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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: lukieg on September 18, 2011, 04:12:04 pm
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I have one lifter thats just a pounding when my oil pressure is down at idle and warm.. oil is scarce on that one push rod.. Im short on cash.. whats the odds the cams all beat to shoot.. or can I get away with tossing some lifters in it?
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Odds are good, but check the rocker arm movement compared to the other. This will give you a good indication of if you can get away with a lifter. Usually they are put in as a matched set just replacing a lifter to get you by for a while should work if the cam doesn't have a flat lobe on it.
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The rocker arm seems to move roughly the same...is that any indacation of anything?
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It runs decent... might be a little tiny bit choppy. Thanks for the fast reply... this kind of stupidness bugs me.. My summer work term ended.. so Im broke.. did a swap.. engines great... i had planned a cam swap at some point.. but didnt think it would be an issue yet... shoudl have known really.. high mileage engine. Should it be running like crap with a lifter that bad.? im troubleshooting... loud metallic tick.. whenwarm at low rpm but goes away with higher oil pressure.. and much less noticable when cold... pulled valbe cpver.. noticed noise was in rythem with one of the rocker arms... and it was putting out half the oil of the rest... sounds like a lifter to me..
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Get that certain noisy lift to the valve closed point(no tension on it), take the rocker arm off and inspect the push rod for clogs, lack of oil or not polished where it meets the lifter or rocker arm. If it all checks out I would put it all back together and slowly tighten it up until the clatter disappears and see what happens. My $.02
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The pushrods were very clean and not clogged.. i put a rag on the end of one and turned the lifters to see if they were stuck.. one that was putting out a bit less came compleatly around but the bad one on the passenger bank is still not putting out as much oil when cold almost none and when warm only 1/3 as much as the rest... I really dont want to pull the intake.. I dont have the extra flow at the moment.. but i need the truck... im at a loss
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I dont have the extra flow at the moment.. but i need the truck... im at a loss
Price out a cam with lifters/timing chain/gaskets. Put the valve cover on and only use it when you have to. While it is parked you will be saving gas money that can go into parts.
You didn't say anything about the engine or if you have any plans for it in the future. You can change just one lifter to get you by. I did that once with a used lifter after I broke one. Shade tree style 100 miles away from the garage...haha. I did not think of that repair as long term, I had another engine for my truck, but it worked for months until I changed motors.
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Its an older engine.. mis 80s maybe.. unknown km... sounds good.. runs great... oil comes out really clean.. no smoke.. doesnt use oil... so I opted to put it in not knowing km... this one is a 366 tall deck.. i mean other then this clacking sound.. i have no complaints... i just hate using unknown engines... but the truck needed an engine.. and it was free.
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beware installing a new cam. it will change things enough that i bet within 10k miles you'll have to have a valve job done on your heads, unless the new cams specs are the same as the worn out cams specs.
in an older engine, if you want to do it once and be done, you need cam n lifters, timing set, and a valve job or new heads.
ive done this 3 times, and its always burns a valve between 10k and 15k miles after the cam install. on an OLD engine though.
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NOt that im saying your wrong.. but im curious as to why the valves would be ruined.?.. I have never heard of this before.
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I know this is going to sound horrible but... i just started school and im broke.. really broke.. what if I pull off the intake.. replace the bad lifter/lifters hopefully only 2 and reinstall the intake withthe same gaskets coated in ultra copper.. or the red spray junk.. ghetto I know.. but will it work?
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beware installing a new cam. it will change things enough that i bet within 10k miles you'll have to have a valve job done on your heads, unless the new cams specs are the same as the worn out cams specs.
There is NO relationship to what your suggesting. Sorry, you've just chose to change the cams on 3 worn out engines. Those engines would have needed a valvejob in the next 10,000 miles regardless if you changed the cams or not. My Two Cents, Lorne
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Make sure you are properly adjusting the valves and if the cam has a wiped lobe it's time for a cam and lifters. Reusing old intake gaskets to me is like reusing toilet paper. Why would you want to? Save a few bucks or borrow the cash but unless you enjoy doing things twice just do it right the first time.
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Thanks guys... pretty much what i figured... the engine sat for quite some time... any chance (wishful thinking) a lifter might just be a bit sticky? ;D
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Yeah i adjusted them as best as possible... only one is funky... theres not alot of slack in the rockerarm...
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How are you adjusting the lifter?
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Im doing it running.. get it to zero lash.. then a semi turn and done... I adjusted them all without issue.. Just the one problem lifter.. with a long screwdriver to the intake.. you can hear the little bugger a rapping
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beware installing a new cam. it will change things enough that i bet within 10k miles you'll have to have a valve job done on your heads, unless the new cams specs are the same as the worn out cams specs.
There is NO relationship to what your suggesting. Sorry, you've just chose to change the cams on 3 worn out engines. Those engines would have needed a valvejob in the next 10,000 miles regardless if you changed the cams or not. My Two Cents, Lorne
No, it happens. probably just lucky, or I'm unlucky. the valves get worn into a certain spot and suddenly you put in a higher lift cam, itll make the valves eat the valve guides up. they wouldnt have needed the valve job if i hadnt changed anything.
Swear on my kids it happened. one engine had 65k on it, one had 120k on it and one had 180k on it, they all did the same thing. only engine it didnt do it to, was a 400 i had, i put a cam in it and got 40k more out of it before i got rid of it. i just dont like doing it cuz it sucks to take the engine down that far, twice in a relatively short period.
I thought of an analogy, tho bear with me. :)
everybody knows what the ridge is at the top of a cylinder in an older engine. you have to use a reamer to get the piston out. these ridges (not as big tho, exist in worn valves and OE rocker arms)
I know this wouldnt work in real life but say you put longer rods in the engine and thats it. dont worry about clearancing and oil pans and stuff, as this wouldnt work anyway. but if you did nothing to the ridge at the top of the cylinder and suddenly you want the piston to run higher in its bore than it used to, it would hit that that ridge and cause damage. while the valve wont get that dramatic of damage, suddenly your making them hit that ridge they've worn in themselves against the cast iron guides in the heads.
when I changed cams, the valve runners were pretty clean and then not long after when i burnt a valve the intake and exhaust runners were gunked up from the oil leaking by into the intake runners, which carboned up and chunks of that stuff eventually kept an intake valve from closing all the way and then not seating right i ended up with a burnt valve.