Tampa 928s

Restoring an 88 from 10 years of hibernation got it running but hearing a metal to metal knock seems like its coming from the water pump area.
What I did find is both cams two teeth off ahead how much does this relate in timing and how far is too far?

the flyin' scotsman

thats quite far off.

The timing is typically 3 teeth off (retarded) with the crank at 45 BTDC...........your 2 teeth advanced so 30 degrees?

Tampa 928s

Why would someone set this like that, I assume to advance the torque curve?
So how many more teeth until crashing the valves takes place?

SeanR

Bet that ran like crap.

NoVector

Maybe just an accident and didn't have it at TDC when changing the belt (crappy fly-wheel lock?) and didn't spin it around a couple times after changing the belt to make sure everything lined up.

Mrmerlin

its also possible the timing belt jumped if say the lower roller bearing was missing from under the crank drive gear

Imo000

Learn from Guageman69's misfortune. Take the front apart and find the reason for the knock.

SeanR

If the belt is loose enough to jump from that point, the slack in the rest of the belt system would be way worse. I've not seen a lower roller yet that has ever made contact with the belt and there have been some real loose ones out there.

hacker-pschorr

Incompetence is usually my first guess.

MainePorsche

Ditto.

Sounds like it was set wrong if both cam settings are identically off.

Tampa 928s

Setting the crank to 45 now moves the timing marks where the 0 should be in this postion.
If I remove the belt if a cam slips would it hit the valves?
Should I set crank TDC and reset cams to 0 before doing anything else?

the flyin' scotsman

with the crank set and locked at 45 BTDC both banks of cams can be turned freely with fear of valves hitting pistons. You then need to position the cam gear timing mark 3 positions retarded, restring the belt, tention, spin the engine clockwise 2 times to come back to 0 TDC and recheck timing.

If I were you I would throw on a new Gates belt.

pic from Dwaynes epic:

hinchcliffe

Is it me or is that red pointer upside down? Not sure if the pointer is centered on the holes it mounts to?

Edit, looking back at my TB job i just finished, flip the pointer and see where it is......

docmirror

Given the direction of rotation is CW as viewed looking backward, a jump would lag the timing components - right? I believe this show the timing has 'leaped'. Don't think that's possible, given the mech drag.

Kiln_Red

Excellent advice and photo, Malcolm!