[twisted91]

i have a 1991 camaro with a carbed 355 sbc, and th 350. the motor came out of our street stock race car. the motor ran great in the race car, but after swapping motor the rocker arms keep rattling loose, also motor runs rougher. also poor performance on acceleration and rattling on cceleration. any help would be apreciated.

 

[poncho62]

Are you using any type of locking nuts on the rockers?

If it is rattling under acceleration, sounds like the timing is too far advanced.

 

[twisted91]

i am using nylon sealed nuts, but are double stacked, timing is set at 12 degrees at idle. also rocker arm studs are not moving .

 

[poncho62]

Hydraulic lifters?

Maybe they are collapsing.................Cam going bad. How much oil pressure do you have?

 

[red65mustang]

check to be sure the dist mech advance is not pinned/held at full advance, common on a race motor

it does sound like timing/ hi compression/detonation, banging the rockers lose

start it, turn the base timing back to 6, add a can of 104 octane boost, see if drives better, if it does test the compression

? small chance ? is it one or all the rockers rattling? you could have bent a push rod and now have to much preload

 

[twisted91]

it is only on #2 and 4 cylinders. that are rattleing loose. also i will change the distributor back 6 degrees thanks for the help

 

[NXS]

Hydraulic lifters?

Maybe they are collapsing.................Cam going bad? How much oil pressure do you have?

 

[red65mustang]

take the push rods out of #2 and #4, roll them on a formica counter to be sure they aren't bent, NO wobble allowed

swap #2 and #4 rods with rods from 2 other cylinders, problem still in 2 and 4, most likely the lifters

small-small chance for a (sticking-dirty lifter) cure without tearing it down, give it a dose of Marvel Mystery Oil or Wynn's, won't hurt and will clean the varnish out of the motor if you do have to replace the lifters

You need to fix the valve train first and now before addressing what maybe a timing issue,

Clarification? I meant (it's OK) to start it with 12 deg, then turn it back to 6 while it's idling so during the test drive the timing will come in later and less to test for detonation.

till the valve train is fixed, set it at? 8 so it starts easy

 

[twisted91]

finally figured it out the rocker arm studs on the iron eagle heads had loosened up about .030. replaced studs and used stud locker. thanks for the help.