1.6 rocker arms to use with stock shaft?

[xmoparx]

Hi!

I'm planing to put a pair of Edelbrock RPM heads on my mild 440. My plan was to use the stock non-adjustable steel stamped rocker arms and shaft and all from my 915 heads to use with my new RPM heads. Since i got a pretty mild hydraulic cam XE268H, 224/230 @.50 and .477/.480 lift. I was thinking of changing to 1.6 rockers.
So is there any 1.6 rocker arms that I can use with my stock rocker arm shaft and other stock parts from my 915 heads?

Thanks
Lars

[cudabob496]

I had some built 915 heads once on my 440. In my opinion, I'd get some better quality rockers. I used Cranes, or something. May buy you another 30 hp, and make you safer at higher rpms. Also, don't remember why, but I was told not to go to 1.6 rockers. A valve/piston clearance or geometry issue or something.

[bulldog426]

yeah it can make the valve hit the piston from too much lift sometimes but as long as you have deep valve relief pistons you should be ok, plus that cam don't have a bunch of lift anyway. also it can create too much lift for the valvesprings, so if you are borderline on the valvesprings you may not want to do it.
they do make rockers that you can use with stock shafts, but you may want to check out 440source.com they have pretty good deals on their stuff and some people don't like em, but i haven't found any problems yet with the products i've got from em.

[djswwg]

going from 1.5 to 1.6 rockers will take your .480" lift to .512" and will definitly increase power output. but be positive the springs can handle the increased lift. the 2 things to watch for are coil bind, which will bring istant damage, and valve float at higher rpm. the other issue is that increasing the RAR moves the pushrod closer to the intake runner. on 440source heads THIS IS A BIG PROBLEM that requires lots of clearancing (grinding) on the intake runners. been there and done that, twice.........djs

[xmoparx]

Thanks all for inputs an recommendations.
I have been looking at the Crane Ductile Iron 1.6 rocker (64771-16) to use with my stock shaft and hold downs from my 915. No worries and the give the impression of to last forever.
But at the same time PRW 1.6 roller kits tempts me.... all new stuff, more power etc and all benefits of roller rocker. The price for Crane ductile iron and the PRW alu kit is almost the same.........
What to do? ;-)
By the way I guess I will bee having new numbers at Duration @ .050" with the 1.6 ratio?

Thanks!
Lars

[djswwg]

the duration will increase, but only slightly, not enough to make much difference, but still a step in the right direction. i've used PRW's in several engines and they seem up to the task, no trouble so far. i don't think anything will ever surpass the Crane Golds for durability, to bad they are no longer available...............djs

[cudabob496]

Well, I think going to 1.6 rockers will end up being a mistake, but I hope not.
Why not get a better Mopar cam, and use the right valve springs.


From this article, little power gain:

http://www.moparmusclemagazine.com/h...all/index.html

[djswwg]

if you needed a new cam and had good 1.5 rockers, then yes it's a mistake, but if the cam is fine and you need new rockers why not go to 1.6 and increase performance-bearing in mind the the pre-mentioned issues to watch for..........djs

[75Dart_Sport]

I just put the E-brock heads on my 440 with Harland Sharp roller rockers and on the site it says they are designed directly for the E-brock RPM heads cause they take up to .600 of lift. I have a comp cam and when i put the 1.6 on it moved my lift to .520/.523 and cleared my kieth black flat top piston.

[cudabob496]

The cam you have may not make the power those heads are designed for (flowrate). Going to 1.6 rockers may make a minimal horsepower increase, with the risks, as stated, of valve float, coil bind, and the need for head grinding. Maybe a chat with E-brock tech people can tell you what would be the best cam (especially duration wise) for those heads, and if the 1.6 rockers will work ok? Also, I think you need to have at least .070 inches of clearance between the valves and pistons. Maybe a cam with less lift but more duration will make more power?

[xmoparx]

I finally made a decision to buy the Hughes 1.6 rocker arm kit with shafts (HUG 1520S-16). Hope they are good?.... since I got brand new assembled Edelbrock RPM heads why not for once buy something that's brand new and I have never had roller rockes before, why not try it.
Any recomendations for pushrods, size, material etc?

Thanks!
Lars

[djswwg]

try www.pushrods.com, that is Smith Bros. pushrods website. i've used a couple sets from them and they are really good..........djs

[djswwg]

sorry, thats www.pushrods.net.............djs