Project Creep: Stuck Lifter ?
Thread Starter
Melting Slicks
Joined: Oct 2011
Posts: 2,748
Likes: 90
From: Sacramento California
C2 of Year Finalist (performance mods) 2019
2018 C2 of Year Finalist
Project Creep: Stuck Lifter ?
Been feeling a miss, replaced a burnt plug wire, but no improvement.
Pulled the valve cover to find a bent pushrod.
Now do I assume its a bad lifter? DO I replace the lifter? All of the lifters? Cam and lifter? Do I just pony up and do heads now too?
If I throw a new lifter(s) in, what are the chances of damaging the cam?
Can I throw a set of aftermarket roller lifters and not swap the cam?
My quick pre-winter project is quickly growing.....
Pulled the valve cover to find a bent pushrod.
Now do I assume its a bad lifter? DO I replace the lifter? All of the lifters? Cam and lifter? Do I just pony up and do heads now too?
If I throw a new lifter(s) in, what are the chances of damaging the cam?
Can I throw a set of aftermarket roller lifters and not swap the cam?
My quick pre-winter project is quickly growing.....
Instructor
Joined: Nov 2012
Posts: 219
Likes: 0
From: Irma Northern WI
I do not think that a bad lifter will bend a pushrod. That is more common the result of over revving an engine. Replace the push rod and hope that a valve is not bent. If the valve is bent, you will need to pull the head, you can examine your cam at that time. Good luck
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
No, roller lifters can't go on your flat tappet cam.
Inspect that lifter first - look for concave wear = bad - should be convex. Even if that one is good u should inspect every lifter as the vlv adjustment is suspect whenever u bend p-rods.
If the cam is wiped then u have major decision - to replace just cam or remove engine to complete disassemble and hot tank. This pretty much means a re-ring and re-bearing overhaul. Its all up to you. If your cam ate the lobes badly then u have a lot of metal in the oil pan and inside oil drains.
If just one lobe has damage then not so much metal is loose inside and possible still have long life with just a cam change. This is all up to your resources of time and money.
For example my "Hecho in Mexhico" crate 350 had one wiped lobe on the original cam with <35k mi. For a $1000 target motor i just put in another cam. Problem is that next cam wiped 3 lopes and when i checked the bearings i had a small gouge on 1 main bearing and one tiny gouge on 1 rod bearing. Yep, i replaced the bad bearings, hand polished the journals, and put in cam #3. Cam #3 is doing fine.
Just take one step at time and first find out status of cam. Let us know what u find so we can help give u better advice.
Hope i didn't scare u,
cardo0
If the cam is wiped then u have major decision - to replace just cam or remove engine to complete disassemble and hot tank. This pretty much means a re-ring and re-bearing overhaul. Its all up to you. If your cam ate the lobes badly then u have a lot of metal in the oil pan and inside oil drains.
If just one lobe has damage then not so much metal is loose inside and possible still have long life with just a cam change. This is all up to your resources of time and money.
For example my "Hecho in Mexhico" crate 350 had one wiped lobe on the original cam with <35k mi. For a $1000 target motor i just put in another cam. Problem is that next cam wiped 3 lopes and when i checked the bearings i had a small gouge on 1 main bearing and one tiny gouge on 1 rod bearing. Yep, i replaced the bad bearings, hand polished the journals, and put in cam #3. Cam #3 is doing fine.
Just take one step at time and first find out status of cam. Let us know what u find so we can help give u better advice.
Hope i didn't scare u,
cardo0
Thread Starter
Melting Slicks
Joined: Oct 2011
Posts: 2,748
Likes: 90
From: Sacramento California
C2 of Year Finalist (performance mods) 2019
2018 C2 of Year Finalist
Ok
Step one.
Replaced pushrod, turned motor over. Valve moves fine, full range of motion. (At least nothing obviously wrong at this point.)
Step Two
Compression test. The suspect cylinder #3 had the highest rating at 165. The others were all between 130-140. That tells me the rings and valves are sealing OK.
I would expect a bent intake valve to not seal.
Ill button her up and run it and see what happens.
If it occurs again, Ill order those AFR heads Ive been droolin over....
Step one.
Replaced pushrod, turned motor over. Valve moves fine, full range of motion. (At least nothing obviously wrong at this point.)
Step Two
Compression test. The suspect cylinder #3 had the highest rating at 165. The others were all between 130-140. That tells me the rings and valves are sealing OK.
I would expect a bent intake valve to not seal.
Ill button her up and run it and see what happens.
If it occurs again, Ill order those AFR heads Ive been droolin over....
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
U have a wiped cam/lobe(s).
Sorry for the bad news and maybe for my sake i shouldn't say anything.
But as a cams lobes wear the compression increases - more mixture is trapped inside the cylinder. Less flow area as the intake goes shut while starting the compression stroke trapping more mixture. And less overlap on that cylinder - this has more effect on idle quality than compression.
Most expect compression to go down with cam wear but it really the opposite - compression increases.
U need to look at that lobe and lifter.
My sympathies,
cardo0
But as a cams lobes wear the compression increases - more mixture is trapped inside the cylinder. Less flow area as the intake goes shut while starting the compression stroke trapping more mixture. And less overlap on that cylinder - this has more effect on idle quality than compression.Most expect compression to go down with cam wear but it really the opposite - compression increases.
U need to look at that lobe and lifter.
My sympathies,
cardo0
