR's. The Brodix IK 200's are very good for the $ but the new AFR eliminator 195's beat everythink else out there hands down. http://users.erols.com/srweiss/tablehdc.htm#Chevy

 

The AFR eliminators have 2.05 or 2.08 valves.

Kind of hard to compare.

I think most of the newer motors are going to larger ports and smaller valves.

I have thought about the new eliminators. I would like AFR to do something with vortec style heads.

 

All three of my present heads have 2.08 - 2.10 intake valves. many years ago I had a head porter explain to me that 2.02 valve size even with the narrow stem, multi valve angle, or radiused head becomes a restriction at some point below 200 cc on high flowing ports. So without any other changes going to a larger seat and valve diameter increases CFM. At the time I had bought the Sportsman 200 cc and had them ported with 2.055/1.60 Manley Proflows.

My 383 has used AFR210. Dart 215 and Dart 227cc. I never really noticed a performance difference between the heads.

You might just buy the 200cc heads bare and have a local shop install 2.055's or 2.08 if they fit.

 

This is weird to me.

Since flow is related to area of the opening, your typical 1.25 x 2.125 port (bit on the big side) has the same area as a 1.83" valve.

I will take your word for it, as in big blocks your 2.19" valve is about 26.55% of a 4.25" bore. A 2.02" valve is 25.5% of a 4" bore, a 2.08" valve might just be appropriate.

Dart doesnt even offer all the valve choices they used too. 2.02 on the 200cc heads, 2.05 on the 215cc heads, and 2.08 on the 227cc heads. seems your *** out of luck if you want the 1.625" exhaust valve too.

I would probably use a ferrea comp hollow stem valve for the intake and a sodium filled valve for the exhaust.

 

Wasnt this part of the reason why in the vortec and LS engines the ports are taller and skinnier to take advantage of valve size while still maintaining vacuum?

Tall ports and small valves seem to be the way engines are going?

Now the LS7 on the other hand has a big *** 2.2" valve. Thats a freaking big *** valve in a small block!!!!!

That is what I am talking about!

 

The reason for higher intake ports and low degree intake valve angles is simple physics. If the air and fuel has to make a 90 turn it looses velocity compared to a straight pipe.

The square inch area of the valve heads is only part of the flow problem. The rounded venturee above the valve seat is the smallest diameter of the port.

When you install larger valves you can install or just grind a larger valve seat hole. On racing heads the valve and seat have just a tiny contact band and it is open as large a possible above the valve head

 

http://www.camaros.net/forums/archiv.../t-112467.html

Interesting.