68 replies to this topic

[kavesh]

Just some interesting reading that you may or may not be interested in:

 

https://www.aussiev8...ins-oiling.html

 

http://www.gmh-toran...iction-for-308/

Thanks yes I have seen both of those before.

My understanding and correct me if I am wrong, those oil mods were more for race engines that run constant high revs.

 

Besides the oil pump mods including a 3mm shim on the oil pump spring, nothing else was done to the oiling system

[LXCHEV]

Correct those guys were focused on race engines.

[kavesh]

Do you mean Bar as in the pressure measurement unit? 1 Bar = 1 x atmospheric pressure = 14 psi.

 

Or do you mean bar as in your oil pressure gauge has a number of bars representing the scale?

 

My gauge reads in bars, as per your first comment, 1 bar = 14.5psi.

My instrument cluster is similar to the Monaro cluster except I don't have the rev counter

[kavesh]

Engine Freshened up

A couple of years ago

Guys, just some history on this engine, was a decent running motor which did not smoke but consumed 500ml of oil very tank of fuel.

Previous owner removed motor to fit bigger chev 400.

The 308 stood on the floor for 5 years before I bought it.

I freshened up the motor because it was stored poorly for so long under a car port.

When stripped, I found a lobe badly worn on cam, so replaced with new standard cam and lifters. (Replacement lifters looked the same, except the little hole on the side was a little bigger compared to the original)

All bearings were replaced.

Bore was honed and standard rings fitted as bores looked fine.

When motor was fired up it smoked constantly, to reduce smoke I disconnected the PCV which seemed to improve, however, the dipstick was being pushed when driven.

Found valve covers with oil fillers which worked nicely to assist with engine venting and dipstick no longer was pushed up.

Motor always smoked a lot when cold and for about 5 minutes of driving, then would clear up. There would be a little puff when taking off from standstill once engine was hot.

Other than that motor ran strong,.

 

Present time

This year I was determined to fix the smoking issue when cold, decided to do a full rebuild.

Found the valves guides needed Kliners so had that done, reused original valves, used O ring seal, installed correctly for a 308 and used an additional umbrella seal which floats inside the spring.

Went 30 over on the pistons and fitted plasma molly hasting rings.

As the camshaft and lifters were relatively new and had no signs of wear I decided to reuse these parts.

When the engine was fired up I performed the cam run in procedure again, just to be sure there is no damage.

Motor continued to smoke like before, only more as I had the PCV now connected. 

When I looked at the amount of oil in the rocker covers I knew that this was too much oil.

 

I have now hammered roll pins into my pushrods which did not seem to make a difference, well perhaps it has reduced oil flow, but it still is a lot. (The pushrod end that has the roll pins are facing the rockers)

 

My gut is telling me there may be an issue with the valve lifters which is sending too much oil upstairs,. I can get chev straight 6 lifters which look identical to the original 308 lifters. What are your thoughts on this being a possible solution to my too much oil upstairs?

[Lima31]

Yes i reckon try different lifters, and while you're at it check the drainbacks and head gasket. Personally I'd pull the heads, drill out the drain backs one size and use a die grinder to clean up any sharp edges along the flow paths and radius the drain brack openings.

Maybe also something going on between the top of pushrod and rocker contact?

[ls2lxhatch]

I would try draining the 40W oil and using 20W-50 or similar that you plan to use once the engine is run-in.

 

If the rocker covers still fill with oil then you can rule out the 40W oil as the problem. Put the 40W oil back in and save the 20W-50 for when the engine is run-in.

 

If the 20W-50 solves the problem then get a 20W-50 or similar run-in oil.

[kavesh]

When roll pins are installed on pushrods, are the pushrods with the roll pin end facing the lifter or rocker? Would this even be a consideration?

[S pack]

I may be wrong but the way I read your run down on the engine it is the oil pooling in the rocker covers that is the major issue. Sure reducing the oil flow to the top end with the roll pins in the pushrods should help but it appears that the oil drainage flow from the top end is the issue that now needs to be resolved. You say the umbrella oil seals are floating inside the valve springs. My understanding is they are fitted to the top end of the valve guides where they should stay in position not float around. That is how they are installed on my 202 6cyl. I agree with Lima31, Pull the heads and rework the oil drain back holes to improve the flow and ensure the umbrella seals are fitted onto the ends of the valve guides. This may require the tops of the valve guides be machined to size for the seals to fit over.

