Robin L

The heads will be fully machined.

They will not sell as an unported peanut port type heads.


Robin

Robin L

Ported LS7 don't cut it. The new CT and DR heads from GMPP have a ton of features that the LS7 lacks.

The design of the LS7 is a street low lift emissions head. It's meant to make 500 horsepower and pass emissions. It works very well.

For a true race head the LS3/L92 or the LS7 cannot be modified to hang.

The chambers on the LS7 cause turbulance at lifts over .700. There are guys making them work past that but it is easier to get a race head.

Thicker Deck
Large Spring Pads
Better chamber design
Larger chamber
Larger valves
6 Bolts

My heads flow clean past one inch of valve lift. That isn't easy.

The C5R is good for smaller cubic inch combinations. The chambers are too small for big inch power adder engines.


Hope this helps!

Robin

Robin L

I currently have the smaller CT style heads on the Nova. They are actually a little small for what I am running. I have a set of the larger DR style heads going on a 454 NA dyno mule.

I intend to test the cast GMPP 4 barrel intake on that engine.

I am hoping to see close to 900 on the single carb deal. With the twin dominators on the sheet metal intake I hoping to see close to 970.

I am still waiting for a couple more parts. It should be ready soon.

Robin

LS6427

iTrader: (2)

Yeah, I'm talking about 427ci and bigger engines...the LS7 head will make more power than a C5R can, right?

But in your opinion, if someone is building a 440ci-454ci engine with say a dual TB sheet metal intake, those new DR heads would be a great choice, right? Just an N/A engine.

UGotBeaT

an all out race 427 on either the C5R will stomp the hell out of a LS7...like robin noted...the ls7 is good for street stuff but is no where near a race head like the C5R is.

LS6427

iTrader: (2)

Ok, cool, I didn't realize that.

So, is this new DR head gonna be a good choice for someone building a max effort pump gas engine, for a street car with a sheet metal intake?

Robin L

No, while I am sure there are people that will build engines for the street using these heads they are not intented to fill that need.

They are a race head that will have cast intakes available. One is a domnator flange and the other is a 4150 flange. I am sure that there will be guys building sheet metal intakes.

We are currently working on upgraded LS7 heads that will accept the larger springs and have the 6 bolt feature. That is the head intended for the GM Performance Parts 454 LSX Crate engine.

Again the LS7 is a production style head. While it can be modified and improvements found it is not a race head.

The C5R head was/is good for what it was designed. With all the advancement in the LS engines it is not at the top of the heap any more. Things change. But the C5R is still better than 90% of what is available today. I mean right now go buy it today.

That should change in about 2 to 3 months (where have we heard that before)

I like the heads that ET has done......if you can get them.
For a street application I like the Total Engine Airflow heads with the 6 bolt deal.
Edelbrock has some cool heads coming soon.
Of course I hope we have ours out son also

You really have to seperate what you are going to do with these heads. Toom many people think that the biggest is the best. I see guys wanting to have 700 hosepower daily drivers. They expect them to idle like stock, pull great milage and then go 9's at the strip and 200 at the Maxton Mile.

Good luck!

Robin

Beaflag VonRathburg

iTrader: (176)

Seeing the specs on these I'm starting to agree with Robin L. With a 50cc chamber you are going to have a rough time getting the compression to a pump gas level with a large stroke piston. You're also going to be running 1.66 diameter springs . The pressure on springs like that are insane. I thought the 1.550s I am planning on running are pretty hardcore for the street. 1.66s are insane.

Robin L

Here is a little more background on what we went through.


Just put up today

http://www.maxchevy.com/


Robin

GrannySShifting

iTrader: (10)

See what i posted 3 pages ago. Using a sheetmetal intake on your pumpgas street motor doesnt make these heads the choice to make. Robin has eluded to the same thing. 7k rpm .650 lift street stuff does not equal a race head like this. The converters in cars with a head like that flash higher than most serious NA street cars shift

Beaflag VonRathburg

iTrader: (176)

That's quite the story Robin. This is my favorite part :

CARRY-OVER PARTS
Oil pan
Oil pump
Distributor
Valve covers
Lifters
Valve spring retainers and keepers
Block studs

TJ

iTrader: (10)

if he didnt want it repeated, he shouldnt have told you.
posts like this drive me crazy.
"i know, but i cant repeat it."

Beaflag VonRathburg

iTrader: (176)

Are there any updates on these?

jonathan8751

iTrader: (7)

and a estimated price tag?

Robin L

Guys I did some checking with the guys at GMPP. The program is still alive and moving forward.
It's not moving nearly as fast as me and others would hope. With the cutbacks at GM people are stretched thin.

I hope to have another update in a month or so.

For now the word is another few months.

Robin

Beaflag VonRathburg

iTrader: (176)

Thanks for the update Robin. I was thinking about dropping some major money on a set of heads and remembered about this. My car isn't going to be done for probably another couple years so I figured as long as they are sticking with making them I will eventually pick up a set.

Anonymous

Almost a month.

Any updates yet?

Robin L

OK things are moving slowly. Under consideration is selling the heads un ported. That way shops and builders could develop their own program and finish them the way that they prefer.

Several have been cast and are undergong further development.

I was told they could be out within 2 months.

Please don't kill me if that doesn't come true

I'll let you know.

Robin

UGotBeaT

Let us know on pricing for the unported castings

Anonymous

Thanks for the quick response Robin.

Not to get off topic, but are you going to be at Maple Grove June 5th-7th.

You can PM me back, so this thread stays on point.