Date: Tue, 15 May 2012 21:21:33 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: what clues about engine health can I get...
In-Reply-To: <A780D19D-341C-45B8-B004-6C4EF885F26F@gmail.com>
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ok..
not to have any big debate..
page 17.3 is for air-cooled engines.
I hope we're not talking about one of those !
the specs are the same for a waterboxer , which is on page 17.9 in my
Bentley .
spec oil temp is 176 F ..which is what it better be running at if the
thermostat and cooling system are working correctly ..
so sure ..
my only point is that having that temp info is plenty sufficient to do a
valid test.
it's not like it just *has to be between exactly 174 and 178 F ' ..and
that any such test is totally invalid unless one has a proper oil temp
guage ..and that's a properly calibrated one, right !!
just 'fully warmed up to the proper normal level' ..how handy of them to
specify the temp at point.
and ...
regarding oil weight they have a chart on 17.8 ..so one assumes the
test is done with the right oil for the conditions.
for more normal temps in multi-grade oils they have
20 W 50
20 W 40
15 W 50
and 15 W 40.
and what happens with oil temp as you drive, depending on conditions ..
it can easily get to say 210 F , even 230 and 250 F is overdoing it for
a non-synthetic I think is safe to say.
so even if an engine makes say 29.2 psi at 2K rpm at the exact
specified oil temp, with the specified oil weights ..
it could still be underspec at higher oil temps.
but if you need a go-no go cut off point, that's why they specifiy a
test like this .
I'm sure someone could have 180K miles on a 2.1 waterboxer ...with 10W40
and pass this exact test, and still blow up their engine due to lack of
enough OP at high speed and temps.
Over and out.
On 5/15/2012 6:29 PM, Chris S. wrote:
> Factory oil pressure spec is based on 3 data points: engine speed, temperature and pressure. 2000rpm, 80C, 2 bar. If you're not using 3 data points, you're guessing.
>
> After 2 years of looking at my oil temp and pressure gauges I can tell you that water temp is a poor indicator of oil temp. Therefore, for the purpose of determining engine health, which I though we were discussing, you must use 3 data points or, again, you're guessing. And if a guess is close enough then you're ok.
>
> Chris.
>
> Wysłane z iPhone'a
>
> Dnia May 15, 2012 o godz. 20:02 Scott Daniel - Turbovans<scottdaniel@turbovans.com> napisał(a):
>
>> yes and no..
>> oil temp at first tracks coolant temp.
>> it's going to be at least that warm.
>> then....the more you drive, and the hotter things are ...oil temp goes up and up gradually ..
>> so in terms of not exceeding redline oil temp ...a gauge is useful..
>> otherwise ..
>> you know when it's normal and when it's extra hot ..
>> like when ambient temps are high ....under a lot of load , that's when oil temps can get dangerously high without much in the way of an oil cooler.
>> otherwise ..you know when it's well warmed up but likley not 'that hot.'
>>
>> oil pressure at an oil temp of 'par warmed up' is what of interest.
>>
>> On 5/15/2012 2:22 PM, Chris S. wrote:
>>> Oil pressure gauge is a good start, but you also need oil temp, since the two are very closely related. Half the information is close to no information.
>>>
>>>
>>> Chris.
>>>
>>> Wysłane z iPhone'a
>>>
>>> Dnia May 15, 2012 o godz. 15:33 Scott Daniel - Turbovans<scottdaniel@TURBOVANS.COM> napisał(a):
>>>
>>>> that's how to tell really how good/bad it is ..
>>>> running it.
>>>> oil pressure gauge on it then would be nice too. That's important info
>>>> on gauging engine condition and life remaining of course.
>>>>
>>>> On 5/15/2012 7:59 AM, Alistair Bell wrote:
>>>>> will do. I bet some of the lifters will be collapsed, motor has been sitting as is for a few years.
>>>>>
>>>>> Depending on the comp. test results, I might swap the engine in early next month. I'll be dropping trans and engine on my van then (for other reasons) and the current engine has a couple of annoying leaks that need dealing with. So I might gamble with the spare while I fix up the other one.
>>>>>
>>>>> alistair
>>>>>
>>>>>
>>>>> On 2012-05-15, at 4:49 AM, Kenneth Lewis wrote:
>>>>>
>>>>>> Alistar,
>>>>>> Pull the rocker arms and look for mushrooming valve stem ends. If you are
>>>>>> not going to use the engine for a while, just leave them off to relieve
>>>>>> pressure on the springs and hydraulic lifters. Check for collapsed or
>>>>>> spongy lifters.
>>>>>>
>>>>>> Ken
>>>>>>
>>>>>>
>>>>>> On Mon, May 14, 2012 4:11 pm, Alistair Bell wrote:
>>>>>>> when engine on bench?
>>>>>>>
>>>>>>> I had to move my spare engine, again, while working in the barn. I need
>>>>>>> to decide what to do with it. Came as a spare with my syncro. was given to
>>>>>>> the seller by a friend. Supposedly pulled from van to make way for
>>>>>>> conversion.
>>>>>>>
>>>>>>> What I can see upon casual observation:
>>>>>>>
>>>>>>> - oil leak from base of crankcase breather tower (seen that before!)
>>>>>>> - minor oil weeping from one valve cover
>>>>>>> - pushrod tubes shiny, oil and rust free
>>>>>>> - oil pump endplay 0.004" (good)
>>>>>>> - water pump seized
>>>>>>> - crank can be rotated, there is compression. I suppose I could rig up my
>>>>>>> spare bellhousing and starter to spin the bugger and test compression.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> So what else can I look at apart from pulling the heads?
>>>>>>>
>>>>>>> alistair
>>>>>>>
>>>>>>>
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