LT4/Hotcam question (again)
Thread Starter
Racer
Joined: Aug 2002
Posts: 432
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From: Ashford CT
LT4/Hotcam question (again)
I have a '96 LT4. Can I just order the hotcam itself or do I need the whole kit? My car already has roller rockers being that it's an LT4. If I could just order the cam over the whole kit it would save me a ton of money. Do I really need the whole kit or will this do?:
GM PART # 24502586
This is just the cam. Also, if I do need the whole kit to do the upgrade, do I need to change my valve covers for the new rocker arms? I plan on doing this upgrade fairly soon so anyone that has done this to an LT4 please let me know...What other parts might be needed for an LT4?
By looking at the part #'s on gmparts-direct it seems all the other parts listed in the kit are already in the LT4 engine, other than the cam itself.
The difference in price is $170.00 for the cam compared to $475.00 for the whole kit.
Thanks,
Ted
[Modified by Hamert, 3:55 AM 1/8/2003]
GM PART # 24502586
This is just the cam. Also, if I do need the whole kit to do the upgrade, do I need to change my valve covers for the new rocker arms? I plan on doing this upgrade fairly soon so anyone that has done this to an LT4 please let me know...What other parts might be needed for an LT4?
By looking at the part #'s on gmparts-direct it seems all the other parts listed in the kit are already in the LT4 engine, other than the cam itself.
The difference in price is $170.00 for the cam compared to $475.00 for the whole kit.
Thanks,
Ted
[Modified by Hamert, 3:55 AM 1/8/2003]
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: LT4/Hotcam question (GS345)
:iagree: Just order the cam and springs from Jeff Kopp and you are there. But, you'll need an intake gasket kit, timing cover gasket kit and maybe the oil pan gasket. All that isn't too bad but needs to be figured if you are budget conscious.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: LT4/Hotcam question (Hamert)
I would fully agree on changing the springs, but I wouldn't put the LT4 springs back on it. I would highly consider something better. Sure it will work but a lot of people have had issues with the long term durability of LT4 springs with that cam. I would spend a little more on the springs that way you only have to do it once.
Le Mans Master
Joined: May 1999
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From: Louisville,KY
Cruise-In I Veteran
Cruise-In II Veteran
Re: LT4/Hotcam question (Nathan Plemons)
I would fully agree on changing the springs, but I wouldn't put the LT4 springs back on it. I would highly consider something better. Sure it will work but a lot of people have had issues with the long term durability of LT4 springs with that cam. I would spend a little more on the springs that way you only have to do it once.
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Thread Starter
Racer
Joined: Aug 2002
Posts: 432
Likes: 0
From: Ashford CT
Re: LT4/Hotcam question (Zora)
Like what springs? Does GM make better springs than the ones that would come with the kit or do I need to get aftermarket springs? Also, I assume the optispark has to come out to change the cam. Does that have a seperate seal or is it part of the timing cover gasket set? One other thing, does the cam affect emissions? I will need to pass CT emissions with the car once they open the program back up.
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
Re: LT4/Hotcam question (Nathan Plemons)
I would fully agree on changing the springs, but I wouldn't put the LT4 springs back on it. I would highly consider something better. Sure it will work but a lot of people have had issues with the long term durability of LT4 springs with that cam. I would spend a little more on the springs that way you only have to do it once.
At rpms above 6000, I don't like the idea of my springs doing the hula hoop around the valve guide boss.
If someone knows of and can pass along the specific info on a drop-in spring that uses a locator or fits the stock locator, and has a seat pressure of ~120# closed, I'm all ears. I've tried Isky, CompCams, Crane, and Engine Works to name a few.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: LT4/Hotcam question (Hamert)
There are better springs that will fit stock locators. I'm not 100% sure which ones but call up Total Engine Airflow and find out, 270-782-6397, ask for Brent.
