When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
well, here is the dilemma I have been facing for the last few weeks.
had a 5.3 block bored to .040 over (cheaper for pistons cause of oddball size)
pistons are stock replacement flat tops (not forged and are LITERALLY flat tops).
got the engine together and running with an Elgin E1841P cam (595/595) and it did not have the rough idle the owner wanted.
I recommended switching to the Howards Rattler cam (625/625) and low and behold all exhaust valves hit the pistons.
Got the heads off, switched to a different set of same number heads (862's) and switched cam again to an Elgin E1839P (575/575).
This produced the really choppy idle that he wanted and was working and running great on my run stand. until.....................
a whole side of a piston let go and went into the bottom end. skirt to oil ring land.
Rod bearing for the same piston also decided spin and chewed up the crank.
He ordered new pistons, but finding the rod and crank damage were pretty much the straws that broke the camels back for both of us for this engine.
I got ready to take it off the stand and 2 of the stand bolts stripped out the block.
When I got ready to remove the ARP harmonic balancer bolt, it BENT my foot long 1/2 extension into damn near a j-hook...
So yeah..... I am definitely taking a sledgehammer to this block once I have all the internals out of it.
cam and heads are going on a bored 6.0 (.040 over makes it a 6.1)
It is getting a brand new Melling oil pump, new double roller timing set, new lifters and trays, new LS9 9 (7-layer MLS) head gaskets, brand new Clevite rod/main/cam bearings.
Block is machine shop fresh and was thoroughly cleaned before I brought it home.
Hopefully this 6.1L manages to fair better than the 5.4L
as for the 5.4, the whole time I was running it, it had great oil pressure (40+ at idle and went as high as 100 on revving up)
engine made no unusual noises except for when the piston broke.
pistons did have small dents from the exhaust valves (howards rattler cam), but none of the pistons showed signs of a crack even when inspecting them from the bottom.
The new pistons have not been installed and the crank will have to be ground down minimum .010/010 to remove the damage. not really worth it when machine shop charges $200 to do it.
If you're going to mention cams, DURATION is far more important to discuss than lift. Lift does not affect idle quality at all.
So what are the duration specs of the cams discussed above?
well, here is the dilemma I have been facing for the last few weeks.
had a 5.3 block bored to .040 over (cheaper for pistons cause of oddball size)
pistons are stock replacement flat tops (not forged and are LITERALLY flat tops).
got the engine together and running with an Elgin E1841P cam (595/595) and it did not have the rough idle the owner wanted.
I recommended switching to the Howards Rattler cam (625/625) and low and behold all exhaust valves hit the pistons.
Got the heads off, switched to a different set of same number heads (862's) and switched cam again to an Elgin E1839P (575/575).
This produced the really choppy idle that he wanted and was working and running great on my run stand. until.....................
a whole side of a piston let go and went into the bottom end. skirt to oil ring land.
Rod bearing for the same piston also decided spin and chewed up the crank.
He ordered new pistons, but finding the rod and crank damage were pretty much the straws that broke the camels back for both of us for this engine.
I got ready to take it off the stand and 2 of the stand bolts stripped out the block.
When I got ready to remove the ARP harmonic balancer bolt, it BENT my foot long 1/2 extension into damn near a j-hook...
So yeah..... I am definitely taking a sledgehammer to this block once I have all the internals out of it.
cam and heads are going on a bored 6.0 (.040 over makes it a 6.1)
It is getting a brand new Melling oil pump, new double roller timing set, new lifters and trays, new LS9 9 (7-layer MLS) head gaskets, brand new Clevite rod/main/cam bearings.
Block is machine shop fresh and was thoroughly cleaned before I brought it home.
Hopefully this 6.1L manages to fair better than the 5.4L
as for the 5.4, the whole time I was running it, it had great oil pressure (40+ at idle and went as high as 100 on revving up)
engine made no unusual noises except for when the piston broke.
pistons did have small dents from the exhaust valves (howards rattler cam), but none of the pistons showed signs of a crack even when inspecting them from the bottom.
The new pistons have not been installed and the crank will have to be ground down minimum .010/010 to remove the damage. not really worth it when machine shop charges $200 to do it.
That's a bad turn of events. Sorry to hear that happened. It sucks when stuff breaks.
Checking piston to valve clearance when using big duration cams avoids heart ache and expensive repairs.
Probably be easier on the wallet to stay with stock bottom ends from the junkyard and proven heads & cam packages that are known to have good P to V clearance.
Both Elgin cams cleared fine. The big rattler was what caused the problems. The E1839P is going in the 6.1 and staying with cathedral heads. The rectangle port heads would cause a huge drop in port velocity. If I had the money to buy forged pistons with valve reliefs in the crown, then I could use them with the rectangle port heads and the rattler cam. But neither of us has the extra $500 right now.
So far, everything has gone together fine except for one small hiccup.
A rod was touching the crankshaft counterweight.
I gave it light sanding with a flap disc and got the clearance taken care of.
The amount of material that came off was minimal so I don't feel it will affect the engine adversely.
Does anyone use the HIGH ZINC oil when first starting up an engine after its been rebuilt like this one?
I have never done it, but have watched shows say that high zinc on startup is highly recommended.
I do plan to pre-lube the engine since I have built a 4 quart capacity pre-lube assembly that feeds in behind the oil pump into the oil galley.
Although I am wondering if any of the oil galley ports would work since I have to change the one at the top of the engine over to the oil pressure gauge feed.
But I can't feed oil in that way cause it would take 2 days to go in through that little hole!! LOL
I guess I will stick with using the one at the front of the block since that is where I have always done the pre-lube from.
All because the customer didn't have the "rough idle" sound they wanted. Why not just change the way the car idled via tuning and not messed with any changing of cams which started the whole engine issue?
All because the customer didn't have the "rough idle" sound they wanted. Why not just change the way the car idled via tuning and not messed with any changing of cams which started the whole engine issue?
because I run them with a carb on the run stand. Someone else does the tuning with HP TUNERS.
and he is a friend who is footing the bill to mostly give me something to do.
so I just tell him what’s going on and he decides if he wants to mess with it anymore. I have a full set of pistons to go in the 5.4, but it is gonna need a crank also. And I haven’t gotten a new set of rod and main bearings for it as of yet. Plus the block has 2 bolt holes for the bell housing that are stripped. So I am also considering having the block heli-coiled to a standard thread.
High zinc oil doesn't prevent a piston from cracking due to poor PTV. I would be more concerned about assembly and proper clearances than I would the oil used on startup. Just change it after the first heat cycle.
High zinc oil doesn't prevent a piston from cracking due to poor PTV. I would be more concerned about assembly and proper clearances than I would the oil used on startup. Just change it after the first heat cycle.
It’s all under control now.
remain calm
I expect to be finishing the engine And getting it on the run stand tonight and will wait to start it tomorrow morning.
that way I am well rested, alert and awake and not tired or sleepy at all.
04-18-2020, 08:53 PM
CURSED 5.4 (bored 5.3)!! 
6.0 (6.1) assembly (so far) 
