Date: Fri, 18 May 2007 00:53:25 -0300
Reply-To: Bob Donalds <donalds1@VERIZON.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bob Donalds <donalds1@VERIZON.NET>
Subject: Re: oil pressure -- next round
Content-type: text/plain; format=flowed; charset=iso-8859-1; reply-type=response
My ears are burning so I checked the list. I must admit to failings short
term as a lerker and contributor
I did my best to quickly reread the thread and to sumerize fresh rebuild 2.1
with dynamic warning buzzer doing off and some 10 pds oil pressure at idle
no one said hot or cold oil temps but I did read 20/50 is being used. Also
new oil pump and bearings are in use.
Having bought alot of cores some blocks have come to me torn down and
looking like they had just been redone and then taken apart. While that
might sound like a good thing its not. This sends red flags flying this is a
sign of an abandonded progect
and I do not want have the same fate time wasted ego brused and so on.
Rods do distort and fail when reused but do not have symtoms of this type
Crank bores also distort mostly center main bores and oposit the parting
line they typicly gain .0015ths no big deal.
Other main bearing problems incorrect sizes. when this happens much noise
and 0 pressure
If the main siezed the block might not touch and this would cause a gap and
oil pressure would not as much of a problem as leaking oil.
I am always looking for that dam reman stickers on the blocks I take back in
and when I see it I pay extra attenton to the main rod and cam bearings as
the engne comes apart. The dealer remain program tried alot of ways to reuse
blocks some where not pritty. I oftens see cam main bores that have been
bored and need oversize Od bearings. I suspect this as on of the possible
problems Thomas has. I stock these if needed
Some other possiblitys are trusting the oil pump cover gaskets provided
with the gasket set to be the correct thickness. I have seen them as thick
as .013ths when they need to be .004ths. This is all it would take to create
the low oil pressure problem
we are talking about.
Oils have changed and I do note see the at speed temps the bentleys suggests
When talking about the oil pressure I first ask hot or cold is the light out
and do you have that dam VDO gauge sender combo. it shows no oil pressure
hot at idle and makes the light come on if you use the switch they provide
a couple of last thoughts bad gauge wrong switches stuck oil relief plunger
Call me if you like and we can spend some time going over any details I may
have misunderstood or any follow up info
Its always good info to know why the engine was taken apart what was found.
oil pressure is about clearances and oil temps and viscosity
measure measure measure
Bob Donalds
Boston Engine
508 358 6264
----- Original Message -----
From: "Dennis Haynes" <d23haynes57@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, May 17, 2007 6:10 PM
Subject: Re: oil pressure -- next round
> Maybe Boston Bob can chime in here. It sounds to me like the case needed
> an
> align bore and the rods needed to be resized.
>
> Dennis
>
>
>>From: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>Reply-To: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>To: vanagon@GERRY.VANAGON.COM
>>Subject: Re: oil pressure -- next round
>>Date: Thu, 17 May 2007 10:04:03 -0700
>>
>>Hi Dennis,
>>I was using 20W50.
>>Yes O had new gears and a new pump housing in, but the old cover, which
>>i will replace now. I know that I am almost above the pressure, and this
>>is OK. However that was measured without load. I did try it without the
>>pressure gauge before and had it run for more than half an hour. No
>>buzzer. Ok Lets go on a small trip (a couple of hundred meters). As soon
>>as i was outside, the buzzer went on.
>>So It is really something wrong when the engine gets hot. I will check
>>the housing for wear but I ordered it from busdepot just before
>>reassembly, and the engine run in total after reassembly not more than
>>say 1.5 hours. The scratches though are weird. I did sand the cover down
>>and now there are clear scratches again. Perhaps I am sucking air and
>>not oil, as David suggested. Hm Will see.
