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Discussion Starter · #1 ·
Looking at an LT4 Hot cam. Can buy for 250.00 and install for 200. not bad lol, so just wondering do i need Better springs other than stock and also do i need better rocker arms and push rods for this?
 

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Looking at an LT4 Hot cam. Can buy for 250.00 and install for 200. not bad lol, so just wondering do i need Better springs other than stock and also do i need better rocker arms and push rods for this?
Read the sticky covering this topic It's very helpful, "lt1 valvetrain and cam selection guide"
 

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Discussion Starter · #3 ·
Okay, sounds good. I was lookin at some but couldnt find them usefull
 

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Lt4 hotcam is a great proven Cam. idles nice or nasty depending on tune, passes emmissions test, gets good gas mileage, is billet not cast, and hey those newer lobes and/or a custom cam will give you about 5-10 more horsepower and cost 50-100$ more Require $200 more valvetrain to control.

Try driving a choppy 7000RPM cam with 1/4 mile suspension just North of me I'll enjoy a small cam and large disc brakes.


Have to watch out for bicyclists and deer.




I live 100yds from the Animas River Deer Ducks Geese in Back Yard Eagles Golden and Bald Whooping Cranes Wild Turkey Doves Racoons Squirrels Pheasant etc. If I drive north Large Brakes and Road race suspension and small cam are better. If I drive south Larger Cam and Road Race suspension and tires are better. Altitude 5950 ft is higher than Bandimere DA here 7450.
Reliability is a factor 30 below zero North and 110 Degrees to the South.

Spring Coyote Pups howling now. Gotta Go.

Drought and fires destroying the Forests and wilderness sucks to see the Planet Dying due to human negligence.

 

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Looking at an LT4 Hot cam. Can buy for 250.00 and install for 200. not bad lol, so just wondering do i need Better springs other than stock and also do i need better rocker arms and push rods for this?
I run the hotcam and like it alot. I run the stock stamped rockers and pushrods. In my experience the cam needs better valve springs than the LT4 springs. I run PAC 1212x springs, they install with stock retainers and seats and work well in the hotcams useful rev range. Some new thickwall pushrods would be a good addition too.
Get a new GM timing set for the install and plan for a tune. I have a Madtuner tune and she runs good!
 

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Discussion Starter · #9 ·
Thank you for the info everybody! I ordered some Beehive springs, And push rods. NOT JAPANESE lol. And also the LT4 cam comes with a beautiful set of rockers, Install within the next mont or so!
 

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I can see why GuppyMech likes the Hotcam with the 4.11's

https://www.youtube.com/watch?v=B3kLwhZzqno&list=PLAC3028AD893F4D6D&index=8


I think quality can vary with any type or brand of springs. My exhaust duration is less than the Hotcam. I'm reducing the intake valve weights and running hotcam springs and retainers with lunati Locks. My choice not everyones.

http://ls1tech.com/forums/lt1-lt4-modifications/1590758-broken-valve-spring-dampers-2.html

http://ls1tech.com/forums/lt1-lt4-m...alve-springs-you-running-your-lt4-hotcam.html

http://www.camaroz28.com/forums/lt1...ctual-lt4-valve-spring-install-height-693627/
 

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Make it as painless as possible.

LT4 hot cam with LT4 springs (only 40 bucks for those springs). Use the old LT1 parts. No high ratio rockers - not with stock LT1 head. New vlv seals if u like.

cardo0:thumbsup:
 

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Discussion Starter · #12 ·
LT4 hot cam with LT4 springs (only 40 bucks for those springs). Use the old LT1 parts. No high ratio rockers - not with stock LT1 head. New vlv seals if u like.

cardo0:thumbsup:
Im going to trust your answer.
 

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The Hot Cam is a pretty small cam with a weird exhaust/intake duration split. There are much better cam grinds out there. If you're going to go through the trouble, I'd definitely have a custom cam ground. Send your core to the cam grinder and tell them what you want. It's cheaper that way and you still have a steel cam core when you're done.

I wouldn't use LT4 springs, either. I'd use LS6 springs with Comp 787 retainers. They're a much better spring, plus they're a beehive...
 

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I would not run the LT4 springs with 1.6 rocker arms From my calculations .515 Lift is the most that should be run with a .050" Safety margin to coil bind. 1.5 or 1.52 rocker arms are perfect. I would limit lift to .510 these are best with smaller cams 210-218 duration and stock cams with 1.6 rocker arms engine rpm up to 6000.

Those that want more RPM More clearance to coil bind etc can run beehives the stock ls6 springs comp 918s pacs 1212x are all good choices as are Bullet valve springs vs 574 and vs 2700. Howards cams 98213 Springs are a good choice also

Valve Springs

Perf. Hyd. Roller/Mech. Flat Tappet Valve Springs by Howards Cams - Competition Products



Here is a post from Lloyd Elliot :
Beehive Valve springs - Page 3 - Chevrolet Impala SS Forum : Chevy Impala SS Forums




These are a low cost alternative to the Competition Cams 787 Retainers to save more when running beehive springs.

BEEHIVE VALVE SPRING RETAINERS FOR 7 DEGREE 11/32" APPLICATIONS - Alex's Parts Sales

They also sell mild cam beehives similar to LT4 springs 104 seat psi and 273 over the nose or open pressure. Rated at 110 seat 265 open.

