68 replies to this topic

[kavesh]

Hi guys

 

I am in the process of rebuilding my Holden 308 motor. Its a stock standard rebuild going 30 over on the bores.

 

I will be ready to assemble the motor hopefully by the weekend once my cam bushes arrive. All my research indicate that the best position of the cam bushes oil hole is around 2 o clock or between 12 and 4 o clock, so i am thinking 2 o clock is a good position for bearings 2 to 5. Number 1 will be lined up to the hole on the block.

 

I have also read that blocking of the hole in the cam bolt retainer is a good idea. Some even suggest removing the chain sprayer, but I would rather leave that in place. This may increase oil pressure.

I will also be putting a little shim in the oil pump to try lift oil pressure a little.

 

Would you agree with the above and that there would not be any negative effects on a standard rebuild. 

 

I would be driving mostly normally so would not be in the red line zone.

 

Would really appreciate any advice you can offer.

 

Thanks in advance

Kavesh

 

[yel327]

Get yourself a new oil pump, and have a read on this forum about mods to make to the pump.
Use new high tensile screws for the oil pickup attachment, seen plenty of the originals stretch.
Also get a new timing chain set, these have adjustable timing and degree your cam in.
I’d recommend getting an original HT or HQ service manual too, here is a closed EBay auction but you can see what I mean. Even a Gregory’s or SP manual will help with the reassembly of 253/308.

https://www.ebay.com..._app-cvip-panel

[kavesh]

Thanks for the reply, I have seen the oil pump mods and have done this as best i can. That mainly helps with oil flow rather the pressure.

 

I was more looking for confirmation on the minor tricks to improve oil pressure.

[Lima31]

Yes you could consider the following
- a 100-120 thou shim in the pump
- resticting no4 gallery
- punching in the cam bolt hole (not block it off but keep a small hole)
- restricted pushrods
- 2 thou oversize cam bearings

[gtrboyy]

cam bolt hole & chain sprayer are plugged up prevent pressure drop not really increase...there is enough oil splash they're not needed.

 

All the mods sound good along with shimming the spring & porting oil pump with cam bearing clearances will see it have constant oil pressure..all the stuff as seen on av8 site.

 

Another one I liked was tapping roll pins intro pushrod ends...unsure if recommended for rocker assemblies though moreso roller rockers

[kavesh]

Thanks for the replies guys.

 

The weird thing is that the 0.002 cam bearings were either not installed correctly as they locked up the cam. I eventually got a new set of standard cam bearings which were installed last night and they are fine.

 

Will begin assembly this weekend, wish me luck.

 

I will look at trying to punch the cam retainer bolt a little to restrict the hole size.

 

I have done the oil pump mod already as best as i could and will go with a little shim in there

[kavesh]

Hi all

 

I have completed the engine assembly and have started up the engine. Had instant oil pressure so was happy with that, vaseline and full of oil in the oil filter did the trick.
 
The main reason i rebuilt this engine was because of the excessive amount of smoke i was getting at startup, which seemed to be valve seals but it was not the case. Another thing that i was not able to have connected was the PCV valve to the base of the carb as it was sucking oil straight in. So i had this port blocked off and the PCV hose just sits on the intake.

So just to recap what was done to the motor on rebuild, we rebored 30 over and used hastings plasma molly rings. We fitted Kliners on the heads, valve seats were ground to make a good seal. Replaced all bearings. Felpro head gaskets were also used.

Here are the results of the engine build. NOT A DAMN THING HAS CHANGED,

1. PCV cannot be connected as it is sucking oil straight into the intake, looks like a coal train behind me, I could not see the cars in my rear view mirror
2. Motor is still smoking with the PCV disconnected.

With the oil cap removed from the drivers side rocker cover, i can see the oil squiring around, perhaps this is too much oil.

I am at my wits end with this, motor, its taken a long time and cost a heap of cash and I have no improvement to oil burn. Feeling freaking depressed...

See videos posted to youtube



https://www.youtube.com/watch?v=O2lBOWWqSlU

Edited by kavesh, 15 December 2020 - 09:22 PM.

[Bigfella237]

1. PCV cannot be connected as it is sucking oil straight into the intake, looks like a coal train behind me, I could not see the cars in my rear view mirror
2. Motor is still smoking with the PCV disconnected.

