lifter noise

[chas52]

have a 5k engine rebuild. lately after about 5 miles on the highway at 55 60 mph the lifters seem to bleed down and it starts to clack then the cylinder starts to misfire. 206 206 cam gm lifters all parts from weber racing on total rebuild anyn suggest?

 

[mikestertwo]

What's your oil pressure? How much preload on the lifters?

 

[chas52]

oil pressure hard to tell as the guage is screwy.
preload on lifters have no idea as the engine was built.
if you let the car sit for 10 minutes and start it up the lifters must fill up as ther is no clatter. all new cover and pump from weber and only 5k on the motor
no racing has been done. it has the iron heads ported etc

 

[chas52]

after talking to a mech he suggests checking the pressure relief valve on the oil pump assembly. sound familiar? at idle the lifters dont clack but after 5 min of 55 mph they clack alot

 

[earlbrown]

I'd pop the valve covers and make sure you don't have a cam lobe going flat.

 

[chas52]

if a cam lobe was going bad wouldnt the car run rough all the time?
as it is now the car runs smooth until about 5 miles of highway speed then rough. bad cam lobe run rough all the time?

 

[TurboBuRick]

Bad cam lobe would first show signs at wot. As the the lobe wore down more, the popping would get worse and start showing signs down low too.

First thing that comes to mind is a bad/clogged oil filter.

Fix your oil pressure gauge so you know whats going on that.

Need to get a powerlogger.

 

[chas52]

using a acpf52 with mobil1 10-30
who sells a o press guage that fits our cars and the 2 guage pack in the console? also whats a powerlogger? why does it run good when cold but start clacking after 5 min. motor only got 5k on it and not beat on.