Valve train problems...
02-11-2002, 06:41 PM
#1
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Location: North Myrtle Beach SC
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Valve train problems...
Alright, my brother was helping me build up my engine,
and I let him put on the timing chain unsupervised.
Anyway, we got the motor ready to crank and turned it
over, it wouldn't crank and I didn't know why. So I pulled
the front end off the motor and sure enough my brother
had botched the timing chain install. I put it to OEM settings
and put the front end back together, set the distributer properly
and tried to crank...no go. Then I got to looking and my push
rods were bent. So I pulled off the heads and sure enough my
intake valves were all messed up. So I took them to the machine shop
where they are currently having new valves put in.
But I got to looking, and turned the motor over (with the heads off)
with a pull handle and watched. The intake lifter comes up on
every cylinder when the piston is at the top (not on the compression
stroke, but the other one).
Am I mistaken in thinking that this is a bad thing? I know that my cam is
timed right now.... I'm thinking that it is ok, but want to be sure as I
don't want to put in another set of valves.
The motor is a 350 with Sportsman II 64cc heads (with 2.02 valves),
flat top hypereutectic pistons, cloyes double roller timing chain, and
a Crane Energizer cam # 100072.
My first thought was that my brother's botched timing chain install (he didn't have the dots lined up, it was WAY off) was what bent the valves, but the fact that when manually turning the motor, my intake lifter is up when the piston is at the top makes me suspicious...should I worry??
and I let him put on the timing chain unsupervised.
Anyway, we got the motor ready to crank and turned it
over, it wouldn't crank and I didn't know why. So I pulled
the front end off the motor and sure enough my brother
had botched the timing chain install. I put it to OEM settings
and put the front end back together, set the distributer properly
and tried to crank...no go. Then I got to looking and my push
rods were bent. So I pulled off the heads and sure enough my
intake valves were all messed up. So I took them to the machine shop
where they are currently having new valves put in.
But I got to looking, and turned the motor over (with the heads off)
with a pull handle and watched. The intake lifter comes up on
every cylinder when the piston is at the top (not on the compression
stroke, but the other one).
Am I mistaken in thinking that this is a bad thing? I know that my cam is
timed right now.... I'm thinking that it is ok, but want to be sure as I
don't want to put in another set of valves.
The motor is a 350 with Sportsman II 64cc heads (with 2.02 valves),
flat top hypereutectic pistons, cloyes double roller timing chain, and
a Crane Energizer cam # 100072.
My first thought was that my brother's botched timing chain install (he didn't have the dots lined up, it was WAY off) was what bent the valves, but the fact that when manually turning the motor, my intake lifter is up when the piston is at the top makes me suspicious...should I worry??
02-12-2002, 07:55 AM
#3
Re: Valve train problems... (JackCooper)
When the timing gears are aligned it is not always TDC #1 cylinder. Could be #6 .So watch for that when adjusting valves when you put it back together.Mark your balancer 180 degrees from TDC and then two more marks 90 degrees from there.Then adjust both intake and exhaust in the firing order.Recheck and if some are really loose go back and correct starting point.
Are you using a 3 keyway bottom gear?If so,put it on 0.That cam has advance ground into it.
Are you using a 3 keyway bottom gear?If so,put it on 0.That cam has advance ground into it.