Tinner oil with a higher flow pump?

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Brit33

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I've got hold of a higher flow oil pump. alfa romeo 16v pump that is compatible with my 8v engine.
33mm gears instead of 30mm. Commonly used with racing 8v engines.

Hasn't arrived yet but as I've had issues with low OP especially as hot idle I'm hoping this will enable me to run a thinner oil to improve lubrication and all else that is beneficial from using a thinner oil. Maybe a 5w40 or 10w40.
The 16v models can use these oils.

Anything I should know about using a higher flow pump?
In relation to OP etc?
Currently only get 10 psi at hot idle with Castrol 10w60 TWS.

What kind of improvement will I see (if any?)
2 gears that are 3mm higher. (33mm instead of 30mm)



Thanks
 
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The thing to remember about an oil pump is that it's main function is to provide oil to every part of the engine that needs it in sufficient volume. As long as sufficient oil is being provided, a higher volume pump, and therefore higher pressure, will not provide improved lubrication. What it will provide is higher oil flow for more of a cooling effect in higher output engines.

Assuming the bearing clearances etc are the same for the 8V and 16V engines, then you could likely follow the OP spec's provided for the 16V engine.
 
Originally Posted By: CATERHAM
The thing to remember about an oil pump is that it's main function is to provide oil to every part of the engine that needs it in sufficient volume. As long as sufficient oil is being provided, a higher volume pump, and therefore higher pressure, will not provide improved lubrication. What it will provide is higher oil flow for more of a cooling effect in higher output engines.

Assuming the bearing clearances etc are the same for the 8V and 16V engines, then you could likely follow the OP spec's provided for the 16V engine.

Yes the clearances are the same.
So let's hope I can use a thinner oil. Better cooling less fuel consumption and I hope a better idle op of 15 min as stated in the manual.
Keep you updated. Maybe I will try a 15w 50 first.
We will see.
 
Originally Posted By: Miller88
4 camshafts on an I4 engine?


Yes guys four
It's a flat four. I rebuilt my 8 v with new cams
16v has 2 either side.
8v 1 either side
8 lifters and 16 respectively. A lot of oil channels to feed
 
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Originally Posted By: CATERHAM
You mean one more camshaft.
It shouldn't make a difference.


Why should a larger amount of cams, lifter, rod journals, etc NOT make a difference??? Assuming equal clearances, the engine with additional components will require additional oil flow to maintain the same pressure...
 
Originally Posted By: TFB1
Originally Posted By: CATERHAM
You mean one more camshaft.
It shouldn't make a difference.


Why should a larger amount of cams, lifter, rod journals, etc NOT make a difference??? Assuming equal clearances, the engine with additional components will require additional oil flow to maintain the same pressure...

Exactly. That is why it was supplied with a larger pump
The lifters are hydraulic also which need lubrication
 
The engineer in me says to put on the new pump, and use the same oil as before so that you can definitely tell the difference in oil pressure at idle. A 10% increase in pump displacement doesn't seem like it will make a huge difference.
 
Originally Posted By: A_Harman
The engineer in me says to put on the new pump, and use the same oil as before so that you can definitely tell the difference in oil pressure at idle. A 10% increase in pump displacement doesn't seem like it will make a huge difference.


Me too. Was thinking the same. The if I do see an improvement I could go down to a thinner oil like Motul X-cess 5w40 or similar.
Just hoping it will bump up the hot idle pressure to the factory recommendation of 15 psi or more.
Also consider that my current pump may have some lateral shaft play. I could be getting some leakage here also.
The 16v one is off a newer model and has no play.
 
Brit33:

The new oil pump could add significantly more oil pressure to the system.

At any rate, it seems like a good move. The 10 psi idle pressure is not too bad, but that is some thick oil to produce it. You never did say how your high RPM oil pressure is. Also try to run an oil that dosent produce too high a high RPM oil pressure.

post-186-1158077139.jpg


post-186-1158076964.jpg
 
Originally Posted By: Brit33
Originally Posted By: CATERHAM
You mean one more camshaft.
It shouldn't make a difference.

No two more. 8v has two. 16v has four

Sorry Brit33, I forgot this was a boxer engine and not an I4.
 
Originally Posted By: Jeff_in_VABch
Brit33:

The new oil pump could add significantly more oil pressure to the system.

At any rate, it seems like a good move. The 10 psi idle pressure is not too bad, but that is some thick oil to produce it. You never did say how your high RPM oil pressure is. Also try to run an oil that dosent produce too high a high RPM oil pressure.

post-186-1158077139.jpg


post-186-1158076964.jpg



Hi.
Thanks for that info.
Nice looking new pump. very rare pieces now. Unfortunately I missed out on an auction for some new ones but I did find a used one but in very good condition from a seller I know well.

OP at high revs (5000+) reaches about 55-60 psi. No more than 60.
Bypass valve is fully open at 88 psi so still some headroom there.
yes and we are talking about a thick 10w60 oil here.
Should be no problem if I step down to a 40 or 50 oil. Hopefully 5w40 or 10w40.
Maybe the original Selenia or AGIP originally recommended for this engine.

Caterham: No problems sir. I understood.
 
Originally Posted By: A_Harman
I didn't even know that Alfa had a horizontally opposed 4 cylinder.


grin2.gif


for us British alfa fans they are the most fun!
Huge fan base in Europe for these boxer engines. High revving, low centre of gravity, robust crank and journals.

from the alfsud in the 70's to the sprint and then the 33 models through to 1995 production. 25 years of flat four production.


The sound is lovely also!
 
I would love to know if this is regulated or not. If not then the changes I see are all good. Bigger pump means more volume, no regulation means you can actually get all the newfound flow.

I strongly endorse getting some lighter oil in that sump. With 60w and that bigger pump you will be breaking the pump drive!!!! Not to mention the power loss and added heat, etc...
 
Originally Posted By: SteveSRT8
I would love to know if this is regulated or not. If not then the changes I see are all good. Bigger pump means more volume, no regulation means you can actually get all the newfound flow.

I strongly endorse getting some lighter oil in that sump. With 60w and that bigger pump you will be breaking the pump drive!!!! Not to mention the power loss and added heat, etc...


regulated you mean having a bypass valve? yes of course. this is fully open at 88 psi.
with 60wt castrol it never exceeds 60 psi when hot.
15w50 is going in with the new pump and we'll see from there is I can go down to 40wt which would be ideal.

10w60 castrol has actually been widely and successfully used in our boxers with other drivers in Europe. Remember the HTHS is fairly low with the TWS 10w60. Not such a thick 60wt oil.
oil has never exceeded 100 degrees c flat out at 140kmh.
85-90 under 120 kmh
 
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