No cam retainer=engine knock
#1
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From: BUFFALO, NY
Car: '89 IROC-Z
Engine: 355
Transmission: 700r4 edge 3000 stall
Axle/Gears: 9-bolt 3.73
No cam retainer=engine knock
been trying to figure out why my motor was knocking and I just realized there was no cam retaining plate! and moving the cam back and forth made a knocking sound. Has anyone heard of this happening, I know it must be rare because i dont think that many people have forgot to the put cam retaining plate in when they rebuilt their motors. I think they only thing holding it in place was a brand new double roller that once it loosened up in 500 miles started knocking. Thoughts? Also I think the guy that rebuilt this motor was retarded, b/c the bearings we pulled out where 020, we put in 020 and the crank will barely turn with just the mains torqued down.
#2
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Car: 91 RS
Engine: 350 vortec
Transmission: T-5
Axle/Gears: not the best not the worst
Re: No cam retainer=engine knock
is it a roller cam or a flat tappet?
if it was a roller cam all of the lifters are junk by now even if they dont look damaged they are... and the cam is obviously a meat stick too
and what about the bearings? you have a .020 under crank and installed .020 over bearings? now it doesnt turn?
if it was a roller cam all of the lifters are junk by now even if they dont look damaged they are... and the cam is obviously a meat stick too
and what about the bearings? you have a .020 under crank and installed .020 over bearings? now it doesnt turn?
#3
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Joined: Apr 2007
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From: BUFFALO, NY
Car: '89 IROC-Z
Engine: 355
Transmission: 700r4 edge 3000 stall
Axle/Gears: 9-bolt 3.73
Re: No cam retainer=engine knock
its a roller cam in a roller block, it didnt have a cam retaining plate (and no autozones carry one) the cam and the lifters both look perfectly fine. So I think the cam was "walking" or banging into the block which had to of been what was knocking (sounded like a BAD rod knock). The bearings we pulled out when we tore the motor down were 020 bearings, we put new 020 bearings and now the crank doesnt want to turn. Taking the crank to the machine shop tommorow to be checked out. Just wondering if anyone has ever heard this sort of knock.
#4
Re: No cam retainer=engine knock
I suppose it could happen. It prevents the cam from walking forward and also provides a surface for the cam gear to push against so it can't go backward in the block either. In short, that cam can move front to back quite a distance without the retaining plate. The fact that the cam and lifters aren't chewed up is pretty amazing. I'm sure the timing chain is toast, though! I certainly wouldn't use it again even if it looks OK to your eye.
Not sure why anyone would leave it out, but it's definitely a necessary part if you're using a factory-style roller cam!
Not sure why anyone would leave it out, but it's definitely a necessary part if you're using a factory-style roller cam!
#5
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: No cam retainer=engine knock
Thats a part you'll either have to get from the dealer or a used engine. Its too.... specific?... for most general parts stores like Auto Zone.
Check the distributor gear as well as the cam gear - they may have some funky wear on them now, even if the lobes and lifters seemed ok. Distributor gears are fairly cheap to replace if it needs one, but if the drive gear on the cam is worn, it'll mean replacing the cam.
Check the distributor gear as well as the cam gear - they may have some funky wear on them now, even if the lobes and lifters seemed ok. Distributor gears are fairly cheap to replace if it needs one, but if the drive gear on the cam is worn, it'll mean replacing the cam.
#6
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Joined: May 2003
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From: bay area, CA
Car: 89 IROCZ
Engine: L98 4150 carb
Transmission: Transgo 700-r4
Axle/Gears: 10 bolt/3.23
Re: No cam retainer=engine knock
wow nice save, thats pretty scary, I know of a member who's roller cam busted through the timing chain cover.
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