Decks are about .500", like our other small block heads. We've had people pushing lots of boost and nitrous through those over the years. Right now we're just offering the one chamber size.

This is PSI's latest version of their beehive spring. They say it's good to .625".

PSI does the springs for Isky. They also supply Comp with some springs. I'm not sure about the beehive specifically.

I know a few sets are going to magazines for testing/build-up articles. I think the rest are going to major distributors for a first look.

They will accept traditional dual springs if you prefer. We're using traditional 11/32" stem severe duty valves, not metric valves. They're more readily available, and thoroughly proven. As for valvetrain weight, it's not an issue at the rpm range most street/strip cars will see. For those people wanting a different valvetrain setup, sticking with SBC style components means there are far more parts available to choose from.

 

Perhaps this seems worse than it actually is, simply because we havn't had a choice to use the available SBC stuff in the past. The hard part is eating the cost of valve spring kits that we already have. What are the install heights and spring diameter limitations? Will we be able to simplpy go by the advertized SBC specs on the springs? Or will this be a non standard application where math will need to be applied?

 

Is this 11/32 stem lighter than the 8mm type in the same size?

 

The weight difference is negligible.

 

Thanks for registering! this is GREAT news for our community.

It's nice to FINALLY see prices inline with the SBC stuff.

You are going to sell a TON of these.

I am guessing you are using 918 springs?

 

Thanx Moxie

 

hey chrispy i believe he is talking about these springs
http://www.iskycams.com/productdispl...=101&dealer=no

 

i have a question moxie, i have a 98 transam and was wondering if my valve covers will bolt to these heads, i know there is a difference in the years and was wondering if these heads were for both perimeter and center bolt valve covers?

 

No, theyre not using LS1 specific springs and retainers. Theyre going to be regular SBC stuff since theyre using SBC valves. There are some good quality pieces available at less inflated prices (compared to LSx stuff). but many of the familliar names and models weve come to recognize wont apply with these heads.

 

Can we get them WOT guides? or 5/16 or 7mm guides... I know thats asking a lot but you have to put them in the heads anyways. If I could get them without guides that would be cool by me.

Bret

 

See now this is Bullshit! I spend all this moeny on 921s and now I can't use them on these heads I was waiting for.....thanks Dart, I appreciate it.

 

Are you freakin serious?? Get over it..

 

there is a forsale section

 

LOL Give me a break

 

Birdonnos... I do believe they are all centerbolt style.

Moxie....

What affect does using SBC parts have on the rest of the valve train? Pushrod length? Does that change if using a stock lifters, or one of the aftermarket OEM clones?

What about Rocker Arms? What is needed? LS1 specific Rocker Arms, or SBC type rocker arms?

You say the weight difference between LS1 and SBC valves is negligible.... but what is the difference?

Thanks in advanced!

 

With the traditional SBC valvtrain components, will there possibly be a harmonics change? I wonder if there is if it will mess with the knock sensors? Looks like a killer set up Dart.

 

Ha, OK.....give you a break? These have been in the car for about a week? Paid upwards of $700 completed, and now I have to sell them as used even though they have nothing on them?

It doesn't matter anymore though, I am getting some 6.0L ported by a great guy......not mad any more.......

 

There still seems to be alot of questions regarding these heads and some confusion so I will attempt to clear that up! These heads are made to be direct replacements, and with the exception of the valve stem diameter that is the case. We chose the larger stem for a variety of reasons, strength, cost, availability of parts, ease of transition of new products. The 11/32 stem is 8.731mm not much larger than the 8mm stem used, and the 11/32 stem allows us to use the same valves, locks, seals, and guides that we have already made. It however made it so that we had to have Trick Titanium custom make the retainers for the beehive springs and the 11/32 stems. The weight difference on the intake valve is about 1-2 grams and the exhaust is 1 gram, negligable in a pro stock engine probably, in a severe street strip car it wont even matter. We have tested the springs and valves with the spin tron test equipment and the slighter larger and "heavier" valve makes zero difference. The heads will be able to use your stock rockers, stock pushrods, and anything else you may already have. We are using top shelf parts on our assemblies, like the back cut vavles we design and have built by Eaton who furbishes almost everyones valves, PSI springs who makes all the high end springs out there, Trick Titanium retainers who makes all the NHRA Top Fulers bellhousings, and bronzze guides we make in house. These parts we feel are second to none.

In regards to flow testing and engine testing we already know how these will work, and have spent many of a man hour porting the original samples to develop the best out of the box performing head available. Most everyone gets their kicks looking at flow numbers, however we spend most of our time testing in teh real world using our state of the art wet flow bench custom built my Superflow and Joe Mondello, this tool allows us to design a ports and chambers and then test them nto jsut with air but liquid with the same density as fuel. The advantage to this testing versus dry flow testing is pretty simple it allows us to see what happens in the port in the real world and we test at 55" not 28". This has allowed us to make a port that might not necessarily flow as well as others but will typically make more power. Most companies dont have this measure of equipment and can only test the old way. Some people who have seen the benefits of this equipment would be Reher Morrison specifically Darren Morgan who is their chief head guy there, and he couldnt believe the information and its accuracy. Darren frequents places like speedtalk.com and talks highly of this equipment. We use it for head developement everyday both for our customers and our Pro Stock engine program.

An example of a situation would be a Ford engine (no stone throwing please) we used a set of our as cast 195 heads versus AFR ported 205 heads and a set of Victor Jr heads that were as Edelbrock sells them. Roush took their crate engine with the AFR heads and dyno'd the engine then Edelbrock and tehn ours. We made 1.5 more horsepower than the AFR and 12 more than the other. Not too bad being ours flowed less on a dry flow bench but yet we were better on the wet flow bench. Now all of Roush's crate engines use Darts heads.

The reason for the example is to just state dont think about the flow numbers as a huge priority when deciding about what heads to buy, we never care here when we help people on the phones and on the computer, we match the heads to his combination not flow numbers.

Anyways back to the heads if you guys have or need any more information feel free to email us at darttech@dartheads.com Thanks

 

In addition to posting this message I also sent an email to DART and I got this response from their Sales Manager (very promptly)

Nothing else changes, we only changed the valve stem diameter from the 8mm to a 11/32 valve which would be 8.731mm not much to make any difference, these are bolt on heads, we are not reinventing the wheel here, it just makes no sense to use 8mm valves there is no advantage to the smaller stem size. Now if one went to a 5.5 or 6mm valve stem like NASCAR then ok there might be an advantage in weight savings and harmonics, but again they use valves that cost well over $100.00 each. Everything else in use in the same as OE. Thanks

So like Moxie has been saying... it seems that any percieved disadvantages between a 8mm and 11/32 Valve is negligible.

 

Thanks to my coworker, John, for answering those questions. Sporklover, I believe it was John who also answered your tech email. Thanks for the interest. =)

CamaroSS, if you're referring to Comp 921 springs, here are the specs from Comp's website:

O.D.: 1.300
I.D.: 0.655
Seat Load: 135 @ 1.770
Open Load: 400 @ 1.220
Coil Bind: 1.040
Rate (lbs./in.): 408

Now, here are the specs on our springs:

O.D.: 1.290
I.D.: 0.630
Seat Load: 120 @ 1.800
Open Load: 360 @ 1.175
Coil Bind: 1.100
Rate (lbs./in.): 384

We're using a LS1 type spring, and so are you. Either spring will work, you just have to adjust for the different valve stem diameters. You would need retainers and locks to match our valves. The 921's install at a different height, so you would need to use shims. That should do it.

SStrokerAce, you could special order w/o guides.