Getting LT4 Hot Cam kit installed, do I need anything else?
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (ericcer)
Eric,
Could you ask Pete what valve spring seat to use with the Comp Cams 941 springs? I don't think they'll fit over the stock valve spring seat locators. I'd like something better, but I'm not in a postion this year to pull the heads for machine work.
:cheers:
Jim Mason
'96 Grand Sport #007
Could you ask Pete what valve spring seat to use with the Comp Cams 941 springs? I don't think they'll fit over the stock valve spring seat locators. I'd like something better, but I'm not in a postion this year to pull the heads for machine work.
:cheers:
Jim Mason
'96 Grand Sport #007
Drifting
Joined: Jul 2001
Posts: 1,296
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From: Largo Florida
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (96GS#007)
Ok, I will. I plan on doing the hotcam sooner than you so certainly need to know if I am to use Comp Cams 941 springs.
BTW, He also said the factory LT4 retainers are light and of good quality.
They can be used for the hotcam. When I asked these question the assumption was keeping with the stock rev limiter of 6400 rpm.
BTW, He also said the factory LT4 retainers are light and of good quality.
They can be used for the hotcam. When I asked these question the assumption was keeping with the stock rev limiter of 6400 rpm.
Race Director
Joined: May 2001
Posts: 14,165
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Re: Getting LT4 Hot Cam kit installed, do I need anything else? (Patrick96LT4)
44 HP? Any PCM changes? That seems huge.
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (ericcer)
Ok, I will. I plan on doing the hotcam sooner than you so certainly need to know if I am to use Comp Cams 941 springs.
:cheers:
Jim Mason
'96 Grand Sport #007
Melting Slicks
Joined: Oct 2000
Posts: 2,726
Likes: 24
From: Freehold, NJ
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (silver & red CE)
Anyone who has been around here know not to use the lame LT4 springs with an LT4 HOT cam. Not only will the LT4 valves float with the LT4 HOT cam and LT4 springs below 6500 RPM, but the cheesy factory retainers are prone to breaking during valve float. More than one LT4 owner has dropped a valve with that combo. The LT4 springs are too close to coil bind with 0.525" lift. Going with Crane or Comp springs and some Ti retainers will allow you to rev beyond 6500 rpm with the heavier LT1 valves.
Eric
Eric
I am using the stock LT4 springs, and stock LT4 heads. 250+ drag passes where the motor regularly sees 6500 RPM and I have never seen any problems with valve float. Check my dyno graphs and you will see there is no problem with valve float.
I don't think the LT4 springs are as bad you make them out to be.
I think RichS is using them as well (he runs low 12's @ 117 in his GS with ported LT4 heads and a hot cam).
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (Eric Fischer)
Eric
Huh?? Never heard of this before....
I don't think the LT4 springs are as bad you make them out to be....
Huh?? Never heard of this before....
I don't think the LT4 springs are as bad you make them out to be....
Eric
Drifting
Joined: Jul 2001
Posts: 1,296
Likes: 0
From: Largo Florida
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (silver & red CE)
I spoke with Pete at CNC again and he said you could use rest of the factory parts with the Comp Cam springs. I don't know a lot about heads but he said...
Heart (?) seat can be used. All other factory parts can be used.
Install height is important should be at 110-130.
Maybe this makes sense to you guys. Maybe you can correct me on what that really means.
He is a helpful guy. Give him a call.
CNC Cylinder Heads, Inc.
6400 53rd Street
Pinellas Park, FL 33781
727-527-8866
Fax 727-521-3629
For what its worth, he thought the guy that dropped a valve more than likely did not set up the tolerances correctly.
Heart (?) seat can be used. All other factory parts can be used.
Install height is important should be at 110-130.
Maybe this makes sense to you guys. Maybe you can correct me on what that really means.
He is a helpful guy. Give him a call.
CNC Cylinder Heads, Inc.
6400 53rd Street
Pinellas Park, FL 33781
727-527-8866
Fax 727-521-3629
For what its worth, he thought the guy that dropped a valve more than likely did not set up the tolerances correctly.
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Racer
Joined: Oct 2001
Posts: 466
Likes: 27
From: Hendersonville tn
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (dizwiz24)
[QUOTE]Make absolutely sure they use a special water pump driveshaft seal protector when reinstalling the timing cover.