[kavesh]

Hey guys so what I have now determined is that I have either been supplied lifters for a different engine or these are poor designed lifters, chinese crap. CHeck out this video

Those lifters were supplied with the cam when the motor was freshened up. and I always had a smoking issue thereafter, but could not figure out why, nor could any mechanic tell me  conclusively.

 

Anyways I have replaced the lifters with Chev L6 lifters which are basically the same as the original 308 lifters.

 

On startup there was no smoke, however, the motor runs very rough suggesting timing, but I suspect the valves are not closing completely.

A bigger issue is that I am getting too much oil pressure at idle, my gauge is on max oil pressure. After a couple of minutes of idling the pressure popped the oil filter O ring.

What has changed now guys, please help and advise me. Its driving me to loose motivation to fix this 308

 

I have removed the 3mm shim in the oil pump relief spring and it made no difference.

Edited by kavesh, 29 December 2020 - 07:07 PM.

[Lima31]

At least you've narrowed down the likely culprit. Checked the pushrod length & valve lash?

[Lima31]

Also double check that the lifter oil feed hole sits in the right spot, that you are not blocking off the oil gallery feeds. Try not to run the engine too long at such high pressure, otherwise you'll risk the oil pump drive.

[Lima31]

Also double check that the lifter oil feed hole sits in the right spot, that you are not blocking off the oil gallery feeds. 

 

On second thought, ignore that.

[Bigfella237]

What has changed now guys, please help and advise me. Its driving me to loose motivation to fix this 308

Seems pretty straight forward... you've stopped some (or most) of the oil escaping up the pushrods, much like holding your thumb over the end of the garden hose, of course the pressure is going to go up.

 

If the pressure is that excessive then the relief valve can't be working, you said you removed the shim but maybe you need to install a weaker spring as well?

[ls2lxhatch]

Change the oil to a multigrade run-in oil.

Edited by ls2lxhatch, 30 December 2020 - 11:50 AM.

[kavesh]

Hey guys

The piston on the oil pump was seized and I was not able to remove it. Fortunately I had a old pump which had a free relief piston, so I used that half of the pump.

I started her up today and am very happy with the results. I have decent oil pressure and the motor does not have a misfire at att. I still need to fine tune the motor but finally I have something to be smiling about.
The L6 lifters have worked out it seems, I still need to check the preload discussed above.

I ran in the cam again just to make sure the lifters bed in with the cam lobes. Oil pressure was good throughout the 20 minutes of running at higher rpm varying the engine speed from time to time.

The exhaust did smoke for a while still and got progressively less, but I suspect it will still smoke for a while until all the oil in the exhaust burns out.
Have a look at the videos below.



https://www.youtube.com/watch?v=bP_9-0jWWNc

I will hopefully take her for a ride tomorrow morning and advise how it goes, but I am feeling very positive.

With the PCV, I have decided to connect the drivers front rocker cover to vacuum source, and the rear passenger will be used for air from the air cleaner. I know its not how it was designed to be originally but I think it looks neater this way.

Finally some good news,

Thank you to everyone that contributed with advice and suggestions which helped me to eventually find the source of my problem, those bloody lifters.

[308 Sunbird]

Looks like you are finally getting on top of this Kavesh   

[kavesh]

Hey guys, I took the UTE for a short 10km drive today and right from startup there was no smoke so that pleased me.

 

There is still a lot of oil in the tailpipe which will eventually burn or blow out with some highway driving, in the new year.

 

I am just so thrilled that we have managed to get to the root cause of the problem, those damn valve lifters.

 

Time to repair my wiper motor now which got bumped when I was dropping the motor in when the chain slipped. Need to solder the contacts again.

 

Thank you to everyone that contributed to troubleshoot this problem. 

 

May you all have a happy new year, and let hope 2021 is a prosperous and safe one for all.

[LJ RB30]

Awesome mate! Finally a good result 👍
Happy new year 😁

[kavesh]

Awesome mate! Finally a good result
Happy new year

  Happy days indeed