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Yet another 350 build

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Old Feb 10, 2011 | 05:35 PM
  #1  
Black 84 Z's Avatar
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From: Ocala, FL
Car: 1984 Z28
Engine: 350ci
Transmission: 700R4
Axle/Gears: 3.73 12 bolt
Yet another 350 build

I need some opinions on an engine I am planning. What I am looking for is a strong street engine (almost never going to the strip), maybe around 400 HP with the same or higher torque, decent vacuum to run the brakes, and be fairly reliable for occasional longer trips. I already have a TC that (should) stall aroud 2400, a Performer RPM manifold (non Vortec) and Holley 650 DP.
What I am thinking right now is going with a set of TFS super 23 195 intake runner heads and a Comp XE268H cam. Currently I have just stock heads and cam. The compression is 9:1 with the (I believe) 76cc heads. Given the TFS heads are 62cc, what will be the approx CR? I thought about Vortecs, but the CR might be too high for pump gas, and I don't really care to buy a new intake and valve covers. I know everyone will say AFRs, but for as little as it will get driven, I don't think the extra cost will be worth it.
As for the cam, I think the XE268H will do what I need it to, I also thought of the Crane energizer with 272 duration, but I like the higher lift of the Comp. Any other suggestions with the heads or cam? I am a novice at this and have not been able to keep up any new technology for several years, so take it easy on me!!
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Old Feb 10, 2011 | 06:04 PM
  #2  
zraffz's Avatar
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From: Sussex County, NJ
Car: 1994 Z28
Engine: 355 LT1
Transmission: T56
Axle/Gears: 3.42
Re: Yet another 350 build

How will compression be higher with vortecs over 62cc heads? Vortecs are 64cc.

We need to know more about your motor before we can tell you about what your compression will be. It will be roughly .8-1.0 higher though on 62ccs... which will be perfect for a pump fuel build. Think a 650 might be a bit small, can't recommend a cam... someone else can chime in now.
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Old Feb 10, 2011 | 10:25 PM
  #3  
BASSETT IROC 85's Avatar
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From: Heart of Dixie
Car: 1987 Camaro Sport Coupe
Engine: 355
Transmission: 700R4
Axle/Gears: 7.5 inch 342
Re: Yet another 350 build

XE268H is a great cam in a 350. Vortec heads are one of the best heads going in my book. A couple of years ago I built a flat top, Vortec headed 350 using a trick cam round track cam made 462 HP and 420 ft lbs TQ. Same engine with a Erson E110030 cam 218 duration @50 with .458 lift made 375 HP and 400 ft lb tq. Engine ran great in my 85 IROC on pump gas at 10 to 1 compression. The key is the efficient chamber of the heads to keep from pre detonation. Also a high duration cam will let you bleed off compression at low speed where most detonation occurs.
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Old Feb 11, 2011 | 12:24 AM
  #4  
zraffz's Avatar
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From: Sussex County, NJ
Car: 1994 Z28
Engine: 355 LT1
Transmission: T56
Axle/Gears: 3.42
Re: Yet another 350 build

Originally Posted by BASSETT IROC 85
XE268H is a great cam in a 350. Vortec heads are one of the best heads going in my book. A couple of years ago I built a flat top, Vortec headed 350 using a trick cam round track cam made 462 HP and 420 ft lbs TQ. Same engine with a Erson E110030 cam 218 duration @50 with .458 lift made 375 HP and 400 ft lb tq. Engine ran great in my 85 IROC on pump gas at 10 to 1 compression. The key is the efficient chamber of the heads to keep from pre detonation. Also a high duration cam will let you bleed off compression at low speed where most detonation occurs.
More information on your heads and cam! I was invited to race at Watkins Glenn with some rich guys (best performing zo6 on the east coast!) and if I can build a circle track motor cheap enough I'll take them up on it.
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Old Feb 11, 2011 | 11:13 AM
  #5  
Black 84 Z's Avatar
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From: Ocala, FL
Car: 1984 Z28
Engine: 350ci
Transmission: 700R4
Axle/Gears: 3.73 12 bolt
Re: Yet another 350 build

Originally Posted by zraffz
How will compression be higher with vortecs over 62cc heads? Vortecs are 64cc.

We need to know more about your motor before we can tell you about what your compression will be. It will be roughly .8-1.0 higher though on 62ccs... which will be perfect for a pump fuel build. Think a 650 might be a bit small, can't recommend a cam... someone else can chime in now.
Sorry, what I meant was that the compression would be too high for iron heads, but if it only bumps it up to around 10:1 or less, that might work. For some reason I thought the 12 less cc would make a bigger difference in CR. As for the 650, I went with it for more throttle response and since it will almost never see the high side of 5500 RPM.
Good to hear that my cam choice makes sense. That is one thing that I am most leery of since a bad choice can make such a huge difference in drivability. I figured it was a good balance of top end and torque.
Just curious, I know it is a long shot but does anyone have any side by side results of Vortecs vs the TFS heads?
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Old Feb 11, 2011 | 11:37 AM
  #6  
zraffz's Avatar
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Joined: Mar 2009
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From: Sussex County, NJ
Car: 1994 Z28
Engine: 355 LT1
Transmission: T56
Axle/Gears: 3.42
Re: Yet another 350 build

Originally Posted by Black 84 Z
Sorry, what I meant was that the compression would be too high for iron heads, but if it only bumps it up to around 10:1 or less, that might work. For some reason I thought the 12 less cc would make a bigger difference in CR. As for the 650, I went with it for more throttle response and since it will almost never see the high side of 5500 RPM.
Good to hear that my cam choice makes sense. That is one thing that I am most leery of since a bad choice can make such a huge difference in drivability. I figured it was a good balance of top end and torque.
Just curious, I know it is a long shot but does anyone have any side by side results of Vortecs vs the TFS heads?
In theory if everything else stays the same and you were exactly 9:1, you'll end up in the area of 10.2:1. You can alter it with a different head gasket though.
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Old Feb 11, 2011 | 03:22 PM
  #7  
BASSETT IROC 85's Avatar
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From: Heart of Dixie
Car: 1987 Camaro Sport Coupe
Engine: 355
Transmission: 700R4
Axle/Gears: 7.5 inch 342
Re: Yet another 350 build

It was 450 lift rule cam used in circle track racing.
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Old Feb 15, 2011 | 07:55 AM
  #8  
Black 84 Z's Avatar
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Joined: Dec 2000
Posts: 171
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From: Ocala, FL
Car: 1984 Z28
Engine: 350ci
Transmission: 700R4
Axle/Gears: 3.73 12 bolt
Re: Yet another 350 build

OK after looking thru the boards a bit more, I noticed a few people using a Lunati Voodoo cam. When I looked up the specs, there was one that was similar to the XE cam I was looking at, it had a touch less adv duration, but a bit more at .050 as well as a bit more lift. It would seem that it has a more aggressive lobe profile, would this cam make noticeably more power than the XE, and would it be at the cost of valvetrain life? Any opinions are appreciated.
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