Thread: Harmonic balancer on 454 has 4 timing marks.....

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I had a little spare time this evening and finished the compression test. Again, I had charged batteries, TP opened, disconnected fuel and ign and no plugs in. Here's the readings:

1=67psi l 2=120psi
3=65psi l 4=122psi
5=80psi l 6=113psi
7=31psi l 8=72psi

I didnt bother adding any oil. I did start pulling apart the front on motor(pulleys, belts, water pump). I got down the harmonic balancer(didnt have a balancer pulley on hand). Will check the timing chain as soon as I get one.

Originally Posted by repoman3809

I had a little spare time this evening and finished the compression test. Again, I had charged batteries, TP opened, disconnected fuel and ign and no plugs in. Here's the readings:

1=67psi l 2=120psi
3=65psi l 4=122psi
5=80psi l 6=113psi
7=31psi l 8=72psi

I didnt bother adding any oil. I did start pulling apart the front on motor(pulleys, belts, water pump). I got down the harmonic balancer(didnt have a balancer pulley on hand). Will check the timing chain as soon as I get one.

yep you may have bent valves . bbc can not stand much lift and duration with some pistons.yep oils not going to help them holes .i would pull it or pull the heads and timing cover off or just pull the engine out . but with heads off be less weight to play with it your call .l would bit the bullet and pull it

yep you may have bent valves . bbc can not stand much lift and duration with some pistons.yep oils not going to help them holes .i would pull it or pull the heads and timing cover off or just pull the engine out . but with heads off be less weight to play with it your call .l would bit the bullet and pull it

Yeah my thought too. I'm going to do a leakdown anyways. Then I'll pull the balancer and timing cover. Sure that will tell all I need to know. Amazing thing(or at least to me) is that once I got it started, it actually ran well. No load on the motor, but it revved good and idled decent around 1200.

I wish I would have done the compression test the first day I bought it. I'm not even blaming the dealer. I screwed up! But again, lesson learned.

Hopefully I can get out of this with a smile.

Crazy I happened to test the left side first. 2-4-6 were acceptable, 8 made me get ticked and quit the test.

After returning a few days later and seeing 1-3-5-7. I wasnt as mad, I already came to grips with the worst.

If I would have completed the whole test the first day. I might have really put the screws in the cylinders and fired her up. Us repo guys tend to have a short fuse. LOL

Update....with pic.

I pulled balancer and timing chain cover. Before doing so I made sure I was set TDC. The crank and button were both right.

After the pic, I put the balancer and cover back on. The balancer mark was still on 0.

Timing Chain4.jpg

You know the picture is 180 out

You know the picture is 180 out

Not at TDC on #1....right? When the marks are at 6 o'clock on cam and 12o'clock on crank, your TDC on #6.

The 12o'clock / 12o'clock(pictured above) is TDC on #1. Right?

I really, really, really, hope your right and I'm wrong. That would be great.

Charlie is correct. Cam dot needs to be at 6 o'clock & Crank dot needs to be at 12 o'clock with # 1 cylinder @ TDC. (IMHO!)

Originally Posted by 34_40

Charlie is correct. Cam dot needs to be at 6 o'clock & Crank dot needs to be at 12 o'clock with # 1 cylinder @ TDC. (IMHO!)

Again, I sure hope so.

I got to searching the net after I seen Charlie post. I figured what was in the pic was right.

Upon searching the net I got mixed results, but more seemed to say 12 and 12 o'clock was right for #1 TDC. I even found a shop manual pic.

Now I see your post, I'm just confused. LOL

yep 180 out but still need to fix the low cranking psi on the one bank .mark 5 or 6 block ? if thats a mark 6 with a flat lifer cam in it ?. i am short blocking the 330HP mark 6 merc roller engine right now

Originally Posted by pat mccarthy

yep 180 out but still need to fix the low cranking psi on the one bank .mark 5 or 6 block ? if thats a mark 6 with a flat lifer cam in it ?. i am short blocking the 330HP mark 6 merc roller engine right now

My heads spinning right now. LOL

Ok, When I bought the motor I was told the motor was the same gen block as my boats original 1993/454(whatever gen that is).

After recently talking to the dealer who sold me the engine. He said he thought it had rollers, knew it had merlin heads, a high rise weiland intake, an aggressive cam and a built, 30 over bottom end. Said he would get back to me on the exact cam specs(still waiting).

The motor was to be a drop in long block. I only had to add carb and accessories. I trusted the dealer and didnt pull anything off the motor. I just dropped in and hooked up.

After hearing of the possibility rollers the other day, I figured I would pull valve covers and check. Likely was going to do as I was getting ready to pull motor.

Of course, if it does have rollers and the motor is 180 out. I may be able to make adjustments and get back to normal possibly....right?

it not 180 off on cam timming . you need to line the top gear mark at bottom 6 clock and lower crank gear mark pointing to top 12:00 clock one more turn lines the gears in phase this will happen when you turn them crank one more time . if a roller cam engine there is not thust button on the front of the cam gear . not good. the engine i see is a mark5 or 6 if it has hold down towers casted in the lifter valley it a mark 6 mark 5 do not but is about the same block other then that .if a mark 6 roller engine it has a mark 4 cam in it. as the mark 6 has on step nose cam different timming set and needs a hold down plate .there is no cam hold down plate i see at can not be used with the mark 4 /5 cam it can have a roller cam with out roller rockers you will have to pull the intake to see if its a roller cam

Here's that shop manual pic I found....
Marks.jpg

Cam sprocket at 6 and crank sprocket at 12 sets up #6 for ignition firing. Cam sprocket at 12 and crank sprocket at 12 sets up #1 for ignition firing.

Originally Posted by techinspector1

Cam sprocket at 6 and crank sprocket at 12 sets up #6 for ignition firing. Cam sprocket at 12 and crank sprocket at 12 sets up #1 for ignition firing.

So it's in time. The pic with the marks is on #1 TDC.