 

For number 2, depending on how much oil has gone into the intake it's probably gonna take a good drive to suck it all through as it won't burn-off in the intake like it would anywhere else. Either that or pull the intake and clean it out by hand.

 

And number 1, is the little ball bearing free to move around in the PCV valve or is it gummed up? Do you have a baffle on the inside of the rocker cover to stop oil splashing up onto it?

 

One last thought on number 2, are you sure it's not the modulator on the auto trans that's letting oil past? I knew a bloke many years ago that did the same thing, rebuilt his entire motor and then found it was just a modulator!

[sibhs]

Hi Kavesh,

I hope you can get this fixed so we see more of that smile in the number 1 video. Sad face in number two not so good.

Hang in there mate, these things take time but are worth it.

 

Marty

[rexy]

In addition to checking any trans vacuum line connected to the intake (assuming it’s an auto) you should also check the brake booster vac line. Had a 404 that smoked after a weird brake fluid leak.

 

Just disconnect all vacuum port connections. That should eliminate all weird sources.Then you are just stuck with the usual engine causes. 
Do you have access to a compression or leak down tester?

[kavesh]

For number 2, depending on how much oil has gone into the intake it's probably gonna take a good drive to suck it all through as it won't burn-off in the intake like it would anywhere else. Either that or pull the intake and clean it out by hand.

 

And number 1, is the little ball bearing free to move around in the PCV valve or is it gummed up? Do you have a baffle on the inside of the rocker cover to stop oil splashing up onto it?

 

One last thought on number 2, are you sure it's not the modulator on the auto trans that's letting oil past? I knew a bloke many years ago that did the same thing, rebuilt his entire motor and then found it was just a modulator!

 

I am not keen to pull the intake out, purely as replacement gaskets are not available off the shelf here in South Africa. i expect that it is going to take a fair bit of driving to burn out all that oil that is now in the intake. With the festive season here, roads are now very busy so apart from driving around the suburbs, I will not venture too far. Will try and check the roads on a early sunday morning.

The PCV is new and yes it does rattle and yes there are baffles inside the rocker covers, these are original covers, except the one side was modified as an oil filler as well.

I did check out the transmission vacuum pipe to modulator in the past together with the brake pipe and they were fine then, will still double check them again now. (The smoking was an issue before which prompted me to rebuild the engine.

Hi Kavesh,

I hope you can get this fixed so we see more of that smile in the number 1 video. Sad face in number two not so good.

Hang in there mate, these things take time but are worth it.

 

Marty

 

lol, funny guy, yes i was so thrilled when she fired yup quickly and had oil pressure, and initially very little smoking but them that all changed.

In addition to checking any trans vacuum line connected to the intake (assuming it’s an auto) you should also check the brake booster vac line. Had a 404 that smoked after a weird brake fluid leak.

 

Just disconnect all vacuum port connections. That should eliminate all weird sources.Then you are just stuck with the usual engine causes. 
Do you have access to a compression or leak down tester?

Thanks will do, yes trimatic box, that darn thing will not stop leaking, but can live with it

[kavesh]

For now, besides the tests mentioned above, i am thinking of disconnecting the PCV from vacuum source.. Will connect the one rocker to air cleaner.

 

I know this is not ideal but its a new motor and hopefully will breath enough through the 2 oil filler caps, one on the drivers side bank and the original on the timing chain riser.

 

I need to burn out all that damn oil

[Bigfella237]

Positive Crankcase Ventilation is mainly a pollution control thing anyway.

 

Yes there are benefits to evacuating the crankcase on race motors and the like but most engines from the 1960's or older just had an open crankcase breather pipe pointing down toward the road!

 

*IF* you're confident you can drive safely with the brake booster vacuum disconnected then maybe do as Rexy suggested, the Trimatic won't want to up-shift with the modulator disconnected but you can still drive without it, then maybe drive around to get the oil already in the intake through the engine and start diagnosing again?

 

Once the exhaust has cleared up, try reconnecting vacuum lines one at a time, drive it again and make sure you don't have multiple problems.

 

There is still something wrong that needs fixing though. Without knowing the specifics of the engine, maybe there's too much oil getting up top, or maybe it can't drain away quick enough?

