LT1-LT4 Modifications 1993-97 Gen II Small Block V8

cam and head question

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Old 04-19-2010, 10:58 AM
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I have a 97 lt1 TA getting ready to put a forged 383 stoker rolling assembly in it. now I have a comp cams xfi 292 cam (242/248 dur 579/584 lift 113 sep) now I have the stock heads but I have 2.02 intake and 1.6 titanium valves on them now. Just wondering if a REAL good port job will flow enough for that cam? The cam range is 2800-6400 and I plan on spinning up to 6600. I have a Yank stealth 3000 stall pacesetter long tube w cut outs, lt4 timing chain ltcc coil pack conversion melling hivol oil pump, underdrive pulley twin 58 mm TB and intake. and a built tranny all going on when is put back together. so if anyone can shoot some advice to me I would appreciate it.


Old 04-19-2010, 06:14 PM
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Originally Posted by Dark97TA09
I have a 97 lt1 TA getting ready to put a forged 383 stoker rolling assembly in it. now I have a comp cams xfi 292 cam (242/248 dur 579/584 lift 113 sep) now I have the stock heads but I have 2.02 intake and 1.6 titanium valves on them now. Just wondering if a REAL good port job will flow enough for that cam? The cam range is 2800-6400 and I plan on spinning up to 6600. I have a Yank stealth 3000 stall pacesetter long tube w cut outs, lt4 timing chain ltcc coil pack conversion melling hivol oil pump, underdrive pulley twin 58 mm TB and intake. and a built tranny all going on when is put back together. so if anyone can shoot some advice to me I would appreciate it.


IMHO You need max porting to utilize that cam.
That cam is pretty big. In addition, you need a good valve train, for example Patriot Gold Springs or beehives, quality roller rockers, and good retainers, etc.

What are your goals for this car?.....street, drag racing.....daily driver, etc.
Old 04-19-2010, 06:24 PM
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i dont get why your running tit valves..i only use them when im buzzing a motor 8k an up..anything less is just a waste of cash really man..now for heads im not a fan of running all these ported stock or trick flow ****..if you want a head get a good afr,rhs,dart or profiler head an get it converted to use on a lt1...brodix are nice heads but the flow numbers listed are not the true numbers..ive owned plenty of sets though..if you can get a -11 brodix..them in a good porters hands like cfe,bes,rfd,ricky at nrc an others can flow enough an be done right to support well into the mid to upper 800hp range n/a..
Old 04-19-2010, 06:48 PM
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i have beehive ls springs the retainers that came with them hardened push rods and new hyd roller lifters. and I will be spinning around 7K. Gonna be a street strip car.
Old 04-19-2010, 07:09 PM
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you could definetly get those heads opened up enough to work with that cam. people are hauling *** with the factory castings. check out A.I.

i have the same cam and springs. i dont have them in yet but everyone tells me i could never go near 7k with those springs. although the titanium valves are lighter than stainless and wont float as bad....
Old 04-19-2010, 07:20 PM
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the beehives that i have will hold up too a .650 lift why would it not hold up to 6800/7000?
Old 04-19-2010, 07:52 PM
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The Comp rpm ranges are WAY lower than reality with the LT1 and that makes the Comp recommended springs inadequate. Not just a lift capacity thing but a spring pressure issue. If the springs are inadequate they can let the valve bounce off the seat when it closes. Titanium valves are lighter and should buy some rpm capacity BUT it is my understanding they are hard to make work on the street as they don't mate well with most seats.

I would question the quality of the port work based solely on the valve sizes.
The guys getting the best results from the stock castings are using 2.00/1.56 valves not blindly applying "bigger is better" Some of the fastest NA hydraulic cars are running customs cams with less duration than that too.

The 3000 Yank is not a high enough stall.
Underdrive pulleys do little for an LT1 because the WP is not belt driven.
HV oil pump puts unnecessary wear on the oil pump drive.

Your whole plan is a bench racers dream BUT pretty much a train wreck to anyone who knows what they are doing.


Sorry to be so negative but that is the way I see it. If you doubt my credentials see the sig. You don't make a little hydraulic LT1 go mid 11s in a two ton STREET barge by being wrong about what does and doesn't work.
My cam is under 230degrees peaks 6400ish and pulls to 7000 solidly, granted you have a stroker and I do not, the displacement will soak up some duration but IMO you should have gone with less duration and LSA.


I don't understand why people post looking for validation rather than posting earlier and getting the right information BEFORE they have the whole setup picked out.

I wish you luck but believe you will have an under performer on your hands.
Old 04-19-2010, 09:07 PM
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just get heads like i said..you will be able to run a real spring in it and have a sick head..your rpm range wont be 7k..your a stroker so you dont need to buzz the motor high like a 355 or so..you will probley peak around 6200 with that cam an ported stock heads..as for 2.00 vs 2.02 valves your not running into a shrouding issue for a bit..ive had 2.10 an 1.625 valves on a 4.30 bore an spun 7600rpms on a gen 1 engine..
Old 04-19-2010, 09:17 PM
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thank you for the info it may take me a bit got most of what i need but gotta get the machine work done ill let you know what happens.
Old 04-19-2010, 09:42 PM
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That lift doesn't sound right for 1.6s either.
Old 04-19-2010, 10:08 PM
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why doesnt the lift sound right? here are the specs from comp

LT1 & LT4 1993-96

Good mid-range with excellent top end. Will require headers, gears and 2500+ stall. Rough idle.

Operating Range: 2200-6200 RPM
Duration Advertised: 292° Intake / 300° Exhaust
Duration @ .050'' Lift: 242° Intake / 248° Exhaust
Valve Lift w/1.6 Rockers: .584'' Intake / .579'' Exhaust
Lobe Separation Angle: 113°
Old 04-19-2010, 10:11 PM
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Remember the XFI cams are designed for 1.6 rockers so the listed lift is with 1.6 rockers. Most other cam lines list lift with 1.5s.
Old 04-19-2010, 10:16 PM
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The smaller XFI lobes are much more aggressive than that. I thought w that much duration the life would be higher. Guess not. Carry on.
Old 04-20-2010, 12:42 AM
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i meant 4.030 bore.
Old 04-20-2010, 12:50 AM
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weight is key in the valvetrain, those silly titanium valves will be fine rpm wise, but good luck with durability in a street driven application. if you're set on a beehive spring id run a pac 1518 and shim them up to .040-.050 from coilbind. that cam has too little overlap, and too much duration to make any midrange that would allow you to run such a tight converter. id run a 4000 stall minimum and a 4.11 gear, higher if you're a stick.
Old 04-20-2010, 07:06 AM
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Definitly listen to these guys if your looking at making a hard running car that will turn heads at the track not at a car show. As 96CAPRICEMGR would say "Definitly a summit magazine build, but will sound great though" lol......



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