LT4 w/Hot Cam - Noise Solution?
Thread Starter
Advanced
Joined: Apr 2002
Posts: 93
Likes: 0
From: East Stroudsburg PA
LT4 w/Hot Cam - Noise Solution?
I previously ran the Hot Cam in a Gen-1 engine w/Fast Burn heads. It had pushrod guide plates and adjustable rockers. There was no noticeable valvetrain noise.
When my LT4 was stock, the valvetrain was't *too* noisy... But, for two years now, I've been frustrated whenever I drive with the windows down while stopped at a light
I read in another post that it sounds like a sewing machine. That might be putting it mildly!
I want to make the move to adjustable rocker arms. I'm thinking of these two parts from Jegs:
http://www.jegs.com/i/JEGS-Performan...rentProductId=
http://www.jegs.com/i/JEGS-Performan...ductId=1225483
Can anyone comment of whether the studs will work - and if the rockers will fit under the stock covers?
When my LT4 was stock, the valvetrain was't *too* noisy... But, for two years now, I've been frustrated whenever I drive with the windows down while stopped at a light
I read in another post that it sounds like a sewing machine. That might be putting it mildly!I want to make the move to adjustable rocker arms. I'm thinking of these two parts from Jegs:
http://www.jegs.com/i/JEGS-Performan...rentProductId=
http://www.jegs.com/i/JEGS-Performan...ductId=1225483
Can anyone comment of whether the studs will work - and if the rockers will fit under the stock covers?
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Some modded motors seem to be quiet others arent seems like something to just live with unless theres a real problem with the fitment or parts themselves.
Try a solid roller with .026 lash.Personally I love it
Try a solid roller with .026 lash.Personally I love it
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
I have an LT4 and I'm no great fan of it's self aligning rockers; the ears seem just a tad to small to effectively keep th rocker on the valve tip. I'd seriously think of upgrading to guideplates.
Thread Starter
Advanced
Joined: Apr 2002
Posts: 93
Likes: 0
From: East Stroudsburg PA
Thanks everyone. Mtwoolford - do you think guideplates make that much of a difference? I wonder what the cost would be to go with them and hardened pushrods?
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
Let me emphasise that STOCK LT4 rockers may LOOK like other rocker arms, but they are a one of a kind, one year only item and are EXTREMELY expensive (as I recall about $75 each, IF any are still available). What makes them unique is that they are mount on a 10mm non adjustable pedestal style stud. Nothing interchanges with them and they interchange with nothing.
So I believe that changing out the original pedestal studs and original rocker arms for the more usual and proven adjustable studs and rocker arms is the way to go.
Are guide plates and hardened push rods worth the extra cost over a replacement set of self aligning roller rocker arms alone ? Thats a debate for others with more valve train experience than I, but at some time in the future I personally plan on going with guide plates and hardened push rods. Like I said I'm no great fan of self aligning rocker arms.
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
I haven't checked rocker arm prices in a few years. But, at one time you could buy non self-aligning rockers, hardened pushrods, and guide plates for about the same price as self-aligning rockers.
I'm on my third set of roller rockers. If I had it to do over. I would start where I ended, Comp Cams 7/16" 1.6 roller rockers, ARP 7/16" studs, TrickFlow hardened push rods, and TrickFlow guide plates.
I'm on my third set of roller rockers. If I had it to do over. I would start where I ended, Comp Cams 7/16" 1.6 roller rockers, ARP 7/16" studs, TrickFlow hardened push rods, and TrickFlow guide plates.
Thread Starter
Advanced
Joined: Apr 2002
Posts: 93
Likes: 0
From: East Stroudsburg PA
I haven't checked rocker arm prices in a few years. But, at one time you could buy non self-aligning rockers, hardened pushrods, and guide plates for about the same price as self-aligning rockers.
I'm on my third set of roller rockers. If I had it to do over. I would start where I ended, Comp Cams 7/16" 1.6 roller rockers, ARP 7/16" studs, TrickFlow hardened push rods, and TrickFlow guide plates.
I'm on my third set of roller rockers. If I had it to do over. I would start where I ended, Comp Cams 7/16" 1.6 roller rockers, ARP 7/16" studs, TrickFlow hardened push rods, and TrickFlow guide plates.
I decided to go with the self aligning adjustables that GM sells with the HOT Cam kit - and the studs that come with new LT4 heads from GMPP. I'll post how it goes!
Thanks for all the opinions and advice.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Those will work just fine with your setup. The first set of rockers that I ran was Crane Gold self-aligning, the same rockers as the GMPP's. They were the quietest of the three sets I have ran.
Thread Starter
Advanced
Joined: Apr 2002
Posts: 93
Likes: 0
From: East Stroudsburg PA
Update: The installation went pretty well. The rockers still make a little noise - but you have to be about 18" away to hear it with the valve covers on; where you could stand feet from the car before - and still hear it!
Was it worth almost $400? I'm not sure. I'll have a more thorough opinion when I scan and tune if my knock readings are more steady.
I am much happier with how it sounds when I'm next to someone at a light, though!
Was it worth almost $400? I'm not sure. I'll have a more thorough opinion when I scan and tune if my knock readings are more steady.
I am much happier with how it sounds when I'm next to someone at a light, though!
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Cars also got 10 mpg, topped out at 115, car "stereos" had one crappy speaker, and "bucket seats" were a couch, cut into 3rds. Not everything from the "old days" is desirable.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Are you sure you're not hearing your injectors? Oil weight and pressure can make a difference too.
Thread Starter
Advanced
Joined: Apr 2002
Posts: 93
Likes: 0
From: East Stroudsburg PA
STL94LT1, that's exactly what was driving me crazy. There's still a slight noise - but I don't think it's different from when the LT4 was stock.
GREGGPENN, my oil pressure looks good. If my gauge is correct, it's always around 65psi when above idle. I use 5w30.
GREGGPENN, my oil pressure looks good. If my gauge is correct, it's always around 65psi when above idle. I use 5w30.
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Here is a '61 interior. Notice the (ahem) "bucket" seat. Looks about like a bench seat, w/the middle cut out. No head rest at all, no bolsters what so ever...not what *I* would call a bucket seat.
A 'Vette may have gotten mid teens, fuel economy wise due to the lowish weight...but most cars from the solid lifter era got 10-12mpg.
As for top speed...you're telling me that you're '61 went better than ABOUT 115? What did it go? 118?
And how about that '61 ahem...."stereo"? With it's bad-assed single paper wheezer in the center of the dash? I was wrong about that too?
In case you were unable to figure it out, I was pointing out that not all features (such as noisy valve train) are considered desirable today. I'm sure some people like some of those characteristics, but I don't, and the OP doesn't seem to. Just b/c we tolerated it "yesterday", doesn't mean that we have to, today. SO, to make that point, I highlighted some of the less endearing qualities of older cars; crappy gas mileage, crappy seats, crappy radios, etc.
Last edited by Tom400CFI; Apr 8, 2014 at 11:16 AM.
Racer
Joined: Oct 2006
Posts: 438
Likes: 14
From: Tucson/Santa Paula AZ/CA
2017 C4 of Year Finalist
My '61 Fuelie would do more than 115 in 3rd gear. 123MPH 1/4 miles were routine once I found a clutch combination that would hold up. It was a .060 over 327 with a 30/30 Duntov cam. Totally street driven for about 60K miles before I sold it to a guy in LA. It may still be out there somewhere, solid color Fawn Beige original Fuelie that I purchased from the original owner in 1969 while stationed at VAFB, CA.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
Why do you like these parts the best? Or what didn't you like about the others?
Thanks.