BEEHIVE VALVE SPRINGS- SBC, VORTEC & LS SERIES, STOCK TO MILD - Alex's Parts Sales
 

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These are a low cost alternative to the Competition Cams 787 Retainers to save more when running beehive springs.

BEEHIVE VALVE SPRING RETAINERS FOR 7 DEGREE 11/32" APPLICATIONS - Alex's Parts Sales

They also sell mild cam beehives similar to LT4 springs 104 seat psi and 273 over the nose or open pressure. Rated at 110 seat 265 open.

BEEHIVE VALVE SPRINGS- SBC, VORTEC & LS SERIES, STOCK TO MILD - Alex's Parts Sales
These retainers look to be pretty decent (although they're a little on the tall side), but the springs are a little on the light side for my preference.

The LS6 spring has the same seat pressure, quite a bit more pressure over the nose (higher spring rate) and .030" more distance until coil bind...plus, they're about $20 cheaper... They're a great spring for up to a moderate camshaft/rocker setup. I use them all the time with Vortec heads. They're a drop-in when used with the Comp 787 retainers.
 

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Sorry folks but i'm old school.

Ok, so i read the vlv spring sticky. My research says to run as light a spring as needed to get the job done. The LT4 springs #12551485 are designed for the HOT CAM and used for a much bigger cam on the ZZ383 crate engine. Can't beat the price and uses all the LT1 vlv spring hardware. I don't know why the HOT CAM kit uses 1.6 rockers with that spring - margin to bind is too small for me. Just my observation is lifting a vlv on the "stock" LT1 head past 0.5" is a waste for flow or may even be counter productive.
So for the price i can't see how u can beat the LT4 vlv spring - just swap springs and go with the Hot Cam.
And IMHO the stock LT1 spring is barely enough for the stock LT1 cam(s).

Good luck Workman,
cardo
 

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In reference to the LS6 spring, I saw a spec of 1.190 coil bind. With 1.750 install ht and .525 lift hotcam only leaves .035 clearance. If the springs are installed with +.050 locks to get more clearance then you can't use SA rocker arms. This is why I stayed away from the LS6 springs, otherwise I thought they looked pretty good. I suppose I could've bought some retainers and springs and measured this stuff out, but in the end I went with a different spring.
GM has superceded the LS6 spring (12586484) with the LS9 spring (12625033) and Lingenfelter lists that spring with a coil bind of 1.190
http://www.lingenfelter.com/mm5/mer...de=L230045297&Category_Code=C159#.USzlA90y-Q4
So watch installed height vs cam lift on LT1 heads.


Cardo, I tried the LT4 spring on my hotcam and felt it was loosing control of the valves at 6k. I installed some springs with more pressure and the engine runs much better. After my experience I could never recommend the LT4 springs for the hotcam.
 

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GM loves that LT4 spring.

I have no experience with it but curious, did u use 1.6 rockers or 1.5 with the #12551485 spring?

Thx for your reply,
cardo
 

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I have no experience with it but curious, did u use 1.6 rockers or 1.5 with the #12551485 spring?

Thx for your reply,
cardo
Not sure on your p/n but I used the LT4 springs (12495494, set of 16 or 12551483, ea). I used them with both 1.5 and 1.6 ratio stamped rockers. As you would expect the the 1.6 rockers where harder for the springs to control at higher revs than the 1.5 ratio rockers.
While the LT4 springs worked and I used them for 3k miles and went to the track many times I suspected they weren't strong enough. To get the engine to rev cleanly up through 58-6000 rpm I had to play around with reducing the lifter preload. I eventually settled on 1/2 turn, now I consider this just a crutch for weak valve springs to limit the amount that the lifters can pump up when the springs loose control of the valve.
After I installed the stronger springs (PAC1212x) the engine runs much better throughout the rpm range and it is pulling hard at 6k were I have my shift light set. I have no doubt that I could benefit from shifting at a higher rpm now and plan to try 6200 next time I go to the track.

My engine has 120k on it and I have thought that maybe my results with the stronger valve springs are due to my heads oem valve job getting long in the tooth. The heads have never been off the engine and it runs great so I really have no reason to suspect the high milage.

Sorry for the long winded reply.
 

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Wow, great info gupp.

Thx for the reply and it made me think enough to do a little research on this #12551483 spring - yes u were right, i posted the wrong part number. Now first i found that spring was used in quite a few GM crate engines (LT4 Corvette, ZZ4, CT350/400 and ZZ383 Engines) and had to wonder why its not working for our homemade conversions. Well i found all those crate engine heads used the same light weight vlvs:
LT4 Valve, Intake 2.00" (50.8mm) Hollow stem Weight:85 grams, 3.00 ounces #12555331
LT4 Valve, Exhaust 1.55" (39.4mm) Sodium filled stem Weight:75 grams, 2.65 ounces #12551313

Where the LT1 valves weigh in much heaver:
LT1 Valve, Intake 1.94" (49.3mm) Solid stem Weight:110 grams, 3.88 ounces #10241743
LT1 Valve, Exhaust .50" (38.1mm) Solid stem Weight:95 grams, 3.35 ounces #12550909

It don't take many brain cells to realize that spring maybe adequate for the light LT4 type valves but not the heavier solid stem vlvs on an LT1 - at high RPM. So now i'm a believer here. But the bad news is now i on search for replacement vlv springs for my LT1.

Thx again gupp,:LS1LT1flag:
cardo0
 
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