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

correct supporting mods for cam swap?

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Old 01-30-2018, 12:01 PM
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Default correct supporting mods for cam swap?

I have a 1994 camaro z28 thats completely stock and I wanted to do either a cc503 or the hot cams hydraulic roller cam swap in my motor. I know hot cams offers a complete package for their cam, and the comp cam I would need to buy all the valve train parts individually. I was planning to do the pacesetters long tubes and a throttle body along with it, but Im not sure whether or not I should do 52mm, get the manifold ported and go to 58mm, or have the stock one ported. I also wasn't sure if theres any other mods I should do to support the cam swap. Thanks
Old 01-30-2018, 12:22 PM
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What size of cam are you looking to run? The basic rule of thumb is anything over .600 lift requires upgraded springs to avoid floating the valves.

Other considerations are valvetrain weight, and your application. If I recall correctly, every 1 gram of weight loss on your valvetrain is good for 40 rpm. I could be wrong with that since it's been awhile since I've researched that, but basically the lighter the valvetrain, the more rpm you can spin.

You should also consider future mods, and if you are going to add a power adder of some kind. This will affect the choice of cam as well. I had mine spec'd by Pat G. He is a wealth of knowledge on this subject and could definitely point you in the right direction here.

Here is his number (361) 576-5917
Old 01-30-2018, 12:24 PM
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I installed a CC503 in my '97 SS a long time ago and absolutely loved it. I would choose the CC503 over the hotcam any day, but that's just me.

With the CC503 cam I installed comp 1.6 magnum roller rockers, chromoly pushrods, guide plates, rocker studs, and crane dual value springs. I had the heads cleaned and had a valve job done. I left the intake manifold, TB, and SS cold air intake alone. I installed the same Pacesetter LT's and ORY pipe running to the stock 2OTL exhaust. I had the PCM mail order tuned. This was a manual car by the way.

Now if you have the money to get the intake ported, then do it while you are at it. I have seen debates on what TB to use and I think either a 52 or 58 will work just fine to increase air flow. You don't need a crazy amount of air for your intended build.
Old 01-30-2018, 12:52 PM
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With the 503 with good heads, untouched intake manifold, headers and ORY you'll be in the high 300rwhp range. Depending on the gearing used as well as tire you'll be in the mid to low 12 second range. Don't know about TB size and what that would do. I'd see what happens using the stock one first.
Old 01-30-2018, 03:14 PM
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Yup, stock throttle body is good up to 400 rwhp
Old 01-30-2018, 05:26 PM
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OP

at a minimum you will need new valve springs for the cc503 or any cam for that matter

The issue with the "Hot cam kit" is the springs included were designed to work with the lighter valves of the KT4 motor. The heaver LT1 valves they are not a good choice so I wouldn't get that kit

Get RR in the 7/16" NSA (Comp Ultra Pro Mag) and ARP 7/16" rocker studs for guide plates

I prefer the ISKY adjustable guide plates as they allow you to get each valve per cyl dead nuts centered vs one piece guide plates

Trick Flow or CC Chromalloy PR in a .080 thick wall

48mm TB is OK. If you were to go bigger 52mm I would get stock re-bored vs aftermarket TB. But as Moe says the 503 or similar cam on stock heads is good with a stock TB

CAI and CAT back exhaust, headers even better
Old 02-02-2018, 03:27 PM
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Thanks for all the help, I will probably end up going with the comp cam and do the rest of the other valvetrain parts needed for that. Ill see how it runs with the stock throttle body, and then make a decision after that
Old 02-03-2018, 02:20 AM
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Originally Posted by ChopperDoc
What size of cam are you looking to run? The basic rule of thumb is anything over .600 lift requires upgraded springs .......
Wow.....that's a low bar. LOL

The 503 cam has significantly less than .600" and it requires....REQUIRES.....upgraded springs.

Jus' sayin'.....

KW
Old 02-03-2018, 10:27 AM
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Originally Posted by KW Baraka
Wow.....that's a low bar. LOL

The 503 cam has significantly less than .600" and it requires....REQUIRES.....upgraded springs.

Jus' sayin'.....

KW
I wouldn't say required, but recommended. That's actually a pretty small cam. The stock LS3 cam with 1.7 rockers is at .551, and has single springs, stock. Same for a lot of LS engines. Then again that is more my area of expertise. I don't work on too many LT's.

Here are the 503 cam specs with recommended parts.

http://www.compcams.com/Company/CC/c...csid=1107&sb=0

Is the LS world .600 is the number to worry about. Mine is at .647/.644 currently. I have a new one that drops down to .634, but goes over 300 seat to seat. 20* of overlap at .050". Should be fun.
Old 02-03-2018, 11:05 AM
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I should also note that on my engine, as I'm sure you know (from your sig I see you have something similar) that the list of upgraded parts is long, so I'll just list what is still stock... waterpump, alternator, power steering pump, bolts holding these things on. That's literally the only stuff that remains stock. It's not cheap no matter how you build an engine.

I'm no expert on the LT1, but valvetrain weight is probably the biggest consideration when putting together a parts list. I will say, and agree with previous posts that valve weight will also contribute to the need for double springs, or not. I don't see why beehives wouldn't work with that cam. I could easily be wrong on that though.
Old 02-04-2018, 09:32 AM
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Upgraded doesn't necessarily mean double springs, just a fresh set with the proper open and closed pressures for your cam. For LT1s, I would recommend new springs with ANY aftermarket cam. A lot of these motors are so tired by now that I wouldn't be surprised to see gains over 5k rpm with new springs on a bone stock car.

