cam timing skip and rod knock, real head scratcher.

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silverhornet

New Member
Dec 8, 2012
28
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0
Wales, Cardiff
Hi all, after some help. Im really stuck so turning to you guys to hopefully help me.

Right i bought a supra (89 7mgte r154) early this year. I was told by the seller that the bottom end was knocking between 1500 and 2500 rpm. Ok no problem ill re build it. Went to see it. No knock what so ever, engine was quiet. However had no power at all, turbo was glowing with throttle. Odd. Would only rev to 5600rpm. got it home and began work. Had a dead tps, changed it no better. Turned out the exhaust cam had skipped TWO teeth RETARDED. So i advanced the cam two teeth, and timing is now all correct. So started her up, revs perfectly now. However the knock has reappeared. Well its not a proper knock its more of a rumble as such. Ive thought and thought about this. What the hell has happened. Exhaust cam retarded two hole teeth no knock, correct timing knocks?

Heres a video of it. Excuse the state she is in and flames. I was so chuffed it was actually reving properly. Shes undering going a total revamp.

http://www.youtube.com/watch?v=YgBpgJKUz6Q

My mate thinks its the tensioner that is causing this sound. You can here when its revved the rumble. Any help will really be apreciated as im really new to these cars. (on my other videos my charged clio know you yanks love superchargers haha :p)
 
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silverhornet

New Member
Dec 8, 2012
28
0
0
Wales, Cardiff
Today i went about testing two things. compression and shim spacing. The compression as i thought as the cam belt has skipped two teeth retarded on the exhaut it might have bend a valve. and the shim as loads of people were saying this could be it. So i have the result's. can you tell em is this norm / would this cause my noises?

Compression, was done to tsrm EXEPT cold. results (Cylinder 1 being cambelt side)
1 = 185psi
2 = 192psi
3 = 190psi
4 = 185psi
5 = 185psi
6 = 190psi.

I thought this wasnt to bad? Now for shims, ive layed it out as cylinder 1 is cambelt side and then valves could in teh same direction. All mesuments in imperial as thats what i work in work. So pinched a few measuring tools for the night.

Inlet;

Cyl 1
v1 in tolerance
v2 in tolerance
Cyl 2
V3 0.002'' over
v4 0.002'' over
Cyl 3
v5 0.002'' over
v6 0.002'' over
Cyl 4
v7 0.001'' over
v8 0.001'' over
Cyl 5
v9 0.001'' over
v10 0.002'' over
Cyl 6
v11 0.002'' over (On recheck was 0.004'' over)
v12 0.002'' over 9On recheck was 0.004'' over)

Exhaust;

Cyl 1
v1 0.002'' over
v2 0.003'' over
Cyl 2
V3 0.003'' over
v4 0.003'' over (on remesure 0.004'' over)
Cyl 3
v5 0.004'' over
v6 0.004'' over
Cyl 4
v7 0.003'' over
v8 0.003'' over
Cyl 5
v9 0.005'' over (on recheck 0.006'' over)
v10 0.006'' over
Cyl 6
v11 0.005'' over (On recheck was 0.004'' over)
v12 0.006'' over 9On recheck was 0.004'' over)

By 0.002 over i mean tolerance was 0.012 top and it was 0.014. inlet tolerance 0.006 - 0.010 exhaust 0.008-0.012
 
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