Rocker setup for magnum heads on an LA engine

-
D

dieselman966

Well-Known Member
Joined
May 31, 2013
Messages
77
Reaction score
28
Location
Milwaukee
We bought some heads from performance injection equipment. They are magnum style heads. I'm guessing the stock or magnum style rocker assemblies can be used with them?
 
I believe in most cases that with a stock style head stock rockers can be used you will just need to mock them up paying close attention to pushrod length. then check for clearance between the retainer and rocker arm at the top of the spring. Another area to inspect would be sweep across the tip of the valve making sure that it is centered on the tip of the valve. I would attached the heads to the block with a head gasket just snuggling them up, with rocker arm assemblies in place I would rotate the motor checking the aforementioned areas
 
You will need to use a lifter that allows oiling through the push rod and proper push rods. AMC lifters are drop in and oil through push rod.
 
read the B3 racing "rocker arm geometry" utube vid which will show you how high on the pedestal to lock down the rockers. basically you want a 90 deg (right) angle between the rocker & the valve at 1/2 cam lift. getting a horizontle CL on the stock "sled" type rockers takes a bit of work. then check the pushrod length needed with an adjustable pushrod (add on your desired preload amt)
 
go to youtube & type in "pushrod geometry for engines" & its the 1st video listed there & it is by straub industries -scott foxwell
 
PIE is a few minutes away from me here in Delaware. Call them and ask them what they suggest. I haven't personally delt with them, but they built a 408 stroker for a friend of mine that made 580ish hp on the dyno.
 
magniflux the heads for fatal cracks b4 spending any money on them
I also PT...pressure test
do a search on the subject
the stock rockers do work fine
 
While I would not use a Magnum or any head that is cracked. Most cracks aren’t fatal. I’m sure I have them on my 245K engine as well as my 85K engine.

All the gurus said so!

But yet it still runs, needs no plugs, loose no coolant etc...
 
If these heads came from PIE in Delaware, they use EQ heads for their cores, not factory ones, from what I have heard.
 
You can buy rocker studs/guide plates from Comp which allow you to use a SBF roller rocker if you so desire. Oil thru the pushrod.
 
rumblefish360 said:
While I would not use a Magnum or any head that is cracked. Most cracks aren’t fatal. I’m sure I have them on my 245K engine as well as my 85K engine.

All the gurus said so!

But yet it still runs, needs no plugs, loose no coolant etc...
Click to expand...

Krooser said:
I've had six Magnum heads mag'd and all passed without cracks...
Click to expand...

Lucky guys.
The used 96k mile Magnum I bought for my car both heads were cracked at both ends on the last cylinder between the intake and exhaust valves, but the seats were not cracked. (just the cast iron)
But it was running without issue's.

One weird thing was that I could turn any of the valves 180 degrees and see light through the valve to seat.
It looked like they just sat in that one spot and the seat and valves both got out of round to match.
 
With or without springs installed?
The valves were just sitting on the valve seat with no springs when you seen the light?
 
dieselman966 said:
We bought some heads from performance injection equipment. They are magnum style heads. I'm guessing the stock or magnum style rocker assemblies can be used with them?
Click to expand...
Which version did you buy? They have a stage ii ported EQ head with 2.05 intake valve. That they say flows 290 cfm at 0.600 lift
 
dieselman966 said:
We bought some heads from performance injection equipment. They are magnum style heads. I'm guessing the stock or magnum style rocker assemblies can be used with them?
Click to expand...

Did you just buy these heads, or have you had them sitting around for a while? Would you be willing to post up a few pictures here? I am curious to see if you have the new version Engine Quest heads or the original version of the Engine Quest heads, and if we'd even be able to tell from the outside.
I am not worried anything is wrong with yours, I am just curious what they changed.
 
Yep

useless (1).gif
 
mopar65 said:
Which version did you buy? They have a stage ii ported EQ head with 2.05 intake valve. That they say flows 290 cfm at 0.600 lift
Click to expand...


We got level one heads. They flow 270 cfm @.500 lift

Bobzilla said:
Did you just buy these heads, or have you had them sitting around for a while? Would you be willing to post up a few pictures here? I am curious to see if you have the new version Engine Quest heads or the original version of the Engine Quest heads, and if we'd even be able to tell from the outside.
I am not worried anything is wrong with yours, I am just curious what they changed.
Click to expand...

I'll snag some pictures of them tomorrow fir you.
 
Hughes Engines offers some really nice shaft mounted rockers for them as well.
 
I used the Crane rockers made for a small bock Chevy. There the 1.6 ratio like the stock Magnum heads.
The Hughes rockers are really nice as Rob said. They use a shaft between the intake and exhaust minimizing movement.
 
Ive got a pair of heads that are running the crane 5/16 - 3/8 conversion studs with a pair of 1.6 crane sbc rockers and jomar stud girdles. No complaints here.
 
You must log in or register to reply here.
-

Back
Top