lifter / rocker rattle hot re-start
Thread Starter
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,336
From: North of Toronto - Ontario
lifter / rocker rattle hot re-start
Here's a new one, at least new to me anyway.
Maybe three or four times late this summer I've had the engine give a clattering valve-train rattle at a hot re-start. After filling up the gas tank type of thing or grabbing a quick bite to eat where the car was turned off for maybe 2, 3, 4 or 10 minutes and then restarted.
BB, rebuilt not all that many miles ago, CompCams Retro-roller cam/lifters. Oil pressure is 20ish pounds + at hot idle, and a little more at hot re-start, closer to 30
Goes away after a few (2, 3, 4?) seconds, I didn't rev it to see if that mattered but the mechanical oil pressure gauge shoots right up
No problem during a cold start after a few hours or days. (but does crank a little longer to start of course)
No noise or rattle when running
Fresh oil change in-between occurrences,
Only thing I can think of is that I've got a problem with a lifter / lifters or lifter pair / link where they're bleeding down "sometimes" and need a few seconds of oil pressure to build back up.
I've got a call into Comp-Cams tech but who knows when I'll hear back or what they'll say.
Anyway, anyone ever come across this situation before or let the speculation begin
M
Maybe three or four times late this summer I've had the engine give a clattering valve-train rattle at a hot re-start. After filling up the gas tank type of thing or grabbing a quick bite to eat where the car was turned off for maybe 2, 3, 4 or 10 minutes and then restarted.
BB, rebuilt not all that many miles ago, CompCams Retro-roller cam/lifters. Oil pressure is 20ish pounds + at hot idle, and a little more at hot re-start, closer to 30
Goes away after a few (2, 3, 4?) seconds, I didn't rev it to see if that mattered but the mechanical oil pressure gauge shoots right up
No problem during a cold start after a few hours or days. (but does crank a little longer to start of course)
No noise or rattle when running
Fresh oil change in-between occurrences,
Only thing I can think of is that I've got a problem with a lifter / lifters or lifter pair / link where they're bleeding down "sometimes" and need a few seconds of oil pressure to build back up.
I've got a call into Comp-Cams tech but who knows when I'll hear back or what they'll say.
Anyway, anyone ever come across this situation before or let the speculation begin
M
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Ive heard that a lot of the newer roller lifters have had issues with pump up. I forget which top end ones dont do it...Lunati maybe. THey discussed it on Engine master a year or so ago. You could run solid rollers on it but you should be buying bushed rollers. I had a set of roller bearing rollers break and destroy the cam and then lost a head gasket and mils shaked the motor..it was a bad day...my lifters were comp cams. Im still running comp cams flat tappets currently without issues. So many companies subcontract roller lifters its hard to tell who really makes them
heres part of the episode...they cut it for youtube when they answer why at the end which is when they talk about who makes them
Im subscribed so i can dig up the episode..I'll see if I can find it
IT was Crane Cams hydraulic lifters whuch they like a lot and they discuss solid vs hydraulic for a long time
They say buy Crane
heres part of the episode...they cut it for youtube when they answer why at the end which is when they talk about who makes them
Im subscribed so i can dig up the episode..I'll see if I can find it
IT was Crane Cams hydraulic lifters whuch they like a lot and they discuss solid vs hydraulic for a long time
They say buy Crane
Last edited by Rescue Rogers; Oct 27, 2022 at 01:11 PM.
Pro
Joined: Dec 2014
Posts: 699
Likes: 46
From: Charlotte NC
Any any crank position at shut off I would say there are 4 lifters sitting on the nose of the cam. Those lifters get the oil squeezed out of them while the engine is off. Wouldn't it take a few seconds for them to pump back up?
Thread Starter
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,336
From: North of Toronto - Ontario
I was going to drop the oilpan for a different reason but I'm thinking while it's off I might consider replacing the oil pump. I don't think it's an issue but while the pan is off...
M
Team Owner
Joined: Jan 2007
Posts: 53,648
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From: Southern Cal Ca
St. Jude Donor '22
sumptin ain't right.
lifters should hold.
when a car I drive with hyd lifters
does that,,,, old worn motor.
unless your valve spring pound pressure is at or exceeds the lifter spec,,, something is wrong
lifters should hold.
when a car I drive with hyd lifters
does that,,,, old worn motor.
unless your valve spring pound pressure is at or exceeds the lifter spec,,, something is wrong
Thread Starter
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,336
From: North of Toronto - Ontario
I'd agree if it was consistent and / or if it was a fresh rebuild or old and worn
Most any day it's fine and works as it should without issue. That's what's got me scratching my head over this one.
M
Most any day it's fine and works as it should without issue. That's what's got me scratching my head over this one.
M
