My 360 Magnum is sick

[zhandfull]

Poor motor is coughing and sputtering. Problem started over a month ago. On a Thursday night test and tune, last run of the night during a burn out, the motor back fired. Should of known them but I ran it anyways and it coughed and sputtered down the eight mile. I had been having some ignition problems and had already decided to switch over to a complete MSD ignition system. So I drove it 20 miles home. This all happened the week prior to the local Summit race on Sunday.

So as usual I waited till early Sunday morning to switch over the ignition and had some problems. I did get them straighten out and made the race that day. Only problem was the car was still sick. Went out first round against the series leader and drove it home. Been dreading working on it for the last three or four weeks and the car has just been sitting while I work on other less important projects.

Tonight I figured I better look at it as next Sunday is the next summit race. Here is what I found. Looks like I broke a valve spring. I'm pretty sure that is not a big deal. I've heard you can pressurize the cylinder and change them. Sounds easy, anybody have tips, tricks, or methods. For doing this work. Will be my first time messing with the springs. I usually leave valve work to the machine shop.

 

[Abodybomber]

I do,Z. Go the Hughes 1110 springs,matching retainers. This will give you 110 on the seat,320 @.500. The retainers bump the lift,good to .530,.540 safe. Iirc,you have 4.10's out back. Would start there. Spend the money,Napa/K.D. valve spring tool. Anything else fails. Pick up the matching,spark plug adapter. I pulled rhe Schrader valve,out of my compression gauge threaded hose. Worked out nice.

 

[OldmanRick]

Air, or even a piece of rope fed thru the spark plug hole pushed up with the piston, will keep the valve from dropping. Main problem I see is you need a spring compressor that works on the top side only.

 

[sireland67]

You will need a tool that looks like this to change the springs.
NAPA sells them.

[ame="http://www.amazon.com/gp/product/B0002STSGC/ref=pd_lpo_k2_dp_sr_1/186-9199631-2449421?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=lpo-top-stripe-1&pf_rd_r=0DK82QAH2TZ62XZN03HN&pf_rd_t=201&pf_rd_p=1535523722&pf_rd_i=B0002STSG2"]Amazon.com: KD Tools 2078 Universal Overhead Valve Spring Compressor: Automotive[/ame]

 

[inkjunkie]

Pretty much covered already. Sometimes the keepers can be a bit of a pita. I Have taken a large socket placed on the retainer and give it a sharp shot with a hammer to help free them, after you have pressurized/filled the cylinder with rope. Keep a magnet handy. Use a dab of white lithium to help with keeping the keepers in place....

 

[crackedback]

Well that sure helps solve a bit of the mystery.

 

[zhandfull]

Summit has the spec'ed spring P5249464. Going to just get one to patch this thing up. Thanks for the tips. If I have any more spring problems I will just replace them all. This motor doesn't have any miles on it, hoping it was just a fluke that the spring broke.