Thread: Dropped a valve

Tweet

Hey, Y'all,
short version of long story:
Removed 4.3L from 90 GMC 1500. Rebuilt a 350 from a '87 van.
Installed a Comp cam (kit with Gross valve lift Int .434 / Exh .444) flat top pistons, bored .030 over, crank turned .010 under. Approx 10K miles on rebuild, dropped a valve. Have not removed head yet to verify extent of damage. Can't afford to go with vortec / new intake / carb setup, so am looking for least expensive alternative to get it going for a couple of months until I get money to "do it right". What heads should I avoid? Any suggestions on which are best? Should I use new lifters and springs? sigh... i'm such a noob

Originally posted by run_gmc
Hey, Y'all,
short version of long story:
Removed 4.3L from 90 GMC 1500. Rebuilt a 350 from a '87 van.
Installed a Comp cam (kit with Gross valve lift Int .434 / Exh .444) flat top pistons, bored .030 over, crank turned .010 under. Approx 10K miles on rebuild, dropped a valve. Have not removed head yet to verify extent of damage. Can't afford to go with vortec / new intake / carb setup, so am looking for least expensive alternative to get it going for a couple of months until I get money to "do it right". What heads should I avoid? Any suggestions on which are best? Should I use new lifters and springs? sigh... i'm such a noob

hi, heres some food for thought for ya, a few years back same thing happened to me through a machinist who put the wrong springs in, but i was like you and thought oh boy whole engine down the tubes, but i checked it out and it did put a nick in the piston which i thought what the heck im not going to be out anything if i mess up so i cleaned up the piston and got rid of all the sharp edges put a new valve in and the right springs and run her for a good 50,000 before pulling it for the 514 im putting in now so i would examine the damage and see what you got first and then decide you never know.

yes go with new springs thats recommended for the cam you put in if you dont youll be back doing this all over.

Thanks for the quick reply... even tho you don't like chebbies.. hehehe. Will certainly have head checked thoroughly before doing anything. Hopefully not too much damage to piston. Can't pull it apart until Sat. (tomorrow) afternoon.
Thanks again!

Originally posted by run_gmc
Thanks for the quick reply... even tho you don't like chebbies.. hehehe. Will certainly have head checked thoroughly before doing anything. Hopefully not too much damage to piston. Can't pull it apart until Sat. (tomorrow) afternoon.
Thanks again!

pssst hey i got a chebby almost new one, but lets keep that a secret ok, dont want the blue oval dudes thinking im a trader