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Engine setup help, ideas?

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Old Jun 8, 2011 | 12:56 PM
  #21  
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Not to be rude but a distributor recurve is pretty much a basic and required performance item.
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Old Jun 8, 2011 | 02:58 PM
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From: Graceland in a Not Correctly Restored Stingray
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Originally Posted by Scott Marzahl
Not to be rude but a distributor recurve is pretty much a basic and required performance item.

IIRC the old timing sticky thread covered that in detail, although it's worth pointing out there's no one-size-fits-all advance curve.

And, you might have to rethink the $1500 budget.
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Old Jun 9, 2011 | 02:41 AM
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Originally Posted by Scott Marzahl
Not to be rude but a distributor recurve is pretty much a basic and required performance item.
sorry but i've never heard of it. ill search for the old timing sticky thread and read up on it
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Old Jun 9, 2011 | 09:55 AM
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Hey guys
Quick update...
I've decided on rebuilding the Q-jet.

As for now I'm leaning towards the GM Vortec heads 64cc and Vortec intake manifold and a good set of 64cc headers from summit racing. Can this work well with my car and can I get the hp gain I want?

As for the camshaft, I would like the retrofit hydraulic roller set from comp cams that includes the pushrods, lifters, camshaft, timing set, and even valve springs.

However, I've read that the downsides to the hydraulic roller is the excessive weight which adds more stress to the springs in high rpm and they aren't meant for high mileage.
Is this true?
Would I have to replace the valve springs on the Vortec heads or can they handle it?

As for the pistons Im still trying to decide.

So far u guys have helped me out so much with all this and I would be lost without all of you.

Many thanks!,
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Old Jun 9, 2011 | 12:06 PM
  #25  
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You must machine the Vortec heads to accept roller cam springs. The roller cam will require springs with much more force than the wimpy stock Vortec heads come with, always use the required springs stated by the cam company. I wouldn't worry about excessive valve train weight for a mild hydraulic roller cam.
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Old Jun 9, 2011 | 03:13 PM
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Originally Posted by Scott Marzahl
You must machine the Vortec heads to accept roller cam springs. The roller cam will require springs with much more force than the wimpy stock Vortec heads come with, always use the required springs stated by the cam company. I wouldn't worry about excessive valve train weight for a mild hydraulic roller cam.
Ok...so I should buy the set that also comes with the valve springs that support the camshaft.
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Old Jun 9, 2011 | 03:20 PM
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Alright,
Im looking up hydraulic roller kits on summit and so far so good...However what should be the recommended lift for performnce street car? I was thinking a lift of .520/.540

Also, summit says that I should use this cam with a wear plate and thrust button. What are these products?

And just to make sure the headers should have the combustion chamber volume the exact same as the the cc in the cylinder heads right?
Eg. Vortec 64cc heads with 64cc headers from summit

Thanks
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Old Jun 9, 2011 | 03:47 PM
  #28  
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The lift depends on what the heads can handle, for example the Summit brand Vortecs can only handle .520" lift max. You can't pick combustion chamber size without knowing what piston you have, the block deck height and head gasket to achieve the target compression that you want to run.

With a flat top 2VR piston, std deck height, .028" thick head gasket, a 224-230 degree duration cam, you can probably choose 64cc heads for an approximately 10:1 build.

For a daily driver I would stick with a cam in the 224-230 duration @.050" and a compression target of no more than 9.5-10.0:1 and you will run pump gas fine.

Also when buying a roller make sure you get one that allows the use of a standard distributor gear and you may need a special fuel pump push rod, and the cam button for the timing cover to keep the cam from moving forward.

If you are going with a roller, its probably best to start with a roller block from a late 80's truck/van.
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Old Jun 10, 2011 | 11:32 AM
  #29  
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Originally Posted by Scott Marzahl
The lift depends on what the heads can handle, for example the Summit brand Vortecs can only handle .520" lift max. You can't pick combustion chamber size without knowing what piston you have, the block deck height and head gasket to achieve the target compression that you want to run.

With a flat top 2VR piston, std deck height, .028" thick head gasket, a 224-230 degree duration cam, you can probably choose 64cc heads for an approximately 10:1 build.

For a daily driver I would stick with a cam in the 224-230 duration @.050" and a compression target of no more than 9.5-10.0:1 and you will run pump gas fine.

Also when buying a roller make sure you get one that allows the use of a standard distributor gear and you may need a special fuel pump push rod, and the cam button for the timing cover to keep the cam from moving forward.

If you are going with a roller, its probably best to start with a roller block from a late 80's truck/van.
How about the Magnum hydraulic roller? It says it works for people who want a 9.5:1 compression or more and has a 230int/230exh.
The Vortec heads I'm thinking of buying are GMPP brand.
Do those heads handle more than the summit brand?
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Old Jun 10, 2011 | 12:50 PM
  #30  
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The stock GMPP heads do not handle roller cams without added machine work, look at Scroggin Dickey's website for modified GMPP Vortecs for use with roller cams.
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Old Jun 11, 2011 | 10:05 PM
  #31  
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Ok, i looked up scroggin Dickey's and this is what i came up with...

GMPP Vortec Heads
"Machined 2.00"intake and 1.55"exhaust
65cc, 175cc intake and 65cc exhaust ports

Will these heads fit the Magnum Roller 286 HR Kit and will it be able to give me the 10:1 compression?
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Old Jun 11, 2011 | 11:49 PM
  #32  
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Ok guys hopefully this is the final draft for my top end!

1. Q-Jet Carb
2. GMPP Vortec Heads, PN25534421, from Scoggin Dickey's machined
2"intake and 1.55" exhaust. 65cc
3. Summit Shorty Headers, PN SUM-G9005 Collector Diameter 2.500 Cylinder Port shape: Oval

4. Now for the Camshaft I have 4 choices but don't know which one to choose:
1. Magnum 270HR Kit RPM 1800-5800 lift (.500 intake/.500 exhaust)
2. Pure Energy 246PE RPM 1200-5200 lift (.429 intake/.438 exhaust)
3. xtreme Energy XR264HR RPM 1200-5200 lift (.429 int/.438 exhaust)
4. Xtreme Energy XR 270HR RPM 1600-5400 lift(.495 int/ .502 exhaust)

I feel that the XR 270HR will give me the power that I want and still serve as an everyday driver, what do you guys think. They are all retro fit hydraulic rollers except for the Pure Energy which is Hydraulic Flat Tappet.

These Cams should work with the machined out heads Right?

Thanks
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