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Bobkelso Alfa Sprint
Joined: 09 Aug 2011 Posts: 190 Location: Milan - Italy
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Posted: Wed Feb 01, 2012 8:09 pm Post subject: Hi Brit01 |
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Hi Brit01,
I read that people that race with 33 does a modification about that..
mounting a plate that prevent cam shaft seal to pop out when cornering
very fast and oil pressure arise in the external head..
Sorry I can find now the link..
Wondering if it can be related to a bad seal or to very high oil pressure
(fast cornering + racing motor with uprated oil pump, or very high
revving and high pressure release oil valve not working?)
Never suspected it could happen with street motor,
probably you have a racing motor and didn't know yet _________________ Alfa 33 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Wed Feb 01, 2012 8:54 pm Post subject: |
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it happens more often than you think.
AHM sell the plates but for 80 quid!!!!!!!!!!!!!
I've made a couple of little pieces of metal that will sit under the back plate, the 2 x 10mm bolts will go through them and the edge will just sit over the seal rim to prevent it from popping out.
Hopefully fit those tonight.
Maybe with my new pump and all new shells etc the pressure was quite high while cornering. Or just a bad seal or badly placed.
I have several spare luckily and popped one in the other night.
[/b] _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Bobkelso Alfa Sprint
Joined: 09 Aug 2011 Posts: 190 Location: Milan - Italy
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Posted: Wed Feb 01, 2012 11:34 pm Post subject: |
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..I did a double post..cancelled.. _________________ Alfa 33
Last edited by Bobkelso on Thu Feb 02, 2012 1:17 pm; edited 2 times in total |
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Bobkelso Alfa Sprint
Joined: 09 Aug 2011 Posts: 190 Location: Milan - Italy
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Posted: Wed Feb 01, 2012 11:34 pm Post subject: |
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Brit01 wrote: |
it happens more often than you think.
AHM sell the plates but for 80 quid!!!!!!!!!!!!!
[/b] |
Just visited, the site of AHM is impressive!
but the price of these plates make me laugh a bit.
http://www.ahmotorsports.co.uk/photos/Race%20Parts/8vBox/CamSealRet.jpg
Interesting, they say heads fill up of oil (only?) when cornering,
so normally the external part of the heads have inside mostly air
(+oil at the lower part), still at some positive pressure,
(may be not too much pressure if they are the last part of the oil
circuit before the sump, may be 1 bar? fast cornering should add
almost one another bar (o,9g acceleration) to it?
So these seals are quite weaks by default..uhm..tomorrow I go to
the alfa store to say to them they must change them with better ones
on my car on guarantee ( or buy for me the AHM plates ) _________________ Alfa 33 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 02, 2012 1:44 am Post subject: |
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Just changed the timing belts.
Slipped a couple of aluminium strips across the rims of the seals and tightened them between the back plate and cam box with the 10mm bolts.
Tried to fit the bolts through drilled holed but was too fiddly, I just couldn't get them to allign.
Could have used a large washer but they means the back plate needs to come off and just could't be bothered doing that now, with the annoying bolt under the engine.
Anyway they shouldn't pop out now.
pressure relieve valve works well. Blip on the throttle and it stops at 90 psi. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Bobkelso Alfa Sprint
Joined: 09 Aug 2011 Posts: 190 Location: Milan - Italy
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Posted: Thu Feb 02, 2012 1:39 pm Post subject: |
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Hi, well done. I imagine now you can do it faster than a professional mechanic
Ps.: one more little question:
I'm a little confused because RFlower was thinking 90 psi on his car was quite high:
http://www.alfa-pages.co.uk/viewtopic.php?t=6785
but now also you have a similar value ( you read it at high rev. and motor half hot? ) with release valve visibly working.
So 90psi could be considered an healthy value ?
(new pump and release valve with strong coil but perfectly working + possible 10% error in the oil pressure gauge) ? _________________ Alfa 33 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 02, 2012 1:57 pm Post subject: |
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Quote: |
but now also you have a similar value ( you read it at high rev. and motor half hot? ) with release valve visibly working.
So 90psi could be considered an healthy value ?
(new pump and release valve with strong coil but perfectly working + possible 10% error in the oil pressure gauge) ?
