Head Comparison - OEM 990's to Dart Pro 1 2.25/310's

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wikd69
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Head Comparison - OEM 990's to Dart Pro 1 2.25/310's

#1 Post by wikd69 » Thu Apr 02, 2009 4:18 pm

Here's a CamQuest comparison between stock port OEM 990's and out of the box Dart Pro 1 310 heads using my blower motor as the platform.

The 990's seem to do a good job of providing flow and delivering HP/TQ with this build - 671 blower @ 8psi, 427 ci, 8:1 forged, hydraulic roller 252@.050, .612 lift, 110 LSA. I know folks have done extensive port and bowl work to make them flow better, bit with what results I don't know, as I have not done that.

These heads are certainly old technology and have a limit on how much Int/Exh flow they will provide. Comparing them to a set of Dart Pro 1 Aluminum heads (for example) is an eye opener. The published flow numbers tell the story. Below are flow numbers and a chart comparing the heads I'm looking at with my current 990's. Note that I had to do some extrapolation on the 990 flow numbers to fill in some gaps in the original data. I think tho, that the data below is pretty accurate.

Really a huge difference in performance, especially for my blower motor. I pretty much peaked at 612 hp / 561 ft/lbs in CamQuest with these 990's. Same build but with these Dart heads, CamQuest showed 743 hp / 601 ft/lbs. Big difference between them. :shock:

Now, having said all that, it really comes down to your application. What sort of horsepower do you need, how will you use your ride, and what is your budget like ? A pair of out of the box assembled Pro 1's run between $2,500 to $2,900 dollars, depending on how you dress them up.

How fast do you want to go ? :mrgreen:

Image

Image
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

Ls7camaro
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Joined: Tue Mar 25, 2008 11:31 am
Location: Medina, OH

Re: Head Comparison - OEM 990's to Dart Pro 1 2.25/310's

#2 Post by Ls7camaro » Fri Apr 03, 2009 11:26 am

I have basically an LS 6 motor, when I bought it, I pd 3500 bucks, and got everything, I just had to put it together, it originally had LS7 Pistons / GM 180 cam. I switched the pistons to TRW LS6 replacements, and that killed the GM 180 LS7 Cam, The car with the ls6 pistons and comp ls6+ camshaft, has run 12.01 with the exhaust open and launching at 2500 rpm any higher and I spin.

This past winter, I embarked on a project to put weld in subframe connectors and formed rear frame rails in my car. way more project than I wanted. so now the spring schackles are moved 6 inches inward, and instead of trying to modify the wheel wells, I just put the tubs in. So now I have the room to rum bigger rims, but don't want to buy them until I narrow the rear end.

So back to the motor, I still have the LS7 pistons / cam, springs and lifters. My plan now is to freshen the bottom end up I was thinking stroker, but want to see how fast the LS7 can go, I want to switch it to E85, to I can still go to cruise ins. I know this is old technology stuff, but I already have it.

The whole package I think was a good deal, I got the four bolt block w/the green/purple dabs of paint on the front(not sure what that means) a High Perf 4 bolt block, GM 990 heads, dimple rods, pistons, rings, and everything from intake to oilpan.
I can't wait for race season, this has got to be the year.

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wikd69
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Re: Head Comparison - OEM 990's to Dart Pro 1 2.25/310's

#3 Post by wikd69 » Fri Apr 03, 2009 11:29 am

Ls7camaro wrote:I have basically an LS 6 motor, when I bought it, I pd 3500 bucks, and got everything, I just had to put it together, it originally had LS7 Pistons / GM 180 cam. I switched the pistons to TRW LS6 replacements, and that killed the GM 180 LS7 Cam, The car with the ls6 pistons and comp ls6+ camshaft, has run 12.01 with the exhaust open and launching at 2500 rpm any higher and I spin.

This past winter, I embarked on a project to put weld in subframe connectors and formed rear frame rails in my car. way more project than I wanted. so now the spring schackles are moved 6 inches inward, and instead of trying to modify the wheel wells, I just put the tubs in. So now I have the room to rum bigger rims, but don't want to buy them until I narrow the rear end.

So back to the motor, I still have the LS7 pistons / cam, springs and lifters. My plan now is to freshen the bottom end up I was thinking stroker, but want to see how fast the LS7 can go, I want to switch it to E85, to I can still go to cruise ins. I know this is old technology stuff, but I already have it.

The whole package I think was a good deal, I got the four bolt block w/the green/purple dabs of paint on the front(not sure what that means) a High Perf 4 bolt block, GM 990 heads, dimple rods, pistons, rings, and everything from intake to oilpan.
Sounds like a great combination and it sounds like you're having fun :mrgreen:
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

sc racing
Posts: 1773
Joined: Sun Jun 11, 2006 1:45 pm
Location: Sahuartia Az

Re: Head Comparison - OEM 990's to Dart Pro 1 2.25/310's

#4 Post by sc racing » Fri Apr 03, 2009 7:27 pm

If you keep the LS7 cam it should be at least 1/2 second faster than the old set up.

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