If not the water pump driveshaft seal will get kinked causing an oil leak, slow at first, and then get worse.
Made my own the 2nd, 3rd, and 4th times I did it. Borrowed one from the GM dealer the 1st time. A must have. Some mechanic not familiar with the LT1 won't know they even need it.
Replace the timing chain with an LT4 extreme duty and you won't have to open up the front end again.
If not the water pump driveshaft seal will get kinked causing an oil leak, slow at first, and then get worse.
Made my own the 2nd, 3rd, and 4th times I did it. Borrowed one from the GM dealer the 1st time. A must have. Some mechanic not familiar with the LT1 won't know they even need it.
Replace the timing chain with an LT4 extreme duty and you won't have to open up the front end again.
Drifting
Joined: Jul 2001
Posts: 1,296
Likes: 0
From: Largo Florida
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (BryanC)
I spoke with Pete at CNC again concerning the 941 springs. He recommends them for all applications and said the factory LT4 springs would work for my drving style. For NOS, the 941 are a must and the factory ones won't hold. Also with the 941 there is a possiblity that some machining would have to be done because of tolerences. Either way he said to check the springs you get to make sure you don't have some springs that are "bad".
He said that road racing is really not that hard on the valve train unlike drag racing.
He said that road racing is really not that hard on the valve train unlike drag racing.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (ericcer)
Ericcer,
Thanks for following up and posting the info from Pete @ CNC! Given my intended use, I'm sticking with the LT4 springs :yesnod:
:cheers:
Jim Mason
'96 Grand Sport #007
Thanks for following up and posting the info from Pete @ CNC! Given my intended use, I'm sticking with the LT4 springs :yesnod:
:cheers:
Jim Mason
'96 Grand Sport #007
Thread Starter
Racer
Joined: Jun 2002
Posts: 262
Likes: 0
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (96GS#007)
Well the work is underway, now on its 5th day! So far in addition to hot cam kit, I have needed a new water pump, new opti spark, new lifters, new a/c line, and now I just found out my 92 valve covers won't work, even after the drip tabs have been ground down. For anyone interested, this is major work and has turned into a huge expense. Do not undertake lightly. I just ordered new valve covers from Jeff kopp. Hopefully they will work. If the valve covers are too high, I'm told they will interfere with A/C and Alternator.
God I hope this is all worth right.
Right now I don't think it will be, approaching 4 grand
Should have listened to my buddy and just got NOS
God I hope this is all worth right.
Right now I don't think it will be, approaching 4 grand
Should have listened to my buddy and just got NOS
Race Director
Joined: May 2001
Posts: 14,165
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Re: Getting LT4 Hot Cam kit installed, do I need anything else? (dscottr)
I just found out my 92 valve covers won't work, even after the drip tabs have been ground down.
Thread Starter
Racer
Joined: Jun 2002
Posts: 262
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Re: Getting LT4 Hot Cam kit installed, do I need anything else? (Nathan Plemons)
I checked out the valve covers and the mechanic really ground the drip tabs off. He said one side fit fine, but the side with the oil cap just would not clear.
What next!
[Modified by dscottr, 12:37 PM 8/13/2002]
What next!
[Modified by dscottr, 12:37 PM 8/13/2002]
Drifting
Joined: Jul 2001
Posts: 1,296
Likes: 0
From: Largo Florida
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (dscottr)
I got my heads back from CNC and talked to Pete about the LT4 intake being more restrictive than the LT1. He said the reason GM did that was becasuse of emissions at idle or low RPM. I know this sound wrong but that is what he says.
His port job of a LT4 intake is worth 10 rwhp on a totally stock engine! He charges $395 for that.
His port job of a LT4 intake is worth 10 rwhp on a totally stock engine! He charges $395 for that.
Drifting
Joined: Jul 2001
Posts: 1,296
Likes: 0
From: Largo Florida
Re: Getting LT4 Hot Cam kit installed, do I need anything else? (all4c4lt4)
I just had them do the new springs and seals for me. They did not work the heads at all. I think LT4 heads are $1500 -1700. You have to add $400 on top of that for the LT4 intake port job.