[Lima31]

Positive Crankcase Ventilation is mainly a pollution control thing anyway.

Yes there are benefits to evacuating the crankcase on race motors and the like but most engines from the 1960's or older just had an open crankcase breather pipe pointing down toward the road!

*IF* you're confident you can drive safely with the brake booster vacuum disconnected then maybe do as Rexy suggested, the Trimatic won't want to up-shift with the modulator disconnected but you can still drive without it, then maybe drive around to get the oil already in the intake through the engine and start diagnosing again?

Once the exhaust has cleared up, try reconnecting vacuum lines one at a time, drive it again and make sure you don't have multiple problems.

There is still something wrong that needs fixing though. Without knowing the specifics of the engine, maybe there's too much oil getting up top, or maybe it can't drain away quick enough?

It does look like a lot of oil in the head with that last video, i don't have oil pooling like that at all. i would try the restrictor pushrods i suggested earlier. I know it was mentioned at the start, but are we 100% sure the valve stem seals are right? Some seals aren't designed to be flooded like that.

Edited by Lima31, 16 December 2020 - 02:40 PM.

[kavesh]

So this morning after disconnecting the PCV from Vacuum I took her about for a short run. Even with hard acceleration after an initial puff of smoke it clears up.

 

Had a short burst of about 5km at 90km/h and no smoke behind me, so that was good.

 

However, once a slow down and give gas again it puffs smoke again, I am pretty sure that the smoke is caused by engine oil.

 

My passenger tail pipe had traces of oil drip, see pic below.. I think it is finally coming out. Need a few more higher speed runs to clear and burn the oil in the exhaust. With the holiday season here, roads are too busy to drive around during the day. Today being a public holiday here it was ideal to sneak out early for a drive.

Attached Files

•  Left Tailpipe.jpg   201.82K   0 downloads
•  Plug1.jpg   77.87K   0 downloads
•  Plug2.jpg   77.96K   0 downloads
•  Plug3.jpg   84.8K   0 downloads
•  Plug4.jpg   93.76K   0 downloads

[kavesh]

Here is a link to the pics

 

https://drive.google...6uK?usp=sharing

[kavesh]

I have been looking at some images of this build and came across my valve lifters. I compared the original ones to the replacement lifters and noticed that the hole on the side on the new one was larger than the old. How much of a difference is that going to make. The larger hole will send through more oil to the rockers right?

 

See link for pics

 

https://drive.google...6uK?usp=sharing

[Bigfella237]

Wow, raw oil dripping out of the exhaust!

 

I wouldn't think the size of that hole in the side of the lifter would make any difference, the lifters need oil pressure to pump them up.

 

It's how much then travels up the pushrods into the top of the cylinder head that you may need to restrict?

[S pack]

Kavesh, what type of valve stem oil seals were installed?

Were the splash shields re-installed under the valve caps?

[kavesh]

Kavesh, what type of valve stem oil seals were installed?

Were the splash shields re-installed under the valve caps?

 

Hey man, I used the O ring seals and also used a umbrella floating seal lower down.

 

Yes the splash shields were reinstalled 

[rexy]

Oil out the exhaust?

Are you running a vacupan system?

[rodomo]

Have you used the correct dipstick?

[gtrboyy]

Overfilled the sump?

Line for trimatic is sucking oil?

Fitted a catch can or add some breathers to rocker covers.

 

Doubt they'd care or know about pollution control crap over there for thast ol' jalopy.

[kavesh]

Oil out the exhaust?

Are you running a vacupan system?

 

NO sir, not even sure what that is, everything is  standard on my motor

Have you used the correct dipstick?

I think so, that was attached to the motor when I got it. Besides the book says 4.8 litres, including the filter, I probably still have more than half a litre left in the can. I am sure I don't have too much oil.

[kavesh]

Overfilled the sump?

Line for trimatic is sucking oil?

Fitted a catch can or add some breathers to rocker covers.

 

Doubt they'd care or know about pollution control crap over there for thast ol' jalopy.

You suggesting I just run without the PCV connected?

At this point that is what I am going to do. I have 2 breathers 1 on the timing chain riser and another on a valve cover.

I need to know why this is happening though. If I can find a set of valve covers with PCV at the top that will also assist in resolving my problem I suspect.