Rocker arms question ?

[RevTheory]

Give us your cam specs; you sure might be right. Unless the duration is already on the edge of being too much, I'd be inclined to go 1.6, especially with a 112 LSA.

[wyrmrider]

Mild engine stock rockers work fine
If you do not have screw in studs already you can get the 7/16 long slots
stock ratio is fine
you can tr some 1.6s on the intakes later
before you put a lot of money into roller rockers
just use some good assembly lube
Another back in the day story
we developed the 400 degree cam because all we had were stock rockers and lousy springs
really gentle with long ramps
let's do see the cam specs and see how "intense" it is
a fast action cam is harder on the rocker balls/ tips and requires a bigger spring-stock have limits
so do the roller tip/ ball ones
actually they all do

[Monza355]

Give us your cam specs; you sure might be right. Unless the duration is already on the edge of being too much, I'd be inclined to go 1.6, especially with a 112 LSA.

Yes. What more would you like to know about the camshaft ?
Advertised duration is 278/284
0.050" 225/231
Lsa 112 Icl 106 or 108
.500"/.510" lift with 1.5 ratio.

[Chipster]

On my rule limited dirt engines I have found a 3/8 pro stud w/nitro rocker holds up better than 7/16 set up with ball rockers.

edit with cams up to .555 or so

[RevTheory]

Just looking at the cam specs and wanting to hit 6k, I'd likely do what wyrmrider mentioned and do a 1.6/1.5 split but, when you throw a stock converter into the mix, I'm on the fence.

Going to a 1.6, you can figure roughly 2, maybe 3 degrees more duration at .050 so keep that in mind.

[Monza355]

It wouldn't bother me at all if it would only pull to 5600 rpm at all. I just thought based on similar builds this cam should probably carry the power up to 6000 rpm's with the 200cc heads with ease.

But the stock converter is a must for this application and hopefully it won't suffer much from the stock converter with this camshaft.

[Old School]

It wouldn't bother me at all if it would only pull to 5600 rpm at all. I just thought based on similar builds this cam should probably carry the power up to 6000 rpm's with the 200cc heads with ease.

But the stock converter is a must for this application and hopefully it won't suffer much from the stock converter with this camshaft.

If the stock converter is a must I would drop 6-10 degrees off the cam on both intake and exhaust. A smaller cam will have more torque and just as much power to 3500-4000. It doesn't sound like this engine will spend a lot of time above 4000. The smaller camshaft will do everything better at the lower rpm's including fuel consumption.

[Monza355]

I totally agree with you. However it happens I have the cam new on the shelf. I was going to use it in a larger engine. But it would spend quite some time at higher rpm's when off roading in the low range. So if I this engine would be going into a heavy Camaro with tall gears and stock stall I would probably opt for a smaller camshaft as well..

[RevTheory]

I don't think I'd have a single problem just running the 1.52 Magnum rockers on a 3/8 stud in your application. I don't really see any need to make your intake any larger than it already is and I don't see where that lobe or the required spring for it justifies a 7/16 stud.

But do give serious consideration to those lock nuts. I had one of the regular nuts back off on me about 30 miles out of town once. By the time I hit town, it had backed off enough to spit the lifter out and I lost the cam because of it. If I hadn't been drinking, I'd have pulled over and tried to get a ride back into town instead of pushing my luck

[Monza355]

I also have an old generic Crane 214/224 flat tappet camshaft in the box with lifters.
How much power would I give up going with this smaller cam compared to the roller cam I already have and how much would the gain be in low end power

Crane Hyd FT.
It's 214/224 @ .050"
442"/465" lift w 1.5rr
112 lsa

[n2oracer]

The Comp Magnum roller tip rockers & posi-locks will most likely cost more than the KMJ stainless rockers someone else mentioned.

[wyrmrider]

That 214 grind appears to be left over from when Crane owned a big Detroit camgrinder- really obsolete grind (similar to the 204-214) but precision made and long lived - it's not a fast action grind
most do not need that much exhaust split today but you can use with 1.6 rockers on the intake only
just look at the intake close point and determine where you want your torque curve where do you want the power?
that 214-224 profile may be ground on either 112 (most likely and as you say) or 110 LCA
one application would be smog legal EFI
recall I said go 7/16 if you did not have studs already- If you do have 3/8 screwed in or even pinned you'll be fine
do get better poly-locks Elgin-PEP etc
(isn't poly an Isky trademark?) Where's the parrot when you need him?

[Old School]

I also have an old generic Crane 214/224 flat tappet camshaft in the box with lifters.
How much power would I give up going with this smaller cam compared to the roller cam I already have and how much would the gain be in low end power

Crane Hyd FT.
It's 214/224 @ .050"
442"/465" lift w 1.5rr
112 lsa

I have the exact cam in a 350. Engine is 8.5 compression, 882 heads, Z28 intake and 600 Holley. In a 3800lb 1969 Chevelle, powerglide with 3.08 gear.

That cam is all the stock converter wants. I have recurved the distributor for 20degrees advance, 16 more in by 2800, 14 more degrees with the old 1810 vacuum advance canister for crusing. Car is responsive, still sorta sluggish until about 3000, pulls strong to 5800. It can't help but be sluggish with the glide and 3.08. You have much better parts, I just threw what I had together for a driving engine. It will get 18-20 mpg on the mountainous roads here. I use the Z28 springs. stock rocker arms and factory pressed in studs. The cam has a slight choppy idle to it.

I don't know how the seat duration will compare between the roller and hydraulic. I have never ran the roller you have so I cannot give a personal opinion. I would be tempted to use the flat tappet and save the roller for a larger engine or a looser converter. More compression will help the low end torque.

I am well satisfied how the 214-224 works for me. Nice idle, good fuel mileage, smooth while driving, plenty of power for passing. I am sure there are lots more cams that would just as good or better. One thing I do not want is any bigger cam in my combination. Best of luck with whatever you decide.

[jtb032295]

The Comp Magnum roller tip rockers & posi-locks will most likely cost more than the KMJ stainless rockers someone else mentioned.

They sure seem like a great deal.. but unfortunately, KMJ gained a record for being poor quality awhile ago. They have supposedly redesigned their roller rockers and hold them to a higher quality now. I thought maybe someone would chime in and tell us about the "new" rockers KMJ is selling and how they compare to others.. It just seems no one wants to try the new stuff because of their previous bad reputation.

[rfoll]

A 400 HP/6000 RPM 350 and a stock converter would seem to be mutually exclusive. More cubes or converter is likely necessary to achieve all of your goals.