Crossflow 10w/40 oil

[andy couchman]

Opie has been very helpful, as usual, in recommending a 10w/40 oil for the crossflow (new steel internals so rev limit hopefully up to 8500). There's a range though from fully synthetic to semi. Anyone any recommendations? For mainly road use, would a fully synthetic give a great advantage? In the past I've used Shell HX7 quite happily and the engine internals were perfect when we stripped it down.

Andy 

[eric]

Hello

I personally use a Motul 300V   15W50  which is a great oil for road and track use .  A 15W40 is good but at high rev and with the higher temperature will be less protective than a 15W50 .

A good synthetic oil with slip additives will help the engine to rev more freely .  All that makes an happy motorist .

 

[eric]

Hello

I personally use a Motul 300V   15W50  which is a great oil for road and track use .  A 15W40 is good but at high rev and with the higher temperature will be less protective than a 15W50 .

A good synthetic oil with slip additives will help the engine to rev more freely .  All that makes an happy motorist .

 

[OliverSedlacek]

I've always used Mobil One 10W40 in my crossflow. As it's dry sumped, I like the fact that it flows well at low temperatures, i.e just after start up.

[eric]

I understand that, but at idle when the engine is hot the pressure is far better .I used a long time ago the Agip Sint 2000 semi synthetic 10w40  fine but not so good than the Motul Synthetic

Now the Agip doesn't exist anymore .

As my 1600 sprint is a former race car and they use d the Motul in it . Now all my car use this brand of oil .

10W40 for the Golf series 1 ( 200 000 Miles )   and the Honda CRX ( 300 000 miles )

15w50 for the Caterham and the Alfa 164 2L V6 Turbo ( 200 000 miles )

[andy couchman]

Thanks all.

Oliver, is this the Mobil 1 high mileage oil or the Mobil 2000 X1 oil? I'm struggling to find anywhere that sells the former. Where do you get yours from?

Thanks.

Andy

[OliverSedlacek]

I last bought my Mobil 1 a good few years ago. It was discounted so I stockpiled a good few cans. All modern quality oils are much better than anything that was available when the crossflow was designed, so I don't think you can go too far wrong. As for the lower pressure at idle of the 40 grade oil, the crossflow guru Roger King told me that the thinner oil was good as it flowed through the drillings in the block better.

[Golf Juliet Tango]

I am using Millers semi-synthetic CTV Mini 20w50 at the moment.

[eric]

All these oils are very good .  But 8500 revs are too much , 7000 revs is  the limit , your engine will accept from time to time without some rebuilt at low mileage .

8500 revs is for a race engine with all the costs it need . 

[andy couchman]

With the standard crank I'd agree Eric but after the rebuild we'll have steel crank, rods and flywheel and forged pistons. So, everything is both lighter and stronger. Those I've spoken to reckon 8,500 should be OK but very happy to consider alternative views! Most of the time, I'll probably run no more the 7 or 7 and a half.

[HendrixsWhiteStratReturns]

Hi Andy - I was always told (very firmly) to use a mineral oil in my crossflow - Valvoline VR1  ...

 

(EDIT: Sorry Andy, my fault for not reading the start of the thread...didn't see you'd had a rebuild !)

[eric]

Above 7000, you will use the bearing Shells ....  So you will change them very often .  That means open the engine .Steel components will not break, normally  ....  But the bearing shells, above 7000  are ok for 10 000 miles or less.

However a  Synthetic oil at this level of revs is stronger .  

The mineral oil is good for an old engine but yours is new .