454 gen v

Saverio · Nov 14, 2018

my port engine seemed down on power and I had a miss. My compression in between 130 to 115. So I thought I would do my heads. 545 hours fresh water cooled. I think I found my problem. How did happen and what do I do next.

gdavis67 · Nov 14, 2018

Is that a chunk of metal or is that the lobe of the camshaft? Either way, not good. If that is the cam it looks like it is badly scored from the lifter. Valve might be bent preventing the proper operation of the lifter and pushrod. A closer pic or better description would help. Either way, I would say it's time to figure out how to pull the motor.

Saverio · Nov 14, 2018

I was planning on pulling heads. I had a miss at times And shakes but it would come and go. The cam lobe looks to be shaved down. I was going to replace cam and lifters now

PlayDate · Nov 14, 2018

Saverio said:
I was planning on pulling heads. I had a miss at times And shakes but it would come and go. The cam lobe looks to be shaved down. I was going to replace cam and lifters now

The highlighted area does not look like a cam lobe. The cam lobe is next to it. Hard to speculate what the white material is (could be original paint). Before you pull the heads, get a dial indicator to check the cam at the rocker arms. I few minutes of diagnostic will tell you whether a problem with the cam is real.

How many hours are on the engine?

hottoddie · Nov 14, 2018

How many hours? Flat tappet camshafts will fail if the wrong oil is used. The oil must contain the proper amount of ZDDP. I use Valvoline VR1 racing oil that is formulated with ZDDP and is used in old race cars with flat tappet camshafts. The oil pan needs to come off to clean out the metal shavings and pull the main bearing caps to see if they are scored. Good chance a complete long block rebuild is in order.

Saverio · Nov 14, 2018

The engine has 570 hours
Had the boat three season used merc sysntic since I owned it. I think play date is right I was tired and drinking. I think it is white paint

sdarc · Nov 14, 2018

That may be a paint chip or something but it does look to be over a cam lobe. Another thing I noticed is some of the push rods seem to be "crooked". Not straight. It looks like you haven't pulled the valve covers off yet. Pull them and see if the push rods are in the rocker arms. And that they are adjusted correctly.

PlayDate · Nov 14, 2018

Saverio said:
The engine has 570 hours
Had the boat three season used merc sysntic since I owned it. I think play date is right I was tired and drinking. I think it is white paint

I have built a lot of engines for race cars and race boats and we used to color code the camshafts by painting a band of color on them. I haven't seen it on original camshafts but it wouldn't surprise me if it was a quality control if they were assembling different engines at the same facility.

Back to your original problem.....570 hours on a 23 year old engine ......a valve job will help. The guides, seals and seats will all benefit as well as your performance. I would suggest that you check the camshaft at the rocker arm (or the lifter) just to have a baseline going forward. The original cams will last a long time.

ttmott · Nov 14, 2018

sdarc said:
That may be a paint chip or something but it does look to be over a cam lobe. Another thing I noticed is some of the push rods seem to be "crooked". Not straight. It looks like you haven't pulled the valve covers off yet. Pull them and see if the push rods are in the rocker arms. And that they are adjusted correctly.

It's a BBC - the push rods are splayed due to the valve spacing.
The cam looks fine from what the picture shows; barely worn in.
The number seven intake port looks like it has a bit of a carbon build up which is unusual; indicates exhaust reversion which may be an intake valve not sealing and would cause the MAP sensor to fuel the engine (if fuel injected) thus causing a very rich fuel mixture and, consequently, be down on power. Would not, however cause a firing miss. Most miss firing situations in engines are caused by electrical issues especially if not consistent.

PlayDate · Nov 14, 2018

Just for fun....this is your engine with Edelbrock Marine Aluminum heads:

Saverio · Nov 15, 2018

That looks amazing!!!!!!
I keep thinking if it was worn out it would still be oily and scarped but it was smooth.

Now whats happening at cycl 7 I was surprised to see all the carbon. the motor looks horrible in the picture. there was so much condensation and spilled some AF when pulling the intake

PlayDate · Nov 15, 2018

Saverio said:
That looks amazing!!!!!!
I keep thinking if it was worn out it would still be oily and scarped but it was smooth.

Now whats happening at cycl 7 I was surprised to see all the carbon. the motor looks horrible in the picture. there was so much condensation and spilled some AF when pulling the intake

They all look like that when you disassemble an older engine.

Once you pull and disassemble the heads......it will provide a much better view of what is going on. It will look a lot cleaner when you put it back together!

sdarc · Nov 15, 2018

ttmott said:
It's a BBC - the push rods are splayed due to the valve spacing.
The cam looks fine from what the picture shows; barely worn in.
The number seven intake port looks like it has a bit of a carbon build up which is unusual; indicates exhaust reversion which may be an intake valve not sealing and would cause the MAP sensor to fuel the engine (if fuel injected) thus causing a very rich fuel mixture and, consequently, be down on power. Would not, however cause a firing miss. Most miss firing situations in engines are caused by electrical issues especially if not consistent.

OOPS!!! My bad. Didn't pay attention to what was written. Just looked at the pics. Some looked straight others not so much.

Saverio · Nov 15, 2018

Going to try tomorrow. I’m battling a stripped head on a head bolt by exhaust.

PlayDate · Nov 15, 2018

If it is a lower head bolt....it is just a question of getting it loose. It is only 3" long. If you can tap it with a hammer or get a six point metric socket on it that may help. Unfortunately....there is no easy way depending where it is located.

Also ARP replacement bolts are the best to use when you put it back together.

scoflaw · Nov 15, 2018

Probably the middle set of long bolts that trap water above the exhaust. I drill as large as possible,. then Dremel a slot and finish it off with a hammer and chisel. Lift the head off the studs

ttmott · Nov 16, 2018

PlayDate said:
If it is a lower head bolt....it is just a question of getting it loose. It is only 3" long. If you can tap it with a hammer or get a six point metric socket on it that may help. Unfortunately....there is no easy way depending where it is located.

Also ARP replacement bolts are the best to use when you put it back together.

And always have the ARP hardened washers between the bolt and head casting.