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Author Topic:   Help !!
eaton89
Dirt Freak

Total posts: 268
posted May 19, 2005 09:17 PM  
I've lost 2 cams now to what I suspect to be improper brake in. I have not had problems with smaller hyd cams but I started using a bigger solid cam and larger springs and the first failed badly. So I bought the same cam and it is in a differnt block and I lost one lobe. I was being what I thought was very carefull the second time. I took the inside spring out and just run a old set of outer springs. I brought the idel up very quickly and run it about 2000 for 30 min. Shut it down. Cooled it and changed all the springs and then run it to temp and reset the valves. I run 4 race nights with this motor and it still was running good. I reset valves every race weekend and suspected it going down but prayed I was ok. Off season I tore it down to find it was down. The only thing I am not sure about is break in lube. I used 2 different kinds. 1st was comp and second was something I had left over from a couple years ago and cant remember what it was. What am I doing wrong!It is a sbc 355, roller rocker 1.6 and 1.5, solid cam from speedway,.533-.555 lift. Like I said I think I was being careful the second time with the lesser spring pressure.

jpotter94
Dirt Forum Racer

Total posts: 94
posted May 19, 2005 09:21 PM  
sounds to me like too stiff of springs and maybe too tight of valve lash..other then that it seems your doing everything correctly

eaton89
Dirt Freak

Total posts: 268
posted May 19, 2005 09:27 PM  
I set the vale lash as specified by the cam card and made the adjustment for being cold.I am worried about the spring presure. But I figured taking out the inner spring would help this.

sc1 racing
Dirt Freak

Total posts: 419
posted May 19, 2005 10:33 PM  
how did you set valves? i always break engine in with a little loose, then when its up to tempature i rest valves and change oil. did it mushroom the lifters?

90% of the time if springs are to much it will bend pushrods and bust rocker arms. you either got a cam built on friday afternoon, or had valves adjusted wrong.

just remeber there are 10 diff ways to adjust a solid cam, but only one true flat spot on the cam.

Ego Racing
Dirt Forum Champ
Total posts: 724
posted May 20, 2005 06:04 AM  
Set them as the cam card specs. If it is hot or cold do it as the card says. Remember as your engine heats up the adjustment will get loose because the block and head expand more than the steel pushrods. If the card specs a cold setting and you are re-adjusting them to that setting hot when the motor cools down it will be to tight and could cause damage.
Are you running oil restrictors? We have started breaking in the motors without them then installing them before they go to race, it just adds oil to the top of the motor during run in.

eaton89
Dirt Freak

Total posts: 268
posted May 20, 2005 10:10 PM  
I did adjust for cold. I dont remember for sure what I did. I have it writin down out in the shop. I did make it tighter when cold. Then when it was to temp I rechecked them. Only 1 lifter and lobe failed and it was cupped pretty bad and the lobe was close to half gone. I have always adjusted the valves a different way as far as the point on the lobe in relationship to the lifter. I used a adjustment from a GM crate engine manuel. Know I have used the one in speedways catalog. I changed only do to speeds way is a little faster. Is their way ok. Can I break in the new cam with a little looser lash until broke in? Do I need to change valve springs like I did before?

eaton89
Dirt Freak

Total posts: 268
posted May 20, 2005 10:15 PM  
Also, I do not run restrictors for the oil. I read on here and it seemed to be about 50-50 on reather to run them so I figured I would not run them tell I had a little more experiance with the solid cam. I rather have to much oil then not enough.

dirtracer14
Dirt Forum Champ
Total posts: 1261
posted May 20, 2005 10:35 PM  
I have had some bad luck breaking cams in in the past. I went with the lifter with the oil hole in the bottom and have had no problems!!! I also run pretty stiff springs on my solid cams...with these lifters i run higher rpm also. They are well worth the $$$ about 80 or 90 a set.

52mod
Dirt Roller

Total posts: 11
posted May 24, 2005 07:48 AM  
Your springs should be around 130 lbs on the seat and 400 lbs over the nose with that cam. Check for coil bind or your retainers hitting the top of the guides as well.

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