Oil squirters in 944 Turbo block

[944 turbo cabrio]

I am thinking of building in oil squirters like in the 968 in my 2,8 stroker build.
I have read a few times now of people doing this when more thoroughly upgrading their engine but having never seen a 968 block I would like to tell my machinist exactly where and how to do it best but I simply don't know :-(

Does any one here have pictures or perhaps measures as where to modify?

Cheers

Niels

 

[TTM]

Here is a picture from my 968 block. Hope this helps.

 

[944 turbo cabrio]

Thanks

/Niels

 

[robwright]

Niels I can't answer your question directly although I do have experience of engines with oil squirters albeit they are 3000HP 2 stroke diesle locomotive engines. In my experience the piston cooling lines bolt onto the bottom of the liner but they also have a corresponding recess in the piston carrier to squirt the oil to the correct places but the carrier is always fixed and the pistons free to rotate. Sorry if I digress just really interested in this one.

 

[333pg333]

A couple of other pics for reference.

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[bmnelsc]

Hello - As I couldn't see the squirters very well - I started looking around. I found references to machine work companies installing them for around $200 and a few posts on modifying con rods to provide an oil stream to the pistons.

The con rod modifications looked pretty dodgy to me as there MUST be loss of oil pressure associated with these modifications - after all, side play on connecting rods is specified for a reason. The nice thing about the Porsche squirts is they have a pressure spring so they don't work until oil pressure is over 30-40 psi so you never starve any bearings.

It looks like you have to machine the block off the main bearing journals (top side) to provide the oil passages and then the upper half of the main bearings have two "holes" in them - one the standard hole to let oil into the bearing and the other is a hole to provide oil to the squirter. Looks like a job for professional machinists to me []

 

[Jonny944CS]

Like this Bruce (images from a 928 WSM):

The 968 retains the same oil pump capacity as the S2, thus keeping engine internal friction losses low. During testing a reduction in the wrist pin boss bearing temperature of 20°C was found across the rev range.


Some info on the oil squirter part #'s I had saved from Rennlist:

You can get the oil squirters from the dealer there are a few to chose from. 930, 964 or 993 part #s.
MY 89 2.7L, 944S2 share the same block with the 968. The 968 is the only block to have the oil squirters.

Here is the info you need, double check before ordering (just in case of a typing error).

Both the 964 & 930 are the same external size L: 21.55mm D:6.25 (close enough)
The orfice on the 930 is smaller than the 964.

Part #:
930.101.015.00
964.101.020.00

There is also a 993 part # 993.101.018.51 (33mm length)

You might need to mix & match the 964 and 993 parts based on the thickness of the block.

They were around £10-20ea from an OPC, last time I checked.

 

[944 turbo cabrio]

Really getting good info here

Thanks a lot to you all!

/Niels

 

[bmnelsc]

Thanks for the info - I did whip through the 928 manual but I must have missed that page - the 911 implementation appears a little different - at least from looking at the bearings.

I didn't find anything in the 968 manual - even in the description of cleaning the oil system. But if the 2.7, S2 and 968 blocks are all the same (except for squirters) then I would think Porsche should be able to supply the part #s for the 968 implementation as well.

It appears that the squirters are installed by boring right through the main journals. I came across a reference to staking the squirts to hold them in place (again on a 911 discussion) but it was ambiguous as to whether that was done from the bearing side or the top side. Important to figure this out as if one comes loose you could either damage a bearing (and potentially the crank) or lose oil pressure and damage them all..... Still looks like a job for professionals to me [].

The Rennlist discussion you included above is interesting as it mentions different orifice sizes - a smaller orifice would provide less volume of oil at the same pressure so it seems the 964s needed more cooling than a 930 - interesting[8|]

 

[bazhart]

You can buy M96 oil squirters and drill reducing sized holes from where the shell fits upwards so they cannot fall out. We are experimenting with this in a 997 to improve cylinder lubrication but expected a reduction of oil pressure on hot tick over. Instead it went up because oil also cools the engine, lowers oil temperature overall and therefore improves viscosity - so good all round.

The 3 litre 944 mk 2 turbo engine we were building will similarly be fitted with squirters (it has a modified 2.5 block) it seems beneficial all round.

Will post photos later.

Baz

 

[TTM]

Baz, do you know at what oil pressure 968 squirters open?

 

[nick_968]

I think it's about 3 bar.

 

[Jonny944CS]

I had a figure of 1.8 bar from an article by Herbert Ampferer.

 

[George Elliott]

with either of those pressures, the squirters would be operating once rpm was the high side of 2000 on any healthy engine i guess?

 

[u63af]

If anyone wants a 968 block then I am selling mine now as I have decided not to do a 3.0 due to lack of funds and time.

I have 968 block, crank and sump available cheap.

email me for info sandyfalconer@hotmail.co.uk