Cam and lifter question
11-24-2015, 09:56 PM
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Car: 84 Z-28
Engine: 355 4 bolt main
Transmission: 700 R4
Axle/Gears: Posi 3.73
Cam and lifter question
Here is what I am working with 355 with flat tops it already has a comp 280H cam in it, but I want more so I have a 305H to put in it. Now since I will be going from 480 lift to 525 lift what would you guys recommend as far as lifters and rocker arms go?
11-25-2015, 01:59 AM
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Car: 1988 Camaro
Engine: 355, 10.34:1, 249/252 @.050", IK200
Transmission: TH-400, 3500 stall 9.5" converter
Axle/Gears: Ford 9", detroit locker, 3.89 gears
Re: Cam and lifter question
The lift is not that big of deal. .525" aint that much really.
Man, do NOT run that cam. It's a monster and will not be happy under 4000 rpm. You will not be happy with it.
I run a 249/252*@.050" cam in my camaro which is pretty much a street legal race car.
3" hg vac (will not work with power brakes)
1000-1200 rpm idle (will not idle any lower)
Brodix IK 200cc heads
10.5 compression (which is the bare min to work right with this kinda duration, 11:1 would be better).
3500 stall (bare min. 4500 would be better but I was trying to keep it somewhat streetable)
3.89 gear (again bare min, 4.10 to 4.56 would be a better match)
The 305H has no advance ground into it. It MUST be degree'd in
What heads do you have? All GM iron heads really stalls out around .500" lift, so no real gain in going above that lift point.
You may have to machine valve guides down to get clearance for .525" lift, or install longer valves, raised install height locks, etc.
With that duration you may also have valve to piston clearance probs. You will need to clay a piston to see, or measure. I had P2V probs with mine and 4 VR 5cc flat top pistons. So I had to go with Wisco 2 VR 5cc deep valve cut pistons.
Why are you looking at 30 year old cam tech? If you want gains in power, get away from the magnum cam line. Those are very dated, slow ramp speed cams.
Look into more modern cam designs, they will beat the power of those magnum cams and do it with better manners.
But to answer your question... I now only use direct lube oiling lifters for any/all flat tappet cams above .500" lift.
For rocker arms any good long slot rocker will work. I have even used stock rockers at .530" lift. Just have to elongate the slot to keep rocker from binding on stud.
If your looking at steel roller tip... I really like Elgin rockers.
If looking for billet alum, full roller... I like Howards (that's what I run on my camaro)
Do not buy off brand, cheap brand full rollers. They will fail and when they do, they will send needle bearings through your engine.
Man, do NOT run that cam. It's a monster and will not be happy under 4000 rpm. You will not be happy with it.
I run a 249/252*@.050" cam in my camaro which is pretty much a street legal race car.
3" hg vac (will not work with power brakes)
1000-1200 rpm idle (will not idle any lower)
Brodix IK 200cc heads
10.5 compression (which is the bare min to work right with this kinda duration, 11:1 would be better).
3500 stall (bare min. 4500 would be better but I was trying to keep it somewhat streetable)
3.89 gear (again bare min, 4.10 to 4.56 would be a better match)
The 305H has no advance ground into it. It MUST be degree'd in
What heads do you have? All GM iron heads really stalls out around .500" lift, so no real gain in going above that lift point.
You may have to machine valve guides down to get clearance for .525" lift, or install longer valves, raised install height locks, etc.
With that duration you may also have valve to piston clearance probs. You will need to clay a piston to see, or measure. I had P2V probs with mine and 4 VR 5cc flat top pistons. So I had to go with Wisco 2 VR 5cc deep valve cut pistons.
Why are you looking at 30 year old cam tech? If you want gains in power, get away from the magnum cam line. Those are very dated, slow ramp speed cams.
Look into more modern cam designs, they will beat the power of those magnum cams and do it with better manners.
But to answer your question... I now only use direct lube oiling lifters for any/all flat tappet cams above .500" lift.
For rocker arms any good long slot rocker will work. I have even used stock rockers at .530" lift. Just have to elongate the slot to keep rocker from binding on stud.
If your looking at steel roller tip... I really like Elgin rockers.
If looking for billet alum, full roller... I like Howards (that's what I run on my camaro)
Do not buy off brand, cheap brand full rollers. They will fail and when they do, they will send needle bearings through your engine.
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