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Sorry should have specified : this is COLD oil not hot.
20W/50 oil. So pretty thick when cold. Valve will be fully open at 87 psi and the MANN filter also has a bypass valve to stop it exploding under high pressure.
Best not to rev the engine too high before the oil heats up and thins out in case you pop an oil seal or gasket. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Bobkelso Alfa Sprint
Joined: 09 Aug 2011 Posts: 190 Location: Milan - Italy
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Posted: Thu Feb 02, 2012 4:35 pm Post subject: |
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Ok, thanks. I'm starting understand all the oil stuff. I'm almost ready to fit
a oil gauge myself on the car and use it well to test oil type and motor health.
I'm taking notes :
a) in practice when motor is cold you can have pressure levels very higt at low rev.,
expecially with a "strong" oil (you gave an experimental prove), and revving
a bit with a gauge on the car you can verify if the action of the pump release valves
(87psi) is effective in keeping max pressure within 90psi.
Over this value motor valve release is suspected non working well
and motor seals are a bit under stress.
b) when hot a motor should give the data of the manual posted in the forum:
" with the oil at 90ºC, the pressure (checked after the filter) should be
between 1.18 ( 17 psi ) and 2.75 bar ( 40 psi ) at 800 rpm
between 4.12 ( 60 psi ) and 5.69 bar ( 83 psi ) at 5500 rpm "
And if the pump is new the motor will probably stay a bit on the high of the intervall.
c) befofe the filter pressure can be at maximun 10-15 psi more than
what checked after the filyer because ot the bypass valve of the filter. _________________ Alfa 33
Last edited by Bobkelso on Thu Feb 02, 2012 4:49 pm; edited 1 time in total |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 02, 2012 4:48 pm Post subject: |
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Quote: |
a) in practice when motor is cold you can have pressure levels very higt at low rev.,
expecially with a "strong" oil (you gave an experimental prove),
and revving a bit you can verify if the action of the release valves
(motor and filter) is effective in keeping max pressure within 90psi.
Over this value motor valve release (87psi) is suspected non working well
and motor seals are a bit under stress. |
yes cold oil pressure values mean nothing for the engine.
Only in extreme winter conditions. W = winter.
15/20w is fine for my climate here.
and 50 is the viscosity @ 100 degrees. This is the important value.
Oil pressure sensors = buy a mechanical gauge with the capillary tube.
Quote: |
b) when hot a motor should give the data of the manual posted in the forum:
" with the oil at 90ºC, the pressure should be
between 1.18 ( 17 psi ) and 2.75 bar ( 40 psi ) at 800 rpm
between 4.12 ( 60 psi ) and 5.69 bar ( 83 psi ) at 5500 rpm "
And if the pump is new the motor will probably stay a bit on the high of the intervall |
hot idle pressure can vary a lot even between cars that come out of the factory even due to tiny tolerances in bearing clearances.
some get 15 psi, others 20/30 I've seen.
I'm struggling to get mine above 10. I think with the rebuild it's going to be about 15 psi. no load at idling so should be fine
Before the oil seal popped out I think it was idling around 15-20 psi
Crank is a little worn but still within specs (0.063mm or is it 0.0063mm)
But it jumps up quickly once the revs are above 1200 rpm so no worries.
3000 rpm around 50 psi _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Bobkelso Alfa Sprint
Joined: 09 Aug 2011 Posts: 190 Location: Milan - Italy
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Posted: Thu Feb 02, 2012 5:07 pm Post subject: |
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Ok, I keep taking notes:
- so 17-40psi at 800rpm is optimistic, may be when motor is completely new
- 15-20 psi is more usual, and 10 psi for motor with some kms.
Also my mechanic with other motors in general sais he is usually happy
when he as 1 bar (14,5 psi) at idle, and worryed when he as not at least 0.5 bar (7 psi).
To be safe with pressure he usually raise a bit the minimum of the motor at least at 800-850 rpm,
also when a motor rev well also at 600 rpm. _________________ Alfa 33 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 02, 2012 5:55 pm Post subject: |
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Quote: |
and worryed when he as not at least 0.5 bar (7 psi). |
yep the warning light should come on at 7 psi. not good. Mine never comes on, only after changing the oil and filter where it flickers on for a second.
