2nd wiped Camshaft OMC 460

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Trevthefox

Petty Officer 2nd Class
Joined
Sep 25, 2018
Messages
101
jhande said:
Old cam mix up old lifters = bad.
Old cam with new lifters usually = bad.
New cam, new lifters all properly pre-lubed (cam break in lube) = good.
Some motors the lifters don't sit 100% over the cam lobe. Some overhang to one side a bit. Lifters tend to spin slowly in it's bore which wears the contact points evenly. Not all, but some.

Old GM 305 cu.in. cams were made for awhile with a softer metal which caused very short life spans. Done tons of those recall/fixes at the dealership.

If the motor had a lot of miles/hours on it before taking it apart and messing with it, I highly doubt the lifter bore is not parallel with the cam lobe. If it was, cams and lifters would get chewed up "really" quick.

I really think it's all due to improper cam & lifter match. Improper spring pressure and possibly spring height. As long as evrything is getting properly oiled, which it sounds like it is
Click to expand...
This time I'll have the recommended springs and everything else for the cam. Fingers crossed that this does the trick
 
T

Trevthefox

Petty Officer 2nd Class
Joined
Sep 25, 2018
Messages
101
gm280 said:
I am pretty sure by now you have learned a ton about engines. Never, ever, ever mix lifters, rockers, pushrods, valve springs and anything that wears together. You get what you have now doing that...
Click to expand...
Unfortunately I feel like I'm getting to know this engine way too well. Lol. Yes, lesson learned. I'll keep you updated once everything goes back together. Hopefully is a success.
 
T

Trevthefox

Petty Officer 2nd Class
Joined
Sep 25, 2018
Messages
101
jhande said:
Old cam mix up old lifters = bad.
Old cam with new lifters usually = bad.
New cam, new lifters all properly pre-lubed (cam break in lube) = good.
Some motors the lifters don't sit 100% over the cam lobe. Some overhang to one side a bit. Lifters tend to spin slowly in it's bore which wears the contact points evenly. Not all, but some.

Old GM 305 cu.in. cams were made for awhile with a softer metal which caused very short life spans. Done tons of those recall/fixes at the dealership.

If the motor had a lot of miles/hours on it before taking it apart and messing with it, I highly doubt the lifter bore is not parallel with the cam lobe. If it was, cams and lifters would get chewed up "really" quick.

I really think it's all due to improper cam & lifter match. Improper spring pressure and possibly spring height. As long as evrything is getting properly oiled, which it sounds like it is.
Click to expand...
Now that I have everything apart. I want to make sure this block is as clean as I can get it before reassembling everything especially because there are metal particles in the oil. We had a magnet at the bottom of the pan and everything seemed to be almost microscopic. That being said, what are the best ways of cleaning the internal passages?

Pressure wash with water, then compressed air? I was also thinking of hooking up the oil pump and spinning it with a drill with some sea foam and clean oil just to get clean oil through all the passages.

Any thoughts or advice?
 
gm280

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,605
Some machine shop have engine block cleaner tanks. Maybe you could find one and let them tank it to clean it.
 
T

Trevthefox

Petty Officer 2nd Class
Joined
Sep 25, 2018
Messages
101
So I figured I'd post an update. Huge thanks to everyone who replied to this post.

Yesterday my cousin and I dropped in our '89 460 back into our boat and started her up and we had a successful break in for 30 mins. Needless to say we were super nervous because we have been here before thinking we did everything right and we ended up wiping a brand new cam back in Feb. We got through 30 minutes of running the engine between 2000 and 2500 rpm with no issues and it seems like we finally fixed the issues...(fingers crossed)

Here's a list of the things we did and the new parts we put in the old 460:
  • new comp cams Camshaft-Xtreme Marine(TM) Comp Cams 34-232-4
  • new lifters, rocker arms, valve springs, valve stem seals, gaskets, pushrods, valve keepers, oil pump, and pistons.
  • had a professional valve job done (guy said we definitely needed it).
    • he also had to do some machining to fit our new dual valve springs and valve stem seals. Also did some work to make sure our spring height was correct.
  • 2 of the old pistons we're moving very freely so we replaced the pistons and had them professionally balanced along with the crankshaft. (i think the wiped lobe and destroyed old lifter material crept its way into the piston pin causing it not to move freely)
  • honed out the problem lifter bore.
  • checked clearances on everything possible. But most importantly checked valve clearance and found out we needed .06 longer pushrods for all the exhaust valves. Not sure if this was a product of the valve job that was done but we originally had all the same length push rods.
  • lubed the **** out of the lifters and lobes on cams with lifter/lobe lube from comp cams. all journals and everything else got assembly lube. Used lucas break in oil. Primed her. Set timing to 10º BTDC to fire on cylinder 1.
  • Cut the top off the valve covers and marked all the pushrods to make sure they were all spinning during break in. (we weren't going to take any chances this time).
All went well and we changed the oil after break and put a new oil filter on. Now I just have to re-install the inner valve springs and she'll be ready for the water.
 
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