>>I am not sure about the loose mains, I brought it to a shop with good
>>reputation to to the job and they ordered the bearings for me. Also I do
>>not have a cam bearing left around, so I doubt I forgot one. They were
>>new as well. I did the valve adjustment as written down in the Bentley,
>>but for the two cam followers (see my reply from 11:41 PDT last night
>>why two were different), it was a bit hard as they were not completely
>>filled with oil, hence i could not feel the exact point when to start
>>counting the 1 3/4 turns. Could these two followers (actually the valve
>>adjustment) cause such a pressure drop? Hm will check again when the
>>engine is filled with oil ....
>>But first i will check all other stuff once it is open ....
>>
>>Thanks a lot
>>Thomas
>>
>>
>>
>>Dennis Haynes wrote:
>>>What viscosity oil are you using? This may have been mentioned but
>>>remind me.
>>>I doubt you have a blockage. The lenght of hose going to the guage
>>>will not efect the reading unless you are actually flowing oil. It may
>>>delay the reading but the final pressure reading is good.
>>>Scratches in the oil cover is common. Dirt. Was it a new pump and
>>>housing? You can check the housing for wear with a striaght edge and
>>>feeler guages. The Bentley has the specs.
>>>
>>>12.5 psi is almost .9 bar. While not quite the pressure that should be
>>>there you are clsoe to satifying the switch, (.9 Bar). If you can get
>>>maintain 2 bar, (28 psi) at 4,000 rpm, you should be safe to run.
>>>These pressures are an indication of loose mains or out of round rods
>>>or a missing/bad cam bearing shell. Also, how are the vlaves adjusted?
>>>If you set the lifters with clearance, you will have some excess flow
>>>there. They should be tight, ( touching + 1-2 turns) so that all oil
>>>flowing through has to get forced through the rockers.
>>>
>>>Dennis
>>>
>>>>From: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>>>Reply-To: Thomas Pfrommer <pfrommer@PHAS.UBC.CA>
>>>>To: vanagon@GERRY.VANAGON.COM
>>>>Subject: oil pressure -- next round
>>>>Date: Wed, 16 May 2007 22:03:22 -0700
>>>>
>>>>Hi again,
>>>>OK I am in bad luck i guess .....
>>>>after I measured the pressure (I posted the readings a few days ago) I
>>>>realized its really oil pressure and not electronics or other stuff. OK
>>>>got the muffler off, got the tin sheet off (I really hate this f!@#$%
>>>>sheet), and the engine support bracket. Unfortunately, the water pipe
>>>>did not allow to unscrew the upper nuts completely, so in the end I had
>>>>to get the pulley off and then the water pipe.
>>>>
>>>>I did not make any mistakes with the gaskets. Everything as it is
>>>>supposed to be. BUT I do see quite obvious new scratches in the cover.
>>>>Together with the bit of oil that I saw at the pump after I ran the
>>>>engine a bit, it looks like I have some backpressure and a blockage
>>>>somewhere. Any other ideas? Hm in cold run I got 55psi at 1000rpm. Only
>>>>when it warmed up, I had 12.5psi at 2000rpm (and 3 meters of tubing
>>>>before the gauge, which will drop the pressure a bit, but not that much
>>>>I guess). Also that was still beofer the fan of the radiator went on,
>>>>but the engine was quite hot already.
>>>>
>>>>I have to admit I don't know what to do any more. I just don't want to
>>>>open the beast again ..... I checked all oil gallys with an air pump and
>>>>felt air coming equally out of every opening. I could not sense any
>>>>obstacle sitting somewhere. Also the indication of the new scratches on
>>>>the cover rather show some backpressure than too loose bearings or
>>>>similar. I sanded the old cover flat before I put it on (now I have a
>>>>new cover ready to be put on). Also the scratches show that all areas
>>>>are equally scratched, so i did not flatten it at an angle.
>>>>
>>>>Hope someone can help me. Oh man, I hope i could drive around now, and
>>>>now it seems that all effort wasn't worth it (besides the gain in
>>>>knowledge about these engines ...)
>>>>
>>>>I need rum now
>>>>Cheers
>>>>Thomas
>>>
>>>
>
|