I like dual springs, but most recommend beehives for modest street cams. I like the insurance of the internal damper spring potentially preventing a dropped valve in the event of a spring failure, and they also have higher closed pressures vs a similar beehive. For cams this mild though, there are many options.
Old 02-04-2018, 10:01 PM
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Pretty sure the stock valve springs will coil bind with a CC503. Hot cam has less lift yet it comes with different springs.

I went with a beehive spring on my setup. PAC1518. Don't think they make them anymore, but I do plan on going with whatever they recommend as a replacement for the 1518.

CAI, headers, 1.6 roller rockers, valve springs, and catback exhaust are my recommendations at a minimum. Opening that exhaust is a must. I've got experience with leaving on the stock exhaust manifolds after my CC503 swap and they are extremely restrictive.
Old 02-04-2018, 10:17 PM
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Originally Posted by ChopperDoc
I wouldn't say required, but recommended. That's actually a pretty small cam. The stock LS3 cam with 1.7 rockers is at .551, and has single springs, stock. Same for a lot of LS engines. Then again that is more my area of expertise. I don't work on too many LT's.

Here are the 503 cam specs with recommended parts.

http://www.compcams.com/Company/CC/c...csid=1107&sb=0

Is the LS world .600 is the number to worry about. Mine is at .647/.644 currently. I have a new one that drops down to .634, but goes over 300 seat to seat. 20* of overlap at .050". Should be fun.
I don’t want anyone to read the above post and think it’s okay to run stock valve springs with a cc503 or any other aftermarket cam in an LT1. Springs must be upgraded on an LT1 motor when running an aftermarket cam, period. Also, there’s more than just the lift of the cam that dictates what spring is required. The factory LT1 springs are not up for the job and using them with an aftermarket cam will very likely result in/essentially guarantee engine damage. LSx and LTx motors are vastly different and the general rules or practices from one engine family do not necessarily apply to the other. FWIW stock LT1 cams have lift in the .450” territory, way less than the factory LS stuff.
Old 02-04-2018, 10:27 PM
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OP, I’d choose the 503 over the Hot Cam, it’s a better grind. I had the 503 in my ‘97 for a couple years, great street cam. Better yet I’d see what Lloyd Elliott has that’s comparable. As mentioned by others, I’d keep the stock throttle body and intake manifold alone. I usually don’t recommend touching them until head work is in the picture.
Old 02-05-2018, 11:47 PM
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Originally Posted by ChopperDoc
I wouldn't say required, but recommended. That's actually a pretty small cam. The stock LS3 cam with 1.7 rockers is at .551, and has single springs, stock. Same for a lot of LS engines. Then again that is more my area of expertise. I don't work on too many LT's.

Here are the 503 cam specs with recommended parts.

http://www.compcams.com/Company/CC/c...csid=1107&sb=0

Is the LS world .600 is the number to worry about. Mine is at .647/.644 currently. I have a new one that drops down to .634, but goes over 300 seat to seat. 20* of overlap at .050". Should be fun.
OK.....LOL.

YOU use stock LT1 springs with the 503 cam and get back with us.....

Yeah.....the 503 cam, even with 1.5 rockers, will required a spring upgrade.

Originally Posted by ACE1252
Pretty sure the stock valve springs will coil bind with a CC503.......
Pretty sure you're right.....even if they were new!

KW
Old 02-06-2018, 01:29 AM
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Lol, really put my foot in my mouth on that one. Not sure why I'm even bothering to try and compare apples and oranges in that post. I guess I kept thinking double springs were "upgraded springs" and not just some good beehives. It's been quite a few years since I built a SBC, don't recall the numbers for those anymore. Skipped the LT scene and went straight building LS motors. I made a mistake with that post, that is pretty clear.
Old 02-06-2018, 10:53 AM
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Originally Posted by ChopperDoc
Lol, really put my foot in my mouth on that one. Not sure why I'm even bothering to try and compare apples and oranges in that post. I guess I kept thinking double springs were "upgraded springs" and not just some good beehives. It's been quite a few years since I built a SBC, don't recall the numbers for those anymore. Skipped the LT scene and went straight building LS motors. I made a mistake with that post, that is pretty clear.
No worries at all man. I for one f*** up on a daily basis, just ask my wife.
Old 02-06-2018, 02:10 PM
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Originally Posted by ChopperDoc
......I guess I kept thinking double springs were "upgraded springs" and not just some good beehives. It's been quite a few years since I built a SBC, don't recall the numbers for those anymore. Skipped the LT scene and went straight building LS motors. I made a mistake with that post, that is pretty clear.
Yep......but no biggie!

BTW.....stock LT1 springs were/are a pretty crappy single spring that was barely good for .500" lift......and weren't beehives. The beehives didn't come along unto the early 2000's (2002 if memory serves).

KW
Old 02-07-2018, 03:09 PM
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How many miles on the engine, if it were me I'd either pull the heads and send them to Lloyd Elliott or Advanced Inductions and have the heads ported along with the intake or buy a set of ported heads and get a matching custom cam. I'd also replace the timing set and all of the gaskets and seals as well.



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