Your opti will be fine, you will need to replace the seal from the opti to the timing cover, but the opti itself never comes apart. A cam will very much affect emissions but the hot cam is mild enough to still pass. In the LT4 you can probably pass with no other tuning, if not with a good solid custom tune you can probably pass with lower emissions then you did stock. :cheers:
Your opti will be fine, you will need to replace the seal from the opti to the timing cover, but the opti itself never comes apart. A cam will very much affect emissions but the hot cam is mild enough to still pass. In the LT4 you can probably pass with no other tuning, if not with a good solid custom tune you can probably pass with lower emissions then you did stock. :cheers:
Melting Slicks
Joined: Dec 2001
Posts: 2,437
Likes: 1
From: Gainesville Fl
Re: LT4/Hotcam question (Nathan Plemons)
how much hp will you be putting out at the rear wheel since you already have the LT4 to begin with? if it is a stock 300rwhp are you looking at like a 330-345 rwhp possibly? that would be some damn nice power! what are the other things in the LT4 conspericy theory? 52mm throttle body and LT1 head gaskets? If i remember correctly if you do the hotcam and these other two things that your LT4 will dyno close to 400 flywheel hp!
Race Director
Joined: May 2001
Posts: 14,165
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Re: LT4/Hotcam question (1996man)
If you get the cylinder heads ported the upper limit for the hot cam seems to be about 370 hp or so regardless of if it's an LT1/LT4. The cam is the limit, not the airflow of the motor.
On stock cylinder heads you'll probably see more peak power out of the hot cam on the LT4 than the LT1, but not a whole lot more. Oh and BTW the 52mm TB is a crock and I've got the dyno graphs to prove it.
On stock cylinder heads you'll probably see more peak power out of the hot cam on the LT4 than the LT1, but not a whole lot more. Oh and BTW the 52mm TB is a crock and I've got the dyno graphs to prove it.
Safety Car
Joined: Jul 2001
Posts: 3,524
Likes: 1
From: Pinellas Florida Misfit
Cruise-In III Veteran
Re: LT4/Hotcam question (1996man)
how much hp will you be putting out at the rear wheel since you already have the LT4 to begin with? if it is a stock 300rwhp are you looking at like a 330-345 rwhp possibly? that would be some damn nice power! what are the other things in the LT4 conspericy theory? 52mm throttle body and LT1 head gaskets? If i remember correctly if you do the hotcam and these other two things that your LT4 will dyno close to 400 flywheel hp!
Melting Slicks
Joined: May 2002
Posts: 2,670
Likes: 4
From: Severna Park MD
Re: LT4/Hotcam question (Hamert)
Like what springs? Does GM make better springs than the ones that would come with the kit or do I need to get aftermarket springs? Also, I assume the optispark has to come out to change the cam. Does that have a seperate seal or is it part of the timing cover gasket set? One other thing, does the cam affect emissions? I will need to pass CT emissions with the car once they open the program back up.
Le Mans Master
Joined: Jun 2002
Posts: 6,097
Likes: 2
From: Cincinnati Oh
Re: LT4/Hotcam question (Springer's LT4)
I know the LT4 intake gaskets are restrictive.
Thread Starter
Racer
Joined: Aug 2002
Posts: 432
Likes: 0
From: Ashford CT
Re: LT4/Hotcam question (94lt1torchred)
Is it possible to change the springs without pulling off the heads? I really didn't want to have to do that but then again, I'd hate to drop a valve into a cylinder. :eek:
Safety Car
Joined: Jul 2001
Posts: 3,524
Likes: 1
From: Pinellas Florida Misfit
Cruise-In III Veteran
Re: LT4/Hotcam question (Hamert)
I believe it is with the correct tools... when I did my hot cam Norris was going to charge me 300 more to do the springs, thats certainly a lot less then it would cost to remove the heads... I would be worried about setting up the correct spring pressures thou if you did it on the car.
I didn't change my springs when I did the cam, but I also don't race the car more then once or twice a year and I didn't increase my rev limiter.
I didn't change my springs when I did the cam, but I also don't race the car more then once or twice a year and I didn't increase my rev limiter.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Re: LT4/Hotcam question (Hamert)
Is it possible to change the springs without pulling off the heads? I really didn't want to have to do that but then again, I'd hate to drop a valve into a cylinder. :eek:
http://www.hashmarks.com/techtips/valve_springs.htm
:cheers:
[Modified by 96GS#007, 3:16 PM 1/9/2003]