Also yes it's common to raise the rpm at idle a little to keep it in the 15 psi range. maybe just 900 or so like the 16v.
Or use a 10w/60 or 20w/60 oil. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 1:05 pm Post subject: |
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Not sure if I mentioned this but I've been using Motul 300v 20w/60 oil for 3 weeks now.
My engine loves it so far.
Engine runs easier, and cooler (meaning it's lubricating/cooling the bearings more efficiently).
When very hot I get 50 psi at 3-3200 rpm!
Much more comforting.
I'll be staying with the 60 oil now. Maybe 10w/60 in winter and 20w/60 in the summer.
_________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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Posted: Thu Feb 23, 2012 1:19 pm Post subject: |
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That was kind of my plan, to use 10w40 in the winter and 20w50 in the summer but when changing the oil you can never get all the old stuff out, so you will be mixing some. My oil will be from different manufactures and have different additives.... _________________ x2 33 16v
pictures http://www.alfa-pages.co.uk/viewtopic.php?t=5203 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 1:32 pm Post subject: |
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Quote: |
but when changing the oil you can never get all the old stuff out, so you will be mixing some. My oil will be from different manufactures and have different additives... |
Very true bigAl.
Usually takes a few changes of the same oil to fully change it.
I did leave it draining for half a day to try and get a lot of the 20w/50 mineral I had in before.
Unfortunately Motul 300v doesn't offer a 10w/60 here, only Castrol and Liqui moly.
So after changing to Castrol 10w/60 in winter I might just stick with this.
I wanted to try the 60 viscosity oil as an experiment. Worked a charm but wish I had chosen the Castrol now.
I heard it became available here just a day after I bought the Motul!!!!!!
The 10w/60 will need to be changed more often than the 20w/60 though. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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Posted: Thu Feb 23, 2012 1:51 pm Post subject: |
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On my old 8v, which had mech tappets, i used to take off the cam covers and suck out the oil that was left in there with a bike pump , i think you have hydraulic heads dont you.
I have a 16v now and dont know how much is left in them there heads.
I normally do a change every 2.5k 2 times a year but will do it more often due to my engine. _________________ x2 33 16v
pictures http://www.alfa-pages.co.uk/viewtopic.php?t=5203 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 2:00 pm Post subject: |
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Yep bummer to have hydraulic tappets especially the flat tappet kind.
One guy made an access hole on each cam support so he could prime the heads with oil on dry start ups - also useful for draining I guess.
16v - a substantial amount with the 4 cams I guess.
Quote: |
2 times a year but will do it more often due to my engine |
what's up with your engine? Why more than 2 times a year? _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 3:28 pm Post subject: |
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ah you're talking miles not kms.
makes good sense. I plan on changing mine twice a year or every 4000 kms from now on. It will be twice a year I expect as we don't use the car daily. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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Posted: Thu Feb 23, 2012 3:40 pm Post subject: |
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lol yes miles, 1 thousand miles
I think Iain resets his trip counter and changes his oil when it gets back to 0.
I can't see anything wrong with frequent oil changes, I hate the idea of long life crap but every 1k miles will be costly to keep up. _________________ x2 33 16v
pictures http://www.alfa-pages.co.uk/viewtopic.php?t=5203 |
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 3:51 pm Post subject: |
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omg yes every 1K!!!
at 100 USD for 4 litres synthetic here!! mine has to last at least 6 months
Even the mineral is about 40 USD here. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 5:47 pm Post subject: |
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link isn't working.
Helix 10w/40 oil? _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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Brit01 Gold Cloverleaf
Joined: 24 May 2010 Posts: 665
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Posted: Thu Feb 23, 2012 6:34 pm Post subject: |
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Nice oil. Not available here though.
Also the 50 viscosity at times gets too thin when we start getting days over 35 degrees in the shade here.
Factory specs recommend 15w/50 for my S2 but that is when all is new and clearances are small.
After 24 years it needs a bit more in my case. _________________ S2 33 1988 1.7 QV
Dellorto DRLA40 (32mm venturi) |
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BigAl P4
Joined: 06 May 2003 Posts: 2990 Location: U.K Surrey
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